[Federal Register Volume 81, Number 113 (Monday, June 13, 2016)]
[Proposed Rules]
[Pages 38516-38567]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-13655]
[[Page 38515]]
Vol. 81
Monday,
No. 113
June 13, 2016
Part VI
Department of Commerce
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National Oceanic and Atmospheric Administration
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50 CFR Part 219
Taking and Importing Marine Mammals; Taking Marine Mammals Incidental
to Northwest Fisheries Science Center Fisheries Research; Proposed Rule
Federal Register / Vol. 81 , No. 113 / Monday, June 13, 2016 /
Proposed Rules
[[Page 38516]]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 219
[Docket No. 151027994-6421-01]
RIN 0648-BF47
Taking and Importing Marine Mammals; Taking Marine Mammals
Incidental to Northwest Fisheries Science Center Fisheries Research
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments.
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SUMMARY: NMFS' Office of Protected Resources has received a request
from NMFS' Northwest Fisheries Science Center (NWFSC) for authorization
to take marine mammals incidental to fisheries research conducted in
the Pacific Ocean off the northwest United States, over the course of
five years from the date of issuance. As required by the Marine Mammal
Protection Act (MMPA), NMFS is proposing regulations to govern that
take, and requests comments on the proposed regulations.
DATES: Comments and information must be received no later than July 13,
2016.
ADDRESSES: You may submit comments on this document, identified by
NOAA-NMFS-2016-0060, by any of the following methods:
Electronic submission: Submit all electronic public
comments via the federal e-Rulemaking Portal. Go to
www.regulations.gov, enter 0648-BF47 in the ``Search'' box, click the
``Comment Now!'' icon, complete the required fields, and enter or
attach your comments.
Mail: Comments should be addressed to Jolie Harrison,
Chief, Permits and Conservation Division, Office of Protected
Resources, National Marine Fisheries Service, 1315 East West Highway,
Silver Spring, MD 20910.
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Attachments to electronic comments will be
accepted in Microsoft Word or Excel or Adobe PDF file formats only. To
help NMFS process and review comments more efficiently, please use only
one method to submit comments. All comments received are a part of the
public record and will generally be posted on www.regulations.gov
without change. All personal identifying information (e.g., name,
address) voluntarily submitted by the commenter may be publicly
accessible. Do not submit confidential business information or
otherwise sensitive or protected information. NMFS will accept
anonymous comments (enter N/A in the required fields if you wish to
remain anonymous).
FOR FURTHER INFORMATION CONTACT: Ben Laws, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
A copy of NWFSC's application and any supporting documents, as well
as a list of the references cited in this document, may be obtained by
visiting the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm. In case of problems accessing these documents, please
call the contact listed above (see FOR FURTHER INFORMATION CONTACT).
Purpose and Need for Regulatory Action
This proposed rule, to be issued under the authority of the Marine
Mammal Protection Act (MMPA) (16 U.S.C. 1361 et seq.), would establish
a framework for authorizing the take of marine mammals incidental to
the NWFSC's fisheries research activities in the California Current and
Pacific Northwest.
The NWFSC collects a wide array of information necessary to
evaluate the status of exploited fishery resources and the marine
environment. NWFSC scientists conduct fishery-independent research
onboard NOAA-owned and operated vessels or on chartered vessels. A few
surveys are conducted onboard commercial fishing vessels, but the NWFSC
designs and executes the studies and funds vessel time.
We received an application from the NWFSC requesting five-year
regulations and authorization to take multiple species of marine
mammals. Take would occur by Level B harassment incidental to the use
of active acoustic devices, as well as by visual disturbance of
pinnipeds, and by Level A harassment, serious injury, or mortality
incidental to the use of fisheries research gear. The regulations would
be valid from 2016 to 2021. Please see ``Background'' below for
definitions of harassment.
Legal Authority for the Proposed Action
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs
the Secretary of Commerce to allow, upon request, the incidental, but
not intentional taking of small numbers of marine mammals by U.S.
citizens who engage in a specified activity (other than commercial
fishing) within a specified geographical region for up to five years
if, after notice and public comment, the agency makes certain findings
and issues regulations that set forth permissible methods of taking
pursuant to that activity, as well as monitoring and reporting
requirements. Section 101(a)(5)(A) of the MMPA and the implementing
regulations at 50 CFR part 216, subpart I provide the legal basis for
issuing this proposed rule containing five-year regulations, and for
any subsequent Letters of Authorization. As directed by this legal
authority, this proposed rule contains mitigation, monitoring, and
reporting requirements.
Summary of Major Provisions Within the Proposed Rule
The following provides a summary of some of the major provisions
within the proposed rulemaking for the NWFSC fisheries research
activities. We have preliminarily determined that the NWFSC's adherence
to the proposed mitigation, monitoring, and reporting measures listed
below would achieve the least practicable adverse impact on the
affected marine mammals. They include:
Required monitoring of the sampling areas to detect the
presence of marine mammals before deployment of certain research gear.
Required use of acoustic deterrent devices on surface
trawl nets.
Required implementation of the mitigation strategy known
as the ``move-on rule mitigation protocol'' which incorporates best
professional judgment, when necessary during certain research fishing
operations.
Background
Paragraphs 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1371
(a)(5)(A) and (D)) direct the Secretary of Commerce to allow, upon
request, the incidental, but not intentional, taking of small numbers
of marine mammals by U.S. citizens who engage in a specified activity
(other than commercial fishing) within a specified geographical region
if certain findings are made and either regulations are issued or, if
the taking is limited to harassment, a notice of a proposed
authorization is provided to the public for review.
An authorization for incidental takings shall be granted if NMFS
finds that the taking will have a negligible impact on the species or
stock(s), will not have an unmitigable adverse impact
[[Page 38517]]
on the availability of the species or stock(s) for subsistence uses
(where relevant), and if the permissible methods of taking and
requirements pertaining to the mitigation, monitoring and reporting of
such takings are set forth. NMFS has defined ``negligible impact'' in
50 CFR 216.103 as ``an impact resulting from the specified activity
that cannot be reasonably expected to, and is not reasonably likely to,
adversely affect the species or stock through effects on annual rates
of recruitment or survival.''
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: Any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment].
Summary of Request
On August 10, 2015, we received an adequate and complete request
from NWFSC for authorization to take marine mammals incidental to
fisheries research activities. We received an initial draft of the
request on January 2, 2015, followed by a revised draft on April 28,
2015. On August 28, 2015 (80 FR 52256), we published a notice of
receipt of NWFSC's application in the Federal Register, requesting
comments and information related to the NWFSC request for thirty days.
We received comments jointly from The Humane Society of the United
States and Whale and Dolphin Conservation, which we considered in
development of this proposed rule and which are available on the
Internet at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm.
NWFSC proposes to conduct fisheries research using trawl gear used
at various levels in the water column, hook-and-line gears (including
longlines with multiple hooks, rod and reel, and troll deployments),
purse seine/tangle net gear, and other gear. If a marine mammal
interacts with gear deployed by NWFSC, the outcome could potentially be
Level A harassment, serious injury (i.e., any injury that will likely
result in mortality), or mortality. Therefore, NWFSC has pooled the
estimated number of incidents of take that could reasonably result from
gear interactions, and we have assessed the potential impacts
accordingly. NWFSC also uses various active acoustic devices in the
conduct of fisheries research, and use of these devices has the
potential to result in Level B harassment of marine mammals. Level B
harassment of pinnipeds hauled out may also occur, as a result of
visual disturbance from vessels conducting NWFSC research. The proposed
regulations would be valid for five years from the date of issuance.
NWFSC requests authorization to take individuals of sixteen species
by Level A harassment, serious injury, or mortality (hereafter referred
to as M/SI + Level A) and of 34 species by Level B harassment.
Description of the Specified Activity
Overview
The NWFSC collects a wide array of information necessary to
evaluate the status of exploited fishery resources and the marine
environment. NWFSC scientists conduct fishery-independent research
onboard NOAA-owned and operated vessels or on chartered vessels. A few
surveys are conducted onboard commercial fishing vessels, but the NWFSC
designs and executes the studies and funds vessel time. The NWFSC
proposes to administer and conduct approximately 36 survey programs
over the five-year period. The gear types used fall into several
categories: Towed nets fished at various levels in the water column,
longline and other hook and line gear, seine nets, traps, and other
gear. Only use of trawl nets, hook and line gears, and purse seine nets
are likely to result in interaction with marine mammals. Many of these
surveys also use active acoustic devices.
The federal government has a responsibility to conserve and protect
living marine resources in U.S. waters and has also entered into a
number of international agreements and treaties related to the
management of living marine resources in international waters outside
the United States. NOAA has the primary responsibility for managing
marine finfish and shellfish species and their habitats, with that
responsibility delegated within NOAA to NMFS.
In order to direct and coordinate the collection of scientific
information needed to make informed fishery management decisions,
Congress created six regional fisheries science centers, each a
distinct organizational entity and the scientific focal point within
NMFS for region-based federal fisheries-related research. This research
is aimed at monitoring fish stock recruitment, abundance, survival and
biological rates, geographic distribution of species and stocks,
ecosystem process changes, and marine ecological research. The NWFSC is
the research arm of NMFS in the northwest region of the United States.
The NWFSC conducts research and provides scientific advice to manage
fisheries and conserve protected species in the geographic research
area described below and provides scientific information to support the
Pacific Fishery Management Council and numerous other domestic and
international fisheries management organizations.
Dates and Duration
The specified activity may occur at any time during the five-year
period of validity of the proposed regulations. Dates and duration of
individual surveys are inherently uncertain, based on congressional
funding levels for the NWFSC, weather conditions, or ship
contingencies. In addition, cooperative research is designed to provide
flexibility on a yearly basis in order to address issues as they arise.
Some cooperative research projects last multiple years or may continue
with modifications. Other projects only last one year and are not
continued. Most cooperative research projects go through an annual
competitive selection process to determine which projects should be
funded based on proposals developed by many independent researchers and
fishing industry participants.
Specified Geographical Region
The NWFSC conducts research in the Pacific Northwest and California
Current within three research areas: The California Current Research
Area (CCRA), Puget Sound Research Area (PSRA), and Lower Columbia River
Research Area (LCRRA). Please see Figures 1-2 through 1-4 in the NWFSC
application for maps of the three research areas. We note here that,
while the NWFSC specified geographical region extends outside of the
U.S. Exclusive Economic Zone (EEZ), from the Mexican EEZ (not including
Mexican territorial waters) north into the Canadian EEZ (not including
Canadian territorial waters), the MMPA's authority does not extend into
foreign territorial waters. In addition to general knowledge and other
citations contained herein, this section relies upon the descriptions
found in Sherman and Hempel (2009) and Wilkinson et al. (2009). As
referred to here, productivity refers to fixated carbon (i.e., g C/
m\2\/yr) and can be related to the carrying capacity of an ecosystem.
The NWFSC conducts research surveys off the Pacific coast within
the California Current Large Marine Ecosystem (CCE). This region is
considered to be of moderately high
[[Page 38518]]
productivity. Sea surface temperature (SST) is fairly consistent,
ranging from 9-14 [deg]C in winter and 13-15 [deg]C in summer. Major
biogeographic breaks are found at Point Conception and Cape Mendocino,
and the region includes major estuaries such as San Francisco Bay, the
Columbia River, and Puget Sound. The latter two are areas of research
focus for NWFSC and are described in further detail below. The shelf is
generally narrow in the CCE, and shelf-break topography (e.g.,
underwater canyons) creates localized upwelling conditions that
concentrate nutrients into areas of high topographic relief.
The California Current determines the general hydrography off the
coast of California. The current is part of the North Pacific Gyre,
related to the anticyclonic circulation of the central North Pacific
and brings cool waters southward. In general, an area of divergence
parallels the coast of California, with a zone of convergence 200-300
km from the coastline. The current moves south along the western coast
of North America, beginning off southern British Columbia and flowing
southward past Washington, Oregon and California, before ending off
southern Baja California (Bograd et al., 2010). Extensive seasonal
upwelling of colder, nutrient-rich subsurface waters is predominant in
the area south of Cape Mendocino and supports large populations of
whales, seabirds and important fisheries. Significant interannual
variation in productivity results from the effects of this coastal
upwelling as well as from the El Ni[ntilde]o-Southern Oscillation and
the Pacific Decadal Oscillation. Both oscillations involve transitions
from cooler, more productive conditions to warmer, less productive
conditions, but over different timescales.
On the shoreward side of the California Current, the California
Current Front separates cold, low-salinity upwelled waters from the
warmer, saltier waters close to shore. Offshore frontal filaments
transport the frontal water across the entire ecosystem. In winter, the
wind-driven Davidson Current is the dominant nearshore system, and its
associated front forms along the boundary between inshore subtropical
waters and colder offshore temperate and subarctic waters. Surface flow
of the California Current appears to be diverted offshore at Point
Conception and again at Punta Eugenia, while semi-permanent eddies
exist south of these headlands.
NWFSC conducts research programs specific to two major estuaries of
the CCE: Puget Sound and the Columbia River. Offshore of these
estuaries, the CCE is affected by the Heceta Bank, which rises to
within 80 m of the ocean surface and causes coastal eddies, and
underwater canyons (e.g., Juan de Fuca Canyon), which create upwelling
conditions driving high biologic productivity. This portion of the
region is also affected by high amounts of runoff from the Columbia and
Fraser Rivers (the latter being the largest freshwater input to Puget
Sound). The river plumes stimulate primary productivity, with the
Columbia River plume creating a large surface lens of lower-salinity
water in the spring and summer and the Fraser River plume carrying
nutrients northwards past Vancouver Island year-round.
Puget Sound, with more than 8,000 km\2\ of marine waters and
estuarine environment and a watershed of more than 33,000 km\2\, is one
of the largest estuaries in the United States and is the only inland
sea with fjords in the continental United States. Puget Sound is a
place of great physical and ecological complexity and productivity,
with many diverse and important habitat types. Kelp beds and eelgrass
meadows cover almost 1,000 km\2\, while other major habitat types
include subtidal and intertidal wetlands, mudflats, and sandflats
(Gustafson et al., 2000). Concentrations of nutrients (i.e., nitrates
and phosphates) are consistently high throughout most of Puget Sound,
largely due to the flux of oceanic water into the basin (Harrison et
al., 1994), with circulation driven by tides, gravity, and freshwater
influx. The average surface water temperature is 12.8 [deg]C in summer
and 7.2 [deg]C in winter (Staubitz et al., 1997), but surface waters
frequently exceed 20 [deg]C in the summer and fall. With nearly six
million people (doubled since the 1960s), Puget Sound is also heavily
influenced by human activity.
The Columbia River is the largest in the Pacific Northwest,
draining a watershed of 671,000 km\2\. The Columbia River estuary
encompasses more than 325 km\2\ and is one of the largest on the west
coast. Dams, diking, and dredging have dramatically altered the
hydrologic processes that historically shaped the wetlands of the lower
Columbia River. Prior to these alterations, many of the riverine
islands and much of the floodplain were inundated several times a year,
typically in December and again in May or June. Operation of dams has
substantially reduced peak river flows and has nearly eliminated
flooding in many low-lying areas. Dredging of shipping channels has
required disposal of massive quantities of sediments, resulting in
creation of new islands, filling of many former wetlands, and changing
shoreline sediment types (OWJV, 1994).
The LCRRA includes the Columbia River from its mouth, west of
Astoria, OR, to the Bonneville Dam at river mile (RM) 145. Downstream
of approximately RM 120, the river widens to include a broad floodplain
and elongated islands that divide the river and form sloughs and side-
channels in the formerly marshy lowlands. The floodplain expands around
the confluence with the Willamette River (which accounts for
approximately fifteen percent of Columbia River flow) at RM 101.
Downstream of approximately RM 35 the channel is dotted with low
islands of deposited sediments and widens into several broad bays
(OWJV, 1994).
Detailed Description of Activities
The federal government has a trust responsibility to protect living
marine resources in waters of the United States. These waters extend to
200 nm from the shoreline and include the EEZ. The U.S. government has
also entered into a number of international agreements and treaties
related to the management of living marine resources in international
waters outside of the EEZ (i.e., the high seas). To carry out its
responsibilities over U.S. and international waters, Congress has
enacted several statutes authorizing certain federal agencies to
administer programs to manage and protect living marine resources.
Among these federal agencies, NOAA has the primary responsibility for
protecting marine finfish and shellfish species and their habitats.
Within NOAA, NMFS has been delegated primary responsibility for the
science-based management, conservation, and protection of living marine
resources under statutes including the Magnuson-Stevens Fishery
Conservation and Management Act, the Pacific Salmon Treaty Act, and the
Endangered Species Act, as well as under treaties with Native American
tribes inside the EEZ off the Washington Coast.
Within NMFS, six regional fisheries science centers direct and
coordinate the collection of scientific information needed to inform
fisheries management decisions. Each Fisheries Science Center is a
distinct entity and is the scientific focal point for a particular
region. NWFSC conducts research and provides scientific advice to
manage fisheries and conserve protected species along the U.S. west
coast, including estuaries and freshwater systems of Puget Sound and
the major rivers in Washington and Oregon. NWFSC provides scientific
information to support the Pacific Fishery Management Council and other
[[Page 38519]]
domestic and international fisheries management organizations.
The NWFSC collects a wide array of information necessary to
evaluate the status of exploited fishery resources and the marine
environment. NWFSC scientists conduct fishery-independent research
onboard NOAA-owned and operated vessels or on chartered vessels. A few
surveys are conducted onboard commercial fishing vessels, but the NWFSC
designs and executes the studies and funds vessel time. The NWFSC
proposes to administer and conduct approximately 36 survey programs
over the five-year period.
The gear types used fall into several categories: Towed nets fished
at various levels in the water column, longline and other hook and line
gear, seine nets, traps, and other gear. Only use of trawl nets, hook
and line gears, and purse seine nets are likely to result in
interaction with marine mammals. Many of these surveys also use active
acoustic devices. These surveys may be conducted aboard NOAA-operated
research vessels (R/V), including the Bell M. Shimada, Reuben Lasker,
and assorted other small vessels owned by NWFSC, aboard vessels owned
and operated by cooperating agencies and institutions, or aboard
charter vessels.
In the following discussion, we first summarily describe various
gear types used by NWFSC and then describe specific fisheries and
ecosystem research activities conducted by the NWFSC. This is not an
exhaustive list of gear and/or devices that may be utilized by NWFSC
but is representative of gear categories and is complete with regard to
all gears with potential for interaction with marine mammals.
Additionally, relevant active acoustic devices, which are commonly used
in NWFSC survey activities, are described separately in a subsequent
section. Please see Appendix A of NWFSC's draft EA for further
description, pictures, and diagrams of research gear and vessels.
Trawl nets--A trawl is a funnel-shaped net towed behind a boat to
capture fish. The codend (or bag) is the fine-meshed portion of the net
most distant from the towing vessel where fish and other organisms
larger than the mesh size are retained. In contrast to commercial
fishery operations, which generally use larger mesh to capture
marketable fish, research trawls often use smaller mesh to enable
estimates of the size and age distributions of fish in a particular
area. The body of a trawl net is generally constructed of relatively
coarse mesh that functions to gather schooling fish so that they can be
collected in the codend. The opening of the net, called the mouth, is
extended horizontally by large panels of wide mesh called wings. The
mouth of the net is held open by hydrodynamic force exerted on the
trawl doors attached to the wings of the net. As the net is towed
through the water, the force of the water spreads the trawl doors
horizontally apart. The top of a net is called the headrope, and the
bottom is called the footrope.
The trawl net is usually deployed over the stern of the vessel and
attached with two cables (or warps) to winches on the deck of the
vessel. The cables are played out until the net reaches the fishing
depth. Commercial trawl vessels travel at speeds of 2-5 kn while towing
the net for time periods up to several hours. The duration of the tow
depends on the purpose of the trawl, the catch rate, and the target
species. At the end of the tow the net is retrieved and the contents of
the codend are emptied onto the deck. For research purposes, the speed
and duration of the tow and the characteristics of the net must be
standardized to allow meaningful comparisons of data collected at
different times and locations. Active acoustic devices (described
later) incorporated into the research vessel and the trawl gear monitor
the position and status of the net, speed of the tow, and other
variables important to the research design. NWFSC research trawling
activities utilize pelagic (or midwater) and surface trawls, which are
designed to operate at various depths within the water column but not
to contact the seafloor, as well as bottom trawls.
NWFSC also uses beam trawls, a type of bottom trawl in which the
horizontal opening of the net is provided by a heavy beam mounted at
each end on guides or skids that travel along the seabed. On sandy or
muddy bottoms, a series of `tickler' chains are strung between the
skids ahead of the net to stir up the fish from the seabed and chase
them into the net. On rocky grounds, these ticklers may be replaced
with chain matting. Several trawls are towed, one on each side of the
vessel. NWFSC attaches video camera systems to some beam trawls. The
trawls are towed along the seafloor at speeds of 1-1.5 kn.
Longline--Longline vessels fish with baited hooks attached to a
mainline (or groundline). The length of the longline and the number of
hooks depend on the species targeted, the size of the vessel, and the
purpose of the fishing activity. Hooks are attached to the mainline by
another thinner line called a gangion. The length of the gangion and
the distance between gangions depends on the purpose of the fishing
activity. Depending on the fishery, longline gear can be deployed on
the seafloor (bottom longline), in which case weights are attached to
the mainline, or near the surface of the water (pelagic longline), in
which case buoys are attached to the mainline to provide flotation and
keep the baited hooks suspended in the water. Radar reflectors, radio
transmitters, and light sources are often used to help fishers
determine the location of the longline gear prior to retrieval.
A commercial pelagic longline can be over 100 km long and have
thousands of hooks attached, although longlines used for research
surveys are shorter. The pelagic longline gear used for NWFSC research
surveys typically use 500 hooks attached to a mainline less than 2 km
long, with snap-on gangions less than 1 m long spaced at intervals of
approximately 3 m. There are no internationally-recognized standard
measurements for hook size, and a given size may be inconsistent
between manufacturers. Larger hooks, as are used in longlining, are
referenced by increasing whole numbers followed by a slash and a zero
as size increases (e.g., 1/0 up to 20/0). The numbers represent
relative sizes, normally associated with the gap (the distance from the
point tip to the shank). Because pelagic longline gear is not anchored
to the seafloor, it floats freely in the water and may drift
considerable distances between the time of deployment and the time of
retrieval. Bottom longlines used for commercial fishing can be up to
several miles long, but those used for NWFSC research use shorter lines
with approximately thirty hooks per line.
The time period between deployment and retrieval of the longline
gear is the soak time. Soak time is an important parameter for
calculating fishing effort. For commercial fisheries the goal is to
optimize the soak time in order to maximize catch of the target species
while minimizing the bycatch rate and minimizing damage to target
species that may result from predation by sharks or other predators.
Other hook and line gear--Hook and line is a general term used for
a range of fishing methods that employ short fishing lines with hooks
in one form or another (as opposed to longlines). This gear is similar
to methods commonly used by recreational fishers and may generally
include handlines, hand reels, powered reels, rod/pole and line, drop
lines, and troll lines, all using bait or lures in various ways to
attract target species. NWFSC uses barbed or barbless circle hooks used
depending on the needs of the research (i.e., to retain fish
[[Page 38520]]
or release them with minimal injury) and would typically deploy
multiple lines at once.
Other nets--NWFSC surveys utilize various small, fine-mesh, towed
nets designed to sample small fish and pelagic invertebrates. These
nets can be broadly categorized as small trawls (which are separated
from large trawl nets due to discountable potential for interaction
with marine mammals; see ``Potential Effects of the Specified Activity
on Marine Mammals and Their Habitat'') and plankton nets.
1. The Tucker trawl is a medium-sized single-warp net used to study
pelagic fish and zooplankton. The Tucker trawl consists of a series of
nets that can be opened and closed sequentially via stepping motor
without retrieving the net from the fishing depth. It is designed for
deep oblique tows where up to three replicate nets can be sequentially
operated by a double release mechanism and is typically equipped with a
full suite of instruments, including inside and outside flow meters,
CTD, and pitch sensor.
2. NWFSC also uses various neuston nets, which are frame trawls
towed horizontally at the top of the water column in order to capture
neuston (i.e., organisms that inhabit the water's surface).
3. An epibenthic tow sled is an instrument designed to collect
organisms that live on bottom sediments. It consists of a fine mesh
net, typically 1 m x 1 m opening with 1-mm mesh, attached to a rigid
frame with runners to help it move along the substrate.
The remainder of nets described here are plankton nets, which
usually consist of fine mesh attached to a weighted frame which spreads
the mouth of the net to cover a known surface area in order to sample
plankton and fish eggs from various parts of the water column. Plankton
nets used by NWFSC generally employ 20 to 500-[mu]m mesh.
4. Ring nets are used to capture plankton with vertical tows. These
nets consist of a circular frame and a cone-shaped net with a
collection jar at the codend. The net, attached to a labeled dropline,
is lowered into the water while maintaining the net's vertical
position. When the desired depth is reached, the net is pulled straight
up through the water column to collect the sample.
5. Bongo nets are towed through the water at an oblique angle to
sample plankton over a range of depths. Similar to ring nets, these
nets typically have a cylindrical section coupled to a conical portion
that tapers to a detachable codend constructed of nylon mesh. During
each plankton tow, the bongo nets are deployed to depth and are then
retrieved at a controlled rate so that the volume of water sampled is
uniform across the range of depths. In shallow areas, sampling protocol
is adjusted to prevent contact between the bongo nets and the seafloor.
A collecting bucket, attached to the codend of the net, is used to
contain the plankton sample. Some bongo nets can be opened and closed
using remote control to enable the collection of samples from
particular depth ranges. A group of depth-specific bongo net samples
can be used to establish the vertical distribution of zooplankton
species in the water column at a site. Bongo nets are generally used to
collect zooplankton for research purposes and are not used for
commercial harvest.
Seine nets--Seine nets typically hang vertically in the water with
the bottom edge held down by weights and the top edge buoyed by floats.
Seine nets can be deployed from the shore as a beach seine or from a
boat and are actively fished, in comparison with gillnets which may be
similar but fish passively. NWFSC uses both purse seines and beach
seines. Beach seines are deployed from shore to surround all fish in
the nearshore area, and typically have one end fastened to the shore
while the other end is set out in a wide arc and brought back to the
beach. This may be done by hand or with a small boat. The beach seines
used in NWFSC research are 1.8-2.4 m in depth and 36-45 m in length,
with mesh sizes of less than 25 mm. A pole seine is a type of beach
seine deployed by hand. The net is pulled along the bottom by hand as
two or more people hold the poles and walk through the water. Fish and
other organisms are captured by walking the net towards shore or
tilting the poles backwards and lifting the net out of the water. The
NWFSC pole seine is 12 x 2 m, with mesh smaller than 25 mm.
Purse seines are typically much larger and are deployed from
vessels. Commercial fishers use purse seines to capture schooling
pelagic species by encircling the fish and then using a line at the
bottom that enables the net to be closed like a purse. Commercial purse
seines may be more than 2,000 m in length and 200 m in depth, varying
in size according to vessel, mesh size, and target species. The purse
seines employed by NWFSC are between 150-450 m in length, between 9-27
m in depth and have mesh sizes ranging from 11-33 mm depending on the
location in the net.
Tangle net--Tangle nets are similar to gillnets (i.e., vertical
panels of netting buoyed with floats at top and weighted at bottom) but
are typically considered to be more selective and less lethal than
gillnets, using smaller mesh sizes to allow fish to be caught by nose
or jaw and thus able to be resuscitated. NWFSC uses a 180 x 12 m tangle
net with 108-mm mesh.
Traps and pots--Traps and pots are submerged, three-dimensional
devices, often baited, that permit organisms to enter the enclosure but
make escape extremely difficult or impossible. Most traps are attached
by a rope to a buoy on the surface of the water and may be deployed in
series. The trap entrance can be regulated to control the maximum size
of animal that can enter, and the size of the mesh in the body of the
trap can regulate the minimum size that is retained. In general, the
species caught depends on the type and characteristics of the pot or
trap used. NWFSC uses fyke traps and sablefish (Anoplopoma fimbria)
pots.
Fyke traps are bag-shaped nets held open by frames or hoops, often
outfitted with wings and/or leaders to guide fish towards the entrance
of the actual trap. Fyke trap wings can be set up to form a barrier
across a channel, trapping fish that attempt to proceed through the
channel. As the tide ebbs, fish eventually seek to leave the wetland
channel and are then trapped. NWFSC sets fyke traps with 6.4-mm mesh in
estuarine channels that are approximately 1-5 m wide. NWFSC uses
conical sablefish pots to catch fish. These pots consist of a conical-
frustum-shaped frame covered in nylon netting with one or more funnel-
shaped entrance tunnels and are 1.2 m in diameter.
Conductivity, temperature, and depth profilers (CTD)--A CTD
profiler is the primary research tool for determining chemical and
physical properties of seawater (see Figure A-22 of NWFSC's EA for a
photograph). A shipboard CTD is made up of a set of small probes
attached to a large (1-2 m diameter) metal rosette wheel. The rosette
is lowered through the water column on a cable, and CTD data are
observed in real time via a conducting cable connecting the CTD to a
computer on the ship. The rosette also holds a series of sampling
bottles that can be triggered to close at different depths in order to
collect a suite of water samples that can be used to determine
additional properties of the water over the depth of the CTD cast. A
standard CTD cast, depending on water depth, requires two to five hours
to complete. The data from a suite of samples collected at different
depths are often called a depth profile. Depth profiles for different
variables can be
[[Page 38521]]
compared in order to glean information about physical, chemical, and
biological processes occurring in the water column. Salinity,
temperature, and depth data measured by the CTD instrument are
essential for characterization of seawater properties.
Other instruments--NWFSC uses a continuous water pump with a
thermosalinograph to measure sea surface conductivity and temperature.
The pump continuously pumps seawater from a depth of 3 m near the bow
of the research vessel to the thermosalinograph which sends the
temperature and conductivity data to a shipboard computer. To collect
physical environmental data in riverine and estuarine habitats, NWFSC
uses water level and temperature loggers. These devices are placed
underwater at fixed locations where they continuously record data.
Video cameras--The NWFSC uses several apparatuses to collect
underwater videos of benthic habitats and organisms. These include a
CamPod, a video camera sled, video beam trawls and a remotely operated
vehicle (ROV). Each apparatus includes a video camera system consisting
of a digital video camera, lights, and a power source. The CamPod is a
lightweight, three-legged platform equipped with a video system and
adequate illumination. The frame holds a 35-mm stills camera system and
two video cameras--one that provides a forward-looking oblique view and
a high-resolution video camera that faces downward. Designed primarily
for making images of the benthic environment, the configuration of the
device focuses on minimizing its hydrodynamic presence in the field of
view of the cameras. The CamPod is deployed vertically through the
water column on a cable and is intended to view one point on the
bottom.
A video camera sled consists of a video camera system mounted on a
metal frame with runners to allow it to move along the benthic
substrate. A research vessel tows the sled along the seafloor, allowing
the camera to capture video footage of the benthic environment. NWFSC
uses a video ROV to capture underwater footage of the benthic
environment. The ROV is controlled and powered from a surface vessel.
Electrical power is supplied through an umbilical or tether which also
has fiber optics which carry video and data signals between the
operator and the ROV. This enables researchers on the vessel to control
the ROV's position in the water with joysticks while they view the
video feed on a monitor.
Section 1.6 of the NWFSC's application provides a detailed account
of all surveys planned by NWFSC in the CCRA, PSRA, and LCRRA. We note
here that active acoustic systems are used for data acquisition
purposes only within the CCRA. Many of these surveys also use small
trawls, plankton nets, and/or other gear; however, only gear with
likely potential for marine mammal interaction is described. Table 1.1
of NWFSC's application provides summary information related to these
surveys. Please see those sections for full details of survey activity
planned by NWFSC. Here we provide relevant information related to a
subset of survey programs with potential for marine mammal
interactions.
1. Bycatch Reduction Research--Bycatch reduction research programs
are conducted in the CCRA, from southern Oregon to Canada. This
intermittent research is conducted aboard chartered commercial fishing
vessels, involving thirty to ninety days at sea (DAS) from April to
October, in order to test gear improvements in commercial trawls.
Specific trawl gear tested varies based on survey objectives and vessel
chartered. Projected annual effort is approximately forty bottom trawls
per year (50-1,000 m depth; up to four hour tows), up to sixty midwater
trawls per year (50-1,000 m depth; average two hour tow), and up to an
additional sixty bottom trawls per year with a double-rigged shrimp
trawl (100-300 m depth; thirty to eighty minute tows).
2. Flatfish Broodstock Collection--In order to collect fish for
aquaculture development, intermittent surveys are conducted aboard
charter fishing vessels or small NOAA vessels. These surveys use
commercial bottom trawls and hook and line and are conducted in Puget
Sound and along the Washington coast for approximately twenty DAS. The
hook and line portion involves approximately eighteen trips per year
with up to twelve lines in the water at once, using barbed circle
hooks. Total hook-hours are dependent on target species and catch per
unit effort (CPUE). Trawls (6-24 per year) are deployed for
approximately ten minutes each at depths greater than 10 m.
3. Groundfish Bottom Trawl Survey--This survey is conducted
annually from May to October for at least 190 DAS, extending throughout
the U.S. west coast, and is designed to monitor groundfish distribution
and biomass. Commercial fishing vessels are used to deploy Aberdeen
bottom trawls (5 x 15 m mouth opening) for approximately 750 tows per
year (55-1,280 m depth; fifteen minute tows).
4. Hake Acoustic Survey/Camera Trawl Research--These surveys are
conducted annually from March to September (up to 80 DAS) from southern
California to southeast Alaska, following hake (Merluccius productus)
distribution in order to measure abundance using active acoustic
systems and trawl gear. NOAA vessels as well as commercial fishing
vessels may be used, deploying Aleutian Wing midwater trawls (100 m
headrope) for 225 trawls per year (30-1,500 m depth; variable tow
duration) and Poly Nor'Easter bottom trawls (36 m footrope x 27 m
headrope) for five to ten trawls per year (variable depth and
duration). Results of the survey inform assessments of several rockfish
(Sebastes spp.) populations and may be used in assessments of central
California salmon productivity. It is either conducted on a NOAA ship
or a charter vessel and requires about 45 survey days. The protocols
for this survey include underway multi-frequency active acoustic
devices, modified-Cobb midwater trawls, various plankton tows, and CTD
profiles at fixed stations. The modified-Cobb trawl is deployed for
fifteen-minute tows at 2 kn during dark hours at 15-30 m depth.
5. Juvenile Salmon Pacific Northwest Coastal Survey--This survey
complements similar surveys conducted by NMFS' Southwest Fisheries
Science Center (SWFSC), is conducted annually in May, June, and
September (36 DAS) from Newport, OR, to Cape Flattery, WA, aboard
commercial fishing vessels, and is designed to assess ocean conditions
and growth, relative abundance, and survival of juvenile salmon
(Oncorhynchus spp.). The survey deploys the Nordic 264 surface trawl
(30 m wide x 20 m deep) for 180 trawls per year (surface to 30 m depth;
thirty minute tow).
6. Marine Fish Broodstock Collection, Sampling, and Tagging--This
variable research program occurs annually for approximately ten DAS
aboard charter fishing vessels along the Washington coast. In order to
collect fish, commercial bottom trawls (ten trawls per year; 50-1,000 m
depth, up to four hour tow duration), pelagic longline, and hook and
line gear are used. Approximately thirty longline sets per year, using
five hundred barbed circle hooks per set, are set at approximately 215-
915 m depth (mainline length 1,370-1,830 m; soak time approximately
three hours). Hook and line effort involves eight lines with barbed
circle hooks deployed for six-hour fishing days for a total of ninety
hours or 720 hook-hours per year.
[[Page 38522]]
7. Northern Juvenile Rockfish Survey--This survey complements
similar surveys conducted by SWFSC, is conducted annually from May to
June from Cape Mendocino, CA, to Cape Flattery, WA, for fifteen to
thirty DAS, and targets the pelagic phase of juvenile rockfish using a
modified Cobb midwater trawl net (26 m headrope; 12 x 12 m opening). It
is typically conducted on a charter vessel, with approximately one
hundred trawls per year (fifteen-minute tows at night; 15-30 m depth).
8. Video Beam Trawl Collaborative Research--This survey is
conducted monthly along the continental shelf from Oregon to Washington
aboard partner research vessels or chartered commercial vessels. The
survey uses a 2-m beam trawl system with open codend outfitted with a
digital video camera to assess the seasonal and interannual
distribution of young-of-the-year groundfishes and the potential
impacts of hypoxia and requires twenty DAS annually with twenty to
forty trawl deployments of ten minutes each.
9. Coastwide Groundfish Hook and Line Survey in Untrawlable
Habitat--This survey to monitor groundfish distribution and abundance
along the U.S. west coast is conducted annually from May to October
aboard charter sportfishing vessels (250 DAS). Hook and line gear is
deployed by rod and reel, with approximately 1,000 sites visited
annually. At each site, each of three anglers deploys a line with five
hooks for a five-minute soak and repeats this five times. Therefore, 75
total hooks are deployed per site for five minutes each, yielding an
annual total of 6,250 hook-hours.
10. Near Coastal Ocean Purse Seining--This study of salmon habitat
use is conducted monthly from May to September nearshore near the mouth
of the Columbia River aboard chartered commercial vessels (12 DAS).
Purse seines (228 x 18 m or 305 x 12 m) are deployed for 75 sets per
year, with generally less than one hour set duration.
11. Beam Trawl Survey to Evaluate Effects of Hypoxia--Conducted
only in Puget Sound, with twenty DAS in summer and fall, this survey is
designed to examine effects of hypoxia on demersal fish in Hood Canal.
A 2-m beam trawl, primarily with open codend and outfitted with a video
camera, is deployed for one tow per each of ten sites per season for a
total of twenty tows (each tow at varying depths [30, 60, 90 m]; ten
minute duration).
12. Marine Fish Collections Including Flatfish--This survey,
conducted only in Puget Sound aboard charter vessels with variable
monthly effort (fifteen DAS), utilizes commercial bottom trawls. Annual
effort is forty trawls at 50-1,000 m depth and tow duration is up to
four hours.
13. Movement Studies of Puget Sound Species--These surveys occur in
Puget Sound aboard a variety of small boats, with year-round sampling
totaling 25 DAS. Survey effort involves commercial bottom trawls
(twelve tows per year at greater than 10 m depth and for ten minutes),
hook and line (twenty trips per year with up to twelve barbless hooks
in the water at once), and bottom longline (180-m mainline deployed to
approximately 60 m depth). The latter involves three sets per year with
thirty 16/0 circle hooks per set.
14. Puget Sound Marine Pelagic Food Web--These surveys occur in
Puget Sound only about every five years from April to October aboard
charter vessels and totaling thirty DAS when it occurs. The survey
deploys a Kodiak surface trawl (3.1 x 6.1 m) for five hundred tows of
ten minute duration and depths greater than 10 m.
15. Skagit Bay Juvenile Salmon Survey--This survey occurs in Puget
Sound aboard chartered vessels annually from April to September for
thirty DAS and uses the same Kodiak surface trawl with the same
protocols as the Puget Sound marine pelagic food web survey (180 tows
per year).
16. Elwha Dam Removal--This Puget Sound study of the effects of dam
removal on nearshore fish species includes use of a beach seine (43 x
1.8 m). The survey is conducted monthly using a small vessel, totaling
20 DAS and up to 140 samples per year (less than ten minutes per
sample). Separate studies (``Snohomish Juvenile Salmon Studies'' [up to
200 sets annually during 50 DAS; conducted monthly and twice-monthly
from February to September] and ``Puget Sound Salmon Contaminant
Study'' [up to 100 sets annually during 30 DAS from May to July]) use
similar beach seines in similar ways. Additional surveys in the
Columbia River (``Estuary Tidal Habitats'' [up to 100 sets annually
during 25 DAS, quarterly to monthly] and ``LCR Ecosystem Monitoring''
[up to 200 sets annually during 16 DAS, monthly from February to
December]) also use beach seines similarly.
17. Rockfish Genetics--Hook and line fishing gear is used to
capture bottomfish for biological sampling. Conducted in Puget Sound
aboard charter boats from April to November (35-41 DAS), this survey
uses baited hooks or bottom jigs for approximately 750 hook-hours per
year.
18. Marine Fish Research Including Broodstock Collection, Sampling,
and Tagging--This research involves pelagic longline and hook and line
survey effort conducted in Puget Sound aboard charter vessels for
approximately 15 DAS with effort varying monthly. The gear
specifications and effort are similar to those described previously
(for pelagic longline and hook and line only) for marine fish
broodstock collection in the California Current.
19. Eulachon Arrival Timing--This survey uses a modified Cobb
midwater trawl net 26-m headrope; 12 x 12 m opening) in the Columbia
River estuary and plume to determine the arrival timing and
distribution of spawning eulachon. The survey is conducted from January
to March (15 DAS) aboard NOAA vessels, with sixty trawls per year
(fifteen-minute tow duration at 30-40 m depth).
20. Pair Trawl Juvenile Salmon Survey--This trawl survey is
conducted in the Columbia River between approximately RM 40-50 from
March to August (80 DAS) aboard small vessels. A surface pair trawl
(wings 92 x 92 m; trawl body 9 m wide x 6 m deep x 18 m long) modified
with an open codend (2.4 x 3 m opening) is towed near the surface for
eight to fifteen hours per trawl, totaling 800-1,200 tow-hours per
year. The trawl is outfitted with a flow-through Passive Integrated
Transponder (PIT) tag detector to assess passage of tagged juvenile
salmon.
21. Benefits of Wetland Restoration to Juvenile Salmon--This study,
occurring throughout the LCRRA, uses purse seines (150 x 9 m), beach
seines (46 x 1.8 m), and surface trawls (3 x 6 m opening) to study
salmon habitat use. The surveys are typically conducted aboard small
research vessels and/or skiffs, with purse seine effort occurring for
32 DAS bi-weekly from March to October (ninety sets per year; typically
less than one hour set duration) and beach seines and surface trawls
(fifteen minute tows) occurring quarterly from March to December. The
latter portion is conducted for 16 DAS, at two sites per day with two
to three hauls of each type per site.
22. Migratory Behavior of Adult Salmon--This LCRRA survey uses
tangle nets to catch and tag fish. Tangle nets (180 x 12 m) are
deployed from commercial fishing vessels for 32 DAS from spring to
fall, with up to 75 sets per year deployed for 25-45 minutes each.
Description of Active Acoustic Sound Sources--This section contains
a brief technical background on sound, the characteristics of certain
sound types, and on metrics used in this proposal
[[Page 38523]]
inasmuch as the information is relevant to NWFSC's specified activity
and to a discussion of the potential effects of the specified activity
on marine mammals found later in this document. We also describe the
active acoustic devices used by NWFSC.
Sound travels in waves, the basic components of which are
frequency, wavelength, velocity, and amplitude. Frequency is the number
of pressure waves that pass by a reference point per unit of time and
is measured in hertz (Hz) or cycles per second. Wavelength is the
distance between two peaks or corresponding points of a sound wave
(length of one cycle). Higher frequency sounds have shorter wavelengths
than lower frequency sounds, and typically attenuate (decrease) more
rapidly, except in certain cases in shallower water. Amplitude is the
height of the sound pressure wave or the ``loudness'' of a sound and is
typically described using the relative unit of the decibel (dB). A
sound pressure level (SPL) in dB is described as the ratio between a
measured pressure and a reference pressure (for underwater sound, this
is 1 microPascal [[mu]Pa]), and is a logarithmic unit that accounts for
large variations in amplitude; therefore, a relatively small change in
dB corresponds to large changes in sound pressure. The source level
(SL) represents the SPL referenced at a distance of 1 m from the source
(referenced to 1 [mu]Pa), while the received level is the SPL at the
listener's position (referenced to 1 [mu]Pa).
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. Rms is calculated by squaring all of the
sound amplitudes, averaging the squares, and then taking the square
root of the average (Urick, 1983). Rms accounts for both positive and
negative values; squaring the pressures makes all values positive so
that they may be accounted for in the summation of pressure levels
(Hastings and Popper, 2005). This measurement is often used in the
context of discussing behavioral effects, in part because behavioral
effects, which often result from auditory cues, may be better expressed
through averaged units than by peak pressures.
Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s)
represents the total energy contained within a pulse, and considers
both intensity and duration of exposure. For a single pulse, the
numerical value of the SEL measurement is usually 5-15 dB lower than
the rms sound pressure in dB re 1 [mu]Pa, with the comparative
difference between measurements of rms and SEL measurements often
tending to decrease with increasing range (Greene, 1997; McCauley et
al., 1998). Peak sound pressure is the maximum instantaneous sound
pressure measurable in the water at a specified distance from the
source, and is represented in the same units as the rms sound pressure.
Another common metric is peak-to-peak sound pressure (p-p), which is
the algebraic difference between the peak positive and peak negative
sound pressures. Peak-to-peak pressure is typically approximately 6 dB
higher than peak pressure (Southall et al., 2007).
When underwater objects vibrate or activity occurs, sound-pressure
waves are created. These waves alternately compress and decompress the
water as the sound wave travels. Underwater sound waves radiate in a
manner similar to ripples on the surface of a pond and may be either
directed in a beam or beams (as for the sources considered here) or may
radiate in all directions (omnidirectional sources). The compressions
and decompressions associated with sound waves are detected as changes
in pressure by aquatic life and man-made sound receptors such as
hydrophones.
Even in the absence of sound from the specified activity, the
underwater environment is typically loud due to ambient sound. Ambient
sound is defined as environmental background sound levels lacking a
single source or point (Richardson et al., 1995), and the sound level
of a region is defined by the total acoustical energy being generated
by known and unknown sources. These sources may include physical (e.g.,
wind and waves, earthquakes, ice, atmospheric sound), biological (e.g.,
sounds produced by marine mammals, fish, and invertebrates), and
anthropogenic (e.g., vessels, dredging, construction) sound. A number
of sources contribute to ambient sound, including the following
(Richardson et al., 1995):
Wind and waves: The complex interactions between wind and
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of
naturally occurring ambient sound for frequencies between 200 Hz and 50
kHz (Mitson, 1995). In general, ambient sound levels tend to increase
with increasing wind speed and wave height. Surf sound becomes
important near shore, with measurements collected at a distance of 8.5
km from shore showing an increase of 10 dB in the 100 to 700 Hz band
during heavy surf conditions.
Precipitation: Sound from rain and hail impacting the
water surface can become an important component of total sound at
frequencies above 500 Hz, and possibly down to 100 Hz during quiet
times.
Biological: Marine mammals can contribute significantly to
ambient sound levels, as can some fish and snapping shrimp. The
frequency band for biological contributions is from approximately 12 Hz
to over 100 kHz.
Anthropogenic: Sources of ambient sound related to human
activity include transportation (surface vessels), dredging and
construction, oil and gas drilling and production, seismic surveys,
sonar, explosions, and ocean acoustic studies. Vessel noise typically
dominates the total ambient sound for frequencies between 20 and 300
Hz. In general, the frequencies of anthropogenic sounds are below 1 kHz
and, if higher frequency sound levels are created, they attenuate
rapidly. Sound from identifiable anthropogenic sources other than the
activity of interest (e.g., a passing vessel) is sometimes termed
background sound, as opposed to ambient sound.
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
human activity) but also on the ability of sound to propagate through
the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected
to vary widely over both coarse and fine spatial and temporal scales.
Sound levels at a given frequency and location can vary by 10-20 dB
from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the
specified activity may be a negligible addition to the local
environment or could form a distinctive signal that may affect marine
mammals. Details of source types are described in the following text.
Sounds are often considered to fall into one of two general types:
Pulsed and non-pulsed (defined in the following). The distinction
between these two sound types is important because they have differing
potential to cause physical effects, particularly with regard to
hearing (e.g., Ward, 1997 in Southall et al., 2007). Please see
Southall et al. (2007) for an in-depth discussion of these concepts.
Pulsed sound sources (e.g., explosions, gunshots, sonic booms,
[[Page 38524]]
impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur
either as isolated events or repeated in some succession. Pulsed sounds
are all characterized by a relatively rapid rise from ambient pressure
to a maximal pressure value followed by a rapid decay period that may
include a period of diminishing, oscillating maximal and minimal
pressures, and generally have an increased capacity to induce physical
injury as compared with sounds that lack these features.
Non-pulsed sounds can be tonal, narrowband, or broadband, brief or
prolonged, and may be either continuous or non-continuous (ANSI, 1995;
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals
of short duration but without the essential properties of pulses (e.g.,
rapid rise time). Examples of non-pulsed sounds include those produced
by vessels, aircraft, machinery operations such as drilling or
dredging, vibratory pile driving, and active sonar systems (such as
those used by the U.S. Navy). The duration of such sounds, as received
at a distance, can be greatly extended in a highly reverberant
environment.
We use generic sound exposure thresholds (see Table 1) to determine
when an activity that produces sound might result in impacts to a
marine mammal such that a take by harassment might occur. These
thresholds should be considered guidelines for estimating when
harassment may occur (i.e., when an animal is exposed to levels equal
to or exceeding the relevant criterion) in specific contexts; however,
useful contextual information that may inform our assessment of effects
is typically lacking and we consider these thresholds as step
functions. NMFS is currently revising these acoustic guidelines; for
more information on that process, please visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. NMFS has determined that the 160-dB threshold
for impulsive sources is most appropriate for use in considering the
potential effects of the NWFSC's activities.
Table 1--Current Acoustic Exposure Criteria
------------------------------------------------------------------------
Criterion Definition Threshold
------------------------------------------------------------------------
Level A harassment (underwater) Injury (PTS--any 180 dB (cetaceans)/
level above that 190 dB (pinnipeds)
which is known (rms).
to cause TTS).
Level B harassment (underwater) Behavioral 160 dB (impulsive
disruption. source)/120 dB
(continuous source)
(rms).
------------------------------------------------------------------------
A wide range of active acoustic devices are used in NWFSC fisheries
surveys for remotely sensing bathymetric, oceanographic, and biological
features of the environment. Most of these sources involve relatively
high frequency, directional, and brief repeated signals tuned to
provide sufficient focus and resolution on specific objects. NWFSC also
uses passive listening sensors (i.e., remotely and passively detecting
sound rather than producing it), which do not have the potential to
impact marine mammals. NWFSC active acoustic sources include various
echosounders (e.g., multibeam systems), scientific sonar systems,
positional sonars (e.g., net sounders for determining trawl position),
and environmental sensors (e.g., current profilers).
Mid- and high-frequency underwater acoustic sources typically used
for scientific purposes operate by creating an oscillatory overpressure
through rapid vibration of a surface, using either electromagnetic
forces or the piezoelectric effect of some materials. A vibratory
source based on the piezoelectric effect is commonly referred to as a
transducer. Transducers are usually designed to excite an acoustic wave
of a specific frequency, often in a highly directive beam, with the
directional capability increasing with operating frequency. The main
parameter characterizing directivity is the beam width, defined as the
angle subtended by diametrically opposite ``half power'' (-3 dB) points
of the main lobe. For different transducers at a single operating
frequency the beam width can vary from 180[deg] (almost
omnidirectional) to only a few degrees. Transducers are usually
produced with either circular or rectangular active surfaces. For
circular transducers, the beam width in the horizontal plane (assuming
a downward pointing main beam) is equal in all directions, whereas
rectangular transducers produce more complex beam patterns with
variable beam width in the horizontal plane. Please see Zykov and Carr
(2014) for further discussion of electromechanical sound sources.
The types of active sources employed in fisheries acoustic research
and monitoring may be considered in two broad categories here, based
largely on their respective operating frequency (e.g., within or
outside the known audible range of marine species) and other output
characteristics (e.g., signal duration, directivity). As described
below, these operating characteristics result in differing potential
for acoustic impacts on marine mammals.
Category 1 active fisheries acoustic sources include those with
high output frequencies (>180 kHz) that are outside the known
functional hearing capability of any marine mammal. Sounds that are
above the functional hearing range of marine animals may be audible if
sufficiently loud (e.g., M[oslash]hl, 1968). However, the relative
output levels of these sources mean that they would potentially be
detectable to marine mammals at maximum distances of only a few meters,
and are highly unlikely to be of sufficient intensity to result in
behavioral harassment. These sources also generally have short duration
signals and highly directional beam patterns, meaning that any
individual marine mammal would be unlikely to even receive a signal
that would almost certainly be inaudible.
We are aware of two recent studies (Deng et al., 2014; Hastie et
al., 2014) demonstrating some behavioral reaction by marine mammals to
acoustic signals at frequencies above 180 kHz. These studies generally
indicate only that sub-harmonics could be detectable by certain species
at distances up to several hundred meters. However, this detectability
is in reference to ambient noise, not to NMFS' established 160 dB
threshold for assessing the potential for incidental take for these
sources. Source levels of the secondary peaks considered in these
studies--those within the hearing range of some marine mammals--range
from 135-166 dB, meaning that these sub-harmonics would either be below
the threshold for behavioral harassment or would attenuate to such a
level within a few meters. Beyond these important study details, these
high-frequency (i.e., Category 1) sources and any energy they may
produce below the primary frequency that could be audible to marine
mammals would be dominated by a few primary sources that are
[[Page 38525]]
operated near-continuously, and the potential range above threshold
would be so small as to essentially discount them. Therefore, Category
1 sources are not expected to have any effect on marine mammals and are
not considered further in this document.
Category 2 acoustic sources, which are present on most NWFSC
fishery research vessels, include a variety of single, dual, and multi-
beam echosounders (many with a variety of modes), sources used to
determine the orientation of trawl nets, and several current profilers
with lower output frequencies than Category 1 sources. Category 2
active acoustic sources have moderate to high output frequencies (10 to
180 kHz) that are generally within the functional hearing range of
marine mammals and therefore have the potential to cause behavioral
harassment. However, while likely potentially audible to certain
species, these sources have generally short ping durations and are
typically focused (highly directional) to serve their intended purpose
of mapping specific objects, depths, or environmental features. These
characteristics reduce the likelihood of an animal receiving or
perceiving the signal. A number of these sources, particularly those
with relatively lower output frequencies coupled with higher output
levels can be operated in different output modes (e.g., energy can be
distributed among multiple output beams) that may lessen the likelihood
of perception by and potential impact on marine mammals.
We now describe specific acoustic sources used by NWFSC. The
acoustic system used during a particular survey is optimized for
surveying under specific environmental conditions (e.g., depth and
bottom type). Lower frequencies of sound travel further in the water
(i.e., good range) but provide lower resolution (i.e., are less
precise). Pulse width and power may also be adjusted in the field to
accommodate a variety of environmental conditions. Signals with a
relatively long pulse width travel further and are received more
clearly by the transducer (i.e., good signal-to-noise ratio) but have a
lower range resolution. Shorter pulses provide higher range resolution
and can detect smaller and more closely spaced objects in the water.
Similarly, higher power settings may decrease the utility of collected
data. Power level is also adjusted according to bottom type, as some
bottom types have a stronger return and require less power to produce
data of sufficient quality. Power is typically set to the lowest level
possible in order to receive a clear return with the best data. Survey
vessels may be equipped with multiple acoustic systems; each system has
different advantages that may be utilized depending on the specific
survey area or purpose. In addition, many systems may be operated at
one of two frequencies or at a range of frequencies. Characteristics of
these sources are summarized in Table 2.
(1) Multi-Frequency Narrow Beam Scientific Echosounders--
Echosounders and sonars work by transmitting acoustic pulses into the
water that travel through the water column, reflect off the seafloor,
and return to the receiver. Water depth is measured by multiplying the
time elapsed by the speed of sound in water (assuming accurate sound
speed measurement for the entire signal path), while the returning
signal itself carries information allowing ``visualization'' of the
seafloor. Multi-frequency split-beam sensors are deployed from NWFSC
survey vessels to acoustically map the distributions and estimate the
abundances and biomasses of many types of fish; characterize their
biotic and abiotic environments; investigate ecological linkages; and
gather information about their schooling behavior, migration patterns,
and avoidance reactions to the survey vessel. The use of multiple
frequencies allows coverage of a broad range of marine acoustic survey
activity, ranging from studies of small plankton to large fish schools
in a variety of environments from shallow coastal waters to deep ocean
basins. Simultaneous use of several discrete echosounder frequencies
facilitates accurate estimates of the size of individual fish, and can
also be used for species identification based on differences in
frequency-dependent acoustic backscattering between species. The NWFSC
operates the Simrad EK60 system, which typically transmits and receives
at four frequencies ranging from 38-200 kHz.
(2) Multibeam Echosounder and Sonar--Multibeam echosounders and
sonars operate similarly to the devices described above. However, the
use of multiple acoustic ``beams'' allows coverage of a greater area
compared to single beam sonar. The sensor arrays for multibeam
echosounders and sonars are usually mounted on the keel of the vessel
and have the ability to look horizontally in the water column as well
as straight down. Multibeam echosounders and sonars are used for
mapping seafloor bathymetry, estimating fish biomass, characterizing
fish schools, and studying fish behavior. The NWFSC operates the Simrad
ME70 system, which is mounted to the hull of the research vessel and
emits frequencies in the 70-120 kHz range.
(3) Single-Frequency Omnidirectional Sonar--These sources provide
omnidirectional imaging around the source with different vertical
beamwidths available, which results in differential transmitting beam
patterns. The cylindrical multi-element transducer allows the
omnidirectional sonar beam to be electronically tilted down to -
90[deg], allowing automatic tracking of schools of fish within the
entire water volume around the vessel. NWFSC operates the Simrad SX90
system.
(4) Acoustic Doppler Current Profiler (ADCP)--An ADCP is a type of
sonar used for measuring water current velocities simultaneously at a
range of depths. Whereas current depth profile measurements in the past
required the use of long strings of current meters, the ADCP enables
measurements of current velocities across an entire water column. The
ADCP measures water currents with sound, using the Doppler effect. A
sound wave has a higher frequency when it moves towards the sensor
(blue shift) than when it moves away (red shift). The ADCP works by
transmitting ``pings'' of sound at a constant frequency into the water.
As the sound waves travel, they ricochet off particles suspended in the
moving water, and reflect back to the instrument. Due to the Doppler
effect, sound waves bounced back from a particle moving away from the
profiler have a slightly lowered frequency when they return. Particles
moving toward the instrument send back higher frequency waves. The
difference in frequency between the waves the profiler sends out and
the waves it receives is called the Doppler shift. The instrument uses
this shift to calculate how fast the particle and the water around it
are moving. Sound waves that hit particles far from the profiler take
longer to come back than waves that strike close by. By measuring the
time it takes for the waves to return to the sensor, and the Doppler
shift, the profiler can measure current speed at many different depths
with each series of pings.
An ADCP anchored to the seafloor can measure current speed not just
at the bottom, but at equal intervals to the surface. An ADCP
instrument may be anchored to the seafloor or can be mounted to a
mooring or to the bottom of a boat. ADCPs that are moored need an
anchor to keep them on the bottom, batteries, and a data logger.
Vessel-mounted instruments need a vessel with power, a shipboard
computer to receive the data, and a GPS navigation system so the ship's
movements can be subtracted from the current velocity
[[Page 38526]]
data. ADCPs operate at frequencies between 75 and 300 kHz.
(5) Net Monitoring Systems--During trawling operations, a range of
sensors may be used to assist with controlling and monitoring gear. Net
sounders give information about the concentration of fish around the
opening to the trawl, as well as the clearances around the opening and
the bottom of the trawl; catch sensors give information about the rate
at which the codend is filling; symmetry sensors give information about
the optimal geometry of the trawls; and tension sensors give
information about how much tension is in the warps and sweeps. NWFSC
uses the Simrad ITI Catch Monitoring System, which allows monitoring of
the exact position of the gear and of what is happening in and around
the trawl, and the Simrad FS70 Third Wire Net Sonde, which allows
monitoring of the trawl opening.
Table 2--Operating Characteristics of NWFSC Active Acoustic Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
Operating
Active acoustic system frequencies Maximum source level Single ping duration (ms) and Orientation/ Nominal beamwidth
(kHz) repetition rate (Hz) directionality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Simrad EK60 narrow beam 38, 70, 120, 224 dB............... 1 ms at 1 Hz.................... Downward looking..... 11[deg].
echosounder. 200
Simrad ME70 multibeam echosounder. 70-120 205 dB............... 2 ms at 1 Hz.................... Downward looking..... 140[deg].
Simrad SX90 omnidirectional 70-120 206 dB............... 2 ms at 1 Hz.................... Downward 0[deg]-90[deg] tilt
multibeam sonar. omnidirectional. angle from vertical
(average).
Teledyne RD Instruments ADCP, 75 224 dB............... External trigger................ Downward looking 40[deg] x 100[deg].
Ocean Surveyor. (30[deg] tilt).
Simrad ITI Trawl Monitoring System 27-33 <200 dB.............. 0.05-0.5 Hz..................... Downward looking..... 40[deg] x 100[deg].
Simrad FS70 trawl sonar........... 330 216.................. 1 ms at 120 kHz................. Third wire trawl 40[deg].
sonar for monitoring
net opening and
fishing conditions.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Proposed Mitigation
In order to issue an incidental take authorization under section
101(a)(5)(A) of the MMPA, NMFS must set forth the permissible methods
of taking pursuant to such activity, ``and other means of effecting the
least practicable adverse impact on such species or stock and its
habitat, paying particular attention to rookeries, mating grounds, and
areas of similar significance, and on the availability of such species
or stock for subsistence uses.'' Note that taxonomic information for
certain species mentioned in this section is provided in the following
section (``Description of Marine Mammals in the Area of the Specified
Activity'').
The NWFSC has invested significant time and effort in identifying
technologies, practices, and equipment to minimize the impact of the
proposed activities on marine mammal species and stocks and their
habitat. These efforts have resulted in the consideration of many
potential mitigation measures, including those the NWFSC has determined
to be feasible and has implemented in recent years as a standard part
of sampling protocols. These measures include the move-on rule
mitigation protocol (also referred to in the preamble as the move-on
rule), protected species visual watches and use of acoustic pingers on
trawl gear, as well as use of a marine mammal excluder device (MMED) in
Nordic 264 midwater trawls.
Development of Mitigation Measures
In survey year 2008 in the CCE, NMFS' SWFSC had dramatically more
incidental takes of marine mammals in research gear, in terms of both
interactions and animals captured, than in any other year. The SWFSC
had previously conducted over a thousand midwater trawl survey tows
over more than 25 years, with very few incidents of marine mammal
interactions (Hewitt, 2009), but the number of incidental takes in 2008
exceeded the aggregate total over all preceding years. Following the
first SWFSC survey cruise in April 2008, during which a number of
marine mammals were captured in trawl gear, the SWFSC convened a
workshop involving SWFSC staff with expertise in survey design and
operations and marine mammal bycatch mitigation (Hewitt, 2009).
Participants worked to determine appropriate mitigation measures and to
consider changes to sampling protocols in an effort to reduce marine
mammal interactions.
The SWFSC also allocated resources towards the design,
construction, and testing of a MMED that could be incorporated into the
Nordic 264 trawl net, use of which had resulted in a large portion of
takes. In 2009, the MMED was tested and use of the device added to
SWFSC standard survey protocol for the Nordic 264 net (Dotson et al.,
2010).
These efforts resulted in the consideration of many potential
mitigation measures for all NMFS Science Centers, including those the
NWFSC has determined to be feasible and relevant to their operations.
These measures include the move-on rule, protected species visual
watches and use of acoustic pingers on certain trawl gear, as well as
use of the MMED in Nordic 264 trawls.
General Measures
Coordination and communication--When NWFSC survey effort is
conducted aboard NOAA-owned vessels, there are both vessel officers and
crew and a scientific party. Vessel officers and crew are not composed
of NWFSC staff, but are employees of NOAA's Office of Marine and
Aviation Operations (OMAO), which is responsible for the management and
operation of NOAA fleet ships and aircraft and is composed of uniformed
officers of the NOAA Commissioned Corps as well as civilians. The
ship's officers and crew provide mission support and assistance to
embarked scientists, and the vessel's Commanding Officer (CO) has
ultimate responsibility for vessel and passenger safety and, therefore,
decision authority. When NWFSC survey effort is conducted aboard
cooperative platforms (i.e., non-NOAA vessels), ultimate responsibility
and decision authority again rests with non-NWFSC personnel (i.e.,
vessel's master or captain). Decision authority includes the
implementation of mitigation measures (e.g., whether to stop deployment
of trawl gear upon observation of marine mammals). The scientific party
involved in any NWFSC survey effort is composed, in part or whole, of
NWFSC staff and is led by a Chief Scientist (CS). Therefore, because
the NWFSC--not OMAO or any other entity that may have authority over
survey platforms used by NWFSC--is the applicant to whom any incidental
take authorization issued under the authority of these proposed
regulations would be issued, we require that the NWFSC take all
necessary measures to
[[Page 38527]]
coordinate and communicate in advance of each specific survey with
OMAO, or other relevant parties, to ensure that all mitigation measures
and monitoring requirements described herein, as well as the specific
manner of implementation and relevant event-contingent decision-making
processes, are clearly understood and agreed-upon. This may involve
description of all required measures when submitting cruise
instructions to OMAO or when completing contracts with external
entities. NWFSC will coordinate and conduct briefings at the outset of
each survey and as necessary between ship's crew (CO/master or
designee(s), as appropriate) and scientific party in order to explain
responsibilities, communication procedures, marine mammal monitoring
protocol, and operational procedures. The CS will be responsible for
coordination with the Officer on Deck (OOD; or equivalent on non-NOAA
platforms) to ensure that requirements, procedures, and decision-making
processes are understood and properly implemented.
Vessel speed--Vessel speed during active sampling rarely exceeds 5
kn, with typical speeds being 2-4 kn. Transit speeds vary from 6-14 kn
but average 10 kn. These low vessel speeds minimize the potential for
ship strike (see ``Potential Effects of the Specified Activity on
Marine Mammals and Their Habitat'' for an in-depth discussion of ship
strike). At any time during a survey or in transit, if a crew member
standing watch or dedicated marine mammal observer sights marine
mammals that may intersect with the vessel course that individual will
immediately communicate the presence of marine mammals to the bridge
for appropriate course alteration or speed reduction, as possible, to
avoid incidental collisions.
Other gears--The NWFSC deploys a wide variety of gear to sample the
marine environment during all of their research cruises. Many of these
types of gear (e.g., plankton nets, video camera and ROV deployments)
are not considered to pose any risk to marine mammals and are therefore
not subject to specific mitigation measures. However, at all times when
the NWFSC is conducting survey operations at sea, the OOD and/or CS and
crew will monitor for any unusual circumstances that may arise at a
sampling site and use best professional judgment to avoid any potential
risks to marine mammals during use of all research equipment.
Handling procedures--The NWFSC will implement a number of handling
protocols to minimize potential harm to marine mammals that are
incidentally taken during the course of fisheries research activities.
In general, protocols have already been prepared for use on commercial
fishing vessels. Because incidental take of marine mammals in fishing
gear is similar for commercial fisheries and research surveys, NWFSC
proposes to adopt these protocols, which are expected to increase post-
release survival. In general, following a ``common sense'' approach to
handling captured or entangled marine mammals will present the best
chance of minimizing injury to the animal and of decreasing risks to
scientists and vessel crew. Handling or disentangling marine mammals
carries inherent safety risks, and using best professional judgment and
ensuring human safety is paramount.
Captured live or injured marine mammals are released from research
gear and returned to the water as soon as possible with no gear or as
little gear remaining on the animal as possible. Animals are released
without removing them from the water if possible and data collection is
conducted in such a manner as not to delay release of the animal(s) or
endanger the crew. NWFSC staff will be instructed on how to identify
different species; handle and bring marine mammals aboard a vessel;
assess the level of consciousness; remove fishing gear; and return
marine mammals to water.
Trawl Survey Visual Monitoring and Operational Protocols
Specific mitigation protocols are required for all trawl operations
conducted by the NWFSC using Nordic 264 surface trawl gear, midwater
trawl gear (modified Cobb, Aleutian Wing, and various commercial nets),
and bottom trawl gear (double-rigged shrimp, Poly Nor'easter, modified
Aberdeen, beam, and various commercial nets). Separate protocols
(described below) are in place for the Kodiak surface trawl and pair
trawl gear. Marine mammal watches will be conducted for at least ten
minutes prior to the beginning of the planned set and throughout the
tow and net retrieval, by scanning the surrounding waters with the
naked eye and rangefinding binoculars (or monocular). Lookouts
immediately alert the OOD and CS as to their best estimate of the
species and number of animals observed and any observed animal's
distance, bearing, and direction of travel relative to the ship's
position. The CS must confirm with the OOD that no marine mammals have
been seen within 500 m (or as far as may be observed if less than 500
m) of the ship or appear to be approaching the ship during the pre-set
watch period prior to the deployment of any trawl gear. During
nighttime operations, visual observation may be conducted using the
naked eye and available vessel lighting but effectiveness is limited.
The visual observation period typically occurs during transit leading
up to arrival at the sampling station, rather than upon arrival on
station. However, in some cases it may be necessary to conduct a
plankton tow or other small net cast prior to deploying trawl gear. In
these cases, the visual watch will continue until trawl gear is ready
to be deployed. Aside from pre-trawl monitoring, the OOD/CS and crew
standing watch will visually scan for marine mammals during all daytime
operations.
It is important to note that the 500 m distance is provided only as
a frame of reference for marine mammal observations that would
nominally be of greater concern as regards the potential for
interaction with research fishing gear. The primary concern is to avoid
all marine mammal interactions (regardless of the numbers of takes
proposed for authorization here), and the most appropriate course of
action to achieve this goal in any given instance is likely to be
related more to event-specific elements than to an arbitrary distance
from the vessel. Depending on unpredictable contextual elements,
animals sighted at distances greater than 500 m could provoke
mitigation action or, conversely, animals sighted at closer range could
be determined to not be at risk of interacting with research fishing
gear. The NWFSC considers 500 m to be the average effective observation
distance, but the actual effective range is determined by numerous
factors related to the weather, ship observations, and the species
observed.
The primary purpose of conducting pre-trawl visual monitoring is to
implement the move-on rule. If marine mammals are sighted within 500 m
(or as far as may be observed if less than 500 m) of the vessel and are
considered at risk of interacting with the vessel or research gear, or
appear to be approaching the vessel and are considered at risk of
interaction, NWFSC may elect to either remain onsite to see if the
animals move off or may move on to another sampling location. When
remaining onsite, the set is delayed (typically for at least ten
minutes) and, if the animals depart or appear to no longer be at risk
of interacting with the vessel or gear, a further ten minute
observation period is conducted. If no further observations are made or
the animals still do not appear to be at risk of interaction, then the
set may be made. If the vessel is moved to a different section of the
sampling area,
[[Page 38528]]
move-on rule mitigation protocols would begin anew. If, after moving
on, marine mammals remain at risk of interaction, the CS or watch
leader may decide to move again or to skip the station. Marine mammals
that are sighted further than 500 m from the vessel would be monitored
to determine their position and movement in relation to the vessel. If
they appear to be closing on the vessel, the move-on rule protocols may
be implemented even if they are initially further than 500 m from the
vessel.
For surface trawl surveys (i.e., those surveys deploying the Nordic
264 net), which have historically presented the greatest risk of marine
mammal interaction, dedicated crew are assigned to marine mammal
monitoring duty (i.e., have no other tasks) and care is taken to
provide some rest periods for observers to avoid fatigue. At least two
pairs of binoculars are available for verification of potential
sightings. As the vessel approaches the station, the OOD and at least
one assigned member of the scientific party monitor for marine mammals.
Within several minutes of arriving on station and finishing their
sampling duties, two additional members of the scientific party are
assigned to monitor for marine mammals and, for the remainder of the
tow, there would be a minimum of three members of the scientific party
watching for marine mammals. Depending on the situational context
(e.g., numbers of marine mammals seen during the station approach or
expected at that particular place and season), additional crew may be
assigned to stand watch as necessary to provide full monitoring
coverage around the vessel. Up to eight observers in total (including
ship's crew standing watch) may be on duty during active trawling. The
focus on the full area around the ship continues until trawl retrieval
begins, at which point observational focus turns to the stern and the
trawl net itself.
For midwater and bottom trawl surveys, the pre-set watch period is
conducted by the OOD and bridge crew and typically occurs during
transit prior to arrival at the sampling station, but may also include
time on station if other types of gear or equipment (e.g., bongo nets)
are deployed before the trawl. For these trawls, risk of interaction
during the tow is lower and monitoring effort is reduced to the bridge
crew until trawl retrieval.
For all surveys, although the minimum pre-set watch period is ten
minutes, the actual monitoring period is typically longer. During
standard trawl operations, at least some of the trackline to be towed
is typically traversed prior to setting gear in order to check for
hazards. On surface trawl surveys, CTD casts and plankton/bongo net
hauls are made prior to setting the trawl. These activities can take
25-35 minutes after the vessel arrives on station, depending on water
depth, and monitoring for marine mammals continues throughout these
activities. Midwater trawls and bottom trawls do not typically deploy
other gears before deploying trawl gear but reconnaissance of the
trackline often takes ten to fifteen minutes after arriving on station.
In addition, once the decision is made to deploy the trawl gear,
monitoring continues while the net is unspooled, which may take about
ten minutes. Before the trawl doors are deployed, the net floats closed
on the surface behind the vessel, and appropriate actions can be taken
if marine mammals are sighted near the ship. Therefore, the marine
mammal monitoring period--which begins before the vessel arrives on
station and extends continuously through gear deployment--typically
extends for over thirty minutes for all trawl types.
The effectiveness of visual monitoring may be limited depending on
weather and lighting conditions. The OOD, CS or watch leader will
determine the best strategy to avoid potential takes of marine mammals
based on the species encountered and their numbers and behavior,
position, and vector relative to the vessel, as well as any other
factors. For example, a whale transiting through the sampling area in
the distance may only require a short move from the designated station,
whereas a pod of dolphins in close proximity to the vessel may require
a longer move from the station or possibly cancellation of the planned
tow if the group follows the vessel.
In general, trawl operations will be conducted immediately upon
arrival on station (and on conclusion of the pre-watch period) in order
to minimize the time during which marine mammals (particularly
pinnipeds) may become attracted to the vessel. However, in some cases
it will be necessary to conduct small net tows (e.g., bongo net) prior
to deploying trawl gear.
Once the trawl net is in the water, the OOD, CS, and/or crew
standing watch will continue to visually monitor the surrounding waters
and will maintain a lookout for marine mammal presence as far away as
environmental conditions allow. If marine mammals are sighted before
the gear is fully retrieved, the most appropriate response to avoid
marine mammal interaction will be determined by the professional
judgment of the CS, watch leader, OOD and other experienced crew as
necessary. This judgment will be based on past experience operating
trawl gears around marine mammals (i.e., best professional judgment)
and on NWFSC training sessions that will facilitate dissemination of
expertise operating in these situations (e.g., factors that contribute
to marine mammal gear interactions and those that aid in successfully
avoiding such events). Best professional judgment takes into
consideration the species, numbers, and behavior of the animals, the
status of the trawl net operation (e.g., net opening, depth, and
distance from the stern), the time it would take to retrieve the net,
and safety considerations for changing speed or course. We recognize
that it is not possible to dictate in advance the exact course of
action that the OOD or CS should take in any given event involving the
presence of marine mammals in proximity to an ongoing trawl tow, given
the sheer number of potential variables, combinations of variables that
may determine the appropriate course of action, and the need to
consider human safety in the operation of fishing gear at sea.
Nevertheless, we require a full accounting of factors that shape both
successful and unsuccessful decisions, and these details will be fed
back into NWFSC training efforts and ultimately help to refine the best
professional judgment that determines the course of action taken in any
given scenario (see further discussion in ``Proposed Monitoring and
Reporting'').
If trawling operations have been suspended because of the presence
of marine mammals, the vessel will resume trawl operations (when
practicable) only when the animals are believed to have departed the
area. This decision is at the discretion of the OOD/CS and is dependent
on the situation.
Standard survey protocols that are expected to lessen the
likelihood of marine mammal interactions include standardized tow
durations and distances. Standard tow durations of not more than thirty
minutes at the target depth will typically be implemented, excluding
deployment and retrieval time (which may require an additional thirty
minutes, depending on target depth), to reduce the likelihood of
attracting and incidentally taking marine mammals. Short tow durations
decrease the opportunity for marine mammals to find the vessel and
investigate. Trawl tow distances will be less than 3 nm--typically 1-2
nm, depending on the specific survey and trawl speed--which is expected
to reduce the likelihood of attracting and incidentally taking marine
mammals. In addition, care will be taken when
[[Page 38529]]
emptying the trawl to avoid damage to marine mammals that may be caught
in the gear but are not visible upon retrieval. The gear will be
emptied as quickly as possible after retrieval in order to determine
whether or not marine mammals are present. The vessel's crew will clean
trawl nets prior to deployment to remove prey items that might attract
marine mammals. Catch volumes are typically small with every attempt
made to collect all organisms caught in the trawl.
Marine mammal excluder device--Excluder devices are specialized
modifications, typically used in trawl nets, which are designed to
reduce bycatch by allowing non-target taxa to escape the net. These
devices generally consist of a grid of bars fitted into the net that
allow target species to pass through the bars into the codend while
larger, unwanted taxa (e.g., turtles, sharks, mammals) strike the bars
and are ejected through an opening in the net. Marine turtle bycatch in
the commercial shrimp trawl industry led to the development of turtle
excluder devices (TED) (e.g., Mitchell et al., 1995) in the 1970s. TEDs
are perhaps the most commonly used excluder devices, but devices
designed specifically for the exclusion of marine mammals have also
been developed for various fisheries around the world where marine
mammal interactions are problematic (e.g., Gibson and Isakssen, 1998;
Northridge, 2003).
Similar to TEDs, MMEDs generally consist of a large aluminum grate
positioned in the intermediate portion of the net forward of the codend
and below an escape opening constructed into the upper net panel above
the grate. These devices enable target species to pass through a grid
or mesh barrier and into the codend while preventing the passage of
marine mammals, which are ejected out through an escape opening or swim
back out of the mouth of the net. The angled aluminum grate is intended
to guide marine mammals through the escape opening. For full details of
design and testing of the MMED designed by the SWFSC for the Nordic 264
net, please see Dotson et al. (2010).
MMEDs have not been proven to be fully effective at preventing
marine mammal capture in trawl nets (e.g., Chilvers, 2008) and are not
expected to prevent marine mammal capture in NWFSC trawl surveys. It is
difficult to effectively test such devices, in terms of effectiveness
in excluding marine mammals as opposed to effects on target species
catchability, because realistic field trials would necessarily involve
marine mammal interactions with trawl nets. Use of artificial
surrogates in field trials has not been shown to be a realistic
substitute (Gibson and Isakssen, 1998). Nevertheless, we believe it
reasonable to assume that use of MMEDs may reduce the likelihood of a
given marine mammal interaction with trawl gear resulting in mortality.
We do not infer causality, but note that annual marine mammal
interactions with the Nordic 264 trawl net have been much reduced for
the SWFSC (relative to 2008) since use of the MMED began.
Multiple types of midwater trawl nets are used in NWFSC trawl
surveys. The Nordic 264 trawl net, used as a surface trawl by NWFSC, is
generally much larger than the midwater trawls, is fished at faster
speeds, and has a different shape and functionality than these nets.
Very few marine mammal interactions with NWFSC pelagic trawl gear have
involved nets other than the Nordic 264 (one of 37 total incidents
since 1999; Table 4). Therefore, MMED use is not proposed for nets
other than the Nordic 264.
The NWFSC has tested the MMED design used by the SWFSC and found
that it caused a significant loss of some salmon species that were the
target of their research. More recent experiments have used video
cameras attached to the net opening and near the excluder device to
test different configurations of the excluder device to minimize loss
of target species. The experiments have looked at adding weight and
stiffeners to the flap covering the escape hatch to keep it closed and
flipping the MMED so the escape hatch faces down rather than up. Based
on preliminary results, this downward-pointing escape hatch appears to
be the best design for minimizing loss of target species. Additional
research will be necessary to calibrate catch levels in tows with the
excluder device compared to past tows that did not contain the excluder
(i.e., to align the new catchability rates with historical data sets).
During these configuration and calibration experiments some nets will
be fished without the MMED in order to provide controls for
catchability. Once the NWFSC completes these experiments the MMED will
be used in all future trawls with the Nordic 264. Please see ``Proposed
Monitoring and Reporting'' for additional discussion.
Acoustic deterrent devices--Acoustic deterrent devices (pingers)
are underwater sound-emitting devices that have been shown to decrease
the probability of interactions with certain species of marine mammals
when fishing gear is fitted with the devices. Multiple studies have
reported large decreases in harbor porpoise mortality (approximately
eighty to ninety percent) in bottom-set gillnets (nets composed of
vertical panes of netting, typically set in a straight line and either
anchored to the bottom or drifting) during controlled experiments
(e.g., Kraus et al., 1997; Trippel et al., 1999; Gearin et al., 2000).
Using commercial fisheries data rather than a controlled experiment,
Palka et al. (2008) reported that harbor porpoise bycatch rates in the
northeast U.S gillnet fishery when fishing without pingers was about
two to three times higher compared to when pingers were used. After
conducting a controlled experiment in a California drift gillnet
fishery during 1996-97, Barlow and Cameron (2003) reported
significantly lower bycatch rates when pingers were used for all
cetacean species combined, all pinniped species combined, and
specifically for short-beaked common dolphins (85 percent reduction)
and California sea lions (69 percent reduction). While not a
statistically significant result, catches of Pacific white-sided
dolphins (which are historically one of the most frequently captured
species in NWFSC surveys; see Table 4) were reduced by seventy percent.
Carretta et al. (2008) subsequently examined nine years of observer
data from the same drift gillnet fishery and found that pinger use had
eliminated beaked whale bycatch. Carretta and Barlow (2011) assessed
the long-term effectiveness of pingers in reducing marine mammal
bycatch in the California drift gillnet fishery by evaluating fishery
data from 1990-2009 (with pingers in use beginning in 1996), finding
that bycatch rates of cetaceans were reduced nearly fifty percent in
sets using a sufficient number of pingers. However, in contrast to the
findings of Barlow and Cameron (2003), they report no significant
difference in pinniped bycatch.
To be effective, a pinger must emit a signal that is sufficiently
aversive to deter the species of concern, which requires that the
signal is perceived while also deterring investigation. In rare cases,
aversion may be learned as a warning when an animal has survived
interaction with gear fitted with pingers (Dawson, 1994). The
mechanisms by which pingers work in operational settings are not fully
understood, but field trials and captive studies have shown that sounds
produced by pingers are aversive to harbor porpoises (e.g., Laake et
al., 1998; Kastelein et al., 2000; Culik et al., 2001), and it is
assumed that when marine mammals are deterred from interacting with
gear fitted with pingers that it is because the sounds produced by the
devices are aversive.
[[Page 38530]]
Two primary concerns expressed with regard to pinger effectiveness in
reducing marine mammal bycatch relate to habituation (i.e., marine
mammals may become habituated to the sounds made by the pingers,
resulting in increasing bycatch rates over time; Dawson, 1994; Cox et
al., 2001; Carlstr[ouml]m et al., 2009) and the ``dinner bell effect''
(Dawson, 1994; Richardson et al., 1995), which implies that certain
predatory marine mammal species (e.g., sea lions) may come to associate
pingers with a food source (e.g., fish caught in nets) with the result
that bycatch rates may be higher in nets with pingers than in those
without.
Palka et al. (2008) report that habituation has not occurred on a
level that affects the bycatch estimate for the northeast U.S. gillnet
fishery, while cautioning that the data studied do not provide a direct
method to study habituation. Similarly, Carretta and Barlow (2011)
report that habituation is not apparent in the California drift gillnet
fishery, with the proportion of pinger-fitted sets with bycatch not
significantly different for either cetaceans or pinnipeds between the
periods 1996-2001 and 2001-09; in fact, bycatch rates for both taxa
overall were lower in the latter period. We are not aware of any long-
term behavioral studies investigating habituation. Bycatch rates of
California sea lions, specifically, did increase during the latter
period. However, the authors do not attribute the increase to pinger
use (i.e., the ``dinner bell effect''); rather, they believe that
continuing increases in population abundance for the species (Carretta
et al., 2015a) coincident with a decline in fishery effort are
responsible for the increased rate of capture. Despite these potential
limitations on the effectiveness of pingers, and while effectiveness
has not been tested on trawl gear, we believe that the available
evidence supports an assumption that use of pingers is likely to reduce
the potential for marine mammal interactions with NWFSC trawl gear.
If one assumes that use of a pinger is effective in deterring
marine mammals from interacting with fishing gear, one must therefore
assume that receipt of the acoustic signal has a disturbance effect on
those marine mammals (i.e., Level B harassment). However, Level B
harassment that may be incurred as a result of NWFSC use of pingers
does not constitute take that must be authorized under the MMPA. The
MMPA prohibits the taking of marine mammals by U.S. citizens or within
the U.S. EEZ unless such taking is appropriately permitted or
authorized. However, the MMPA provides several narrowly defined
exemptions from this requirement (e.g., for Alaskan natives; for
defense of self or others; for Good Samaritans [16 U.S.C. 1371(b)-
(d)]). Section 109(h) of the MMPA (16 U.S.C. 1379(h)) allows for the
taking of marine mammals in a humane manner by federal, state, or local
government officials or employees in the course of their official
duties if the taking is necessary for ``the protection or welfare of
the mammal,'' ``the protection of the public health and welfare,'' or
``the non-lethal removal of nuisance animals.'' NWFSC use of pingers as
a deterrent device, which may cause Level B harassment of marine
mammals, is intended solely for the avoidance of potential marine
mammal interactions with NWFSC research gear (i.e., avoidance of Level
A harassment, serious injury, or mortality). Therefore, use of such
deterrent devices, and the taking that may result, is for the
protection and welfare of the mammal and is covered explicitly under
MMPA section 109(h)(1)(A). Potential taking of marine mammals resulting
from NWFSC use of pingers is not discussed further in this document.
Pingers will be deployed during all surface trawl operations (i.e.,
using the Nordic 264 net), with two pairs of pingers installed near the
net opening. The vessel's crew will ensure that pingers are operational
prior to deployment. Pinger brands typically used by NWFSC include the
Aquatec Subsea Limited model AQUAmark and Fumunda Marine models F10 and
F70, with the following attributes: (1) Operational depth of 10-200 m;
(2) tones range from 200-400 ms in duration, repeated every five to six
seconds; (3) variable frequency of 10-160 kHz; and (4) maximum source
level of 145 dB rms re 1 [mu]Pa. Please see ``Marine Mammal Hearing''
below for reference to functional and best hearing ranges for marine
mammals present in the CCE.
Kodiak surface trawl and pair trawl gear--The Kodiak surface trawl,
used only in Puget Sound, has only limited potential for marine mammal
interaction. This gear type is a small net towed at slow speeds (about
2 kn) as close to shore as the net can be fished, and these
characteristics mean that marine mammals would likely be able to avoid
the net or swim out of it if necessary. However, rules for cetaceans
would be similar as for other net types (i.e., delay and/or move-on if
cetaceans observed within approximately 500 m or clearly approaching
from greater distance). If killer whales are observed at any distance,
the net would not be deployed and the move-on rule invoked.
The pair trawl is used only in the Columbia River, and is fished
with an open codend. Although unlikely, there is some potential for
pinnipeds to become entangled in the net material. NWFSC's practice,
which would be allowed under section 109(h) of the MMPA, is to deter
pinnipeds from encountering the net using pyrotechnic devices and other
measures. Therefore, separate mitigation is not warranted, and we do
not discuss NWFSC deterrence of pinnipeds associated with pair trawl
surveys further in this document. Please see the NWFSC's draft
Programmatic Environmental Assessment for further information about
this practice.
Longline and Other Hook and Line Survey Visual Monitoring and
Operational Protocols
Visual monitoring requirements for all longline surveys are similar
to the general protocols described above for trawl surveys. Please see
that section for full details of the visual monitoring protocol and the
move-on rule mitigation protocol. In summary, requirements for longline
surveys are to: (1) Conduct visual monitoring during the thirty-minute
period prior to arrival on station; (2) implement the move-on rule if
marine mammals are observed within the area around the vessel and maybe
at risk of interacting with the vessel or gear; (3) deploy gear as soon
as possible upon arrival on station (depending on presence of marine
mammals); and (4) maintain visual monitoring effort throughout
deployment and retrieval of the longline gear. As was described for
trawl gear, the OOD, CS, or watch leader will use best professional
judgment to minimize the risk to marine mammals from potential gear
interactions during deployment and retrieval of gear. If marine mammals
are detected during setting operations and are considered to be at
risk, immediate retrieval or suspension of operations may be warranted.
If operations have been suspended because of the presence of marine
mammals, the vessel will resume setting (when practicable) only when
the animals are believed to have departed the area. If marine mammals
are detected during retrieval operations and are considered to be at
risk, haul-back may be postponed. These decisions are at the discretion
of the OOD/CS and are dependent on the situation. If killer whales are
observed at any distance, the set would not occur and the move-on rule
would be invoked.
Other types of hook and line surveys (e.g., rod and reel) generally
use the same protocols as longline surveys.
[[Page 38531]]
However, for hook and line surveys in Puget Sound the move-on rule is
not required for pinnipeds because they are commonly abundant on shore
nearby hook and line sampling locations. Use of the move-on rule in
these circumstances would represent an impracticable impact on NWFSC
survey operations, and we note that no marine mammals have ever been
captured in NWFSC hook and line surveys (Table 4). However, the NWFSC
would implement the move-on rule for hook and line surveys in Puget
Sound for any cetaceans that are within 500 m and may be at risk of
interaction with the survey operation. If killer whales are observed at
any distance, fishing would not occur.
As for trawl surveys, some standard survey protocols are expected
to minimize the potential for marine mammal interactions. Soak times
are typically short relative to commercial fishing operations, measured
from the time the last hook is in the water to when the first hook is
brought out of the water. NWFSC longline protocols specifically
prohibit chumming (releasing additional bait to attract target species
to the gear) and spent bait and offal is retained on the vessel until
all gear has been retrieved. Some hook and line surveys use barbless
hooks, which are less likely to injure a hooked animal.
Seine Survey Visual Monitoring and Operational Protocols
Visual monitoring and operational protocols for seine surveys are
similar to those described previously for trawl surveys, with a focus
on visual observation in the survey area and avoidance of marine
mammals that may be at risk of interaction with survey vessels or gear.
For purse seine operations, visual monitoring is focused on avoidance
of cetaceans and aggregations of pinnipeds. Individual or small numbers
of pinnipeds may be attracted to purse seine operations, especially in
Puget Sound, and are frequently observed to enter operational purse
seines to depredate the catch and exit the net unharmed. Use of the
move-on rule in these circumstances would represent an impracticable
impact on NWFSC survey operations, and we note that no marine mammals
have ever been captured in NWFSC seine surveys (Table 4).
If pinnipeds are in the immediate vicinity of a purse seine survey,
the set may be delayed until animals move away or the move-on rule is
determined to be appropriate, but the net would not be opened if
already deployed and pinnipeds enter it. However, delay would not be
invoked if only few pinnipeds are present (e.g., less than five), and
they do not appear to obviously be at risk.
If any dolphins or porpoises are observed within approximately 500
m of the purse seine survey location, the set would be delayed. If any
dolphins or porpoises are observed in the net, the net would be
immediately opened to free the animals. If killer whales or other large
whales are observed at any distance the net would not be set, and the
move-on rule would be invoked.
Beach seines are typically set nearshore by small boat crews, who
visually survey the area prior to the set. The set would not be made
within 200 m of any hauled pinnipeds. Otherwise, marine mammals are
unlikely to be at risk of interaction with NWFSC beach seine
operations, as the nets are relatively small and deployed and retrieved
slowly. If a marine mammal is observed attempting to interact with the
beach seine gear, the gear would immediately be lifted and removed from
the water.
Tangle net protocols--Tangle nets are used only in the Columbia
River. NWFSC attempts to avoid pinnipeds by rotating sampling locations
on a daily basis and by avoiding fishing near haulout areas. However,
as was described for NWFSC use of pair trawl gear in the LCRRA, NWFSC
also deters pinnipeds from interacting with tangle net gear as
necessary using pyrotechnic devices and visual presence, a practice
allowed under section 109(h) of the MMPA. Therefore, we do not discuss
NWFSC deterrence of pinnipeds associated with tangle net surveys
further in this document. Please see the NWFSC's draft Programmatic
Environmental Assessment for further information about this practice.
If pinniped presence in the vicinity of tangle net surveys is so
abundant as to be uncontrollable through deterrence, sampling would be
discontinued for a given day.
We have carefully evaluated the NWFSC's proposed mitigation
measures and considered a range of other measures in the context of
ensuring that we prescribed the means of effecting the least
practicable adverse impact on the affected marine mammal species and
stocks and their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another: (1)
The manner in which, and the degree to which, the successful
implementation of the measure is expected to minimize adverse impacts
to marine mammals, (2) the proven or likely efficacy of the specific
measure to minimize adverse impacts as planned; and (3) the
practicability of the measure for applicant implementation.
Any mitigation measure(s) we prescribe should be able to
accomplish, have a reasonable likelihood of accomplishing (based on
current science), or contribute to the accomplishment of one or more of
the general goals listed below:
(1) Avoidance or minimization of injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may contribute to this goal).
(2) A reduction in the number (total number or number at
biologically important time or location) of individual marine mammals
exposed to stimuli expected to result in incidental take (this goal may
contribute to 1, above, or to reducing takes by behavioral harassment
only).
(3) A reduction in the number (total number or number at a
biologically important time or location) of times any individual marine
mammal would be exposed to stimuli expected to result in incidental
take (this goal may contribute to 1, above, or to reducing takes by
behavioral harassment only).
(4) A reduction in the intensity of exposure to stimuli expected to
result in incidental take (this goal may contribute to 1, above, or to
reducing the severity of behavioral harassment only).
(5) Avoidance or minimization of adverse effects to marine mammal
habitat, paying particular attention to the prey base, blockage or
limitation of passage to or from biologically important areas,
permanent destruction of habitat, or temporary disturbance of habitat
during a biologically important time.
(6) For monitoring directly related to mitigation, an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation.
Based on our evaluation of the NWFSC's proposed measures, as well
as other measures we considered, we have preliminarily determined that
the proposed mitigation measures provide the means of effecting the
least practicable adverse impact on marine mammal species or stocks and
their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.
Description of Marine Mammals in the Area of the Specified Activity
We have reviewed NWFSC's species descriptions--which summarize
available information regarding status and trends, distribution and
habitat preferences, behavior and life history, and auditory
capabilities of the
[[Page 38532]]
potentially affected species--for accuracy and completeness and refer
the reader to Sections 3 and 4 of NWFSC's application, as well as to
NMFS' Stock Assessment Reports (SARs; www.nmfs.noaa.gov/pr/sars/),
instead of reprinting the information here. Table 3 lists all species
with expected potential for occurrence in the specified geographical
region where NWFSC proposes to conduct the specified activity and
summarize information related to the population or stock, including
potential biological removal (PBR). For taxonomy, we follow Committee
on Taxonomy (2015). PBR, defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population, is discussed in greater detail later in
this document (see ``Negligible Impact Analyses''). Species that could
potentially occur in the proposed research areas but are not expected
to have the potential for interaction with NWFSC research gear or that
are not likely to be harassed by NWFSC's use of active acoustic devices
are described briefly but omitted from further analysis. These include
extralimital species, which are species that do not normally occur in a
given area but for which there are one or more occurrence records that
are considered beyond the normal range of the species. For status of
species, we provide information regarding U.S. regulatory status under
the MMPA and ESA.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study area. NMFS' stock
abundance estimates for most species represent the total estimate of
individuals within the geographic area, if known, that comprises that
stock. For some species, this geographic area may extend beyond U.S.
waters. Survey abundance (as compared to stock or species abundance) is
the total number of individuals estimated within the survey area, which
may or may not align completely with a stock's geographic range as
defined in the SARs. These surveys may also extend beyond U.S. waters.
Thirty-four species (with 43 managed stocks) are considered to have
the potential to co-occur with NWFSC activities. Extralimital species
or stocks in the California Current include the Bryde's whale
(Balaenoptera edeni brydei) and the North Pacific right whale
(Eubalaena japonica). In addition, the sea otter is found in coastal
waters, with the southern sea otter (Enhydra lutris nereis) found in
California and the northern (or eastern) sea otter (E. l. kenyoni;
Washington stock only) found in Washington. However, sea otters are
managed by the U.S. Fish and Wildlife Service and are not considered
further in this document. All stocks are assessed in NMFS' U.S. Pacific
SARs (Carretta et al., 2015a,b), with the exception of the west coast
transient and northern resident stocks of killer whales, the eastern
North Pacific stock of the northern fur seal, and the eastern stock of
the Steller sea lion, which are considered in the U.S. Alaska SARs
(Allen and Angliss, 2015; Muto and Angliss, 2015). Values presented in
Table 3 reflect the most recent information available (i.e., final 2014
and draft 2015 reports, as appropriate).
Two populations of gray whales are recognized, eastern and western
North Pacific (ENP and WNP). WNP whales are known to feed in the
Okhotsk Sea and off of Kamchatka before migrating south to poorly known
wintering grounds, possibly in the South China Sea. The two populations
have historically been considered geographically isolated from each
other; however, recent data from satellite-tracked whales indicate that
there is some overlap between the stocks. Two WNP whales were tracked
from Russian foraging areas along the Pacific rim to Baja California
(Mate et al., 2011), and, in one case where the satellite tag remained
attached to the whale for a longer period, a WNP whale was tracked from
Russia to Mexico and back again (IWC, 2012). Between 22-24 WNP whales
are known to have occurred in the eastern Pacific through comparisons
of ENP and WNP photo-identification catalogs (IWC, 2012; Weller et al.,
2011; Burdin et al., 2011), and WNP animals comprised 8.1 percent of
gray whales identified during a recent field season off of Vancouver
Island (Weller et al., 2012). In addition, two genetic matches of WNP
whales have been recorded off of Santa Barbara, CA (Lang et al., 2011).
More recently, Urban et al. (2013) compared catalogs of photo-
identified individuals from Mexico with photographs of whales off
Russia and reported a total of 21 matches. Therefore, a portion of the
WNP population is assumed to migrate, at least in some years, to the
eastern Pacific during the winter breeding season.
However, the NWFSC does not believe that any gray whale (WNP or
ENP) would be likely to interact with its research gear, as it is
extremely unlikely that a gray whale in close proximity to NWFSC
research activity would be one of the approximately twenty WNP whales
that have been documented in the eastern Pacific. The likelihood that a
WNP whale would interact with NWFSC research gear is insignificant and
discountable, and WNP gray whales are omitted from further analysis.
Table 3--Marine Mammals Potentially Present in the Vicinity of NWFSC Research Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Occurrence ESA/MMPA Stock abundance
------------------------ status; (CV, Nmin, most Annual M/
Common name Scientific name Stock strategic (Y/ recent abundance PBR SI \3\
CC LCR PS N) \1\ survey) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale...................... Eschrichtius Eastern North X ...... X -; N 20,990 (0.05; 624 132
robustus. Pacific. 20,125; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.................. Megaptera California/Oregon/ X ...... X E/D; Y 1,918 (0.03; \12\ 11 >=5.5
novaeangliae Washington (CA/OR/ 1,855; 2011).
kuzira. WA).
Minke whale..................... Balaenoptera CA/OR/WA........... X ...... X -; N 478 (1.36; 202; 2 0
acutorostrata 2008).
scammoni.
Sei whale....................... B. borealis Eastern North X ...... ...... E/D; Y 126 (0.53; 83; 0.17 0
borealis. Pacific. 2008).
Fin whale....................... B. physalus CA/OR/WA........... X ...... ...... E/D; Y 3,051 (0.18; 16 2.2
physalus. 2,598; 2008).
[[Page 38533]]
Blue whale...................... B. musculus Eastern North X ...... ...... E/D; Y 1,647 (0.07; \12\ 2.3 0.9
musculus. Pacific. 1,551; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale..................... Physeter CA/OR/WA........... X ...... ...... E/D; Y 2,106 (0.58; 2.7 1.7
macrocephalus. 1,332; 2008).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Kogiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy sperm whale............... Kogia breviceps.... CA/OR/WA........... X ...... ...... -; N 579 (1.02; 271; 2.7 0
2008).
Dwarf sperm whale............... K. sima............ CA/OR/WA \5\....... X ...... ...... -; N Unknown........... Undet. 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Ziphiidae (beaked whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale........... Ziphius cavirostris CA/OR/WA........... X ...... ...... -; Y 6,590 (0.55; 45 0
4,481; 2008).
Baird's beaked whale............ Berardius bairdii.. CA/OR/WA........... X ...... ...... -; N 847 (0.81; 466; 4.7 0
2008).
Hubbs' beaked whale............. Mesoplodon CA/OR/WA \6\....... X ...... ...... -; Y 694 (0.65; 389; 3.9 0
carlhubbsi. 2008).
Blainville's beaked whale....... M. densirostris.... ................... X ...... ......
Ginkgo-toothed beaked whale..... M. ginkgodens...... ................... X ...... ......
Perrin's beaked whale........... M. perrini......... ................... X ...... ......
Lesser (pygmy) beaked whale..... M. peruvianus...... ................... X ...... ......
Stejneger's beaked whale........ M. stejnegeri...... ................... X ...... ...... ............ .................. ........ ........
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Common bottlenose dolphin....... Tursiops truncatus CA/OR/WA Offshore.. X ...... ...... -; N 1,006 (0.48; 684; 5.5 >=2
truncatus. 2008).
................... California Coastal. X ...... ...... -; N 323 (0.13; 290; 2.4 0.2
2005).
Striped dolphin................. Stenella CA/OR/WA........... X ...... ...... -; N 10,908 (0.34; 82 0
coeruleoalba. 8,231; 2008).
Long-beaked common dolphin...... Delphinus capensis California......... X ...... ...... -; N 107,016 (0.42; 610 13.8
capensis. 76,224; 2009).
Short-beaked common dolphin..... D. delphis delphis. CA/OR/WA........... X ...... ...... -; N 411,211 (0.21; 3,440 64
343,990; 2008).
Pacific white-sided dolphin..... Lagenorhynchus CA/OR/WA........... X ...... X -; N 26,930 (0.28; 171 17.8
obliquidens. 21,406; 2008).
Northern right whale dolphin.... Lissodelphis CA/OR/WA........... X ...... ...... -; N 8,334 (0.4; 6,019; 48 4.8
borealis. 2008).
Risso's dolphin................. Grampus griseus.... CA/OR/WA........... X ...... ...... -; N 6,272 (0.3; 4,913; 39 1.6
2008).
Killer whale.................... Orcinus orca \4\... West Coast X X X -; N 243 (n/a; 2009)... 2.4 0
Transient \7\.
................... Eastern North X ...... ...... -; N 240 (0.49; 162; 1.6 0
Pacific Offshore. 2008).
................... Eastern North X ...... X E/D; Y 78\10\ (n/a; 2014) 0.14 0
Pacific Southern
Resident.
................... Eastern North X ...... X -; N 261 (n/a; 2011)... 1.96 0
Pacific Northern
Resident.
Short-finned pilot whale........ Globicephala CA/OR/WA........... X ...... ...... -; N 760 (0.64; 465; 4.6 0
macrorhynchus. 2008).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise................. Phocoena phocoena Morro Bay.......... X ...... ...... -; N 2,917 (0.41; 21 >=0.6
vomerina. 2,102; 2012).
................... Monterey Bay....... X ...... ...... -; N 3,715 (0.51; 25 0
2,480; 2011).
................... San Francisco- X ...... ...... -; N 9,886 (0.51; 66 0
Russian River. 6,625; 2011).
................... Northern CA/ X ...... ...... -; N 35,769 (0.52; 475 >=0.6
Southern OR. 23,749; 2011).
................... Northern OR/WA X X ...... -; N 21,487 (0.44; 151 >=3
Coast. 15,123; 2011).
................... Washington Inland ...... ...... X -; N 10,682 (0.38; 63 >=2.2
Waters. 7,841; 2003).
Dall's porpoise................. Phocoenoides dalli CA/OR/WA........... X X X -; N 42,000 (0.33; 257 >=0.4
dalli. 32,106; 2008).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Guadalupe fur seal.............. Arctocephalus ................... X ...... ...... T/D; Y 7,408 (n/a; 3,028; 91 \13\ 0
philippii 1993).
townsendi.
[[Page 38534]]
Northern fur seal............... Callorhinus ursinus Pribilof Islands/ X ...... ...... D; Y 648,534 (0.2; 11,802 439
Eastern Pacific. 548,919; 2012).
................... California......... X ...... ...... -; N 14,050\10\ (n/a; 451 1.8
7,524; 2013).
California sea lion............. Zalophus United States...... X X X -; N 296,750 (n/a; 9,200 389
californianus. 153,337; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion................ Eumetopias jubatus Eastern U.S.\9\.... X X X D; Y 60,131-74,448 (n/ 1,645 92.3
monteriensis. a; 36,551; 2013)
\11\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal..................... Phoca vitulina California......... X ...... ...... -; N 30,968 (n/a; 1,641 43
richardii. 27,348; 2012).
................... OR/WA Coast \8\.... X X ...... -; N 24,732 (0.12; Undet. 10.6
22,380; 1999).
................... Washington Northern ...... ...... X -; N 11,036 (0.15; Undet. 9.8
Inland Waters.\8\ 7,213; 1999).
................... Southern Puget ...... ...... X -; N 1,568 (0.15; Undet. 3.4
Sound \8\. 1,025; 1999).
................... Hood Canal \8\..... ...... ...... X -; N 1,088 (0.15; 711; Undet. 0.2
1999).
Northern elephant seal.......... Mirounga California Breeding X ...... X -; N 179,000 (n/a; 4,882 8.8
angustirostris. 81,368; 2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of stock
abundance. In some cases, CV is not applicable. For three stocks of killer whales, the abundance values represent direct counts of individually
identifiable animals; therefore there is only a single abundance estimate with no associated CV. For certain stocks of pinnipeds, abundance estimates
are based upon observations of animals (often pups) ashore multiplied by some correction factor derived from knowledge of the species' (or similar
species') life history to arrive at a best abundance estimate; therefore, there is no associated CV. In these cases, the minimum abundance may
represent actual counts of all animals ashore.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value. All
M/SI values are as presented in the draft 2015 SARs (Carretta et al., 2015b; Muto and Angliss, 2015).
\4\ Transient and resident killer whales are considered unnamed subspecies (Committee on Taxonomy, 2015).
\5\ No information is available to estimate the population size of dwarf sperm whales off the U.S. west coast, as no sightings of this species have been
documented despite numerous vessel surveys of this region (Carretta et al., 2015a). Dwarf and pygmy sperm whales are difficult to differentiate at sea
but, based on previous sighting surveys and historical stranding data, it is thought that recent ship survey sightings were of pygmy sperm whales.
\6\ The six species of Mesoplodont beaked whales occurring in the CCE are managed as a single stock due to the rarity of records and the difficulty in
distinguishing these animals to species in the field. Based on bycatch and stranding records, it appears that M. carlhubbsi is the most commonly
encountered of these species (Carretta et al., 2008; Moore and Barlow, 2013). Additional managed stocks in the Pacific include M. stejnegeri in
Alaskan waters and M. densirostris in Hawaiian waters.
\7\ The abundance estimate for this stock includes only animals from the ``inner coast'' population occurring in inside waters of southeastern Alaska,
British Columbia, and Washington--excluding animals from the ``outer coast'' subpopulation, including animals from California--and therefore should be
considered a minimum count. For comparison, the previous abundance estimate for this stock, including counts of animals from California that are now
considered outdated, was 354.
\8\ Abundance estimates for these stocks are not considered current. PBR is therefore considered undetermined for these stocks, as there is no current
minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as these represent the best available
information for use in this document.
\9\ The eastern distinct population segment of the Steller sea lion, previously listed as threatened, was delisted under the ESA on December 4, 2013 (78
FR 66140; November 4, 2013).
\10\ These are provisional abundance estimates presented in the draft 2015 SARs.
\11\ Best abundance is calculated as the product of pup counts and a factor based on the birth rate, sex and age structure, and growth rate of the
population. A range is presented because the extrapolation factor varies depending on the vital rate parameter resulting in the growth rate (i.e.,
high fecundity or low juvenile mortality).
\12\ These stocks are known to spend a portion of their time outside the U.S. EEZ. Therefore, the PBR presented here is the allocation for U.S. waters
only and is a portion of the total. The total PBR for blue whales is 9.3 (one-quarter allocation for U.S. waters), and the total for humpback whales
is 22 (one half allocation for U.S. waters). Annual M/SI presented for these species is for U.S. waters only.
\13\ This represents annual M/SI in U.S. waters. However, the vast majority of M/SI for this stock--the level of which is unknown--would likely occur in
Mexican waters.
Take reduction planning--Take reduction plans are designed to help
recover and prevent the depletion of strategic marine mammal stocks
that interact with certain U.S. commercial fisheries, as required by
Section 118 of the MMPA. The immediate goal of a take reduction plan is
to reduce, within six months of its implementation, the M/SI of marine
mammals incidental to commercial fishing to less than the PBR level.
The long-term goal is to reduce, within five years of its
implementation, the M/SI of marine mammals incidental to commercial
fishing to insignificant levels, approaching a zero serious injury and
mortality rate, taking into account the economics of the fishery, the
availability of existing technology, and existing state or regional
fishery management plans. Take reduction teams are convened to develop
these plans.
For marine mammals in the California Current Ecosystem, there is
currently one take reduction plan in effect (Pacific Offshore Cetacean
Take Reduction Plan). The goal of this plan is to reduce M/SI of
several marine mammal stocks incidental to the California thresher
shark/swordfish drift gillnet fishery (CA DGN). A team was convened in
1996 and a final plan produced in 1997 (62 FR 51805; October 3, 1997).
Marine mammal stocks of concern initially included the California,
Oregon, and Washington stocks for all CCE beaked whales, short-finned
pilot whales, pygmy sperm whales, sperm whales, and humpback whales.
The most recent five-year averages of M/SI for these stocks are below
PBR, and none of these species were taken in the fishery in 2012-13.
More information is available on the Internet at: www.nmfs.noaa.gov/pr/interactions/trt/poctrp.htm. Of the stocks of concern, the NWFSC has
requested the authorization of
[[Page 38535]]
incidental M/SI + Level A for the short-finned pilot whale only (see
``Estimated Take by Incidental Harassment'' later in this document).
The most recent reported average annual human-caused mortality for
short-finned pilot whales (2004-08) is zero animals. The NWFSC does not
use drift gillnets in its fisheries research program; therefore, take
reduction measures applicable to the CA DGN fisheries are not relevant
to the NWFSC.
Unusual Mortality Events (UME)--A UME is defined under the MMPA as
``a stranding that is unexpected; involves a significant die-off of any
marine mammal population; and demands immediate response.'' From 1991
to the present, there have been sixteen formally recognized UMEs on the
U.S. west coast involving species under NMFS' jurisdiction. The most
recent of these, and the only ones involving currently ongoing
investigations, involve Guadalupe fur seals and California sea lions.
Increased strandings of Guadalupe fur seals (eight times the historical
average) have occurred along the entire coast of California. These
increased strandings were reported beginning in January 2015 and peaked
from April through June 2015. Findings from the majority of stranded
animals include malnutrition with secondary bacterial and parasitic
infections. Beginning in January 2013, elevated strandings of
California sea lion pups were observed in southern California, with
live sea lion strandings nearly three times higher than the historical
average. Findings to date indicate that a likely contributor to the
large number of stranded, malnourished pups was a change in the
availability of sea lion prey for nursing mothers, especially sardines.
These UMEs are occurring in the same areas and the causes and
mechanisms of this remain under investigation (www.nmfs.noaa.gov/pr/health/mmume/guadalupefurseals2015.html; www.nmfs.noaa.gov/pr/health/mmume/californiasealions2013.htm; accessed December 3, 2015).
Additional UMEs in the past ten years include those involving
harbor porpoises in California (2008; cause determined to be ecological
factors); Guadalupe fur seals in the Northwest (2007; undetermined);
large whales in California (2007; human interaction); cetaceans in
California (2007; undetermined); and harbor porpoises in the Pacific
Northwest (2006; undetermined). There is also an ongoing UME in the
western Gulf of Alaska that involves elevated large whale mortalities
and may be affecting eastern North Pacific gray whales, which also
occur in the NWFSC's research areas. For more information on UMEs,
please visit the Internet at: www.nmfs.noaa.gov/pr/health/mmume/events.html.
Potential Effects of the Specified Activity on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity (e.g., gear deployment, use of
active acoustic sources, visual disturbance) may impact marine mammals
and their habitat. The ``Estimated Take by Incidental Harassment''
section later in this document will include a quantitative analysis of
the number of individuals that are expected to be taken by this
activity. The ``Negligible Impact Analysis'' section will include an
analysis of how this specific activity will impact marine mammals and
will consider the content of this section, the ``Estimated Take by
Incidental Harassment'' section, and the ``Proposed Mitigation''
section, to draw conclusions regarding the likely impacts of this
activity on the reproductive success or survivorship of individuals and
from that on the affected marine mammal populations or stocks. In the
following discussion, we consider potential effects to marine mammals
from ship strike, physical interaction with the gear types described
previously, use of active acoustic sources, and visual disturbance of
pinnipeds.
Ship Strike
Vessel collisions with marine mammals, or ship strikes, can result
in death or serious injury of the animal. Wounds resulting from ship
strike may include massive trauma, hemorrhaging, broken bones, or
propeller lacerations (Knowlton and Kraus, 2001). An animal at the
surface may be struck directly by a vessel, a surfacing animal may hit
the bottom of a vessel, or an animal just below the surface may be cut
by a vessel's propeller. More superficial strikes may not kill or
result in the death of the animal. These interactions are typically
associated with large whales (e.g., fin whales), which are occasionally
found draped across the bulbous bow of large commercial ships upon
arrival in port. Although smaller cetaceans or pinnipeds are more
maneuverable in relation to large vessels than are large whales, they
may also be susceptible to strike. The severity of injuries typically
depends on the size and speed of the vessel, with the probability of
death or serious injury increasing as vessel speed increases (Knowlton
and Kraus, 2001; Laist et al., 2001; Vanderlaan and Taggart, 2007; Conn
and Silber, 2013). Impact forces increase with speed, as does the
probability of a strike at a given distance (Silber et al., 2010; Gende
et al., 2011).
Pace and Silber (2005) found that the probability of death or
serious injury increased rapidly with increasing vessel speed.
Specifically, the predicted probability of serious injury or death
increased from 45 to 75 percent as vessel speed increased from 10 to 14
kn, and exceeded ninety percent at 17 kn. Higher speeds during
collisions result in greater force of impact, but higher speeds also
appear to increase the chance of severe injuries or death through
increased likelihood of collision by pulling whales toward the vessel
(Clyne, 1999; Knowlton et al., 1995). In a separate study, Vanderlaan
and Taggart (2007) analyzed the probability of lethal mortality of
large whales at a given speed, showing that the greatest rate of change
in the probability of a lethal injury to a large whale as a function of
vessel speed occurs between 8.6 and 15 kn. The chances of a lethal
injury decline from approximately eighty percent at 15 kn to
approximately twenty percent at 8.6 kn. At speeds below 11.8 kn, the
chances of lethal injury drop below fifty percent, while the
probability asymptotically increases toward one hundred percent above
15 kn.
In an effort to reduce the number and severity of strikes of the
endangered North Atlantic right whale (Eubalaena glacialis), NMFS
implemented speed restrictions in 2008 (73 FR 60173; October 10, 2008).
These restrictions require that vessels greater than or equal to 65 ft
(19.8 m) in length travel at less than or equal to 10 kn near key port
entrances and in certain areas of right whale aggregation along the
U.S. eastern seaboard. Conn and Silber (2013) estimated that these
restrictions reduced total ship strike mortality risk levels by eighty
to ninety percent.
For vessels used in NWFSC research activities, transit speeds
average 10 kn (but vary from 6-14 kn), while vessel speed during active
sampling is typically only 2-4 kn. At sampling speeds, both the
possibility of striking a marine mammal and the possibility of a strike
resulting in serious injury or mortality are discountable. At average
transit speed, the probability of serious injury or mortality resulting
from a strike is less than fifty percent. However, the likelihood of a
strike actually happening is again discountable. Ship strikes, as
analyzed in the studies cited above, generally involve commercial
shipping, which is
[[Page 38536]]
much more common in both space and time than is research activity.
Jensen and Silber (2004) summarized ship strikes of large whales
worldwide from 1975-2003 and found that most collisions occurred in the
open ocean and involved large vessels (e.g., commercial shipping).
Commercial fishing vessels were responsible for three percent of
recorded collisions, while only one such incident (0.75 percent) was
reported for a research vessel during that time period.
It is possible for ship strikes to occur while traveling at slow
speeds. For example, a NOAA-chartered survey vessel traveling at low
speed (5.5 kn) while conducting multi-beam mapping surveys off the
central California coast struck and killed a blue whale in 2009. The
State of California determined that the whale had suddenly and
unexpectedly surfaced beneath the hull, with the result that the
propeller severed the whale's vertebrae, and that this was an
unavoidable event. This strike represents the only such incident in
approximately 540,000 hours of similar coastal mapping activity (p =
1.9 x 10-6; 95% CI = 0-5.5 x 10-6; NMFS, 2013).
In addition, a research vessel reported a fatal strike in 2011 of a
dolphin in the Atlantic, demonstrating that it is possible for strikes
involving smaller cetaceans or pinnipeds to occur. In that case, the
incident report indicated that an animal apparently was struck by the
vessel's propeller as it was intentionally swimming near the vessel.
While indicative of the type of unusual events that cannot be ruled
out, neither of these instances represents a circumstance that would be
considered reasonably foreseeable or that would be considered
preventable.
In summary, we anticipate that vessel collisions involving NWFSC
research vessels, while not impossible, represent unlikely,
unpredictable events for which there are no preventive measures. No
ship strikes have been reported from any fisheries research activities
conducted or funded by the NWFSC in any of the three research areas.
Given the relatively slow speeds of research vessels, the presence of
bridge crew watching for obstacles at all times (including marine
mammals), the presence of marine mammal observers on some surveys, and
the small number of research cruises, we believe that the possibility
of ship strike is discountable and, further, that were a strike of a
large whale to occur, it would be unlikely to result in serious injury
or mortality. No incidental take resulting from ship strike is
anticipated, and this potential effect of research will not be
discussed further in the following analysis.
Research Gear
The types of research gear used by NWFSC were described previously
under ``Detailed Description of Activity.'' Here, we broadly categorize
these gears into those whose use we consider to have an extremely
unlikely potential to result in marine mammal interaction and those
whose use we believe may result in marine mammal interaction. Gears in
the former category are not considered further, while those in the
latter category are carried forward for further analysis. Gears with
likely potential for marine mammal interaction include trawls,
longlines and other hook and line gear, seines (primarily purse
seines), and tangle nets.
Trawl nets, longlines, and purse seines deployed by NWFSC are
similar to gear used in various commercial fisheries, and the potential
for and history of marine mammal interaction with these gears through
physical contact (i.e., capture or entanglement) is well-documented.
Read et al. (2006) estimated marine mammal bycatch in U.S. fisheries
from 1990-99 and derived an estimate of global marine mammal bycatch by
expanding U.S. bycatch estimates using data on fleet composition from
the United Nations Food and Agriculture Organization (FAO). Although
most U.S. bycatch for both cetaceans (84 percent) and pinnipeds (98
percent) occurred in gillnets (a gear type not generally used by
NWFSC), global marine mammal bycatch in trawl nets and longlines is
likely substantial given that total global bycatch is thought to number
in the hundreds of thousands of individuals (Read et al., 2006). In
addition, global bycatch via longline has likely increased, as
longlines have become the most common method of capturing swordfish and
tuna since the U.N. banned the use of high seas driftnets over 2.5 km
long in 1991 (high seas driftnets were previously often 40-60 km long)
(Read, 2008; FAO, 2001).
Marine mammals are widely regarded as being quite intelligent and
inquisitive, and when their pursuit of prey coincides with human
pursuit of the same resources, it should be expected that physical
interaction with fishing gear may occur (e.g., Beverton, 1985).
Fishermen and marine mammals are both drawn to areas of high prey
density, and certain fishing activities may further attract marine
mammals by providing food (e.g., bait, captured fish, bycatch discards)
or by otherwise making it easier for animals to feed on a concentrated
food source. Provision of foraging opportunities near the surface may
present an advantage by negating the need for energetically expensive
deep foraging dives (Hamer and Goldsworthy, 2006). Trawling, for
example, can make available previously unexploited food resources by
gathering prey that may otherwise be too fast or deep for normal
predation, or may concentrate calories in an otherwise patchy landscape
(Fertl and Leatherwood, 1997). Pilot whales, which are generally
considered to be teuthophagous (i.e., feeding primarily on squid), were
commonly observed in association with Atlantic mackerel (Scomber
scombrus) trawl fisheries from 1977-88 in the northeast U.S. EEZ
(Waring et al., 1990). Not surprisingly, stomach contents of captured
whales were observed to have high proportions of mackerel (68 percent
of non-trace food items), indicating that the ready availability of a
novel, concentrated, high-calorie prey item resulted in changed dietary
composition (Read, 1994).
These interactions can result in injury or death for the animal(s)
involved and/or damage to fishing gear. Coastal animals, including
various pinnipeds, bottlenose dolphins, and harbor porpoises, are
perhaps the most vulnerable to these interactions and set or passive
fishing gear (e.g., gillnets, traps) the most likely to be interacted
with (e.g., Beverton, 1985; Barlow et al., 1994; Read et al., 2006;
Byrd et al., 2014; Lewison et al., 2014). Although interactions are
less common for use of trawl nets and longlines (gear used by NWFSC),
they do occur with sufficient frequency to necessitate the
establishment of required mitigation measures for multiple U.S.
fisheries using both types of gear (NMFS, 2014). It is likely that no
species of marine mammal can be definitively excluded from the
potential for interaction with fishing gear (e.g., Northridge, 1984);
however, the extent of interactions is likely dependent on the biology,
ecology, and behavior of the species involved and the type, location,
and nature of the fishery.
Trawl nets--As described previously, trawl nets are towed nets
(i.e., active fishing) consisting of a cone-shaped net with a codend or
bag for collecting the fish and can be designed to fish at the bottom,
surface, or any other depth in the water column. Here we refer to
bottom trawls and pelagic trawls (midwater or surface, i.e., any net
not designed to tend the bottom while fishing). Trawl nets in general
have the potential to capture or entangle marine mammals, which have
been known to be caught in bottom trawls, presumably when feeding on
fish caught therein,
[[Page 38537]]
and in pelagic trawls, which may or may not be coincident with their
feeding (Northridge, 1984).
Capture or entanglement may occur whenever marine mammals are
swimming near the gear, intentionally (e.g., foraging) or
unintentionally (e.g., migrating), and any animal captured in a net is
at significant risk of drowning unless quickly freed. Animals can also
be captured or entangled in netting or tow lines (also called lazy
lines) other than the main body of the net; animals may become
entangled around the head, body, flukes, pectoral fins, or dorsal fin.
Interaction that does not result in the immediate death of the animal
by drowning can cause injury (i.e., Level A harassment) or serious
injury. Constricting lines wrapped around the animal can immobilize the
animal or injure by cutting into or through blubber, muscles and bone
(i.e., penetrating injuries) or constricting blood flow to or severing
appendages. Immobilization of the animal, if it does not result in
immediate drowning, can cause internal injuries from prolonged stress
and/or severe struggling and/or impede the animal's ability to feed
(resulting in starvation or reduced fitness) (Andersen et al., 2008).
Marine mammal interactions with trawl nets, through capture or
entanglement, are well-documented. Dolphins are known to attend
operating nets in order to either benefit from disturbance of the
bottom or to prey on discards or fish within the net. For example,
Leatherwood (1975) reported that the most frequently observed feeding
pattern for bottlenose dolphins in the Gulf of Mexico involved herds
following working shrimp trawlers, apparently feeding on organisms
stirred up from the benthos. Bearzi and di Sciara (1997)
opportunistically investigated working trawlers in the Adriatic Sea
from 1990-94 and found that ten percent were accompanied by foraging
bottlenose dolphins. However, pelagic trawls have greater potential to
capture cetaceans, because the nets may be towed at faster speeds,
these trawls are more likely to target species that are important prey
for marine mammals (e.g., squid, mackerel), and the likelihood of
working in deeper waters means that a more diverse assemblage of
species could potentially be present (Hall et al., 2000).
Globally, at least seventeen cetacean species are known to feed in
association with trawlers and individuals of at least 25 species are
documented to have been killed by trawl nets, including several large
whales, porpoises, and a variety of delphinids (Perez, 2006; Young and
Iudicello, 2007; Karpouzli and Leaper, 2004; Hall et al., 2000; Fertl
and Leatherwood, 1997; Northridge, 1991; Song et al., 2010). At least
eighteen species of seals and sea lions are known to have been killed
in trawl nets (Wickens, 1995; Perez, 2006; Zeeberg et al., 2006).
Generally, direct interaction between trawl nets and marine mammals
(both cetaceans and pinnipeds) has been recorded wherever trawling and
animals co-occur. A lack of recorded interactions where animals are
known to be present may indicate simply that trawling is absent or an
insignificant component of fisheries in that region or that
interactions were not observed, recorded, or reported.
In evaluating risk relative to a specific fishery (or comparable
research survey), one must consider the size of the net as well as
frequency, timing, and location of deployment. These considerations
inform determinations of whether interaction with marine mammals is
likely. Of the net types described previously under ``Trawl Nets,''
NWFSC has recorded marine mammal interactions primarily with the Nordic
264 surface trawl net but also has one recorded interaction with the
modified Cobb midwater trawl. No marine mammal interactions have been
recorded for any bottom trawl survey.
Longlines--Longlines are basically strings of baited hooks that are
either anchored to the bottom, for targeting groundfish, or are free-
floating, for targeting pelagic species and represent a passive fishing
technique. Pelagic longlines, which notionally fish near the surface
with the use of floats, may be deployed in such a way as to fish at
different depths in the water column. For example, deep-set longlines
targeting tuna may have a target depth of 400 m, while a shallow-set
longline targeting swordfish is set at 30-90 m depth. We refer here to
bottom and pelagic longlines. Any longline generally consists of a
mainline from which leader lines (gangions) with baited hooks branch
off at a specified interval, and is left to passively fish, or soak,
for a set period of time before the vessel returns to retrieve the
gear. Longlines are marked by two or more floats that act as visual
markers and may also carry radio beacons; aids to detection are of
particular importance for pelagic longlines, which may drift a
significant distance from the deployment location. Pelagic longlines
are generally composed of various diameter monofilament line and are
generally much longer, and with more hooks, than are bottom longlines.
Bottom longlines may be of monofilament or multifilament natural or
synthetic lines.
Marine mammals may be hooked or entangled in longline gear, with
interactions potentially resulting in death due to drowning,
strangulation, severing of carotid arteries or the esophagus,
infection, an inability to evade predators, or starvation due to an
inability to catch prey (Hofmeyr et al., 2002), although it is more
likely that animals will survive being hooked if they are able to reach
the surface to breathe. Injuries, which may include serious injury,
include lacerations and puncture wounds. Animals may attempt to
depredate either bait or catch, with subsequent hooking, or may become
accidentally entangled. As described for trawls, entanglement can lead
to constricting lines wrapped around the animals and/or immobilization,
and even if entangling materials are removed the wounds caused may
continue to weaken the animal or allow further infection (Hofmeyr et
al., 2002). Large whales may become entangled in a longline and then
break free with a portion of gear trailing, resulting in alteration of
swimming energetics due to drag and ultimate loss of fitness and
potential mortality (Andersen et al., 2008). Weight of the gear can
cause entangling lines to further constrict and further injure the
animal. Hooking injuries and ingested gear are most common in small
cetaceans and pinnipeds, but have been observed in large cetaceans
(e.g., sperm whales). The severity of the injury depends on the
species, whether ingested gear includes hooks, whether the gear works
its way into the gastrointestinal (GI) tract, whether the gear
penetrates the GI lining, and the location of the hooking (e.g.,
embedded in the animal's stomach or other internal body parts)
(Andersen et al., 2008). Bottom longlines pose less of a threat to
marine mammals due to their deployment on the ocean bottom but can
still result in entanglement in buoy lines or hooking as the line is
either deployed or retrieved. The rate of interaction between longline
fisheries and marine mammals depends on the degree of overlap between
longline effort and species distribution, hook style and size, type of
bait and target catch, and fishing practices (such as setting/hauling
during the day or at night).
As was noted for trawl nets, many species of cetaceans and
pinnipeds are documented to have been killed by longlines, including
several large whales, porpoises, a variety of delphinids, seals, and
sea lions (Perez, 2006; Young and Iudicello, 2007; Northridge, 1984,
1991; Wickens, 1995). Generally, direct interaction between
[[Page 38538]]
longlines and marine mammals (both cetaceans and pinnipeds) has been
recorded wherever longline fishing and animals co-occur. A lack of
recorded interactions where animals are known to be present may
indicate simply that longlining is absent or an insignificant component
of fisheries in that region or that interactions were not observed,
recorded, or reported. Hook and line (e.g., rod and reel) gear also
carries some lesser potential for marine mammal interaction, as the use
of baited hooks in the presence of inquisitive marine mammals
necessarily carries some risk. However, the scale of hook and line
operations in relation to longline operations and the lack of extended,
unattended soak times mean that use of other hook and line gear is much
less likely to result in marine mammal interactions. However, due to
the limited potential risk we carry this gear forward for further
analysis with longline in a general category of hook and line gear.
In evaluating risk relative to a specific fishery (or research
survey), one must consider the length of the line and number of hooks
deployed as well as frequency, timing, and location of deployment.
These considerations inform determinations of whether interaction with
marine mammals is likely. NWFSC has not recorded marine mammal
interactions with any longline survey. While a lack of historical
interactions does not in and of itself indicate that future
interactions are unlikely, we believe that the historical record,
considered in context with the frequency and timing of these
activities, as well as mitigation measures employed indicate that
future marine mammal interactions with these gears would be uncommon.
Tangle nets and other set gear--As noted previously, tangle nets
operate in similar fashion to gillnets. Marine mammal interactions with
gillnets are well-documented, with a large proportion of species of all
types of marine mammals (e.g., mysticetes, odontocetes, pinnipeds)
recorded as gillnet bycatch (Reeves et al., 2013; Lewison et al., 2014;
Zollett, 2009). Reeves et al. (2013) note that numbers of marine
mammals killed in gillnets tend to be greatest for species that are
widely distributed in coastal and shelf waters. Because of the well-
documented risk to marine mammals, and to coastally distributed
pinnipeds and small cetaceans in particular, we believe there is some
risk of interaction inherent to NWFSC use of tangle nets, as described
below in ``Estimated Take by Incidental Harassment, Serious Injury, or
Mortality.'' However, this risk is limited by the fact that NWFSC uses
tangle nets only in the LCRRA, for up to 75 sets of 25-45 minutes
duration each.
The NWFSC also uses fyke traps and modified sablefish pots, both of
which are passive fishing gear that have limited species selectivity
and may be set for long durations (FAO, 2001). Thus, these gears have
the potential to capture non-targeted fauna that use the same habitat
as targeted species, even without the use of bait. Mortality in fyke
nets can arise from stress and injury associated with anoxia, abrasion,
confinement, and starvation (Larocque, 2011). In 2010, NMFS' Northeast
Fisheries Science Center captured a harbor seal in a fyke trap.
However, all fyke traps used by the NWFSC are wetland systems designed
to target small fish, and are fished in areas where pinnipeds are rare
(estuarine, wetland channels typically 1-5 m wide, including brackish
and freshwater habitats) and only limited deployments (up to one
hundred sets per year). Sablefish pots are likewise used in only very
limited fashion, with modified pots deployed in some Puget Sound
estuaries to collect herring eggs. The doors are sewed shut such that
marine mammals cannot enter the pot itself, and are unlikely to become
entangled in the line. Therefore, we do not believe that there is a
reasonable potential for marine mammal interaction with fyke traps or
pots used by the NWFSC, and these gears are not considered further in
this document.
Seine nets--Purse seine gear is well-known as a potential source of
marine mammal mortality due to its use in tuna fisheries of the eastern
tropical Pacific Ocean (ETP), where incidental take of dolphins was
very high from the late 1950s into the 1970s (Perrin, 1969). Because
large yellowfin tuna (Thunnus albacares) and several species of dolphin
associate together, dolphins were often captured along with the target
species, resulting in the deaths of hundreds of thousands of dolphins.
Through a series of combined actions, including passage of the MMPA in
1972, subsequent amendments, regulations, and mitigation measures,
dolphin bycatch in the ETP has since decreased 99 percent in the
international fishing fleet, and was eliminated by the U.S. fleet
(Gerrodette and Forcada, 2005). As in the ETP tuna fisheries, the most
significant risk associated with use of purse seines are when marine
mammals and target species associate together, which is not the case
for any NWFSC use of purse seines. Similar to longline gear, NWFSC
purse seines are much smaller than those typically used in commercial
fisheries. However, there is some risk associated with use of purse
seines (and to a lesser extent, seine nets in general), and we
therefore carry seine nets forward for further consideration.
Other research gear--The only NWFSC research gears with any record
of marine mammal interactions are pelagic trawl nets (i.e., Nordic 264
and modified Cobb). Because of ample evidence from commercial fishing
operations, we assume that there is also risk of marine mammal
interaction due to NWFSC use of bottom trawl nets, hook and line gear
(primarily longlines but also including other hook and line gear), and
seine gear (primarily purse seine gear but also including beach
seines). All other gears used in NWFSC fisheries research (e.g., a
variety of plankton nets, CTDs, ROVs) do not have the expected
potential for marine mammal interactions and are not known to have been
involved in any marine mammal interaction anywhere. Specifically, we
consider CTDs, water pump/thermosalinograph, ROVs, small surface
trawls, plankton nets, and vertically deployed or towed imaging systems
to be no-impact gear types.
Unlike trawl nets, seine nets, and longline gear, which are used in
both scientific research and commercial fishing applications, these
other gears are not considered similar or analogous to any commercial
fishing gear and are not designed to capture any commercially salable
species, or to collect any sort of sample in large quantities. They are
not considered to have the potential to take marine mammals primarily
because of their design or how they are deployed. For example, CTDs are
typically deployed in a vertical cast on a cable and have no loose
lines or other entanglement hazards. A Bongo net is typically deployed
on a cable, whereas neuston nets (these may be plankton nets or small
trawls) are often deployed in the upper one meter of the water column;
either net type has very small size (e.g., two bongo nets of 0.5 m\2\
each or a neuston net of approximately 2 m\2\) and no trailing lines to
present an entanglement risk. These other gear types are not considered
further in this document.
Acoustic Effects
We previously provided general background information on sound and
the specific sources used by the NWFSC (see ``Description of Active
Acoustic Sound Sources''). Here, we first provide background
information on marine mammal hearing before discussing the potential
effects of NWFSC use of active acoustic sources on marine mammals.
[[Page 38539]]
Marine mammal hearing--Hearing is the most important sensory
modality for marine mammals underwater, and exposure to anthropogenic
sound can have deleterious effects. To appropriately assess the
potential effects of exposure to sound, it is necessary to understand
the frequency ranges marine mammals are able to hear. Current data
indicate that not all marine mammal species have equal hearing
capabilities (e.g., Richardson et al., 1995; Wartzok and Ketten, 1999;
Au and Hastings, 2008). To reflect this, Southall et al. (2007)
recommended that marine mammals be divided into functional hearing
groups based on directly measured or estimated hearing ranges on the
basis of available behavioral response data, audiograms derived using
auditory evoked potential techniques, anatomical modeling, and other
data. Note that no direct measurements of hearing ability have been
successfully completed for low-frequency cetaceans. The functional
groups and the associated frequencies are indicated below (note that
these frequency ranges correspond to the range for the composite group,
with the entire range not necessarily reflecting the capabilities of
every species within that group):
Low-frequency cetaceans (mysticetes): Functional hearing
is estimated to occur between approximately 7 Hz and 25 kHz (up to 30
kHz in some species), with best hearing estimated to be from 100 Hz to
8 kHz (Watkins, 1986; Ketten, 1998; Houser et al., 2001; Au et al.,
2006; Lucifredi and Stein, 2007; Ketten et al., 2007; Parks et al.,
2007a; Ketten and Mountain, 2009; Tubelli et al., 2012);
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Functional hearing is estimated to occur
between approximately 150 Hz and 160 kHz, with best hearing from 10 to
less than 100 kHz (Johnson, 1967; White, 1977; Richardson et al., 1995;
Szymanski et al., 1999; Kastelein et al., 2003; Finneran et al., 2005a,
2009; Nachtigall et al., 2005, 2008; Yuen et al., 2005; Popov et al.,
2007; Au and Hastings, 2008; Houser et al., 2008; Pacini et al., 2010,
2011; Schlundt et al., 2011);
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, including the hourglass dolphin, on the
basis of recent echolocation data and genetic data [May-Collado and
Agnarsson, 2006; Kyhn et al. 2009, 2010; Tougaard et al. 2010]):
Functional hearing is estimated to occur between approximately 200 Hz
and 180 kHz (Popov and Supin, 1990a,b; Kastelein et al., 2002; Popov et
al., 2005); and
Pinnipeds in water; Phocidae (true seals): Functional
hearing is estimated to occur between approximately 75 Hz to 100 kHz,
with best hearing between 1-50 kHz (M[oslash]hl, 1968; Terhune and
Ronald, 1971, 1972; Richardson et al., 1995; Kastak and Schusterman,
1999; Reichmuth, 2008; Kastelein et al., 2009);
Pinnipeds in water; Otariidae (eared seals): Functional
hearing is estimated to occur between 100 Hz and 48 kHz for Otariidae,
with best hearing between 2-48 kHz (Schusterman et al., 1972; Moore and
Schusterman, 1987; Babushina et al., 1991; Richardson et al., 1995;
Kastak and Schusterman, 1998; Kastelein et al., 2005a; Mulsow and
Reichmuth, 2007; Mulsow et al., 2011a, b).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
Thirty-four marine mammal species (28 cetacean and six pinniped
[four otariid and two phocid] species) have the potential to co-occur
with NWFSC research activities. Please refer to Table 3. Of the 28
cetacean species that may be present, six are classified as low-
frequency cetaceans (i.e., all mysticete species), eighteen are
classified as mid-frequency cetaceans (i.e., all delphinid and ziphiid
species and the sperm whale), and four are classified as high-frequency
cetaceans (i.e., porpoises and Kogia spp.).
Potential effects of underwater sound--Please refer to the
information given previously (``Description of Active Acoustic
Sources'') regarding sound, characteristics of sound types, and metrics
used in this document. Anthropogenic sounds cover a broad range of
frequencies and sound levels and can have a range of highly variable
impacts on marine life, from none or minor to potentially severe
responses, depending on received levels, duration of exposure,
behavioral context, and various other factors. The potential effects of
underwater sound from active acoustic sources can potentially result in
one or more of the following: Temporary or permanent hearing
impairment, non-auditory physical or physiological effects, behavioral
disturbance, stress, and masking (Richardson et al., 1995; Gordon et
al., 2004; Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et
al., 2009). The degree of effect is intrinsically related to the signal
characteristics, received level, distance from the source, and duration
of the sound exposure. In general, sudden, high level sounds can cause
hearing loss, as can longer exposures to lower level sounds. Temporary
or permanent loss of hearing will occur almost exclusively for noise
within an animal's hearing range. We first describe specific
manifestations of acoustic effects before providing discussion specific
to NWFSC's use of active acoustic sources (e.g., echosounders).
Richardson et al. (1995) described zones of increasing intensity of
effect that might be expected to occur, in relation to distance from a
source and assuming that the signal is within an animal's hearing
range. First is the area within which the acoustic signal would be
audible (potentially perceived) to the animal but not strong enough to
elicit any overt behavioral or physiological response. The next zone
corresponds with the area where the signal is audible to the animal and
of sufficient intensity to elicit behavioral or physiological
responsiveness. Third is a zone within which, for signals of high
intensity, the received level is sufficient to potentially cause
discomfort or tissue damage to auditory or other systems. Overlaying
these zones to a certain extent is the area within which masking (i.e.,
when a sound interferes with or masks the ability of an animal to
detect a signal of interest that is above the absolute hearing
threshold) may occur; the masking zone may be highly variable in size.
We describe the more severe effects (i.e., permanent hearing
impairment, certain non-auditory physical or physiological effects)
only briefly as we do not expect that there is a reasonable likelihood
that NWFSC use of active acoustic sources may result in such effects
(see below for further discussion). Marine mammals exposed to high-
intensity sound, or to lower-intensity sound for prolonged periods, can
experience hearing threshold shift (TS), which is the loss of hearing
sensitivity at certain frequency ranges (Kastak et al., 1999; Schlundt
et al., 2000; Finneran et al., 2002, 2005b). TS can be permanent (PTS),
in which case the loss of hearing sensitivity is not fully recoverable,
or temporary (TTS), in which case the animal's hearing threshold would
recover over time (Southall et al., 2007). Repeated sound exposure that
leads to TTS could cause PTS. In severe cases of PTS, there can be
total or partial deafness, while in most cases the animal has an
impaired ability to hear sounds in specific frequency ranges (Kryter,
1985).
[[Page 38540]]
When PTS occurs, there is physical damage to the sound receptors in
the ear (i.e., tissue damage), whereas TTS represents primarily tissue
fatigue and is reversible (Southall et al., 2007). In addition, other
investigators have suggested that TTS is within the normal bounds of
physiological variability and tolerance and does not represent physical
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to
constitute auditory injury.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals--PTS data exists only for a single harbor seal
(Kastak et al., 2008)--but are assumed to be similar to those in humans
and other terrestrial mammals. PTS typically occurs at exposure levels
at least several decibels above (a 40-dB threshold shift approximates
PTS onset; e.g., Kryter et al., 1966; Miller, 1974) that inducing mild
TTS (a 6-dB threshold shift approximates TTS onset; e.g., Southall et
al. 2007). Based on data from terrestrial mammals, a precautionary
assumption is that the PTS thresholds for impulse sounds (such as
impact pile driving pulses as received close to the source) are at
least 6 dB higher than the TTS threshold on a peak-pressure basis, and
PTS cumulative sound exposure level thresholds are 15 to 20 dB higher
than TTS cumulative sound exposure level thresholds (Southall et al.,
2007). Given the higher level of sound or longer exposure duration
necessary to cause PTS as compared with TTS, it is considerably less
likely that PTS could occur.
Non-auditory physiological effects or injuries that theoretically
might occur in marine mammals exposed to high level underwater sound or
as a secondary effect of extreme behavioral reactions (e.g., change in
dive profile as a result of an avoidance reaction) caused by exposure
to sound include neurological effects, bubble formation, resonance
effects, and other types of organ or tissue damage (Cox et al., 2006;
Southall et al., 2007; Zimmer and Tyack, 2007). NWFSC activities do not
involve the use of devices such as explosives or mid-frequency active
sonar that are associated with these types of effects.
When a live or dead marine mammal swims or floats onto shore and is
incapable of returning to sea, the event is termed a ``stranding'' (16
U.S.C. 1421h(3)). Marine mammals are known to strand for a variety of
reasons, such as infectious agents, biotoxicosis, starvation, fishery
interaction, ship strike, unusual oceanographic or weather events,
sound exposure, or combinations of these stressors sustained
concurrently or in series (e.g., Geraci et al., 1999). However, the
cause or causes of most strandings are unknown (e.g., Best, 1982).
Combinations of dissimilar stressors may combine to kill an animal or
dramatically reduce its fitness, even though one exposure without the
other would not be expected to produce the same outcome (e.g., Sih et
al., 2004). For further description of stranding events see, e.g.,
Southall et al., 2006; Jepson et al., 2013; Wright et al., 2013.
1. Temporary threshold shift--TTS is the mildest form of hearing
impairment that can occur during exposure to sound (Kryter, 1985).
While experiencing TTS, the hearing threshold rises, and a sound must
be at a higher level in order to be heard. In terrestrial and marine
mammals, TTS can last from minutes or hours to days (in cases of strong
TTS). In many cases, hearing sensitivity recovers rapidly after
exposure to the sound ends. Few data on sound levels and durations
necessary to elicit mild TTS have been obtained for marine mammals, and
none of the data published at the time of this writing concern TTS
elicited by exposure to multiple pulses of sound.
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), and
frequency range of TTS, and the context in which it is experienced, TTS
can have effects on marine mammals ranging from discountable to
serious. For example, a marine mammal may be able to readily compensate
for a brief, relatively small amount of TTS in a non-critical frequency
range that occurs during a time where ambient noise is lower and there
are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale [Delphinapterus leucas], harbor
porpoise, and Yangtze finless porpoise [Neophocoena asiaeorientalis])
and three species of pinnipeds (northern elephant seal, harbor seal,
and California sea lion) exposed to a limited number of sound sources
(i.e., mostly tones and octave-band noise) in laboratory settings
(e.g., Finneran et al., 2002; Nachtigall et al., 2004; Kastak et al.,
2005; Lucke et al., 2009; Popov et al., 2011). In general, harbor seals
(Kastak et al., 2005; Kastelein et al., 2012a) and harbor porpoises
(Lucke et al., 2009; Kastelein et al., 2012b) have a lower TTS onset
than other measured pinniped or cetacean species. Additionally, the
existing marine mammal TTS data come from a limited number of
individuals within these species. There are no data available on noise-
induced hearing loss for mysticetes. For summaries of data on TTS in
marine mammals or for further discussion of TTS onset thresholds,
please see Southall et al. (2007) and Finneran and Jenkins (2012).
2. Behavioral effects--Behavioral disturbance may include a variety
of effects, including subtle changes in behavior (e.g., minor or brief
avoidance of an area or changes in vocalizations), more conspicuous
changes in similar behavioral activities, and more sustained and/or
potentially severe reactions, such as displacement from or abandonment
of high-quality habitat. Behavioral responses to sound are highly
variable and context-specific and any reactions depend on numerous
intrinsic and extrinsic factors (e.g., species, state of maturity,
experience, current activity, reproductive state, auditory sensitivity,
time of day), as well as the interplay between factors (e.g.,
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007;
Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not
only among individuals but also within an individual, depending on
previous experience with a sound source, context, and numerous other
factors (Ellison et al., 2012), and can vary depending on
characteristics associated with the sound source (e.g., whether it is
moving or stationary, number of sources, distance from the source).
Please see Appendices B-C of Southall et al. (2007) for a review of
studies involving marine mammal behavioral responses to sound.
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most likely to habituate to
sounds that are predictable and unvarying. It is important to note that
habituation is appropriately considered as a ``progressive reduction in
response to stimuli that are perceived as neither aversive nor
beneficial,'' rather than as, more generally, moderation in response to
human disturbance (Bejder et al., 2009). The opposite process is
sensitization, when an unpleasant experience leads to subsequent
responses, often in the form of avoidance, at a lower level of
exposure. As noted, behavioral state may affect the type of response.
For example, animals
[[Page 38541]]
that are resting may show greater behavioral change in response to
disturbing sound levels than animals that are highly motivated to
remain in an area for feeding (Richardson et al., 1995; NRC, 2003;
Wartzok et al., 2003). Controlled experiments with captive marine
mammals have showed pronounced behavioral reactions, including
avoidance of loud sound sources (Ridgway et al., 1997; Finneran et al.,
2003). Observed responses of wild marine mammals to loud pulsed sound
sources (typically seismic airguns or acoustic harassment devices) have
been varied but often consist of avoidance behavior or other behavioral
changes suggesting discomfort (Morton and Symonds, 2002; see also
Richardson et al., 1995; Nowacek et al., 2007).
Available studies show wide variation in response to underwater
sound; therefore, it is difficult to predict specifically how any given
sound in a particular instance might affect marine mammals perceiving
the signal. If a marine mammal does react briefly to an underwater
sound by changing its behavior or moving a small distance, the impacts
of the change are unlikely to be significant to the individual, let
alone the stock or population. However, if a sound source displaces
marine mammals from an important feeding or breeding area for a
prolonged period, impacts on individuals and populations could be
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC,
2005). However, there are broad categories of potential response, which
we describe in greater detail here, that include alteration of dive
behavior, alteration of foraging behavior, effects to breathing,
interference with or alteration of vocalization, avoidance, and flight.
Changes in dive behavior can vary widely and may consist of
increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive (e.g., Frankel
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et
al.; 2004; Goldbogen et al., 2013a, b). Variations in dive behavior may
reflect interruptions in biologically significant activities (e.g.,
foraging) or they may be of little biological significance. The impact
of an alteration to dive behavior resulting from an acoustic exposure
depends on what the animal is doing at the time of the exposure and the
type and magnitude of the response.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Variations in respiration naturally vary with different behaviors
and alterations to breathing rate as a function of acoustic exposure
can be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Various studies have shown that respiration rates may
either be unaffected or could increase, depending on the species and
signal characteristics, again highlighting the importance in
understanding species differences in the tolerance of underwater noise
when determining the potential for impacts resulting from anthropogenic
sound exposure (e.g., Kastelein et al., 2001, 2005b, 2006; Gailey et
al., 2007).
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, echolocation click production, calling, and
singing. Changes in vocalization behavior in response to anthropogenic
noise can occur for any of these modes and may result from a need to
compete with an increase in background noise or may reflect increased
vigilance or a startle response. For example, in the presence of
potentially masking signals, humpback whales and killer whales have
been observed to increase the length of their songs (Miller et al.,
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales
have been observed to shift the frequency content of their calls upward
while reducing the rate of calling in areas of increased anthropogenic
noise (Parks et al., 2007b). In some cases, animals may cease sound
production during production of aversive signals (Bowles et al., 1994).
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors, and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). For example, gray whales
are known to change direction--deflecting from customary migratory
paths--in order to avoid noise from seismic surveys (Malme et al.,
1984). Avoidance may be short-term, with animals returning to the area
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996;
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007).
Longer-term displacement is possible, however, which may lead to
changes in abundance or distribution patterns of the affected species
in the affected region if habituation to the presence of the sound does
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann
et al., 2006).
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996). The result of a flight response could range from
brief, temporary exertion and displacement from the area where the
signal provokes flight to, in extreme cases, marine mammal strandings
(Evans and England, 2001). However, it should be noted that response to
a perceived predator does not necessarily invoke flight (Ford and
Reeves, 2008), and whether individuals are solitary or in groups may
influence the response.
Behavioral disturbance can also impact marine mammals in more
subtle ways. Increased vigilance may result in costs related to
diversion of focus and attention (i.e., when a response consists of
increased vigilance, it may come at the cost of decreased attention to
other critical behaviors such as foraging or resting). These effects
have generally not been demonstrated for marine mammals, but studies
involving fish and terrestrial animals have shown that increased
vigilance may substantially reduce feeding rates (e.g., Beauchamp and
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In
addition, chronic disturbance can cause population declines through
reduction of fitness (e.g., decline in body condition) and subsequent
reduction in reproductive success, survival, or both (e.g., Harrington
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However,
Ridgway et al. (2006) reported that increased vigilance in bottlenose
[[Page 38542]]
dolphins exposed to sound over a five-day period did not cause any
sleep deprivation or stress effects.
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption
of such functions resulting from reactions to stressors such as sound
exposure are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Consequently, a behavioral response lasting less than one day and not
recurring on subsequent days is not considered particularly severe
unless it could directly affect reproduction or survival (Southall et
al., 2007). Note that there is a difference between multi-day
substantive behavioral reactions and multi-day anthropogenic
activities. For example, just because an activity lasts for multiple
days does not necessarily mean that individual animals are either
exposed to activity-related stressors for multiple days or, further,
exposed in a manner resulting in sustained multi-day substantive
behavioral responses.
3. Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle, 1950;
Moberg, 2000). In many cases, an animal's first and sometimes most
economical (in terms of energetic costs) response is behavioral
avoidance of the potential stressor. Autonomic nervous system responses
to stress typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha,
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well-studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002b) and, more rarely, studied in wild populations
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found
that noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003).
4. Auditory masking--Sound can disrupt behavior through masking, or
interfering with, an animal's ability to detect, recognize, or
discriminate between acoustic signals of interest (e.g., those used for
intraspecific communication and social interactions, prey detection,
predator avoidance, navigation) (Richardson et al., 1995; Erbe et al.,
2016). Masking occurs when the receipt of a sound is interfered with by
another coincident sound at similar frequencies and at similar or
higher intensity, and may occur whether the sound is natural (e.g.,
snapping shrimp, wind, waves, precipitation) or anthropogenic (e.g.,
shipping, sonar, seismic exploration) in origin. The ability of a noise
source to mask biologically important sounds depends on the
characteristics of both the noise source and the signal of interest
(e.g., signal-to-noise ratio, temporal variability, direction), in
relation to each other and to an animal's hearing abilities (e.g.,
sensitivity, frequency range, critical ratios, frequency
discrimination, directional discrimination, age or TTS hearing loss),
and existing ambient noise and propagation conditions.
Under certain circumstances, marine mammals experiencing
significant masking could also be impaired from maximizing their
performance fitness in survival and reproduction. Therefore, when the
coincident (masking) sound is man-made, it may be considered harassment
when disrupting or altering critical behaviors. It is important to
distinguish TTS and PTS, which persist after the sound exposure, from
masking, which occurs during the sound exposure. Because masking
(without resulting in TS) is not associated with abnormal physiological
function, it is not considered a physiological effect, but rather a
potential behavioral effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009) and may result in energetic or other costs as
animals change their vocalization behavior (e.g., Miller et al., 2000;
Foote et al., 2004; Parks et al., 2007b; Di Iorio and Clark, 2009; Holt
et al., 2009). Masking can be reduced in situations where the signal
and noise come from different directions (Richardson et al., 1995),
through amplitude modulation of the signal, or through other
compensatory behaviors (Houser and Moore, 2014). Masking can be tested
directly in captive species (e.g., Erbe, 2008), but in wild populations
it must be either modeled or inferred from evidence of masking
compensation. There are few studies addressing real-world masking
sounds likely to be experienced by marine mammals in the wild (e.g.,
Branstetter et al., 2013).
Masking affects both senders and receivers of acoustic signals and
can potentially have long-term chronic effects on marine mammals at the
population level as well as at the individual level. Low-frequency
ambient sound levels have increased by as much as 20 dB (more than
three times in terms of SPL) in the world's ocean from pre-industrial
periods, with most
[[Page 38543]]
of the increase from distant commercial shipping (Hildebrand, 2009).
All anthropogenic sound sources, but especially chronic and lower-
frequency signals (e.g., from vessel traffic), contribute to elevated
ambient sound levels, thus intensifying masking.
Potential effects of NWFSC activity--As described previously (see
``Description of Active Acoustic Sound Sources''), the NWFSC proposes
to use various active acoustic sources, including echosounders (e.g.,
multibeam systems), scientific sonar systems, positional sonars (e.g.,
net sounders for determining trawl position), and environmental sensors
(e.g., current profilers). These acoustic sources, which are present on
most NWFSC fishery research vessels, include a variety of single, dual,
and multi-beam echosounders (many with a variety of modes), sources
used to determine the orientation of trawl nets, and several current
profilers.
Many typically investigated acoustic sources (e.g., seismic
airguns, low- and mid-frequency active sonar used for military
purposes, pile driving, vessel noise)--sources for which certain of the
potential acoustic effects described above have been observed or
inferred--produce signals that are either much lower frequency and/or
higher total energy (considering output sound levels and signal
duration) than the high-frequency mapping and fish-finding systems used
by the NWFSC. There has been relatively little attention given to the
potential impacts of high-frequency sonar systems on marine life,
largely because their combination of high output frequency and
relatively low output power means that such systems are less likely to
impact many marine species. However, some marine mammals do hear and
produce sounds within the frequency range used by these sources and
ambient noise is much lower at high frequencies, increasing the
probability of signal detection relative to other sounds in the
environment.
As noted above, relatively high levels of sound are likely required
to cause TTS in most pinnipeds and odontocete cetaceans. While
dependent on sound exposure frequency, level, and duration, NMFS'
acoustics experts believe that existing studies indicate that for the
kinds of relatively brief exposures potentially associated with
transient sounds such as those produced by the active acoustic sources
used by the NWFSC, SPLs in the range of approximately 180-220 dB rms
might be required to induce onset TTS levels for most species (Southall
et al., 2007). However, it should be noted that there may be increased
sensitivity to TTS for certain species generally (harbor porpoise;
Lucke et al., 2009) or specifically at higher sound exposure
frequencies, which correspond to a species' best hearing range (20 kHz
vs. 3 kHz for bottlenose dolphins; Finneran and Schlundt, 2010).
However, for these animals, which are better able to hear higher
frequencies and may be more sensitive to higher frequencies, exposures
on the order of approximately 170 dB rms or higher for brief transient
signals are likely required for even temporary (recoverable) changes in
hearing sensitivity that would likely not be categorized as
physiologically damaging (Lucke et al., 2009). The corresponding
estimates for PTS would be at very high received levels that would
rarely be experienced in practice.
Based on discussion provided by Southall et al. (2007), Lurton and
DeRuiter (2011) modeled the potential impacts of conventional
echosounders on marine mammals, estimating PTS onset at typical
distances of 10-100 m for the kinds of sources considered here. Kremser
et al. (2005) modeled the potential for TTS in blue, sperm, and beaked
whales (please see Kremser et al. [2005] for discussion of assumptions
regarding TTS onset in these species) from a multibeam echosounder,
finding similarly that TTS would likely only occur at very close ranges
to the hull of the vessel. The authors estimated ship movement at 12 kn
(faster than NWFSC vessels would typically move), which would result in
an underestimate of the potential for TTS to occur, but the modeled
system (Hydrosweep) operates at lower frequencies and with a wider beam
pattern than do typical NWFSC systems, which would result in a likely
more significant overestimate of TTS potential. The results of both
studies emphasize that these effects would very likely only occur in
the cone ensonified below the ship and that animal responses to the
vessel (sound or physical presence) at these extremely close ranges
would very likely influence their probability of being exposed to these
levels. At the same distances, but to the side of the vessel, animals
would not be exposed to these levels, greatly decreasing the potential
for an animal to be exposed to the most intense signals. For example,
Kremser et al. (2005) note that SPLs outside the vertical lobe, or
beam, decrease rapidly with distance, such that SPLs within the
horizontal lobes are about 20 dB less than the value found in the
center of the beam. For certain species (i.e., odontocete cetaceans and
especially harbor porpoises), these ranges may be somewhat greater
based on more recent data (Lucke et al., 2009; Finneran and Schlundt,
2010) but are likely still on the order of hundreds of meters. In
addition, potential behavioral responses further reduce the already low
likelihood that an animal may approach close enough for any type of
hearing loss to occur.
Various other studies have evaluated the environmental risk posed
by use of specific scientific sonar systems. Burkhardt et al. (2007)
considered both the Hydrosweep system evaluated by Kremser et al.
(2005) and the Simrad EK60, which is used by the NWFSC, and concluded
that direct injury (i.e., sound energy causes direct tissue damage) and
indirect injury (i.e., self-damaging behavior as response to acoustic
exposure) would be unlikely given source and operational use (i.e.,
vessel movement) characteristics, and that any behavioral responses
would be unlikely to be significant. Similarly, Boebel et al. (2006)
considered the Hydrosweep system in relation to the risk for direct or
indirect injury, concluding that (1) risk of TTS (please see Boebel et
al. [2006] for assumptions regarding TTS onset) would be less than two
percent of the risk of ship strike and (2) risk of behaviorally-induced
damage would be essentially nil due to differences in source
characteristics between scientific sonars and sources typically
associated with stranding events (e.g., mid-frequency active sonar, but
see discussion of the 2008 Madagascar stranding event below). It should
be noted that the risk of direct injury may be greater when a vessel
operates sources while on station (i.e., stationary), as there is a
greater chance for an animal to receive the signal when the vessel is
not moving.
Boebel et al. (2005) report the results of a workshop in which a
structured, qualitative risk analysis of a range of acoustic technology
was undertaken, specific to use of such technology in the Antarctic.
The authors assessed a single-beam echosounder commonly used for
collecting bathymetric data (12 kHz, 232 dB, 10[deg] beam width), an
array of single-beam echosounders used for mapping krill (38, 70, 120,
and 200 kHz; 230 dB; 7[deg] beam width), and a multibeam echosounder
(30 kHz, 236 dB, 150[deg] x 1[deg] swath width). For each source, the
authors produced a matrix displaying the severity of potential
consequences (on a six-point scale) against the likelihood of
occurrence for a given degree of severity. For the former two systems,
the authors determined on the basis of the volume of water potentially
affected by the system and comparisons between its output and available
TTS
[[Page 38544]]
data that the chance of TTS is only in a small volume immediately under
the transducers, and that consequences of level four and above were
inconceivable, whereas level one consequences (``Individuals show no
response, or only a temporary (minutes) behavior change'') would be
expected in almost all instances. Some minor displacement of animals in
the immediate vicinity of the ship may occur. For the multibeam
echosounder, Boebel et al. (2005) note that the high output and broad
width of the swath abeam of the vessel makes displacement of animals
more likely. However, the fore and aft beamwidth is small and the pulse
length very short, so the risk of ensonification above TTS levels is
still considered quite small and the likelihood of auditory or other
injuries low. In general, the authors reached the same conclusions
described for the single-beam systems but note that more severe
impacts--including fatalities resulting from herding of sensitive
species in narrow sea ways--are at least possible (i.e., may occur in
exceptional circumstances). However, the probability of herding remains
low not just because of the rarity of the necessary confluence of
species, bathymetry, and likely other factors, but because the
restricted beam shape makes it unlikely that an animal would be exposed
more than briefly during the passage of the vessel (Boebel et al.,
2005). More recently, Lurton (2016) conducted a modeling exercise and
concluded similarly that likely potential for acoustic injury from
these types of systems is negligible, but that behavioral response
cannot be ruled out.
We have, however, considered the potential for severe behavioral
responses such as stranding and associated indirect injury or mortality
from NWFSC use of the multibeam echosounder, on the basis of a 2008
mass stranding of approximately one hundred melon-headed whales in a
Madagascar lagoon system. An investigation of the event indicated that
use of a high-frequency mapping system (12-kHz multibeam echosounder;
it is important to note that all NWFSC sources operate at higher
frequencies [see Table 2]) was the most plausible and likely initial
behavioral trigger of the event, while providing the caveat that there
is no unequivocal and easily identifiable single cause (Southall et
al., 2013). The panel's conclusion was based on (1) very close temporal
and spatial association and directed movement of the survey with the
stranding event; (2) the unusual nature of such an event coupled with
previously documented apparent behavioral sensitivity of the species to
other sound types (Southall et al., 2006; Brownell et al., 2009); and
(3) the fact that all other possible factors considered were determined
to be unlikely causes. Specifically, regarding survey patterns prior to
the event and in relation to bathymetry, the vessel transited in a
north-south direction on the shelf break parallel to the shore,
ensonifying large areas of deep-water habitat prior to operating
intermittently in a concentrated area offshore from the stranding site;
this may have trapped the animals between the sound source and the
shore, thus driving them towards the lagoon system.
The investigatory panel systematically excluded or deemed highly
unlikely nearly all potential reasons for these animals leaving their
typical pelagic habitat for an area extremely atypical for the species
(i.e., a shallow lagoon system). Notably, this was the first time that
such a system has been associated with a stranding event.
The panel also noted several site- and situation-specific secondary
factors that may have contributed to the avoidance responses that led
to the eventual entrapment and mortality of the whales. Specifically,
shoreward-directed surface currents and elevated chlorophyll levels in
the area preceding the event may have played a role (Southall et al.,
2013). The report also notes that prior use of a similar system in the
general area may have sensitized the animals and also concluded that,
for odontocete cetaceans that hear well in higher frequency ranges
where ambient noise is typically quite low, high-power active sonars
operating in this range may be more easily audible and have potential
effects over larger areas than low frequency systems that have more
typically been considered in terms of anthropogenic noise impacts. It
is, however, important to note that the relatively lower output
frequency, higher output power, and complex nature of the system
implicated in this event, in context of the other factors noted here,
likely produced a fairly unusual set of circumstances that indicate
that such events would likely remain rare and are not necessarily
relevant to use of lower-power, higher-frequency systems more commonly
used for scientific applications. The risk of similar events recurring
may be very low, given the extensive use of active acoustic systems
used for scientific and navigational purposes worldwide on a daily
basis and the lack of direct evidence of such responses previously
reported.
Characteristics of the sound sources predominantly used by NWFSC
further reduce the likelihood of effects to marine mammals, as well as
the intensity of effect assuming that an animal perceives the signal.
Intermittent exposures--as would occur due to the brief, transient
signals produced by these sources--require a higher cumulative SEL to
induce TTS than would continuous exposures of the same duration (i.e.,
intermittent exposure results in lower levels of TTS) (Mooney et al.,
2009a; Finneran et al., 2010). In addition, intermittent exposures
recover faster in comparison with continuous exposures of the same
duration (Finneran et al., 2010). Although echosounder pulses are, in
general, emitted rapidly, they are not dissimilar to odontocete
echolocation click trains. Research indicates that marine mammals
generally have extremely fine auditory temporal resolution and can
detect each signal separately (e.g., Au et al., 1988; Dolphin et al.,
1995; Supin and Popov, 1995; Mooney et al., 2009b), especially for
species with echolocation capabilities. Therefore, it is likely that
marine mammals would indeed perceive echosounder signals as being
intermittent.
We conclude here that, on the basis of available information on
hearing and potential auditory effects in marine mammals, high-
frequency cetacean species would be the most likely to potentially
incur temporary hearing loss from a vessel operating high-frequency
sonar sources, and the potential for PTS to occur for any species is so
unlikely as to be discountable. Even for high-frequency cetacean
species, individuals would have to make a very close approach and also
remain very close to vessels operating these sources in order to
receive multiple exposures at relatively high levels, as would be
necessary to cause TTS. Additionally, given that behavioral responses
typically include the temporary avoidance that might be expected (see
below), the potential for auditory effects considered physiological
damage (injury) is considered extremely low in relation to realistic
operations of these devices. Given the fact that fisheries research
survey vessels are moving, the likelihood that animals may avoid the
vessel to some extent based on either its physical presence or due to
aversive sound (vessel or active acoustic sources), and the
intermittent nature of many of these sources, the potential for TTS is
probably low for high-frequency cetaceans and very low to zero for
other species.
[[Page 38545]]
Based on the source operating characteristics, most of these
sources may be detected by odontocete cetaceans (and particularly high-
frequency specialists such as porpoises) but are unlikely to be audible
to mysticetes (i.e., low-frequency cetaceans) and some pinnipeds. While
low-frequency cetaceans and pinnipeds have been observed to respond
behaviorally to low- and mid-frequency sounds (e.g., Frankel, 2005),
there is little evidence of behavioral responses in these species to
high-frequency sound exposure (e.g., Jacobs and Terhune, 2002;
Kastelein et al., 2006). If a marine mammal does perceive a signal from
a NWFSC active acoustic source, it is likely that the response would
be, at most, behavioral in nature. Behavioral reactions of free-ranging
marine mammals to scientific sonars are likely to vary by species and
circumstance. For example, Watkins et al. (1985) note that sperm whales
did not appear to be disturbed by or even aware of signals from
scientific sonars and pingers (36-60 kHz) despite being very close to
the transducers, but Gerrodette and Pettis (2005) report that when a
38-kHz echosounder and ADCP were on (1) the average size of detected
schools of spotted dolphins and pilot whales was decreased; (2)
perpendicular sighting distances increased for spotted and spinner
dolphins; and (3) sighting rates decreased for beaked whales. As
described above, behavioral responses of marine mammals are extremely
variable, depending on multiple exposure factors, with the most common
type of observed response being behavioral avoidance of areas around
aversive sound sources. Certain odontocete cetaceans (particularly
harbor porpoises and beaked whales) are known to avoid high-frequency
sound sources in both field and laboratory settings (e.g., Kastelein et
al., 2000, 2005b, 2008a, b; Culik et al., 2001; Johnston, 2002; Olesiuk
et al., 2002; Carretta et al., 2008). There is some additional, low
probability for masking to occur for high-frequency specialists, but
similar factors (directional beam pattern, transient signal, moving
vessel) mean that the significance of any potential masking is probably
inconsequential.
Potential Effects of Visual Disturbance
During NWFSC surveys conducted in coastal areas, including rivers
and estuaries, pinnipeds are expected to be hauled out and at times
experience incidental close approaches by researchers in small vessels
during the course of fisheries research activities. Such circumstances
are expected in Puget Sound and in the Columbia River. NWFSC expects
some of these animals will exhibit a behavioral response to the visual
stimuli (e.g., including alert behavior, movement, vocalizing, or
flushing). NMFS does not consider the lesser reactions (e.g., alert
behavior) to constitute harassment. These events are expected to be
infrequent and cause only a temporary disturbance on the order of
minutes. Monitoring results from other activities involving the
disturbance of pinnipeds and relevant studies of pinniped populations
that experience more regular vessel disturbance indicate that
individually significant or population level impacts are unlikely to
occur.
In areas where disturbance of haul-outs due to periodic human
activity (e.g., researchers approaching on foot, passage of small
vessels, maintenance activity) occurs, monitoring results have
generally indicated that pinnipeds typically move or flush from the
haul-out in response to human presence or visual disturbance, although
some individuals typically remain hauled-out (e.g., SCWA, 2012). The
nature of response is generally dependent on species. For example,
California sea lions and northern elephant seals have been observed as
less sensitive to stimulus than harbor seals during monitoring at
numerous sites. Monitoring of pinniped disturbance as a result of
abalone research in the Channel Islands showed that while harbor seals
flushed at a rate of 69 percent, California sea lions flushed at a rate
of only 21 percent. The rate for elephant seals declined to 0.1 percent
(VanBlaricom, 2010).
Upon the occurrence of low-severity disturbance (i.e., the approach
of a vessel or person as opposed to an explosion or sonic boom),
pinnipeds typically exhibit a continuum of responses, beginning with
alert movements (e.g., raising the head), which may then escalate to
movement away from the stimulus and possible flushing into the water.
Flushed pinnipeds typically re-occupy the haul-out within minutes to
hours of the stimulus.
In a popular tourism area of the Pacific Northwest where human
disturbances occurred frequently, past studies observed stable
populations of seals over a twenty-year period (Calambokidis et al.,
1991). Despite high levels of seasonal disturbance by tourists using
both motorized and non-motorized vessels, Calambokidis et al. (1991)
observed an increase in site use (pup rearing) and classified this area
as one of the most important pupping sites for seals in the region.
Another study observed an increase in seal vigilance when vessels
passed the haul-out site, but then vigilance relaxed within ten minutes
of the vessels' passing (Fox, 2008). If vessels passed frequently
within a short time period (e.g., 24 hours), a reduction in the total
number of seals present was also observed (Fox, 2008).
Level A harassment, serious injury, or mortality could likely only
occur as a result of trampling in a stampede (a potentially dangerous
occurrence in which large numbers of animals succumb to mass panic and
rush away from a stimulus) or abandonment of pups. However, NWFSC
surveys would be unlikely to disturb any sea lion pups, and any
disturbance of harbor seal pups would be unlikely to result in
abandonment. The eastern stock of Steller sea lions breeds in rookeries
located in southeast Alaska, British Columbia, Oregon, and California;
there are no known breeding rookeries in Washington or in the Columbia
River. California sea lions breed in the Gulf of California, western
Baja California, and southern California. Harbor seal pups could be
present at times during NWFSC research effort (harbor seal pupping in
Washington inland waters occurs from approximately June through
September, depending on location), but harbor seal pups are extremely
precocious, swimming and diving immediately after birth and throughout
the lactation period, unlike most other phocids which normally enter
the sea only after weaning (Lawson and Renouf, 1985; Cottrell et al.,
2002; Burns et al., 2005). Lawson and Renouf (1987) investigated harbor
seal mother-pup bonding in response to natural and anthropogenic
disturbance. In summary, they found that the most critical bonding time
is within minutes after birth. As such, it is unlikely that infrequent
disturbance resulting from NWFSC research would interrupt the brief
mother-pup bonding period within which disturbance could result in
separation. In addition, NWFSC researchers take precautions to minimize
disturbance and prevent any possibility of stampedes, including
choosing travel routes as far away from hauled pinnipeds as possible
and by moving sample site locations to avoid consistent haulout areas.
Disturbance of pinnipeds caused by NWFSC survey activities would be
expected to last for only short periods of time, separated by
significant amounts of time in which no disturbance occurred. Because
such disturbance is sporadic, rather than chronic, and of low
intensity, individual marine mammals are unlikely to incur
[[Page 38546]]
any detrimental impacts to vital rates or ability to forage and, thus,
loss of fitness. Correspondingly, even local populations, much less the
overall stocks of animals, are extremely unlikely to accrue any
significantly detrimental impacts.
Anticipated Effects on Marine Mammal Habitat
Effects to prey--In addition to direct, or operational,
interactions between fishing gear and marine mammals, indirect (i.e.,
biological or ecological) interactions occur as well, in which marine
mammals and fisheries both utilize the same resource, potentially
resulting in competition that may be mutually disadvantageous (e.g.,
Northridge, 1984; Beddington et al., 1985; Wickens, 1995). Marine
mammal prey varies by species, season, and location and, for some, is
not well documented. There is some overlap in prey of marine mammals
and the species sampled and removed during NWFSC research surveys, with
primary species of concern being hake, salmonids, and small, energy-
rich, schooling species such as Pacific sardine, anchovies, and jack
mackerel.
However, the total amount of these species taken in research
surveys is very small relative to their overall biomass in the area
(See Section 4.2.3 of the NWFSC EA for more information on fish catch
during research surveys). For example, the average annual catch of
Pacific hake in the course of all NWFSC research surveys during 2008-12
was approximately 1,181 metric tons (mt). Research catch is therefore
negligible compared to the average commercial harvest for the same
period (63,974 mt). For salmonids, in all cases the research take as a
percent of either the average spawning population estimate or the
average total juveniles produced is less than one tenth of one percent.
For most commercial species, the average annual research catch is less
than one percent of the overfishing limit (a fisheries management
metric used to prevent overfishing). Other species of fish and
invertebrates that are used as prey by marine mammals are taken in
research surveys as well but, as indicated by these examples, the
proportions of research catch compared to biomass and commercial
harvest is very small.
In addition to the small total biomass taken, some of the size
classes of fish targeted in research surveys are very small (e.g.,
juvenile salmonids are typically only centimeters long), and these
small size classes are not known to be prey of marine mammals. Research
catches are also distributed over a wide area because of the random
sampling design covering large sample areas. Fish removals by research
are therefore highly localized and unlikely to affect the spatial
concentrations and availability of prey for any marine mammal species.
This is especially true for pinnipeds, which are opportunistic
predators that consume a wide assortment of fish and squid, and judging
by their increasing populations throughout their range and expanding
range into the Pacific Northwest (Caretta et al., 2015a), food
availability does not appear to be a limiting factor (Baraff and
Loughlin, 2000; Scordino, 2010). The overall effect of research catches
on marine mammals through competition for prey may therefore be
considered insignificant for all species.
Acoustic habitat--Acoustic habitat is the soundscape--which
encompasses all of the sound present in a particular location and time,
as a whole--when considered from the perspective of the animals
experiencing it. Animals produce sound for, or listen for sounds
produced by, conspecifics (communication during feeding, mating, and
other social activities), other animals (finding prey or avoiding
predators), and the physical environment (finding suitable habitats,
navigating). Together, sounds made by animals and the geophysical
environment (e.g., produced by earthquakes, lightning, wind, rain,
waves) make up the natural contributions to the total acoustics of a
place. These acoustic conditions, termed acoustic habitat, are one
attribute of an animal's total habitat.
Soundscapes are also defined by, and acoustic habitat influenced
by, the total contribution of anthropogenic sound. This may include
incidental emissions from sources such as vessel traffic, or may be
intentionally introduced to the marine environment for data acquisition
purposes (as in the NWFSC's use of active acoustic sources).
Anthropogenic noise varies widely in its frequency content, duration,
and loudness and these characteristics greatly influence the potential
habitat-mediated effects to marine mammals (please see also the
previous discussion on masking under ``Acoustic Effects''), which may
range from local effects for brief periods of time to chronic effects
over large areas and for long durations. Depending on the extent of
effects to habitat, animals may alter their communications signals
(thereby potentially expending additional energy) or miss acoustic cues
(either conspecific or adventitious). For more detail on these concepts
see, e.g., Barber et al., 2010; Pijanowski et al., 2011; Francis and
Barber, 2013; Lillis et al., 2014.
Problems arising from a failure to detect cues are more likely to
occur when noise stimuli are chronic and overlap with biologically
relevant cues used for communication, orientation, and predator/prey
detection (Francis and Barber, 2013). As described above (``Acoustic
Effects''), the signals emitted by NWFSC active acoustic sources are
generally high frequency, of short duration, and transient. These
factors mean that the signals will attenuate rapidly (not travel over
great distances), may not be perceived or affect perception even when
animals are in the vicinity, and would not be considered chronic in any
given location. NWFSC use of these sources is widely dispersed in both
space and time. In conjunction with the prior factors, this means that
it is highly unlikely that NWFSC use of these sources would, on their
own, have any appreciable effect on acoustic habitat. Sounds emitted by
NWFSC vessels would be of lower frequency and continuous, but would
also be widely dispersed in both space and time. NWFSC vessel traffic--
including both sound from the vessel itself and from the active
acoustic sources--is of very low density compared to commercial
shipping traffic or commercial fishing vessels and would therefore be
expected to represent an insignificant incremental increase in the
total amount of anthropogenic sound input to the marine environment.
Physical habitat--NWFSC conducts some bottom trawling, which may
physically damage seafloor habitat. Physical damage may include
furrowing and smoothing of the seafloor as well as the displacement of
rocks and boulders, and such damage can increase with multiple contacts
in the same area (Morgan and Chuenpagdee, 2003; Stevenson et al.,
2004). Damage to seafloor habitat may also harm infauna and epifauna
(i.e., animals that live in or on the seafloor or on structures on the
seafloor), including corals. In general, physical damage to the
seafloor would be expected to recover within eighteen months through
the action of water currents and natural sedimentation, with the
exception of rocks and boulders which may be permanently displaced
(Stevenson et al., 2004). Biological damage would likely recover within
the same timeframe, although repeated disturbance of an area can
prolong the recovery time (Stevenson et al., 2004), and recovery of
corals may take significantly longer. However, NWFSC catch records show
that only minimal amounts of coral are captured (annual average of 55
kg of coral in all
[[Page 38547]]
surveys from 2008-12). Relatively small areas would be impacted by
NWFSC bottom trawling and, because such surveys are conducted in the
same areas but not in the exact same locations, they are expected to
cause single rather than repeated disturbances in any given area. NWFSC
activities would not be expected to have any other impacts on physical
habitat.
As described in the preceding, the potential for NWFSC research to
affect the availability of prey to marine mammals or to meaningfully
impact the quality of physical or acoustic habitat is considered to be
insignificant for all species. Effects to habitat will not be discussed
further in this document.
Estimated Take by Incidental Harassment, Serious Injury, or Mortality
Except with respect to certain activities not pertinent here, the
MMPA defines ``harassment'' as: Any act of pursuit, torment, or
annoyance which (i) has the potential to injure a marine mammal or
marine mammal stock in the wild [Level A harassment]; or (ii) has the
potential to disturb a marine mammal or marine mammal stock in the wild
by causing disruption of behavioral patterns, including, but not
limited to, migration, breathing, nursing, breeding, feeding, or
sheltering [Level B harassment]. Serious injury means any injury that
will likely result in mortality (50 CFR 216.3).
Take of marine mammals incidental to NWFSC research activities
could occur as a result of (1) injury or mortality due to gear
interaction (Level A harassment, serious injury, or mortality); (2)
behavioral disturbance resulting from the use of active acoustic
sources (Level B harassment only); or (3) behavioral disturbance of
pinnipeds resulting from incidental approach of researchers (Level B
harassment only).
Estimated Take Due to Gear Interaction
Historical Interactions
In order to estimate the number of potential incidents of take that
could occur by M/SI + Level A through gear interaction, we first
consider NWFSC's record of past such incidents, and then consider in
addition other species that may have similar vulnerabilities to NWFSC
trawl gear as those species for which we have historical interaction
records. Historical interactions with NWFSC research gear are described
in Table 4. Available records are for the years 1999 through present.
All historical interactions have taken place in the CCRA, offshore
Washington and Oregon, and have occurred during use of the Nordic 264
surface trawl net, with a few exceptions. There is one historical
interaction in the PSRA (also using the Nordic 264 surface trawl) and
one CCRA historical interaction using the modified Cobb midwater trawl.
NWFSC has no historical interactions for any bottom trawl, hook and
line, or seine gear, and has no historical interactions in the LCRRA.
Please see Figure 6-1 in the NWFSC request for authorization for
specific locations of these incidents.
Table 4--Historical Interactions With Research Gear
----------------------------------------------------------------------------------------------------------------
Number Number
Gear \1\ Survey Date Species killed released alive Total
----------------------------------------------------------------------------------------------------------------
Pelagic trawl........ Juvenile Salmon 5/24/1999 Pacific white- 4 .............. 4
Coastal (JSC). sided dolphin.
Pelagic trawl........ JSC.............. 9/29/1999 Steller sea lion. 1 .............. 1
Pelagic trawl........ JSC.............. 10/1/1999 Steller sea lion. 3 .............. 3
Pelagic trawl........ JSC.............. 5/18/2000 Northern fur seal 1 .............. 1
Pelagic trawl........ Piscine Predator 7/19/2001 California sea 1 .............. 1
and Forage Fish lion.
(PPFF) \2\.
Pelagic trawl........ JSC.............. 9/22/2002 Steller sea lion. 1 .............. 1
Pelagic trawl........ JSC.............. 9/23/2002 Steller sea lion. 1 .............. 1
Pelagic trawl........ JSC.............. 9/24/2002 Steller sea lion. 2 .............. 2
Pelagic trawl........ JSC.............. 6/25/2003 Pacific white- 1 .............. 1
sided dolphin.
Pelagic trawl........ JSC.............. 6/30/2003 Harbor seal...... 1 .............. 1
Pelagic trawl........ JSC.............. 6/30/2003 Pacific white- 2 .............. 2
sided dolphin.
Pelagic trawl........ JSC.............. 6/18/2005 Pacific white- 3 .............. 3
sided dolphin.
Pelagic trawl........ PPFF \2\......... 6/1/2006 Pacific white- 3 .............. 3
sided dolphin.
Pelagic trawl........ PPFF \2\......... 8/28/2006 Pacific white- 2 .............. 2
sided dolphin.
Pelagic trawl........ JSC.............. 9/28/2007 California sea 1 .............. 1
lion.
Pelagic trawl........ Skagit Bay 5/16/2009 Harbor seal...... .......... 1 1
Juvenile Salmon
\3\.
Pelagic trawl........ JSC.............. 5/23/2009 Unidentified 2 .............. 2
small cetacean
\4\.
Pelagic trawl \5\.... Northern Juvenile 5/26/2009 California sea 1 1 2
Rockfish. lion.
Pelagic trawl........ JSC.............. 5/24/2010 Harbor seal...... 1 .............. 1
Pelagic trawl........ JSC.............. 6/28/2012 Pacific white- 3 .............. 3
sided dolphin.
Pelagic trawl........ JSC.............. 6/21/2014 Pacific white- 6 .............. 6
sided dolphin.
------------------------------------------------------
Total individuals captured (total number of Northern fur seal 1 .............. 1
interactions given in parentheses). (1).
California sea 3 1 4
lion (3).
Pacific white- 24 .............. 24
sided dolphin
(8).
Harbor seal (3).. 2 1 3
Steller sea lion 8 .............. 8
(5).
----------------------------------------------------------------------------------------------------------------
\1\ All incidents involved use of the Nordic 264 surface trawl, except as noted below.
\2\ Survey discontinued.
\3\ This incident occurred in Puget Sound; all other incidents occurred in waters offshore Washington and
Oregon.
\4\ Animals not identified before fishing crew returned carcasses to sea.
\5\ This incident involved use of the modified Cobb midwater trawl.
Although some historical interactions resulted in the animal(s)
being released alive, no serious injury determinations (NMFS, 2012a;
2012b) were made, and it is possible that some of these animals later
died. In order to use these historical interaction records in a
precautionary manner as the basis for the take estimation process, and
because
[[Page 38548]]
we have no specific information to indicate whether any given future
interaction might result in M/SI versus Level A harassment, we
conservatively assume that all interactions equate to mortality. Over
the past seventeen years, NWFSC has had only infrequent interactions
with marine mammals, with 0.1-0.5 animals captured per year for the
pinniped species and 1.4 animals captured per year for the Pacific
white-sided dolphin. No Steller sea lion has been captured since 2002,
northern fur seals have been involved in only one incident (none since
2000), and only a few California sea lions and harbor seals have been
involved in interactions with research fishing gear. However, we assume
that any of these species could be captured in any year.
In order to produce the most precautionary take estimates possible,
we consider all of the data available to us (i.e., since 1999). In
consideration of these interaction records, we assume that one
individual of each species of otariid pinniped could be captured per
year over the course of the five-year period of validity for these
proposed regulations, that two individual harbor seals could be
captured per year, and that the worst case event could happen each year
for Pacific white-sided dolphins (i.e., six dolphins could be captured
in a single trawl in each year). Table 5 shows the projected five-year
total captures of these five species for this proposed rule, as
described above, for trawl gear only. Although more than one individual
of the two sea lion species has been captured in a single tow,
interactions with these species have historically occurred only
infrequently, and we believe that the above assumption appropriately
reflects the likely total number of individuals involved in research
gear interactions over a five-year period. We assume that two total
harbor seals could be captured per year in recognition of the
demonstrated vulnerability to capture in the PSRA (all other species
have been captured only in the CCRA). These estimates are based on the
assumption that annual effort (e.g., total annual trawl tow time) over
the proposed five-year authorization period will not exceed the annual
effort during prior years for which we have interaction records.
Table 5--Projected Five-Year Total Take in Trawl Gear for Historically Captured Species
----------------------------------------------------------------------------------------------------------------
CCRA average PSRA average
Gear Species annual take annual take Projected 5-
(total) (total) year total \1\
----------------------------------------------------------------------------------------------------------------
Trawl.............................. Pacific white-sided dolphin 6 (30) .............. 30
California sea lion........ 1 (5) .............. 5
Harbor seal................ 1 (5) 1 (5) 10
Northern fur seal.......... 1 (5) .............. 5
Steller sea lion........... 1 (5) .............. 5
----------------------------------------------------------------------------------------------------------------
\1\ Because there are no historical take records from the LCRRA, we incorporate all projected LCRRA takes in
Table 7 below.
In order to estimate the total potential number of incidents of M/
SI + Level A that could occur incidental to the NWFSC's use of trawl,
hook and line, and seine gear over the five-year period of validity for
these proposed regulations (i.e., takes additional to those described
in Table 4), we first consider whether there are additional species
that may have similar vulnerability to capture in trawl gear as the
five species described above that have been taken historically and then
evaluate the potential vulnerability of these and other species to
additional gears.
As background to the process of determining which species not
historically taken may have sufficient vulnerability to capture in
NWFSC gear to justify inclusion in the take authorization request (or
whether species historically taken may have vulnerability to gears in
which they have not historically been taken or additional vulnerability
not reflected above due to activity in other areas such as the LCRRA),
we note that the NWFSC is NMFS' research arm in the northwest portion
of the West Coast Region and may be considered as a leading source of
expert knowledge regarding marine mammals (e.g., behavior, abundance,
density) in the areas where they operate. The species for which the
take request was formulated were selected by the NWFSC, and we have
concurred with these decisions.
In order to evaluate the potential vulnerability of additional
species to trawl and of all species to hook and line and seine gear, we
first consulted NMFS' List of Fisheries (LOF), which classifies U.S.
commercial fisheries into one of three categories according to the
level of incidental marine mammal M/SI that is known to occur on an
annual basis over the most recent five-year period (generally) for
which data has been analyzed: Category I, frequent incidental M/SI;
Category II, occasional incidental M/SI; and Category III, remote
likelihood of or no known incidental M/SI. We provide summary
information, as presented in the 2015 LOF (79 FR 77919; December 29,
2014), in Table 6. In order to simplify information presented, and to
encompass information related to other similar species from different
locations, we group marine mammals by genus (where there is more than
one member of the genus found in U.S. waters). Where there are
documented incidents of M/SI incidental to relevant commercial
fisheries, we note whether we believe those incidents provide
sufficient basis upon which to infer vulnerability to capture in NWFSC
research gear. For a listing of all Category I, II, and II fisheries
using relevant gears, associated estimates of fishery participants, and
specific locations and fisheries associated with the historical
fisheries takes indicated in Table 6 below, please see the 2015 LOF.
For specific numbers of marine mammal takes associated with these
fisheries, please see the relevant SARs. More information is available
on the Internet at www.nmfs.noaa.gov/pr/interactions/lof/ and
www.nmfs.noaa.gov/pr/sars/.
[[Page 38549]]
Table 6--U.S. Commercial Fisheries Interactions for Trawl, Hook and Line, and Seine Gear for Relevant Species
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vulnerability Hook and line Vulnerability Vulnerability
Species \1\ Trawl \2\ inferred? \3\ \2\ inferred? \3\ Seine \2\ inferred? \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale.............................................. Y N N n/a N n/a
Humpback whale.......................................... Y N Y N Y N
Balaenoptera spp........................................ Y N Y N N n/a
Sperm whale............................................. N n/a Y N N n/a
Kogia spp............................................... N n/a Y Y N n/a
Cuvier's beaked whale................................... N n/a Y N N n/a
Baird's beaked whale.................................... N n/a N n/a N n/a
Mesoplodon spp.......................................... N n/a Y N N n/a
Common bottlenose dolphin............................... Y Y Y Y Y N
Stenella spp............................................ N n/a Y Y N n/a
Delphinus spp........................................... Y Y Y Y Y Y
Lagenorhynchus spp.\4\.................................. n/a n/a N n/a N n/a
Northern right whale dolphin............................ Y \6\ Y N n/a N n/a
Risso's dolphin......................................... Y Y Y Y N n/a
Killer whale............................................ Y N Y N N n/a
Globicephala spp........................................ Y N Y Y Y N
Harbor porpoise......................................... Y Y N n/a N n/a
Dall's porpoise......................................... Y Y Y N N n/a
Guadalupe fur seal \5\.................................. N n/a N n/a N n/a
Northern fur seal \4\................................... n/a n/a Y N N n/a
California sea lion \4\................................. n/a n/a Y \6\ Y Y Y
Steller sea lion \4\.................................... n/a n/a Y Y N n/a
Phoca spp.\4\........................................... n/a n/a N n/a Y Y
Northern elephant seal.................................. Y N N n/a N n/a
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Please refer to Table 3 for taxonomic reference.
\2\ Indicates whether any member of the genus has documented incidental M/SI in a U.S. fishery using that gear in the most recent five-year timespan for
which data is available.
\3\ Where there are no documented incidents of M/SI incidental to relevant commercial fisheries, this is not applicable.
\4\ This exercise is considered ``not applicable'' for trawl gear for those species historically captured by NWFSC gear. Historical record, rather than
analogy, is considered the best information upon which to base a take estimate.
\5\ It is likely that Guadalupe fur seals are taken in Mexican fisheries, but there are no records available to us.
\6\ There are no records of take for California sea lions in commercial hook and line fisheries, but there have been multiple takes of California sea
lions in longline surveys conducted by the SWFSC. There are no records of take for northern right whale dolphins in commercial trawl fisheries, but
this species has been captured in a trawl survey conducted by the SWFSC. We therefore infer vulnerability for those species to those research gears.
Information related to incidental M/SI in relevant commercial
fisheries is not, however, the sole determinant of whether it may be
appropriate to authorize M/SI + Level A incidental to NWFSC survey
operations. A number of factors (e.g., species-specific knowledge
regarding animal behavior, overall abundance in the geographic region,
density relative to NWFSC survey effort, feeding ecology, propensity to
travel in groups commonly associated with other species historically
taken) were taken into account by the NWFSC to determine whether a
species may have a similar vulnerability to certain types of gear as
historically taken species. In some cases, we have determined that
species without documented M/SI may nevertheless be vulnerable to
capture in NWFSC research gear. Similarly, we have determined that some
species groups with documented M/SI are not likely to be vulnerable to
capture in NWFSC gear. In these instances, we provide further
explanation below. Those species with no records of historical
interaction with NWFSC research gear and no documented M/SI in relevant
commercial fisheries, and for which the NWFSC has not requested the
authorization of incidental take, are not considered further in this
section. The NWFSC believes generally that any sex or age class of
those species for which take authorization is requested could be
captured.
In order to estimate a number of individuals that could potentially
be captured in NWFSC research gear for those species not historically
captured, we first determine which species may have vulnerability to
capture in a given gear. Of those species, we then determine whether
any may have similar propensity to capture in a given gear as a
historically captured species. These species are limited to a few
species delphinid species that we believe may have similar risk of
capture as that displayed by the Pacific white-sided dolphin. For these
species, we assume it is possible that a worst-case scenario of take
could occur while at the same time contending that, absent significant
range shifts or changes in habitat usage, capture of a species not
historically captured would likely be a very rare event. The former
assumption also accounts for the likelihood that, for species that
often travel in groups, an incident involving capture of that species
is likely to involve more than one individual.
For example, we believe that the Risso's dolphin is potentially
vulnerable to capture in trawl gear and may have similar propensity to
capture in that gear as does the Pacific white-sided dolphin. Because
the greatest number of Pacific white-sided dolphins captured in any one
trawl tow was six individuals, we assume that six Risso's dolphins
could also be captured in a single incident. However, in recognition of
the fact that any incident involving the capture of Risso's dolphins
would likely be a rare event, we propose a total take authorization
over the five-year period of the number that may result from a single,
worst-case incident (six dolphins). While we do not necessarily believe
that six Risso's dolphins would be captured in a single incident--and
that more capture incidents involving fewer individuals could occur, as
opposed to a single, worst-case incident--we believe that this is a
reasonable approach to estimating
[[Page 38550]]
potential incidents of M/SI + Level A while balancing what could happen
in a worst-case scenario with the potential likelihood that no
incidents of capture would actually occur. The SWFSC historical capture
of northern right whale dolphins in 2008 provides an instructive
example of a situation where a worst-case scenario (six dolphins
captured in a single trawl tow) did occur, but overall capture of this
species was very rare (no other capture incidents before or since).
Separately, for those species that we believe may have a
vulnerability to capture in given gear but that we do not believe may
have a similar propensity to capture in that gear as a historically
captured species, we assume that capture would be a rare event such
that authorization of a single take over the five-year period is likely
sufficient to capture the risk of interaction. For example, from the
LOF we infer vulnerability to capture in trawl gear for the Dall's
porpoise but do not believe that this species has a similar propensity
for interaction in trawl gear as the Pacific white-sided dolphin.
NWFSC requested authorization of incidental take for bottlenose
dolphin, for either the offshore or coastal stock. However, we have had
clarifying conversations with NWFSC to more explicitly understand the
interaction risk posed by NWFSC survey operations. Coastal stock
dolphins are generally found within 1 km of shore, from San Francisco
Bay south to Mexican waters. This distribution has very little overlap
with NWFSC research survey activity and, when coupled with the limited
effort involved in NWFSC survey operations in that range and the
mitigation measure proposed to be implemented, we do not believe that
incidental take of coastal stock bottlenose dolphins is reasonably
likely and do not propose to authorize take from this stock.
Trawl--From the 2015 LOF and SWFSC historical gear interactions, we
infer vulnerability to trawl gear in the CCRA for the Risso's dolphin,
short- and long-beaked common dolphins, northern right whale dolphin,
Dall's porpoise, harbor porpoise, and bottlenose dolphin. We consider
some of these species to have a similar propensity for interaction with
trawl gear as that demonstrated by the Pacific white-sided dolphin
(Risso's dolphin, northern right whale dolphin) and the rest to have
lower risk of interaction.
Due to their likely presence in the relevant areas and inference
based on historical interactions and the LOF, we assume additional
vulnerability and therefore potential take for some of these species in
trawl gear used in the PSRA and LCRRA. In the PSRA, these include the
harbor porpoise and Dall's porpoise and the California sea lion and
Steller sea lion. In the LCRRA these include the harbor porpoise and
the harbor seal, California sea lion, and Steller sea lion.
For the striped dolphin, we believe that there is a reasonable
likelihood of incidental take in trawl gear although there are no
records of incidental M/SI in relevant commercial fisheries. The
proposed take authorization for this species was determined to be
appropriate based on analogy to other similar species that have been
taken either in NWFSC operations or in analogous commercial fishery
operations. We believe that the striped dolphin has a similar
propensity for interaction with trawl gear as that demonstrated by the
Pacific white-sided dolphin.
It is also possible that a captured animal may not be able to be
identified to species with certainty. Certain pinnipeds and small
cetaceans are difficult to differentiate at sea, especially in low-
light situations or when a quick release is necessary. For example, a
captured delphinid that is struggling in the net may escape or be freed
before positive identification is made. This is only likely to occur in
the CCRA due to the greater diversity of pinniped and small cetacean
species likely to be encountered in that area. Therefore, the NWFSC has
requested the authorization of incidental M/SI + Level A for one
unidentified pinniped and one unidentified small cetacean over the
course of the five-year period of proposed authorization.
Hook and line--The process is the same as is described above for
trawl gear. From the 2015 LOF and SWFSC historical interactions, we
infer vulnerability to hook and line gear in the CCRA for the Risso's
dolphin, bottlenose dolphin, striped dolphin, pygmy and dwarf sperm
whale (i.e., Kogia spp.), short- and long-beaked common dolphins,
short-finned pilot whale, and California and Steller sea lions.
Due to their likely presence in the relevant areas and inference
based on historical interactions and the LOF, we assume additional
vulnerability and therefore potential take for some of these species in
hook and line gear used in the PSRA (hook and line gear is not used in
the LCRRA). These include the California sea lion and harbor seal.
Seine--The process is the same as is described above for trawl
gear. From the 2015 LOF, we infer vulnerability to seine and tangle net
gear in the CCRA and/or LCRRA for the short-beaked common dolphin,
harbor seal, and California sea lion. Long-beaked common dolphin is not
included because they are much rarer in Oregon and Washington where
seine surveys are conducted. Seine gear is used infrequently in the
PSRA (e.g., twelve purse seine sets per year) and the move-on rule
applied if any small cetacean is seen within 500 m of the planned set.
We do not believe that any take in seine gear is likely in the PSRA.
We also believe that there is a reasonable potential of seine gear
interaction for a number of species in the CCRA and/or LCRRA for which
there are no LOF records of interaction in commercial fisheries gears.
These proposed authorizations reflect the NWFSC's expert judgment
regarding the distribution of these species in relation to NWFSC use of
seine gear offshore Oregon and Washington. For example, several of
these species have the potential to interact with NWFSC purse seine
surveys in the Columbia River plume, where there are no corresponding
commercial seine fisheries. Therefore, we would not expect the LOF to
adequately reflect the risk of marine mammal interaction posed by NWFSC
survey activities. Species for which we propose to authorize take in
seine gear in the CCRA and/or LCRRA with no LOF interaction records
include the Dall's porpoise, Pacific white-sided dolphin, Risso's
dolphin, northern right whale dolphin, Steller sea lion, and harbor
porpoise. For the harbor porpoise, we expect that there is greater
vulnerability to take in these gears (i.e., we expect it could be taken
in both the CCRA and LCRRA) and have increased the proposed take
authorization relative to the other species accordingly. NWFSC
considers the delphinid species to be at risk because of their
occurrence in coastal waters offshore Oregon and Washington, and
because they often occur in mixed schools and could be caught together
in purse seines.
[[Page 38551]]
Table 7--Total Estimated M/SI + Level A Due to Gear Interaction, 2016-21
----------------------------------------------------------------------------------------------------------------
Estimated 5-year
Species Estimated 5-year total, hook and line Estimated 5-year Total, all
total, trawl \1\ \1\ total, seine \1\ gears
----------------------------------------------------------------------------------------------------------------
Kogia spp.\2\.................... .................... 1................... .................... 1
Bottlenose dolphin \3\........... 1................... 1................... .................... 2
Striped dolphin.................. 6................... 1................... .................... 7
Short-beaked common dolphin...... 1................... 1................... 1................... 3
Long-beaked common dolphin....... 1................... 1................... .................... 2
Pacific white-sided dolphin...... 30.................. .................... 1................... 31
Northern right whale dolphin..... 6................... .................... 1................... 7
Risso's dolphin.................. 6................... 1................... 1................... 8
Short-finned pilot whale......... .................... 1................... .................... 1
Harbor porpoise \4\.............. 3 (CCRA/PSRA/LCRRA). .................... 2 (CCRA/LCRRA)...... 5
Dall's porpoise.................. 2 (CCRA/PSRA)....... .................... 1................... 3
Northern fur seal \5\............ 5................... .................... .................... 5
California sea lion.............. 7 (5 CCRA/PSRA/ 2 (CCRA/PSRA)....... 1 (LCRRA)........... 10
LCRRA).
Steller sea lion................. 7 (5 CCRA/PSRA/ 1................... 1 (LCRRA)........... 9
LCRRA).
Harbor seal \4\.................. 11 (5 CCRA/5 PSRA/ 1 (PSRA)............ 1 (LCRRA)........... 13
LCRRA.
Unidentified pinniped............ 1................... .................... .................... 1
Unidentified small cetacean...... 1................... .................... .................... 1
----------------------------------------------------------------------------------------------------------------
\1\ Please see Table 6 and preceding text for derivation of take estimates. Takes proposed for authorization are
not specific to any area, but our estimates are informed by area-specific vulnerability. All takes are
expected to occur in the CCRA, except where the gear-specific breakdown of expected takes per area is
provided. Note that hook and line surveys are not proposed for LCRRA and only limited seine surveys are
proposed for PSRA.
\2\ We expect that only one Kogia spp. may be taken over the five-year timespan and that it could be either a
pygmy or dwarf sperm whale.
\3\ Incidental take is expected only from the offshore stock.
\4\ Incidental take for these species may be of animals from any stock in California, Oregon, or Washington, but
expected vulnerability may be assigned to CCE or Washington inland waters stocks according to the expected
take proportions shown.
\5\ Incidental take may be of animals from either the eastern Pacific or California stock.
For large whales, beaked whales, and killer whales, observed M/SI
is extremely rare for trawl and seine gear and, for most of these
species, only slightly more common in longline gear. Although large
whale species could become captured or entangled in NWFSC gear, the
probability of interaction is extremely low considering the lower level
of effort relative to that of commercial fisheries. For example, there
were estimated to be three total incidents of sperm whale M/SI in the
Hawaii deep-set longline fishery from 2007-11. This fishery has 129
participants, and the fishery as a whole exerts substantially greater
effort in a given year than does the NWFSC. In a very rough estimate,
we can say that these three estimated incidents between 2007-11
represent an insignificant per-participant interaction rate of 0.005
per year, despite the greater effort. Similarly, there were zero
documented interactions from 2007-11 in the Atlantic Ocean, Caribbean,
Gulf of Mexico large pelagics longline fishery, despite a reported
fishing effort of 8,044 sets and 5,955,800 hooks in 2011 alone
(Garrison and Stokes, 2012). With an average soak time of ten to
fourteen hours, this represents an approximate minimum of almost sixty
million hook hours. For reference, an approximate maximum estimate of
NWFSC effort in the CCRA is 52,000 hook-hours per year. Other large
whales, beaked whales and killer whales have similarly low rates of
interaction with commercial fisheries, despite the significantly
greater effort. In addition, large whales, beaked whales, and killer
whales generally have, with few exceptions, very low densities in the
CCE relative to other species (see Table 10). We believe it extremely
unlikely that any large whale, beaked whale, or killer whale would be
captured or entangled in NWFSC research gear.
There are a number of additional species with various LOF
interaction records where we do not infer vulnerability to NWFSC use of
that gear. Pilot whales have demonstrated vulnerability to midwater
trawl gear in Atlantic fisheries and to purse seine gear, but we do not
infer vulnerability to capture during NWFSC use of these gears because
of the species is not abundant in the CCRA (Table 10). Bottlenose
dolphins have been captured in purse seines, but they are also very
rare in the areas where NWFSC conducts seine surveys. Similarly, we do
not infer vulnerability to hook and line gear for Dall's porpoise or
fur seals or to trawl gear for elephant seals given the amount of
research effort conducted (for hook and line) or the rare nature of
fisheries interactions for elephant seals.
Estimated Take Due to Acoustic Harassment
As described previously (``Potential Effects of the Specified
Activity on Marine Mammals''), we believe that NWFSC use of active
acoustic sources has, at most, the potential to cause Level B
harassment of marine mammals. In order to attempt to quantify the
potential for Level B harassment to occur, NMFS (including the NWFSC
and acoustics experts from other parts of NMFS) developed an analytical
framework considering characteristics of the active acoustic systems
described previously under ``Description of Active Acoustic Sound
Sources,'' their expected patterns of use, and characteristics of the
marine mammal species that may interact with them. We believe that this
quantitative assessment benefits from its simplicity and consistency
with current NMFS acoustic guidance regarding Level B harassment but
caution that, based on a number of deliberately precautionary
assumptions, the resulting take estimates may be seen as an
overestimate of the potential for behavioral harassment to occur as a
result of the operation of these systems. Additional details on the
approach used and the assumptions made that result in these estimates
are described below.
The operating frequencies of active acoustic systems used by NWFSC
sources only go down to 27-33 kHz for the trawl monitoring system,
which is not one of the predominant sources, and to 38 kHz for the EK60
echosounder (see Table 2 and Table 8). These frequencies are above the
hearing range of baleen whales (i.e., mysticetes); therefore, baleen
whales would not be expected to perceive signals from NWFSC active
acoustic sources, and we would not expect any exposures to these
signals to
[[Page 38552]]
result in behavioral harassment. Baleen whales are not considered
further in this section.
The assessment paradigm for active acoustic sources used in NWFSC
fisheries research is relatively straightforward and has a number of
key simplifying assumptions. NMFS' current acoustic guidance requires
in most cases that we assume Level B harassment occurs when a marine
mammal receives an acoustic signal at or above a simple step-function
threshold. For use of these active acoustic systems, the appropriate
threshold is 160 dB re 1 [mu]Pa (rms). Estimating the number of
exposures at the specified received level requires several
determinations, each of which is described sequentially below:
(1) A detailed characterization of the acoustic characteristics of
the effective sound source or sources in operation;
(2) The operational areas exposed to levels at or above those
associated with Level B harassment when these sources are in operation;
(3) A method for quantifying the resulting sound fields around
these sources; and
(4) An estimate of the average density for marine mammal species in
each area of operation.
Quantifying the spatial and temporal dimension of the sound
exposure footprint (or ``swath width'') of the active acoustic devices
in operation on moving vessels and their relationship to the average
density of marine mammals enables a quantitative estimate of the number
of individuals for which sound levels exceed the relevant threshold for
each area. The number of potential incidents of Level B harassment is
ultimately estimated as the product of the volume of water ensonified
at 160 dB rms or higher and the volumetric density of animals
determined from simple assumptions about their vertical stratification
in the water column. Specifically, reasonable assumptions based on what
is known about diving behavior across different marine mammal species
were made to segregate those that predominately remain in the upper 200
m of the water column versus those that regularly dive deeper during
foraging and transit. Methods for estimating each of these calculations
are described in greater detail in the following sections, along with
the simplifying assumptions made, and followed by the take estimates.
Note that NWFSC only uses active acoustic systems for data acquisition
purposes in the CCRA.
Sound source characteristics--An initial characterization of the
general source parameters for the primary active acoustic sources
operated by the NWFSC was conducted, enabling a full assessment of all
sound sources used by the NWFSC and delineation of Category 1 and
Category 2 sources, the latter of which were carried forward for
analysis here (see Table 2). This auditing of the active acoustic
sources also enabled a determination of the predominant sources that,
when operated, would have sound footprints exceeding those from any
other simultaneously used sources. These sources were effectively those
used directly in acoustic propagation modeling to estimate the zones
within which the 160 dB rms received level would occur.
Many of these sources can be operated in different modes and with
different output parameters. In modeling their potential impact areas,
those features among those given previously in Table 2 (e.g., lowest
operating frequency) that would lead to the most precautionary estimate
of maximum received level ranges (i.e., largest ensonified area) were
used. The effective beam patterns took into account the normal modes in
which these sources are typically operated. While these signals are
brief and intermittent, a conservative assumption was taken in ignoring
the temporal pattern of transmitted pulses in calculating Level B
harassment events. Operating characteristics of each of the predominant
sound sources were used in the calculation of effective line-kilometers
and area of exposure for each source in each survey.
Table 8--Effective Exposure Areas for Predominant Acoustic Sources Across Two Depth Strata
----------------------------------------------------------------------------------------------------------------
Effective exposure
Effective exposure area: Sea surface to
Active acoustic system area: Sea surface to depth at which 160-dB
200 m depth (km\2\) threshold is reached
(km\2\)
----------------------------------------------------------------------------------------------------------------
Simrad EK60 narrow beam echosounder........................... 0.0142 0.1411
Simrad ME70 multibeam echosounder............................. 0.0201 0.0201
Simrad FS70 trawl sonar....................................... 0.008 0.008
Simrad SX90 narrow beam sonar \1\............................. 0.0654 0.1634
Teledyne RD Instruments ADCP, Ocean Surveyor.................. 0.0086 0.0187
Simrad ITI trawl monitoring system............................ 0.0032 0.0032
----------------------------------------------------------------------------------------------------------------
\1\ Exposure area varies greatly depending on the tilt angle setting of the SX90. To approximate the varied
usage this system might receive, the exposure area for each depth strata was averaged by assuming equal usage
at tilt angles of 5, 20, 45, and 80 degrees.
Among Category 2 sources (Table 2), six predominant sources (Table
8) were identified as having the largest potential impact zones during
operations, based on their relatively lower output frequency, higher
output power, and their operational pattern of use. Estimated effective
cross-sectional areas of exposure were estimated for each of the
predominant sources using a commercial software package (MATLAB) and
key input parameters including source-specific operational
characteristics (i.e., frequency, beamwidth, source level, tilt angle,
and horizontal and vertical resolution; see Table 2) and environmental
characteristics (i.e., temperature, salinity, pH, and latitude). Where
relevant, calculations were performed for different notional
operational scenarios and the largest cross-sectional area used in
estimating take (e.g., see Figure 6.2 of NWFSC's application, which
displays a simple visualization of a two-dimensional slice of modeled
sound propagation to illustrate the predicted area ensonified to the
160-dB threshold by the nominal EK60 beam pattern assuming side lobes
of ensonification).
In determining the effective line-kilometers for each of these
predominant sources, the operational patterns of use relative to one
another were further applied to determine which source was the
predominant one operating at any point in time for each survey. When
multiple sound sources are used simultaneously, the one with the
largest potential impact zone in each relevant depth strata is
considered for
[[Page 38553]]
use in estimating exposures. For example, when species (e.g., sperm
whales) regularly dive deeper than 200 m, the largest potential impact
zone was calculated for both depth strata and in some cases resulted in
a different source being predominant in one depth stratum or the other.
This enabled a more comprehensive way of accounting for maximum
exposures for animals diving in a complex sound field resulting from
simultaneous sources with different spatial profiles. This overall
process effectively resulted in three sound sources (Table 8; SX90,
EK60, and ME70) comprising the total effective line-kilometers, their
relative proportions depending on the nature of each survey.
Calculating effective line-kilometers--As described below, based on
the operating parameters for each source type, an estimated volume of
water ensonified at or above the 160 dB rms threshold was determined.
In all cases where multiple sources are operated simultaneously, the
one with the largest estimated acoustic footprint was considered to be
the effective source. This was calculated for each depth stratum (0-200
m and greater than 200 m), which in some cases resulted in different
sources being predominant in each depth stratum for all line-kilometers
when multiple sources were in operation; this was accounted for in
estimating overall exposures for species that utilize both depth strata
(deep divers). The total number of line-kilometers that would be
surveyed was determined, as was the relative percentage of surveyed
linear kilometers associated with each source type. The total line-
kilometers for each vessel, the effective percentages associated with
each of the resulting three predominant source types (SX90, EK60, and
ME70), and the effective total line-kilometers of operation for each
source type are given below.
Calculating volume of water ensonified--The cross-sectional area of
water ensonified at or above the 160 dB rms threshold was calculated
using a simple model of sound propagation loss, which accounts for the
loss of sound energy over increasing range. We used a spherical
spreading model (where propagation loss = 20 * log [range]; such that
there would be a 6-dB reduction in sound level for each doubling of
distance from the source), a reasonable approximation over the
relatively short ranges involved, and accounted for the frequency-
dependent absorption coefficient ([alpha] at 8 [deg]C and 34 ppt) and
beam pattern of these sound sources, which is generally highly
directional. The lowest frequency was used for systems that are
operated over a range of frequencies. The vertical extent of this area
is calculated for two depth strata (0-200 m and surface to range at
which the on-axis received level reaches 160 dB rms). These results,
shown in Table 8, were applied differentially based on the typical
vertical stratification of marine mammals (see Table 10).
Following the determination of effective sound exposure area for
transmissions considered in two dimensions, the next step was to
determine the effective volume of water ensonified at or above 160 dB
rms for the entirety of each survey. For each of the three predominant
sound sources, the volume of water ensonified is estimated as the
athwartship cross-sectional area (in square kilometers) of sound at or
above 160 dB rms (as illustrated in Figure 6.2 of NWFSC's application)
multiplied by the total distance traveled by the ship. Where different
sources operating simultaneously would be predominant in each different
depth strata (e.g., ME70 and EK60 operating simultaneously may be
predominant in the shallow stratum and deep stratum, respectively), the
resulting cross-sectional area calculated took this into account.
Specifically, for shallow-diving species this cross-sectional area was
determined for whichever was predominant in the shallow stratum,
whereas for deeper-diving species this area was calculated from the
combined effects of the predominant source in the shallow stratum and
the (sometimes different) source predominating in the deep stratum.
This creates an effective total volume characterizing the area
ensonified when each predominant source is operated and accounts for
the fact that deeper-diving species may encounter a complex sound field
in different portions of the water column.
Marine mammal densities--One of the primary limitations to
traditional estimates of behavioral harassment from acoustic exposure
is the assumption that animals are uniformly distributed in time and
space across very large geographical areas, such as those being
considered here. There is ample evidence that this is in fact not the
case, and marine species are highly heterogeneous in terms of their
spatial distribution, largely as a result of species-typical
utilization of heterogeneous ecosystem features. Some more
sophisticated modeling efforts have attempted to include species-
typical behavioral patterns and diving parameters in movement models
that more adequately assess the spatial and temporal aspects of
distribution and thus exposure to sound (e.g., Navy, 2013). While
simulated movement models were not used to mimic individual diving or
aggregation parameters in the determination of animal density in this
estimation, the vertical stratification of marine mammals based on
known or reasonably assumed diving behavior was integrated into the
density estimates used.
First, typical two-dimensional marine mammal density estimates
(animals/km\2\) were obtained from various sources for each ecosystem
area. These were estimated from marine mammal Stock Assessment Reports
(Allen and Angliss, 2015; Carretta et al., 2015a) and other sources
(Barlow and Forney, 2007; ManTech-SRS Technologies, 2007). There are a
number of caveats associated with these estimates:
(1) They are often calculated using visual sighting data collected
during one season rather than throughout the year. The time of year
when data were collected and from which densities were estimated may
not always overlap with the timing of NWFSC fisheries surveys (detailed
previously in ``Detailed Description of Activities'').
(2) The densities used for purposes of estimating acoustic
exposures do not take into account the patchy distributions of marine
mammals in an ecosystem, at least on the moderate to fine scales over
which they are known to occur. Instead, animals are considered evenly
distributed throughout the assessed area, and seasonal movement
patterns are not taken into account.
In addition, and to account for at least some coarse differences in
marine mammal diving behavior and the effect this has on their likely
exposure to these kinds of often highly directional sound sources, a
volumetric density of marine mammals of each species was determined.
This value is estimated as the abundance averaged over the two-
dimensional geographic area of the surveys and the vertical range of
typical habitat for the population. Habitat ranges were categorized in
two generalized depth strata (0-200 m and 0 to greater than 200 m)
based on gross differences between known generally surface-associated
and typically deep-diving marine mammals (e.g., Reynolds and Rommel,
1999; Perrin et al., 2009). Animals in the shallow-diving stratum were
assumed, on the basis of empirical measurements of diving with
monitoring tags and reasonable assumptions of behavior based on other
indicators, to spend a large majority of their lives (i.e., greater
than 75 percent) at depths shallower than 200 m. Their volumetric
density and thus exposure to
[[Page 38554]]
sound is therefore limited by this depth boundary. In contrast, species
in the deeper-diving stratum were assumed to regularly dive deeper than
200 m and spend significant time at these greater depths. Their
volumetric density and thus potential exposure to sound at or above the
160 dB rms threshold is extended from the surface to the depth at which
this received level condition occurs (i.e., corresponding to the 0 to
greater than 200 m depth stratum).
The volumetric densities are estimates of the three-dimensional
distribution of animals in their typical depth strata. For shallow-
diving species the volumetric density is the area density divided by
0.2 km (i.e., 200 m). For deeper diving species, the volumetric density
is the area density divided by a nominal value of 0.5 km (i.e., 500 m).
The two-dimensional and resulting three-dimensional (volumetric)
densities for each species in each ecosystem area are shown below.
Using area of ensonification and volumetric density to estimate
exposures--Estimates of potential incidents of Level B harassment
(i.e., potential exposure to levels of sound at or exceeding the 160 dB
rms threshold) are then calculated by using (1) the combined results
from output characteristics of each source and identification of the
predominant sources in terms of acoustic output; (2) their relative
annual usage patterns for each operational area; (3) a source-specific
determination made of the area of water associated with received sounds
at either the extent of a depth boundary or the 160 dB rms received
sound level; and (4) determination of a biologically-relevant
volumetric density of marine mammal species in each area. Estimates of
Level B harassment by acoustic sources are the product of the volume of
water ensonified at 160 dB rms or higher for the predominant sound
source for each portion of the total line-kilometers for which it is
used and the volumetric density of animals for each species. These
annual estimates are given below.
We first provide information related to relative annual usage
patterns of predominant active acoustic sources. For example, the use
of the ME70 and EK60 account for predominant sources during all surveys
on the R/V Bell M. Shimada, with the EK60 used during one hundred
percent of distance traveled (Table 9). When the ME70 is on, it is the
dominant source in the 0-200 m depth stratum (0.0201 km\2\ cross-
sectional ensonified area versus 0.0142 km\2\ cross-sectional
ensonified area for the EK60; Table 8); therefore, the ME70 is the
dominant active acoustic source for twenty percent of the line-
kilometers and the EK60 is the dominant active acoustic source for the
other eighty percent. However, in the deeper depth stratum, the EK60 is
always the dominant source when compared with the ME70 (0.1411 km\2\
cross-sectional ensonified area versus 0.0201 km\2\ cross-sectional
ensonified area for the ME70; Table 8); therefore, the EK60 is the
dominant active acoustic source in the deeper depth stratum at all
times for the Shimada. However, of the total line-kilometers of NWFSC
survey activity aboard the Shimada, only forty percent are in waters
greater than 200 m.
Table 9--Annual Linear Survey Kilometers for Each Vessel and Its Predominant Sources Within Two Depth Strata
--------------------------------------------------------------------------------------------------------------------------------------------------------
Line-km/ Line-km/
Line-kms/ % time source dominant % time source dominant
Vessel vessel Source dominant (0- source (0-200 dominant (>200 source (>200
200 m) m) m) m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Lasker.................................................. 4,500 SX90 100 4,500 50 2,250
Shimada................................................. 18,494 ME70 20 3,699 0 0
.............. EK60 80 14,795 40 7,398
--------------------------------------------------------------------------------------------------------------------------------------------------------
Next, we provide volumetric densities for marine mammals in the
CCRA and total estimated takes by Level B harassment, by dominant
source and total, for each species in the CCRA (Table 10). We also
provide a sample calculation.
We first determine the source-specific ensonified volume of water
(i.e., the ensonified volume where we consider a specific source to be
predominant and therefore have the potential to harass marine mammals)
and then determine source- and species-specific exposure estimates for
the shallow and deep (if applicable; Table 10) depth strata. First, we
know the estimated source-specific cross-sectional ensonified area
within the shallow and deep strata (Table 8) and the number of annual
line-kilometers when a given source would be predominant in each
stratum and use these values to derive an estimated source-specific
ensonified volume. In order to estimate the additional volume of
ensonified water in the deep stratum, we first subtract the cross-
sectional ensonified area of the shallow stratum (which is already
accounted for) from that of the deep stratum. Source- and stratum-
specific exposure estimates are the product of these ensonified volumes
and the species-specific volumetric densities (Table 10).
To illustrate the process, we focus on the EK60 and the sperm
whale.
(1) EK60 ensonified volume; 0-200 m: 0.0142 km\2\ * 14,795 km =
210.1 km\3\
(2) EK60 ensonified volume; >200 m: (0.1411 km\2\ - 0.0142 km\2\) *
7,398 km = 938.8 km\3\
(3) Estimated exposures to sound >=160 dB rms; sperm whale; EK60:
(0.003 sperm whales/km\3\ * 210.1 km\3\ = 0.7 [rounded to 1]) + (0.003
sperm whales/km\3\ * 938.8 km\3\ = 3.2 [rounded to 3]) = 4 estimated
sperm whale exposures to SPLs >=160 dB rms resulting from use of the
EK60.
Table 10--Densities and Estimated Source-, Stratum-, and Species-Specific Annual Estimates of Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Area Volumetric Estimated Level B Estimated Level B
density density harassment, 0-200 m harassment, >200 m
Species Shallow Deep (animals/ (animals/ -------------------------------------------------- Total
km\2\) \1\ km\3\) \2\ EK60 ME70 SX90 EK60 SX90
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale................................. ......... X 0.002 0.003 1 0 1 3 1 6
[[Page 38555]]
Kogia spp................................... ......... X 0.001 0.002 0 0 1 2 0 3
Cuvier's beaked whale....................... ......... X 0.004 0.008 2 1 2 7 2 14
Baird's beaked whale........................ ......... X 0.001 0.002 0 0 1 2 0 3
Mesoplodont beaked whales................... ......... X 0.001 0.002 0 0 1 2 0 3
Bottlenose dolphin.......................... X ......... 0.002 0.009 2 1 3 0 0 6
Striped dolphin............................. X ......... 0.017 0.083 18 6 25 0 0 49
Long-beaked common dolphin.................. X ......... 0.019 0.096 20 7 28 0 0 55
Short-beaked common dolphin................. X ......... 0.309 1.547 325 115 455 0 0 895
Pacific white-sided dolphin................. X ......... 0.021 0.105 22 8 31 0 0 61
Northern right whale dolphin................ X ......... 0.010 0.049 10 4 14 0 0 28
Risso's dolphin............................. X ......... 0.010 0.052 11 4 15 0 0 30
Killer whale................................ X ......... 0.001 0.004 1 0 1 0 0 2
Short-finned pilot whale.................... ......... X 0.0003 0.001 0 0 0 1 0 1
Harbor porpoise............................. X ......... \4\ 0.038 0.189 40 14 56 0 0 110
Dall's porpoise............................. X ......... 0.076 0.378 79 28 111 0 0 218
Guadalupe fur seal.......................... X ......... \3\ 0.007 0.037 8 3 11 0 0 22
Northern fur seal........................... X ......... \3\ 0.649 3.245 682 241 955 0 0 1,878
California sea lion......................... X ......... \3\ 0.297 1.484 312 110 437 0 0 859
Steller sea lion............................ X ......... \3\ 0.060 0.301 63 22 89 0 0 174
Harbor seal................................. X ......... \3\ 0.056 0.279 59 21 82 0 0 162
Northern elephant seal...................... ......... X \3\ 0.179 0.358 75 27 105 336 79 622
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ All density estimates from Barlow and Forney (2007) unless otherwise indicated.
\2\ Volumetric density estimates derived by dividing area density estimates by 0.2 km (for shallow species) or 0.5 km (for deep species), corresponding
with defined depth strata.
\3\ Density estimates derived by NWFSC from SAR abundance estimates and notional study area of 1,000,000 km\2\.
\4\ ManTech-SRS Technologies (2007) estimated a harbor porpoise density for coastal and inland waters of Washington, which is used as the best available
proxy here. There are no known density estimates for harbor porpoises in NWFSC survey areas in the CCRA.
Estimated Take Due to Physical Disturbance
Estimated take due to physical disturbance could potentially happen
in the PSRA and LCRRA, and would result in no greater than Level B
harassment. It is likely that some pinnipeds will move or flush from
known haul-outs into the water in response to the presence or sound of
NWFSC vessels or researchers, as a result of unintentional approach
during survey activity. Behavioral responses may be considered
according to the scale shown in Table 11 and based on the method
developed by Mortenson (1996). We consider responses corresponding to
Levels 2-3 to constitute Level B harassment.
Table 11--Seal Response to Disturbance
------------------------------------------------------------------------
Type of
Level response Definition
------------------------------------------------------------------------
1........................... Alert.......... Seal head orientation or
brief movement in
response to disturbance,
which may include
turning head towards the
disturbance, craning
head and neck while
holding the body rigid
in a u-shaped position,
changing from a lying to
a sitting position, or
brief movement of less
than twice the animal's
body length.
2........................... Movement....... Movements away from the
source of disturbance,
ranging from short
withdrawals at least
twice the animal's body
length to longer
retreats over the beach.
3........................... Flight......... All retreats (flushes) to
the water.
------------------------------------------------------------------------
The NWFSC has estimated potential incidents of Level B harassment
due to physical disturbance (Table 12) by considering the number of
seals believed to potentially be present at affected haul-outs and the
number of visits expected to be made by NWFSC researchers. The number
of haul-outs disturbed and number of animals assumed to be on those
haul-outs was determined by NWFSC on the basis of anecdotal evidence
from researchers. Although not all individuals on ``disturbed'' haul-
outs would necessarily actually be disturbed, and some haul-outs may
experience some disturbance at distances greater than expected, we
believe that this approach is a reasonable effort towards accounting
for this potential source of disturbance.
[[Page 38556]]
Table 12--Estimated Annual Level B Harassment of Pinnipeds Associated With Disturbance by Researchers
----------------------------------------------------------------------------------------------------------------
Estimated
total number
of animals on Number of Estimated
Species Location potentially visits per annual Level B
disturbed haul- year harassment
outs
----------------------------------------------------------------------------------------------------------------
Harbor seal........................... Puget Sound............. 1,440 8 11,520
Columbia River.......... 3,000 25 75,000
California sea lion................... Puget Sound............. 350 8 2,800
----------------------------------------------------------------------------------------------------------------
Summary of Estimated Incidental Take
Here we provide a summary of the total proposed incidental take
authorization on an annual basis, as well other information relevant to
the negligible impact analysis. Table 13 shows information relevant to
our negligible impact analysis concerning the total annual taking that
could occur for each stock from NMFS' scientific research activities
when considering incidental take previously authorized for SWFSC (80 FR
58982; September 30, 2015) and take proposed for authorization for
NWFSC. As footnoted in Table 13, the indicated level of take could
occur to any species or stock for those species with multiple stocks
(e.g., Northern fur seal) or considered as a group (e.g., Mesoplodont
beaked whales). However, the harbor porpoise and harbor seal each have
multiple stocks spanning the three NWFSC research areas, and we provide
further detail regarding our consideration of potential take specific
to stocks that may occur in the PSRA and LCRRA. Many stocks do not
occur in those research areas and, therefore, would not be vulnerable
to interaction with research gear deployed in those areas.
For harbor porpoise, we propose to authorize a total of five takes
by M/SI + Level A for all stocks combined over the five-year period of
validity for these proposed regulations. For the purposes of the
negligible impact analysis, we assume that all of these takes could
potentially be in the form of M/SI; PBR is not intended for assessment
of the significance of harassment. These takes could occur to any
stock; however, our proposed take authorization is informed by
reasonable expectation regarding species vulnerability to gear used in
the three research areas. Of the five total takes, we expect that two
might occur in the CCRA, one in the PSRA, and two in the LCRRA.
Therefore, corresponding with the relationship between stock ranges and
the location of NWFSC research activities, the likely maximum takes
that could accrue to any harbor porpoise stock from California to
southern Oregon would be two, while the northern Oregon/Washington
coast stock could potentially accrue four takes because it is
vulnerable to the takes expected in either the CCRA or LCRRA. In Table
13 below, the proposed total take authorization column reflects the
total of four takes that could occur in either the CCRA or LCRRA (and
the one take expected in the PSRA, which would occur to the Washington
inland waters stock). However, the estimated maximum annual take column
reflects the annualized stock-specific risk, i.e., any stock in the CA-
southern OR grouping is expected to be vulnerable to a maximum of two
takes over the five-year period (0.4/year) while the northern OR/WA
coast stock could be vulnerable to as many as four takes over the five
years (0.8/year). This stock-specific accounting does not change our
expectation that a total of five takes would occur for all stocks
combined but informs our stock-specific negligible impact analysis.
Similarly, the harbor seal has separate designated stocks that may
occur in all three research areas. We propose to authorize a total of
thirteen takes by M/SI + Level A for all harbor seal stocks combined,
and expect that five of these may occur in the CCRA, six in the PSRA,
and two in the LCRRA. Therefore, while we would expect that a maximum
of five takes could accrue to the California stock, as many as seven
takes could occur for the Oregon/Washington coastal stock (which is the
only stock that may occur in the LCRRA). Although NMFS has split the
former Washington inland waters stock of harbor seals into three
separate stocks, we do not have sufficient information to assess stock-
specific risk in the PSRA. Separately, we have estimated that 162
incidents of acoustic harassment may occur for harbor seals due to
NWFSC use of active acoustic systems (in the CCRA only) and that, due
to the physical presence of researchers, individual harbor seals on
haul-outs (as many as 3,000) may be disturbed up to 25 times per year
in the LCRRA. Therefore, as shown in Table 13, the California stock of
harbor seals is vulnerable to only the estimated 162 acoustic
harassment takes, but the OR/WA coast stock would be vulnerable to both
the acoustic harassment takes as well as the physical disturbance
takes. However, note that the percent of estimated population is
calculated considering the number of individuals anticipated to be
disturbed rather than the number of incidents of disturbance.
We previously authorized take of marine mammals incidental to
fisheries research operations conducted by the SWFSC (see 80 FR 58982
and 80 FR 68512). This take would occur to some of the same stocks for
which we propose to authorize take incidental to NWFSC fisheries
research operations. Therefore, in order to evaluate the likely impact
of the take by M/SI proposed for authorization in this rule, we
consider not only other ongoing sources of human-caused mortality but
the potential mortality authorized for SWFSC. As used in this document,
other ongoing sources of human-caused (anthropogenic) mortality refers
to estimates of realized or actual annual mortality reported in the
SARs and does not include authorized or unknown mortality. Below, we
consider the total taking by M/SI proposed for authorization for NWFSC
and previously authorized for SWFSC together to produce a maximum
annual M/SI take level (including take of unidentified marine mammals
that could accrue to any relevant stock) and compare that value to the
stock's PBR value, considering ongoing sources of anthropogenic
mortality (as described in footnote 4 of Table 13 and in the following
discussion). PBR and annual M/SI values considered in Table 13 reflect
the most recent information available (i.e., final 2014 and draft 2015
SARs, as appropriate).
[[Page 38557]]
Table 13--Summary Information Related to NWFSC Proposed Annual Take Authorization, 2016-21
--------------------------------------------------------------------------------------------------------------------------------------------------------
Proposed total
annual Level B Percent of Proposed total M/ SWFSC total M/SI Estimated
Species \1\ harassment estimated SI \3\ authorization, maximum annual M/ PBR minus annual Stock
authorization population authorization, 2015-20 SI \4\ M/SI (%) \5\ trend \6\
\2\ abundance 2016-21
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale...................... 6 0.3 0 0 0 n/a ?
Kogia spp........................ 3 0.5 1 1 0.4 2.7 (14.8) ?
Cuvier's beaked whale............ 14 0.2 0 0 0 n/a [darr]
Baird's beaked whale............. 3 0.4 0 0 0 n/a ?
Mesoplodont beaked whales........ 3 0.4 0 0 0 n/a [darr]
Bottlenose dolphin (offshore 6 0.6 2 9 2.6 3.5 (74.3) ?
stock)..........................
Striped dolphin.................. 49 0.4 7 12 4.2 82 (5.1) ?
Long-beaked common dolphin....... 55 0.1 2 12 3.2 596.2 (0.5) [uarr]
Short-beaked common dolphin...... 895 0.2 3 12 3.4 3,376 (0.1) ?
Pacific white-sided dolphin...... 61 0.2 31 35 13.6 159.2 (8.5) ?
Northern right whale dolphin..... 28 0.3 7 10 3.8 44.4 (8.6) ?
Risso's dolphin.................. 30 0.5 8 12 4.4 37.4 (11.8) ?
Killer whale \7\................. 2 0.8 0 0 0 n/a ?
Short-finned pilot whale......... 1 0.1 1 1 0.4 4.6 (8.7) ?
Harbor porpoise (CA-southern OR 110 3.8 4 5 1.8 20.4 (8.8) ?
stocks) \7\.....................
Harbor porpoise (Northern OR/WA ................ ................ ................ ................ 2.2 148 (1.5) ?
coast)..........................
Harbor porpoise (WA inland 0 n/a 1 0 0.2 60.8 (0.3) ?
waters).........................
Dall's porpoise.................. 218 0.5 3 5 2 256.6 (0.8) ?
Guadalupe fur seal............... 22 0.3 0 0 0 n/a [uarr]
Northern fur seal \6\............ \8\ 1,878 0.3 5 5 2.4 449.4 (0.5) [uarr]
California sea lion.............. 3,659 0.4 10 25 7.6 8,815 (0.1) [uarr]
Steller sea lion................. 174 \8\ 0.3 9 10 4.4 1,552.7 (0.3) [uarr]
Harbor seal (CA)................. 75,162 0.6 5 9 3.2 1,598 (0.2) [rarr]
Harbor seal (OR/WA coast)........ ................ 12.8 2 ................ 1.8 Unknown [rarr]
Harbor seal (WA inland waters)... 11,520 10.5 6 0 1.2 Unknown [rarr]
Northern elephant seal........... 622 0.3 5 5 2.2 4,873.2 (0.1) [uarr]
Unidentified small cetacean...... n/a n/a 1 1 n/a n/a n/a
Unidentified pinniped............ n/a n/a 1 2 n/a n/a n/a
--------------------------------------------------------------------------------------------------------------------------------------------------------
Please see Tables 7, 10, and 12 and preceding text for details.
\1\ For species with multiple stocks or for species groups (Kogia spp. and Mesoplodont beaked whales), indicated level of take could occur to
individuals from any stock or species except as indicated in table.
\2\ Level B harassment totals include estimated take due to acoustic harassment and, for harbor seals and California sea lions, estimated take due to
physical disturbance. Active acoustic devices are not used for data acquisition in the PSRA; therefore, no takes by acoustic harassment are expected
for stocks that occur entirely or largely in inland waters (e.g., resident killer whales). Takes by physical disturbance for pinniped species
represent repeated takes of smaller numbers of individuals (e.g., we expect as many as 1,440 harbor seals in the PSRA to be harassed on as many as
eight occasions). The ``percent of estimated population'' column represents this smaller number of individuals taken rather than the total number of
take incidents.
\3\ As explained earlier in this document, gear interaction could result in mortality, serious injury, or Level A harassment. Because we do not have
sufficient information to enable us to parse out these outcomes, we present such take as a pool. For purposes of this negligible impact analysis we
assume the worst case scenario (that all such takes result in mortality).
\4\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock as a result of NMFS'
fisheries research activities and is the number carried forward for evaluation in the negligible impact analysis (later in this document). To reach
this total, we add one to the total for each pinniped or cetacean that may be captured in trawl gear in the CCRA. This represents the potential that
the take of an unidentified pinniped or small cetacean could accrue to any given stock captured in that gear in that area. The proposed take
authorization is formulated as a five-year total; the annual average is used only for purposes of negligible impact analysis. We recognize that
portions of an animal may not be taken in a given year.
\5\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/
SI, which is presented in the SARs) (see Table 3). For the Pacific-white sided dolphin, harbor seal, and California sea lion, we subtract the annual
average of mortalities occurring incidental to NWFSC fisheries research during 2007-11 from the total human-caused M/SI prior to calculating this
value, as we explicitly account for predicted future mortalities incidental to NWFSC fisheries research via the estimated maximum annual M/SI + Level
A column. In parentheses, we provide the estimated maximum annual M/SI expressed as a percentage of this value.
\6\ See relevant SARs for more information regarding stock status and trends. Interannual increases may not be interpreted as evidence of a trend. Based
on the most recent abundance estimates, harbor seal stocks may have reached carrying capacity and appear stable. A time series of stock-specific
abundance estimates for harbor porpoise shows either increasing or stable estimates, but it is not statistically valid to infer a trend.
\7\ These species have multiple stocks that may be affected. Values for ``percent of estimated population'' and ``PBR--annual M/SI'' (where relevant)
calculated for the stock with the lowest population abundance and/or PBR (as appropriate). This approach assumes that all indicated takes would accrue
to the stock in question, which is a very conservative assumption. Stocks in question are the offshore killer whale, Morro Bay harbor porpoise, and
California northern fur seal.
\8\ A range is provided for Steller sea lion abundance. We have used the lower bound of the given range for calculation of this value.
\8\ Calculated on the basis of relative abundance; i.e., of 1,878 total estimated incidents of Level B harassment, we would expect on the basis of
relative abundance in the study area that 98 percent would accrue to the Pribilof Islands/Eastern Pacific stock and two percent would accrue to the
California stock.
[[Page 38558]]
Analyses and Preliminary Determinations
Negligible Impact Analysis
Introduction--NMFS has defined ``negligible impact'' in 50 CFR
216.103 as ``. . . an impact resulting from the specified activity that
cannot be reasonably expected to, and is not reasonably likely to,
adversely affect the species or stock through effects on annual rates
of recruitment or survival.'' A negligible impact finding is based on
the lack of likely adverse effects on annual rates of recruitment or
survival (i.e., population-level effects). An estimate of the number of
takes alone is not enough information on which to base an impact
determination. In addition to considering estimates of the number of
marine mammals that might be ``taken'' by mortality, serious injury,
and Level A or Level B harassment, we consider other factors, such as
the likely nature of any behavioral responses (e.g., intensity,
duration), the context of any such responses (e.g., critical
reproductive time or location, migration), as well as effects on
habitat. We also assess the number, intensity, and context of estimated
takes by evaluating this information relative to population status
(i.e., the environmental baseline).
Consistent with the 1989 preamble for NMFS' implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into these
analyses via their impacts on the environmental baseline (e.g., as
reflected in the regulatory status of the species, population size and
growth rate where known, other ongoing sources of human-caused
mortality, and specific consideration of take by M/SI + Level A
previously authorized for other NMFS research activities).
In 1988, Congress amended the MMPA, with provisions for the
incidental take of marine mammals in commercial fishing operations.
Congress directed NMFS to develop and recommend a new long-term regime
to govern such incidental taking (see MMC, 1994). The need to set
allowable take levels incidental to commercial fishing operations led
NMFS to suggest a new conceptual means for assuring that incidental
take does not cause any marine mammal species or stock to be reduced or
to be maintained below the lower limit of its Optimum Sustainable
Population (OSP) level. That concept, potential biological removal
(PBR), was incorporated in the 1994 amendments to the MMPA, wherein
Congress enacted MMPA sections 117 and 118, establishing a new regime
governing the incidental taking of marine mammals in commercial fishing
operations and stock assessments.
PBR, which is defined by the MMPA (16 U.S.C. 1362(20)) as ``the
maximum number of animals, not including natural mortalities, that may
be removed from a marine mammal stock while allowing that stock to
reach or maintain its optimum sustainable population,'' is one tool
that can be used to help evaluate the effects of M/SI on a marine
mammal stock. OSP is defined by the MMPA (16 U.S.C. 1362(9)) as ``the
number of animals which will result in the maximum productivity of the
population or the species, keeping in mind the carrying capacity of the
habitat and the health of the ecosystem of which they form a
constituent element.'' A primary goal of the MMPA is to ensure that
each stock of marine mammal either does not have a level of human-
caused M/SI that is likely to cause the stock to be reduced below its
OSP level or, if the stock is depleted (i.e., below its OSP level),
does not have a level of human-caused mortality and serious injury that
is likely to delay restoration of the stock to OSP level by more than
ten percent in comparison with recovery time in the absence of human-
caused M/SI.
PBR, a parametric concept that relates survivorship to population
size, was developed in consideration of the principle given by Holt and
Talbot (1978): ``Management decisions should include a safety factor to
allow for the facts that knowledge is limited and institutions are
imperfect'' (Taylor, 1993). PBR values are calculated by NMFS as the
level of annual removal from a stock that will allow that stock to
equilibrate within OSP at least 95 percent of the time, and is the
product of factors relating to the minimum population estimate of the
stock (Nmin); the productivity rate of the stock at a small
population size; and a recovery factor. Determination of appropriate
values for these three elements incorporates significant precaution,
such that application of the parameter to the management of marine
mammal stocks may be reasonably certain to achieve the goals of the
MMPA. For example, calculation of Nmin incorporates the
precision and variability associated with abundance information and is
intended to provide reasonable assurance that the stock size is equal
to or greater than the estimate (Barlow et al., 1995). In general, the
three factors are developed on a stock-specific basis in consideration
of one another in order to produce conservative PBR values that
appropriately account for both imprecision that may be estimated as
well as potential bias stemming from lack of knowledge (Wade, 1998).
PBR was not designed as an absolute threshold limiting human
activities, but as a means to evaluate the relative impacts of those
activities on marine mammal stocks. Specifically, assessing M/SI
relative to a stock's PBR may signal to NMFS the need to establish take
reduction teams in commercial fisheries and may assist NMFS and
existing take reduction teams in the identification of measures to
reduce and/or minimize the taking of marine mammals by commercial
fisheries to a level below a stock's PBR. That is, where the total
annual human-caused M/SI exceeds PBR, NMFS is not required to halt
fishing activities contributing to total M/SI but rather may prioritize
working with a take reduction team to further mitigate the effects of
fishery activities via additional bycatch reduction measures. In
addition, PBR alone is not used to authorize or deny authorization of
commercial fisheries that may incidentally take marine mammals.
Since the introduction of PBR, NMFS has used the concept almost
entirely within the context of implementing sections 117 and 118 and
other commercial fisheries management-related provisions of the MMPA,
including those within section 101(a)(5)(E) related to the taking of
ESA-listed marine mammals incidental to commercial fisheries (64 FR
28800; May 27, 1999). The MMPA requires that PBR be estimated in stock
assessment reports and that it be used in applications related to the
management of take incidental to commercial fisheries (i.e., the take
reduction planning process described in section 118 of the MMPA and the
determination of whether a stock is ``strategic'' [16 U.S.C.
1362(19)]), but nothing in the MMPA requires the application of PBR
outside the management of commercial fisheries interactions with marine
mammals. Although NMFS has not historically applied PBR outside the
context of sections 117, 118, and 101(a)(5)(E), NMFS recognizes that as
a quantitative tool, PBR may be useful in certain instances for
evaluating the impacts of other human-caused activities on marine
mammal stocks.
Our use of PBR here (for NWFSC fisheries research activities) does
not make up the entirety of our impact assessment, but rather is being
utilized as a known, quantitative metric for evaluating whether the
proposed activities are likely to have a population-level effect on the
affected
[[Page 38559]]
marine mammal stocks. Here, we calculate a metric that incorporates
information regarding ongoing anthropogenic mortality into the PBR
value; i.e., PBR minus the reported annual anthropogenic mortality
estimate (also referred to as ``residual PBR''; Wood et al., 2012). We
first consider maximum potential incidental M/SI for NMFS research
relative to this metric for each affected stock (see Table 13), in
consideration of NMFS' defined significance threshold for M/SI (ten
percent of PBR [69 FR 43338; July 20, 2004]). By considering the
maximum potential incidental M/SI in relation to PBR and other ongoing
sources of anthropogenic mortality, we ensure that the potential
incremental addition of M/SI through NMFS' fisheries research
activities does not pose a risk to the stock that bears further
consideration here. We also consider the interaction of those removals
with incidental taking of that stock by harassment pursuant to the
specified activity (i.e., NWFSC fisheries research activities).
Therefore, for those stocks with total incidental M/SI less than
the significance threshold (i.e., ten percent of residual PBR), we
consider the effects of the specified activity to represent an
insignificant incremental increase in ongoing anthropogenic M/SI and
need not consider other factors in making a negligible impact
determination except in combination with additional incidental take by
harassment. For those stocks with incidental M/SI exceeding the
significance threshold, we will consider additional factors that may
either increase or reduce the level of concern related to the
significance of a given level of taking--such as implementation of
mitigation measures or additional population stressors--in addition to
considering the interaction of those removals with incidental taking of
that stock by harassment.
Analysis--Please see Table 13 for information related to this
analysis. The large majority of stocks that may potentially be taken by
M/SI + Level A (18 of 21) fall below the significance threshold, while
an additional four stocks do not have current PBR values and therefore
are evaluated using other factors. We first consider stocks expected to
be affected only by behavioral harassment and those stocks that fall
below the significance threshold. Next, we consider those stocks above
the significance threshold (i.e., Kogia spp.; the offshore stock of
bottlenose dolphin, and Risso's dolphin) and those without PBR values
(harbor seals along the Oregon and Washington coasts and in Washington
inland waters).
As described in greater depth previously (see ``Acoustic
Effects''), we do not believe that NWFSC use of active acoustic sources
has the likely potential to cause any effect exceeding Level B
harassment of marine mammals. In addition, for the majority of species,
the proposed annual take by Level B harassment is very low in relation
to the population abundance estimate (less than one percent). We have
produced what we believe to be precautionary estimates of potential
incidents of Level B harassment. The procedure for producing these
estimates, described in detail in ``Estimated Take Due to Acoustic
Harassment,'' represents NMFS' best effort towards balancing the need
to quantify the potential for occurrence of Level B harassment due to
production of underwater sound with a general lack of information
related to the specific way that these acoustic signals, which are
generally highly directional and transient, interact with the physical
environment and to a meaningful understanding of marine mammal
perception of these signals and occurrence in the areas where NWFSC
operates. The sources considered here have moderate to high output
frequencies (10 to 180 kHz), generally short ping durations, and are
typically focused (highly directional) to serve their intended purpose
of mapping specific objects, depths, or environmental features. In
addition, some of these sources can be operated in different output
modes (e.g., energy can be distributed among multiple output beams)
that may lessen the likelihood of perception by and potential impacts
on marine mammals in comparison with the quantitative estimates that
guide our proposed take authorization.
In addition, otariid pinnipeds are less likely than other taxa to
perceive acoustic signals generated by NWFSC or, given perception, to
react to these signals than the quantitative estimates indicate. This
group of pinnipeds has reduced functional hearing at the higher
frequencies produced by active acoustic sources considered here (e.g.,
primary operating frequencies of 40-180 kHz) and, based purely on their
auditory capabilities, the potential impacts are likely much less than
we have calculated as these relevant factors are not taken into
account.
As described previously, there is some minimal potential for
temporary effects to hearing for certain marine mammals, but most
effects would likely be limited to temporary behavioral disturbance.
Effects on individuals that are taken by Level B harassment will likely
be limited to reactions such as increased swimming speeds, increased
surfacing time, or decreased foraging (if such activity were
occurring), reactions that are considered to be of low severity (e.g.,
Southall et al., 2007). Individuals may move away from the source if
disturbed, but because the source is itself moving and because of the
directional nature of the sources considered here, there is unlikely to
be even temporary displacement from areas of significance and any
disturbance would be of short duration. Although there is no
information on which to base any distinction between incidents of
harassment and individuals harassed, the same factors, in conjunction
with the fact that NWFSC survey effort is widely dispersed in space and
time, indicate that repeated exposures of the same individuals would be
very unlikely. For these reasons, we do not consider the proposed level
of take by acoustic disturbance to represent a significant additional
population stressor when considered in context with the proposed level
of take by M/SI + Level A for any species.
Similarly, disturbance of pinnipeds on haul-outs by researchers
approaching on foot or in small vessels (as is expected for harbor
seals in the lower Columbia River and Puget Sound and for California
sea lions in Puget Sound) are expected to be infrequent and cause only
a temporary disturbance on the order of minutes. As noted previously,
monitoring results from other activities involving the disturbance of
pinnipeds and relevant studies of pinniped populations that experience
more regular vessel disturbance indicate that individually significant
or population level impacts are unlikely to occur. When considering the
individual animals likely affected by this disturbance, only a small
fraction (less than fifteen percent) of the estimated population
abundance of the affected stocks would be expected to experience the
disturbance.
For Kogia spp. and Risso's dolphin, maximum total potential M/SI
due to NMFS' fisheries research activity (SWFSC and NWFSC combined)
approaches fifteen and twelve percent of residual PBR, respectively.
There are no other known sources of anthropogenic M/SI for Kogia spp.
The only known source of other anthropogenic mortality for Risso's
dolphin is in commercial fisheries, but such take is considered to be
insignificant and approaching zero mortality and serious injury. For
example, PBR for Risso's dolphin is currently set at 39 and the annual
average of known ongoing anthropogenic M/SI is 1.6, yielding a residual
PBR value of 37.4. The
[[Page 38560]]
maximum combined annual average M/SI incidental to NMFS fisheries
research activity is 4.4, or 11.8 percent of residual PBR.
M/SI incidental to NMFS' fisheries research activities could be as
much as 74 percent of residual PBR for the offshore stock of bottlenose
dolphin, assuming a worst-case scenario in which take of an
unidentified cetacean is applied to this stock. Fisheries bycatch of
this stock occurs on an annual basis, though this ongoing level of M/SI
is accounted for. The majority of takes in commercial fisheries from
2007-11 were due to interactions with the California drift gillnet
fishery, and it is possible that these interactions have declined since
the use of acoustic pingers was required. Any level of removals up to
PBR could occur while still allowing the stock to reach or maintain its
optimum sustainable population, as indicated in the definition of the
PBR metric. Nevertheless, given the small PBR value, fluctuation in the
amount of incidental take could result in unsustainable levels of
removal from the stock. If bycatch in commercial fisheries increases,
or other sources of mortality are recorded for this stock, we will use
the adaptive management provisions of the proposed regulations to
prescribe increased mitigation sufficient to reduce the likelihood of
incidental take in NMFS fisheries research activities. No population
trends are known for these three stocks.
PBR is unknown for harbor seals on the Oregon and Washington coasts
and in Washington inland waters (comprised of the Hood Canal, southern
Puget Sound, and Washington northern inland waters stocks). The Hood
Canal, southern Puget Sound, and Washington northern inland waters
stocks were formerly a single inland waters stock. Both the Oregon/
Washington coast and Washington inland waters stocks of harbor seal
were considered to be stable following the most recent abundance
estimates (in 1999, stock abundances were estimated at 24,732 and
13,692, respectively). However, a Washington Department of Fish and
Wildlife expert (S. Jeffries) stated an unofficial abundance of 32,000
harbor seals in Washington (Mapes, 2013). Therefore, it is reasonable
to assume that at worst, the stocks have not declined since the last
abundance estimates. Ongoing anthropogenic mortality is estimated at
10.6 harbor seals per year for the coastal stock and 13.4 for inland
waters seals; therefore, we reasonably assume that the maximum
potential annual M/SI incidental to NMFS' fisheries research activities
(1.8 and 1.2, respectively) is a small fraction of any sustainable take
level that might be calculated for either stock. For the reasons stated
above, we do not consider the proposed level of take by acoustic and
physical disturbance for harbor seals to represent a significant
additional population stressor when considered in context with the
proposed level of take by M/SI.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the planned mitigation measures, we
preliminarily find that the total marine mammal take from NWFSC's
fisheries research activities will have a negligible impact on the
affected marine mammal species or stocks. In summary, this finding of
negligible impact is founded on the following factors: (1) The
possibility of injury, serious injury, or mortality from the use of
active acoustic devices may reasonably be considered discountable; (2)
the anticipated incidents of Level B harassment from the use of active
acoustic devices and physical disturbance of pinnipeds consist of, at
worst, temporary and relatively minor modifications in behavior; (3)
the predicted number of incidents of potential mortality are at
insignificant levels (i.e., below ten percent of residual PBR) for a
majority of affected stocks; (4) consideration of additional factors
for Kogia spp. and Risso's dolphin do not reveal cause for concern; (5)
total maximum potential M/SI incidental to NMFS fisheries research
activity for bottlenose dolphin, considered in conjunction with other
sources of ongoing mortality, is currently sustainable because it is
below the residual PBR level; (6) available information regarding two
harbor seal stocks indicates that total maximum potential M/SI is
sustainable; and (7) the presumed efficacy of the planned mitigation
measures in reducing the effects of the specified activity to the level
of least practicable adverse impact. In addition, no M/SI is proposed
for authorization for any species or stock that is listed under the ESA
or considered depleted under the MMPA. In combination, we believe that
these factors demonstrate that the specified activity will have only
short-term effects on individuals (resulting from Level B harassment)
and that the total level of taking will not impact rates of recruitment
or survival sufficiently to result in population-level impacts.
Small Numbers Analysis
Please see Table 13 for information relating to this small numbers
analysis. The total amount of taking proposed for authorization is less
than one percent for a large majority of stocks. The total amount of
taking for remaining stocks ranges from four to thirteen percent.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed mitigation measures,
we preliminarily find that small numbers of marine mammals will be
taken relative to the populations of the affected species or stocks.
Proposed Monitoring and Reporting
In order to issue an incidental take authorization for an activity,
section 101(a)(5)(A) of the MMPA states that NMFS must set forth
``requirements pertaining to the monitoring and reporting of such
taking.'' The MMPA implementing regulations at 50 CFR 216.104 (a)(13)
indicate that requests for incidental take authorizations must include
the suggested means of accomplishing the necessary monitoring and
reporting that will result in increased knowledge of the species and of
the level of taking or impacts on populations of marine mammals that
are expected to be present in the proposed action area.
Any monitoring requirement we prescribe should improve our
understanding of one or more of the following:
Occurrence of marine mammal species in action area (e.g.,
presence, abundance, distribution, density).
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving, or feeding areas).
Individual responses to acute stressors, or impacts of
chronic exposures (behavioral or physiological).
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of an individual; or (2) population,
species, or stock.
Effects on marine mammal habitat and resultant impacts to
marine mammals.
Mitigation and monitoring effectiveness.
NWFSC plans to make more systematic its training, operations, data
collection, animal handling and
[[Page 38561]]
sampling protocols, etc. in order to improve its ability to understand
how mitigation measures influence interaction rates and ensure its
research operations are conducted in an informed manner and consistent
with lessons learned from those with experience operating these gears
in close proximity to marine mammals. It is in this spirit that we
propose the monitoring requirements described below.
Visual Monitoring
Marine mammal watches are a standard part of conducting fisheries
research activities, and are implemented as described previously in
``Proposed Mitigation.'' Dedicated marine mammal visual monitoring
occurs as described (1) for some period prior to deployment of most
research gear; (2) throughout deployment and active fishing of all
research gears; (3) for some period prior to retrieval of longline
gear; and (4) throughout retrieval of all research gear. This visual
monitoring is performed by trained NWFSC personnel with no other
responsibilities during the monitoring period. Observers record the
species and estimated number of animals present and their behaviors,
which may be valuable information towards an understanding of whether
certain species may be attracted to vessels or certain survey gears.
Separately, marine mammal watches are conducted by watch-standers
(those navigating the vessel and other crew; these will typically not
be NWFSC personnel) at all times when the vessel is being operated. The
primary focus for this type of watch is to avoid striking marine
mammals and to generally avoid navigational hazards. These watch-
standers typically have other duties associated with navigation and
other vessel operations and are not required to record or report to the
scientific party data on marine mammal sightings, except when gear is
being deployed or retrieved.
In the PSRA and LCRRA only, the NWFSC will monitor any potential
disturbance of hauled-out pinnipeds, paying particular attention to the
distance at which different species of pinniped are disturbed.
Disturbance will be recorded according to the three-point scale,
representing increasing seal response to disturbance, shown in Table
11.
Training
NWFSC anticipates that additional information on practices to avoid
marine mammal interactions can be gleaned from training sessions and
more systematic data collection standards. The NWFSC will conduct
annual trainings for all chief scientists and other personnel who may
be responsible for conducting dedicated marine mammal visual
observations to explain mitigation measures and monitoring and
reporting requirements, mitigation and monitoring protocols, marine
mammal identification, recording of count and disturbance observations
(relevant to AMLR surveys), completion of datasheets, and use of
equipment. Some of these topics may be familiar to NWFSC staff, who may
be professional biologists; the NWFSC shall determine the agenda for
these trainings and ensure that all relevant staff have necessary
familiarity with these topics. The first training such will include
three primary elements:
First, the course will provide an overview of the purpose and need
for the authorization, including mandatory mitigation measures by gear
and the purpose for each, and species that NWFSC is authorized to
incidentally take.
Second, the training will provide detailed descriptions of
reporting, data collection, and sampling protocols. This portion of the
training will include instruction on how to complete new data
collection forms such as the marine mammal watch log, the incidental
take form (e.g., specific gear configuration and details relevant to an
interaction with protected species), and forms used for species
identification and biological sampling. The biological data collection
and sampling training module will include the same sampling and
necropsy training that is used for the West Coast Regional Observer
training.
NWFSC will also dedicate a portion of training to discussion of
best professional judgment (which is recognized as an integral
component of mitigation implementation; see ``Proposed Mitigation''),
including use in any incidents of marine mammal interaction and
instructive examples where use of best professional judgment was
determined to be successful or unsuccessful. We recognize that many
factors come into play regarding decision-making at sea and that it is
not practicable to simplify what are inherently variable and complex
situational decisions into rules that may be defined on paper. However,
it is our intent that use of best professional judgment be an iterative
process from year to year, in which any at-sea decision-maker (i.e.,
responsible for decisions regarding the avoidance of marine mammal
interactions with survey gear through the application of best
professional judgment) learns from the prior experience of all relevant
NWFSC personnel (rather than from solely their own experience). The
outcome should be increased transparency in decision-making processes
where best professional judgment is appropriate and, to the extent
possible, some degree of standardization across common situations, with
an ultimate goal of reducing marine mammal interactions. It is the
responsibility of the NWFSC to facilitate such exchange.
Handling Procedures and Data Collection
Improved standardization of handling procedures were discussed
previously in ``Proposed Mitigation.'' In addition to the benefits
implementing these protocols are believed to have on the animals
through increased post-release survival, NWFSC believes adopting these
protocols for data collection will also increase the information on
which ``serious injury'' determinations (NMFS, 2012a, b) are based and
improve scientific knowledge about marine mammals that interact with
fisheries research gears and the factors that contribute to these
interactions. NWFSC personnel will be provided standard guidance and
training regarding handling of marine mammals, including how to
identify different species, bring an individual aboard a vessel, assess
the level of consciousness, remove fishing gear, return an individual
to water and log activities pertaining to the interaction.
NWFSC will record interaction information on either existing data
forms created by other NMFS programs or will develop their own
standardized forms. To aid in serious injury determinations and comply
with the current NMFS Serious Injury Guidelines (NMFS, 2012a, b),
researchers will also answer a series of supplemental questions on the
details of marine mammal interactions.
Finally, for any marine mammals that are killed during fisheries
research activities, scientists will collect data and samples pursuant
to Appendix D of the NWFSC DEA, ``Protected Species Handling Procedures
for NWFSC Fisheries Research Vessels.''
Reporting
As is normally the case, NWFSC will coordinate with the relevant
stranding coordinators for any unusual marine mammal behavior and any
stranding, beached live/dead, or floating marine mammals that are
encountered during field research activities. The NWFSC will follow a
phased approach with regard to the cessation of its activities and/or
reporting of such events, as
[[Page 38562]]
described in the proposed regulatory texts following this preamble. In
addition, Chief Scientists (or cruise leader, CS) will provide reports
to NWFSC leadership and to the Office of Protected Resources (OPR). As
a result, when marine mammals interact with survey gear, whether killed
or released alive, a report provided by the CS will fully describe any
observations of the animals, the context (vessel and conditions),
decisions made and rationale for decisions made in vessel and gear
handling. The circumstances of these events are critical in enabling
NWFSC and OPR to better evaluate the conditions under which takes are
most likely occur. We believe in the long term this will allow the
avoidance of these types of events in the future.
The NWFSC will submit annual summary reports to OPR including: (1)
Annual line-kilometers surveyed during which the EK60, ME70, SX90 (or
equivalent sources) were predominant (see ``Estimated Take by Acoustic
Harassment'' for further discussion), specific to each region; (2)
summary information regarding use of all hook and line, seine, and
trawl gear, including number of sets, hook hours, tows, etc., specific
to each research area and gear; (3) accounts of all incidents of marine
mammal interactions, including circumstances of the event and
descriptions of any mitigation procedures implemented or not
implemented and why; (4) summary information related to any disturbance
of pinnipeds, including event-specific total counts of animals present,
counts of reactions according to the three-point scale shown in Table
11, and distance of closest approach; and (5) a written evaluation of
the effectiveness of NWFSC mitigation strategies in reducing the number
of marine mammal interactions with survey gear, including best
professional judgment and suggestions for changes to the mitigation
strategies, if any. The period of reporting will be annually, beginning
one year post-issuance of any LOA, and the report must be submitted not
less than ninety days following the end of a given year. Submission of
this information is in service of an adaptive management framework
allowing NMFS to make appropriate modifications to mitigation and/or
monitoring strategies, as necessary, during the proposed five-year
period of validity for these regulations.
NMFS has established a formal incidental take reporting system, the
Protected Species Incidental Take (PSIT) database, requiring that
incidental takes of protected species be reported within 48 hours of
the occurrence. The PSIT generates automated messages to NMFS
leadership and other relevant staff, alerting them to the event and to
the fact that updated information describing the circumstances of the
event has been inputted to the database. The PSIT and CS reports
represent not only valuable real-time reporting and information
dissemination tools, but also serve as an archive of information that
may be mined in the future to study why takes occur by species, gear,
region, etc.
NWFSC will also collect and report all necessary data, to the
extent practicable given the primacy of human safety and the well-being
of captured or entangled marine mammals, to facilitate serious injury
(SI) determinations for marine mammals that are released alive. NWFSC
will require that the CS complete data forms and address supplemental
questions, both of which have been developed to aid in SI
determinations. NWFSC understands the critical need to provide as much
relevant information as possible about marine mammal interactions to
inform decisions regarding SI determinations. In addition, the NWFSC
will perform all necessary reporting to ensure that any incidental M/SI
is incorporated as appropriate into relevant SARs.
Adaptive Management
The regulations governing the take of marine mammals incidental to
NWFSC fisheries research survey operations would contain an adaptive
management component. The inclusion of an adaptive management component
will be both valuable and necessary within the context of five-year
regulations for activities that have been associated with marine mammal
mortality.
The reporting requirements associated with this proposed rule are
designed to provide OPR with monitoring data from the previous year to
allow consideration of whether any changes are appropriate. OPR and the
NWFSC will meet annually to discuss the monitoring reports and current
science and whether mitigation or monitoring modifications are
appropriate. The use of adaptive management allows OPR to consider new
information from different sources to determine (with input from the
NWFSC regarding practicability) on an annual or biennial basis if
mitigation or monitoring measures should be modified (including
additions or deletions). Mitigation measures could be modified if new
data suggests that such modifications would have a reasonable
likelihood of reducing adverse effects to marine mammals and if the
measures are practicable.
The following are some of the possible sources of applicable data
to be considered through the adaptive management process: (1) Results
from monitoring reports, as required by MMPA authorizations; (2)
results from general marine mammal and sound research; and (3) any
information which reveals that marine mammals may have been taken in a
manner, extent, or number not authorized by these regulations or
subsequent LOAs.
Impact on Availability of Affected Species for Taking for Subsistence
Uses
There are no relevant subsistence uses of marine mammals implicated
by these actions. Therefore, we have determined that the total taking
of affected species or stocks would not have an unmitigable adverse
impact on the availability of such species or stocks for taking for
subsistence purposes.
Endangered Species Act (ESA)
There are multiple marine mammal species listed under the ESA with
confirmed or possible occurrence in the proposed specified geographical
region (see Table 3). The proposed authorization of incidental take
pursuant to the NWFSC's specified activity would not affect any
designated critical habitat. OPR has initiated consultation with NMFS'
West Coast Regional Office under section 7 of the ESA on the
promulgation of five-year regulations and the subsequent issuance of
LOAs to NWFSC under section 101(a)(5)(A) of the MMPA. This consultation
will be concluded prior to issuing any final rule.
National Environmental Policy Act (NEPA)
The NWFSC has prepared a Draft Environmental Assessment (EA; Draft
Programmatic Environmental Assessment for Fisheries Research Conducted
and Funded by the Northwest Fisheries Science Center) in accordance
with NEPA and the regulations published by the Council on Environmental
Quality. It is posted on the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm. We have independently evaluated the Draft EA
and are proposing to adopt it. We may prepare a separate NEPA analysis
and incorporate relevant portions of NWFSC's EA by reference.
Information in NWFSC's application, EA and this notice collectively
provide the environmental information related to proposed issuance of
these regulations for public review and comment. We will review all
comments submitted in response to this notice as we complete the NEPA
process, including a decision
[[Page 38563]]
of whether to sign a Finding of No Significant Impact, prior to a final
decision on the incidental take authorization request.
Request for Information
NMFS requests interested persons to submit comments, information,
and suggestions concerning the NWFSC request and the proposed
regulations (see ADDRESSES). All comments will be reviewed and
evaluated as we prepare final rules and make final determinations on
whether to issue the requested authorizations. This notice and
referenced documents provide all environmental information relating to
our proposed action for public review.
Classification
Pursuant to the procedures established to implement Executive Order
12866, the Office of Management and Budget has determined that this
proposed rule is not significant.
Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA),
the Chief Counsel for Regulation of the Department of Commerce has
certified to the Chief Counsel for Advocacy of the Small Business
Administration that this proposed rule, if adopted, would not have a
significant economic impact on a substantial number of small entities.
NMFS is the sole entity that would be subject to the requirements in
these proposed regulations, and NMFS is not a small governmental
jurisdiction, small organization, or small business, as defined by the
RFA. Because of this certification, a regulatory flexibility analysis
is not required and none has been prepared.
This proposed rule does not contain a collection-of-information
requirement subject to the provisions of the Paperwork Reduction Act
(PRA) because the applicant is a federal agency. Notwithstanding any
other provision of law, no person is required to respond to nor shall a
person be subject to a penalty for failure to comply with a collection
of information subject to the requirements of the PRA unless that
collection of information displays a currently valid OMB control
number. These requirements have been approved by OMB under control
number 0648-0151 and include applications for regulations, subsequent
LOAs, and reports.
List of Subjects in 50 CFR Part 219
Exports, Fish, Imports, Indians, Labeling, Marine mammals,
Penalties, Reporting and recordkeeping requirements, Seafood,
Transportation.
Dated: June 6, 2016.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
For reasons set forth in the preamble, 50 CFR part 219 is proposed
to be amended as follows:
PART 219--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE
MAMMALS
0
1. The authority citation for part 219 continues to read as follows:
Authority: 16 U.S.C. 1361 et seq.
Subpart D [Reserved]
0
2. Add and reserve subpart D.
0
3. Add subpart E to part 219 to read as follows:
Subpart E--Taking Marine Mammals Incidental to Northwest Fisheries
Science Center Fisheries Research in the California Current
Sec.
219.41 Specified activity and specified geographical region.
219.42 Effective dates.
219.43 Permissible methods of taking.
219.44 Prohibitions.
219.45 Mitigation requirements.
219.46 Requirements for monitoring and reporting.
219.47 Letters of Authorization.
219.48 Renewals and modifications of Letters of Authorization.
219.49 [Reserved]
219.50 [Reserved]
Sec. 219.41 Specified activity and specified geographical region.
(a) Regulations in this subpart apply only to the National Marine
Fisheries Service's (NMFS) Northwest Fisheries Science Center (NWFSC)
and those persons it authorizes or funds to conduct activities on its
behalf for the taking of marine mammals that occurs in the area
outlined in paragraph (b) of this section and that occurs incidental to
research survey program operations.
(b) The taking of marine mammals by NWFSC may be authorized in a
Letter of Authorization (LOA) only if it occurs within the California
Current Ecosystem, including Puget Sound and the Columbia River.
Sec. 219.42 Effective dates.
Regulations in this subpart are effective from [EFFECTIVE DATE OF
FINAL RULE] through [DATE 5 YEARS AFTER EFFECTIVE DATE OF FINAL RULE].
Sec. 219.43 Permissible methods of taking.
(a) Under LOAs issued pursuant to Sec. Sec. 216.106 and 219.47 of
this chapter, the Holder of the LOA (hereinafter ``NWFSC'') may
incidentally, but not intentionally, take marine mammals within the
area described in Sec. 219.41(b) of this chapter by Level B harassment
associated with use of active acoustic systems and physical or visual
disturbance of hauled-out pinnipeds and by Level A harassment, serious
injury, or mortality associated with use of hook and line gear, trawl
gear, and seine gear, provided the activity is in compliance with all
terms, conditions, and requirements of the regulations in this subpart
and the appropriate LOA.
Sec. 219.44 Prohibitions.
Notwithstanding takings contemplated in Sec. 219.41 and authorized
by a LOA issued under Sec. Sec. 216.106 and 219.47 of this chapter, no
person in connection with the activities described in Sec. 219.41 of
this chapter may:
(a) Violate, or fail to comply with, the terms, conditions, and
requirements of this subpart or a LOA issued under Sec. Sec. 216.106
and 219.47 of this chapter;
(b) Take any marine mammal not specified in such LOAs;
(c) Take any marine mammal specified in such LOAs in any manner
other than as specified;
(d) Take a marine mammal specified in such LOAs if NMFS determines
such taking results in more than a negligible impact on the species or
stocks of such marine mammal; or
(e) Take a marine mammal specified in such LOAs if NMFS determines
such taking results in an unmitigable adverse impact on the species or
stock of such marine mammal for taking for subsistence uses.
Sec. 219.45 Mitigation requirements.
When conducting the activities identified in Sec. 219.41(a) of
this chapter, the mitigation measures contained in any LOA issued under
Sec. Sec. 216.106 and 219.47 of this chapter must be implemented.
These mitigation measures shall include but are not limited to:
(a) General conditions: (1) NWFSC shall take all necessary measures
to coordinate and communicate in advance of each specific survey with
the National Oceanic and Atmospheric Administration's (NOAA) Office of
Marine and Aviation Operations (OMAO) or other relevant parties on non-
NOAA platforms to ensure that all mitigation measures and monitoring
requirements described herein, as well as the specific manner of
implementation and relevant event-contingent decision-making processes,
are clearly understood and agreed upon.
[[Page 38564]]
(2) NWFSC shall coordinate and conduct briefings at the outset of
each survey and as necessary between ship's crew (Commanding Officer/
master or designee(s), as appropriate) and scientific party in order to
explain responsibilities, communication procedures, marine mammal
monitoring protocol, and operational procedures.
(3) NWFSC shall coordinate as necessary on a daily basis during
survey cruises with OMAO personnel or other relevant personnel on non-
NOAA platforms to ensure that requirements, procedures, and decision-
making processes are understood and properly implemented.
(4) When deploying any type of sampling gear at sea, NWFSC shall at
all times monitor for any unusual circumstances that may arise at a
sampling site and use best professional judgment to avoid any potential
risks to marine mammals during use of all research equipment.
(5) NWFSC shall implement handling and/or disentanglement protocols
as specified in the guidance that shall be provided to NWFSC survey
personnel.
(b) For all research surveys using trawl, hook and line, or seine
gear in Puget Sound, the move-on rule mitigation protocol described in
paragraph (c)(3) shall be implemented upon observation of killer whales
at any distance.
(c) Trawl survey protocols: (1) NWFSC shall conduct trawl
operations as soon as is practicable upon arrival at the sampling
station.
(2) NWFSC shall initiate marine mammal watches (visual observation)
a minimum of ten minutes prior to beginning of net deployment, but
shall also conduct monitoring during pre-set activities including
trackline reconnaissance, CTD casts, and plankton or bongo net hauls.
Marine mammal watches shall be conducted by scanning the surrounding
waters with the naked eye and rangefinding binoculars (or monocular).
During nighttime operations, visual observation shall be conducted
using the naked eye and available vessel lighting.
(3) NWFSC shall implement the move-on rule mitigation protocol, as
described in this paragraph. If one or more marine mammals are observed
within 500 m of the planned location in the ten minutes before setting
the trawl gear, and are considered at risk of interacting with the
vessel or research gear, or appear to be approaching the vessel and are
considered at risk of interaction, NWFSC shall either remain onsite or
move on to another sampling location. If remaining onsite, the set
shall be delayed. If the animals depart or appear to no longer be at
risk of interacting with the vessel or gear, a further ten minute
observation period shall be conducted. If no further observations are
made or the animals still do not appear to be at risk of interaction,
then the set may be made. If the vessel is moved to a different section
of the sampling area, the move-on rule mitigation protocol would begin
anew. If, after moving on, marine mammals remain at risk of
interaction, the NWFSC shall move again or skip the station. Marine
mammals that are sighted further than 500 m from the vessel shall be
monitored to determine their position and movement in relation to the
vessel to determine whether the move-on rule mitigation protocol should
be implemented. NWFSC may use best professional judgment in making
these decisions.
(4) NWFSC shall maintain visual monitoring effort during the entire
period of time that trawl gear is in the water (i.e., throughout gear
deployment, fishing, and retrieval). If marine mammals are sighted
before the gear is fully removed from the water, NWFSC shall take the
most appropriate action to avoid marine mammal interaction. NWFSC may
use best professional judgment in making this decision.
(5) If trawling operations have been suspended because of the
presence of marine mammals, NWFSC may resume trawl operations when
practicable only when the animals are believed to have departed the
area. NWFSC may use best professional judgment in making this
determination.
(6) When conducting surface trawls using the Nordic 264 net,
dedicated crew with no other tasks shall conduct required marine mammal
monitoring. Marine mammal monitoring shall be staffed in a stepwise
process, with a minimum of two observers beginning pre-set monitoring
and increasing to a minimum of four observers prior to and during gear
deployment. During the tow, a minimum of three observers shall conduct
required monitoring.
(7) NWFSC shall implement standard survey protocols to minimize
potential for marine mammal interactions, including maximum tow
durations at target depth and maximum tow distance, and shall carefully
empty the trawl as quickly as possible upon retrieval. Trawl nets must
be cleaned prior to deployment.
(8) NWFSC must install and use a marine mammal excluder device at
all times when the Nordic 264 trawl net is used.
(9) NWFSC must install and use acoustic deterrent devices whenever
the Nordic 264 trawl net is used, with two pairs of the devices
installed near the net opening. NWFSC must ensure that the devices are
operating properly before deploying the net.
(10) For use of the Kodiak surface trawl in Puget Sound, trawl
survey protocols described in this section apply only to cetaceans.
(11) Trawl survey protocols described in this section do not apply
to use of pair trawl gear in the Columbia River.
(d) Hook and line (including longline) survey protocols: (1) NWFSC
shall deploy hook and line gear as soon as is practicable upon arrival
at the sampling station.
(2) NWFSC shall initiate marine mammal watches (visual observation)
no less than thirty minutes prior to both deployment and retrieval of
longline gear. Marine mammal watches shall be conducted by scanning the
surrounding waters with the naked eye and rangefinding binoculars (or
monocular). During nighttime operations, visual observation shall be
conducted using the naked eye and available vessel lighting.
(3) NWFSC shall implement the move-on rule mitigation protocol, as
described in this paragraph. If one or more marine mammals are observed
within 500 m of the planned location in the ten minutes before gear
deployment, and are considered at risk of interacting with the vessel
or research gear, or appear to be approaching the vessel and are
considered at risk of interaction, NWFSC shall either remain onsite or
move on to another sampling location. If remaining onsite, the set
shall be delayed. If the animals depart or appear to no longer be at
risk of interacting with the vessel or gear, a further thirty minute
observation period shall be conducted. If no further observations are
made or the animals still do not appear to be at risk of interaction,
then the set may be made. If the vessel is moved to a different section
of the sampling area, the move-on rule mitigation protocol would begin
anew. If, after moving on, marine mammals remain at risk of
interaction, the NWFSC shall move again or skip the station. Marine
mammals that are sighted further than 500 m from the vessel shall be
monitored to determine their position and movement in relation to the
vessel to determine whether the move-on rule mitigation protocol should
be implemented. NWFSC may use best professional judgment in making
these decisions.
(4) NWFSC shall maintain visual monitoring effort during the entire
period of gear deployment and retrieval. If marine mammals are sighted
before the gear is fully deployed or retrieved,
[[Page 38565]]
NWFSC shall take the most appropriate action to avoid marine mammal
interaction. NWFSC may use best professional judgment in making this
decision.
(5) If deployment or retrieval operations have been suspended
because of the presence of marine mammals, NWFSC may resume such
operations when practicable only when the animals are believed to have
departed the area. NWFSC may use best professional judgment in making
this decision.
(6) NWFSC shall implement standard survey protocols, including
maximum soak durations and a prohibition on chumming.
(7) For hook and line surveys in Puget Sound, but not including
longline surveys, hook and line survey protocols described in this
section apply only to cetaceans.
(e) Seine survey protocols: (1) NWFSC shall conduct seine
operations as soon as is practicable upon arrival at the sampling
station.
(2) NWFSC shall conduct marine mammal watches (visual observation)
prior to beginning of net deployment. Marine mammal watches shall be
conducted by scanning the surrounding waters with the naked eye and
rangefinding binoculars (or monocular).
(3) NWFSC shall implement the move-on rule mitigation protocol, as
described in this paragraph for use of purse seine gear. If one or more
small cetaceans (i.e., dolphin or porpoise) or five or more pinnipeds
are observed within 500 m of the planned location before setting the
seine gear, and are considered at risk of interacting with the vessel
or research gear, or appear to be approaching the vessel and are
considered at risk of interaction, NWFSC shall either remain onsite or
move on to another sampling location. If remaining onsite, the set
shall be delayed. If the animals depart or appear to no longer be at
risk of interacting with the vessel or gear, a further ten minute
observation period shall be conducted. If no further observations are
made or the animals still do not appear to be at risk of interaction,
then the set may be made. If the vessel is moved to a different area,
the move-on rule mitigation protocol would begin anew. If, after moving
on, marine mammals remain at risk of interaction, the NWFSC shall move
again or skip the station. Marine mammals that are sighted further than
500 m from the vessel shall be monitored to determine their position
and movement in relation to the vessel to determine whether the move-on
rule mitigation protocol should be implemented. NWFSC may use best
professional judgment in making these decisions.
(4) NWFSC shall maintain visual monitoring effort during the entire
period of time that seine gear is in the water (i.e., throughout gear
deployment, fishing, and retrieval). If marine mammals are sighted
before the gear is fully removed from the water, NWFSC shall take the
most appropriate action to avoid marine mammal interaction. NWFSC may
use best professional judgment in making this decision.
(5) If seine operations have been suspended because of the presence
of marine mammals, NWFSC may resume seine operations when practicable
only when the animals are believed to have departed the area. NWFSC may
use best professional judgment in making this determination.
(6) If any cetaceans are observed in a purse seine net, NWFSC shall
immediately open the net and free the animals.
(7) NWFSC shall not make beach seine sets within 200 m of any
hauled-out pinniped, and shall immediately remove the gear from the
water upon observation of any marine mammal attempting to interact with
the gear.
Sec. 219.46 Requirements for monitoring and reporting.
(a) NWFSC shall designate a compliance coordinator who shall be
responsible for ensuring compliance with all requirements of any LOA
issued pursuant to Sec. Sec. 216.106 and 219.47 of this chapter and
for preparing for any subsequent request(s) for incidental take
authorization.
(b) Visual monitoring program: (1) Marine mammal visual monitoring
shall occur prior to deployment of trawl, seine, and hook and line
gear, respectively; throughout deployment of gear and active fishing of
research gears (not including longline soak time); prior to retrieval
of longline gear; and throughout retrieval of all research gear.
(2) Marine mammal watches shall be conducted by watch-standers
(those navigating the vessel and/or other crew) at all times when the
vessel is being operated.
(c) Training: (1) NWFSC must conduct annual training for all chief
scientists and other personnel who may be responsible for conducting
dedicated marine mammal visual observations to explain mitigation
measures and monitoring and reporting requirements, mitigation and
monitoring protocols, marine mammal identification, completion of
datasheets, and use of equipment. NWFSC may determine the agenda for
these trainings.
(2) NWFSC shall also dedicate a portion of training to discussion
of best professional judgment, including use in any incidents of marine
mammal interaction and instructive examples where use of best
professional judgment was determined to be successful or unsuccessful.
(3) NWFSC shall coordinate with NMFS' Southwest Fisheries Science
Center (SWFSC) regarding surveys conducted in the California Current
Ecosystem, such that training and guidance related to handling
procedures and data collection is consistent.
(d) Handling procedures and data collection: (1) NWFSC must develop
and implement standardized marine mammal handling, disentanglement, and
data collection procedures. These standard procedures will be subject
to approval by NMFS' Office of Protected Resources (OPR).
(2) When practicable, for any marine mammal interaction involving
the release of a live animal, NWFSC shall collect necessary data to
facilitate a serious injury determination.
(3) NWFSC shall provide its relevant personnel with standard
guidance and training regarding handling of marine mammals, including
how to identify different species, bring an individual aboard a vessel,
assess the level of consciousness, remove fishing gear, return an
individual to water, and log activities pertaining to the interaction.
(4) NWFSC shall record such data on standardized forms, which will
be subject to approval by OPR. NWFSC shall also answer a standard
series of supplemental questions regarding the details of any marine
mammal interaction.
(e) Reporting: (1) NWFSC shall report all incidents of marine
mammal interaction to NMFS' Protected Species Incidental Take database
within 48 hours of occurrence and shall provide supplemental
information to OPR upon request. Information related to marine mammal
interaction (animal captured or entangled in research gear) must
include details of survey effort, full descriptions of any observations
of the animals, the context (vessel and conditions), decisions made,
and rationale for decisions made in vessel and gear handling.
(2) Annual reporting: (i) NWFSC shall submit an annual summary
report to OPR not later than ninety days following the end of a given
year. NWFSC shall provide a final report within thirty days following
resolution of comments on the draft report.
(ii) These reports shall contain, at minimum, the following:
[[Page 38566]]
(A) Annual line-kilometers surveyed during which the EK60, ME70,
SX90 (or equivalent sources) were predominant and associated pro-rated
estimates of actual take;
(B) Summary information regarding use of all hook and line, seine,
and trawl gear, including number of sets, hook hours, tows, etc.,
specific to each gear;
(C) Accounts of all incidents of marine mammal interactions,
including circumstances of the event and descriptions of any mitigation
procedures implemented or not implemented and why;
(D) A written evaluation of the effectiveness of NWFSC mitigation
strategies in reducing the number of marine mammal interactions with
survey gear, including best professional judgment and suggestions for
changes to the mitigation strategies, if any;
(E) Final outcome of serious injury determinations for all
incidents of marine mammal interactions where the animal(s) were
released alive; and
(F) A summary of all relevant training provided by NWFSC and any
coordination with SWFSC or NMFS' West Coast Regional Office.
(f) Reporting of injured or dead marine mammals:
(1) In the unanticipated event that the activity defined in Sec.
219.41(a) clearly causes the take of a marine mammal in a prohibited
manner, NWFSC personnel engaged in the research activity shall
immediately cease such activity until such time as an appropriate
decision regarding activity continuation can be made by the NWFSC
Director (or designee). The incident must be reported immediately to
OPR and the West Coast Regional Stranding Coordinator, NMFS. OPR will
review the circumstances of the prohibited take and work with NWFSC to
determine what measures are necessary to minimize the likelihood of
further prohibited take and ensure MMPA compliance. The immediate
decision made by NWFSC regarding continuation of the specified activity
is subject to OPR concurrence. The report must include the following
information:
(i) Time, date, and location (latitude/longitude) of the incident;
(ii) Description of the incident;
(iii) Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, visibility);
(iv) Description of all marine mammal observations in the 24 hours
preceding the incident;
(v) Species identification or description of the animal(s)
involved;
(vi) Status of all sound source use in the 24 hours preceding the
incident;
(vii) Water depth;
(viii) Fate of the animal(s); and
(ix) Photographs or video footage of the animal(s).
(2) In the event that NWFSC discovers an injured or dead marine
mammal and determines that the cause of the injury or death is unknown
and the death is relatively recent (e.g., in less than a moderate state
of decomposition), NWFSC shall immediately report the incident to OPR
and the West Coast Regional Stranding Coordinator, NMFS. The report
must include the information identified in paragraph (f)(1) of this
section. Activities may continue while OPR reviews the circumstances of
the incident. OPR will work with NWFSC to determine whether additional
mitigation measures or modifications to the activities are appropriate.
(3) In the event that NWFSC discovers an injured or dead marine
mammal and determines that the injury or death is not associated with
or related to the activities defined in Sec. 219.41(a) (e.g.,
previously wounded animal, carcass with moderate to advanced
decomposition, scavenger damage), NWFSC shall report the incident to
OPR and the West Coast Regional Stranding Coordinator, NMFS, within 24
hours of the discovery. NWFSC shall provide photographs or video
footage or other documentation of the stranded animal sighting to OPR.
Sec. 219.47 Letters of Authorization.
(a) To incidentally take marine mammals pursuant to these
regulations, NWFSC must apply for and obtain an LOA.
(b) An LOA, unless suspended or revoked, may be effective for a
period of time not to exceed the expiration date of these regulations.
(c) If an LOA expires prior to the expiration date of these
regulations, NWFSC may apply for and obtain a renewal of the LOA.
(d) In the event of projected changes to the activity or to
mitigation and monitoring measures required by an LOA, NWFSC must apply
for and obtain a modification of the LOA as described in Sec. 219.48
of this chapter.
(e) The LOA shall set forth:
(1) Permissible methods of incidental taking;
(2) Means of effecting the least practicable adverse impact (i.e.,
mitigation) on the species, its habitat, and on the availability of the
species for subsistence uses; and
(3) Requirements for monitoring and reporting.
(f) Issuance of the LOA shall be based on a determination that the
level of taking will be consistent with the findings made for the total
taking allowable under these regulations.
(g) Notice of issuance or denial of an LOA shall be published in
the Federal Register within thirty days of a determination.
Sec. 219.48 Renewals and modifications of Letters of Authorization.
(a) An LOA issued under Sec. Sec. 216.106 and 219.47 of this
chapter for the activity identified in Sec. 219.41(a) shall be renewed
or modified upon request by the applicant, provided that:
(1) The proposed specified activity and mitigation, monitoring, and
reporting measures, as well as the anticipated impacts, are the same as
those described and analyzed for these regulations (excluding changes
made pursuant to the adaptive management provision in paragraph (c)(1)
of this section), and
(2) OPR determines that the mitigation, monitoring, and reporting
measures required by the previous LOA under these regulations were
implemented.
(b) For an LOA modification or renewal requests by the applicant
that include changes to the activity or the mitigation, monitoring, or
reporting (excluding changes made pursuant to the adaptive management
provision in paragraph (c)(1) of this section) that do not change the
findings made for the regulations or result in no more than a minor
change in the total estimated number of takes (or distribution by
species or years), OPR may publish a notice of proposed LOA in the
Federal Register, including the associated analysis of the change, and
solicit public comment before issuing the LOA.
(c) An LOA issued under Sec. Sec. 216.106 and 219.47 of this
chapter for the activity identified in Sec. 219.41(a) may be modified
by OPR under the following circumstances:
(1) Adaptive Management--OPR may modify (including augment) the
existing mitigation, monitoring, or reporting measures (after
consulting with NWFSC regarding the practicability of the
modifications) if doing so creates a reasonable likelihood of more
effectively accomplishing the goals of the mitigation and monitoring
set forth in the preamble for these regulations.
(i) Possible sources of data that could contribute to the decision
to modify the mitigation, monitoring, or reporting measures in an LOA:
(A) Results from NWFSC's monitoring from the previous year(s).
(B) Results from other marine mammal and/or sound research or
studies.
[[Page 38567]]
(C) Any information that reveals marine mammals may have been taken
in a manner, extent or number not authorized by these regulations or
subsequent LOAs.
(ii) If, through adaptive management, the modifications to the
mitigation, monitoring, or reporting measures are substantial, OPR will
publish a notice of proposed LOA in the Federal Register and solicit
public comment.
(2) Emergencies--If OPR determines that an emergency exists that
poses a significant risk to the well-being of the species or stocks of
marine mammals specified in LOAs issued pursuant to Sec. Sec. 216.106
and 219.47 of this chapter, an LOA may be modified without prior notice
or opportunity for public comment. Notice would be published in the
Federal Register within thirty days of the action.
Sec. 219.49 [Reserved]
Sec. 219.50 [Reserved]
[FR Doc. 2016-13655 Filed 6-10-16; 8:45 am]
BILLING CODE 3510-22-P