[Federal Register Volume 83, Number 48 (Monday, March 12, 2018)]
[Notices]
[Pages 10689-10713]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-04857]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XF870
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Service Pier Extension Project
on Naval Base Kitsap Bangor, Washington
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments.
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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for
authorization to take marine mammals incidental to vibratory and impact
pile driving associated with proposed construction of the Service Pier
Extension (SPE) at Naval Base Kitsap Bangor, Washington. Pursuant to
the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on
its proposal to issue an incidental harassment authorization (IHA) to
incidentally take marine mammals during the specified activities. NMFS
will consider public comments prior to making any final decision on the
issuance of the requested MMPA authorizations and agency responses will
be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than April
11, 2018.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service. Physical comments should be sent to
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments
should be sent to [email protected].
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. Comments received electronically, including
all attachments, must not exceed a 25-megabyte file size. Attachments
to electronic comments will be accepted in Microsoft Word or Excel or
Adobe PDF file formats only. All comments received are a part of the
public record and will generally be posted online at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm 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.
FOR FURTHER INFORMATION CONTACT: Rob Pauline, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing these
documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce (as delegated to NMFS) 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 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.
The MMPA states that the term ``take'' means to harass, hunt,
capture, kill or attempt to harass, hunt, capture, or kill any marine
mammal.
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).
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an
incidental harassment authorization) with respect to potential impacts
on the human environment.
This action is consistent with categories of activities identified
in CE B4 of the Companion Manual for NOAA Administrative Order 216-6A,
which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has
preliminarily determined that the issuance of the proposed IHA
qualifies to be categorically excluded from further NEPA review.
We will review all comments submitted in response to this notice
prior to concluding our NEPA process or making a final decision on the
IHA request.
Summary of Request
On August 9, 2017 NMFS received a request from the Navy for an IHA
to take marine mammals incidental to pile driving and removal
associated with proposed construction of the SPE on Naval Base Kitsap
Bangor, Washington. The application was deemed adequate and complete by
NMFS on November 15, 2017.
The Navy's request is for take by Level B harassment of five marine
mammal species and Level A harassment of one species. Neither the Navy
nor NMFS expect serious injury or immortality to result from this
activity and, therefore, an IHA is appropriate.
[[Page 10690]]
Description of Proposed Activity
Overview
The Navy is proposing to extend the service pier to provide
additional berthing capacity and improve associated facilities for
existing homeported and visiting submarines at Naval Base Kitsap
Bangor. The project includes impact and vibratory pile driving and
vibratory pile removal. Sounds resulting from pile driving and removal
may result in the incidental take of marine mammals by Level A and
Level B harassment in the form of auditory injury or behavioral
harassment. Naval Base Kitsap Bangor is located on Hood Canal
approximately 20 miles (32 kilometers) west of Seattle, Washington. The
in-water construction period for the proposed action will occur over 12
months.
Dates and Duration
The proposed IHA would be effective from October 1, 2018, to
September 30, 2019 and cover two in-water work windows. Timing
restrictions would be complied with to avoid conducting activities when
juvenile salmonids are most likely to be present (February-July). To
protect Endangered Species Act (ESA)-listed salmonid species, pile
driving will only be conducted during the designated in-water work
window between July 16 and January 15. A total of 160 days of in-water
work will be required during the effective dates of the proposed IHA.
Approximately 125 days will be required for installation of steel piles
and will use a combination of vibratory (preferred) and impact methods.
An estimated 35 days will be required for impact installation of
concrete piles. Vibratory pile installation and removal may require a
maximum of 5 hours per day while up to 45 minutes of daily impact
driving may be required.
Specific Geographic Region
Naval Base Kitsap Bangor is located north of the community of
Silverdale in Kitsap County on the Hood Canal (Figure 1-1 in
application). Hood Canal is a long, narrow, fjord-like basin of western
Puget Sound. Throughout its 67 mi (108 km) length, the width of the
canal varies from 1 to 2 mi (1.6 to 3.2 km) and exhibits strong depth/
elevation gradients. The tides in Hood Canal are mixed semidiurnal,
with one flood and one ebb tidal event with a small to moderate range
(1 to 6 ft (0.3 to 1.8 m)) and a second flood and second ebb with a
larger range (8 to 16 ft (2.4 to 4.9 m)) during a 24-hour and 50-minute
tidal day (URS and SAIC, 1994; Morris et al., 2008).
The proposed location for the SPE is just north of Carlson Spit and
south of Keyport/Bangor (KB) Dock (Figure 1-2 in application). Two
restricted areas are associated with Naval Base Kitsap Bangor, Naval
Restricted Areas 1 and 2 (33 CFR 334.1220), which are depicted in
Figure 1-2 in the application relative to the project area.
Detailed Description of Specific Activity
As part of the proposed action, the Navy proposes to extend the
existing Service Pier and construct associated support facilities. This
action is needed to accommodate the proposed relocation of two SEAWOLF
Class submarines from Naval Base Kitsap Bremerton. The existing Bangor
waterfront Service Pier will be extended, and associated support
facilities will be constructed, including a Waterfront Support
Building, Pier Services and Compressor Building, roadway and utility
upgrades, a parking lot, and a laydown area. Construction of upland
facilities will not result in harassment of marine mammals; therefore,
these activities are not included in the Navy's IHA request and are not
discussed further.
The proposed extension of the Service Pier will be approximately 68
by 520 ft (21 by 158 m) and will require installation of approximately
203 36-inch (90-centimeter (cm)) diameter steel piles and 50 24-inch
(60 cm) diameter steel pipe support piles. Approximately 103 18-inch
(45 cm) square concrete fender piles will also be installed. In
addition, 27 36-inch (90 cm) diameter steel falsework piles will be
temporarily installed and subsequently removed. The pier extension will
extend to the southwest from the south end of the existing Service Pier
and will parallel Carlson Spit in water depths of 30 to 50 ft (9 to 15
m) below mean lower low water (MLLW), such that the berthing areas for
the new submarines will be in water depths of approximately 50 to 85 ft
(15 to 26 m) below MLLW. A concrete float 150 ft (46 m) long and 15 ft
(4.6 m) wide will be attached to the south side of the SPE. The
existing Port Security Barrier (PSB) system will be reconfigured
slightly to attach to the end of the new pier extension, with
approximately 540 ft (165 m) removed. Removal and disposal of existing
PSBs will be implemented as described for the Land-Water Interface
project (Navy, 2016a). Construction is expected to require one barge
with a crane, one supply barge, a tugboat, and work skiffs. Concurrent
driving of separate piles will not occur.
Construction will be preceded by removal of an existing wave screen
(including piles) and other existing piles from the Service Pier
(Figure 1-4 in application). A total of 36 creosote timber piles (19
18-inch (45 cm) and 17 15-inch (38 cm) piles) will be removed by
wrapping the piles with a cable or chain and pulling them or using
vibratory extraction; piles will be cut at the mudline if splitting or
breakage occurs and they are not able to be pulled. A new wave screen
will be installed under the SPE (Figure 1-4). This screen will be
approximately 200 ft (60 m) long and 27 ft (8 m) high (below 20 ft (6
m) MLLW to above 7 ft (2 m) MLLW), made of concrete or steel, and
attached to steel support piles for the SPE.
Pile driving for steel piles will use a combination of vibratory
and impact driving. Because impact driving of steel piles can produce
underwater noise levels that have been known to be harmful to fish and
wildlife, including marine mammals, vibratory driving will be the
primary method utilized to drive steel piles except when geotechnical
conditions require use of an impact hammer. An impact hammer will also
be used to ``proof'' load-bearing piles driven by vibratory methods.
Driving of the concrete piles will use impact methods only. For impact
driving, there will be a maximum of 1,600 pile strikes per day. All
types of in-water work will occur only during the in-water work period.
Falsework Piles. It is anticipated that 27 36-inch (90 cm) diameter
steel piles will be temporarily installed. Falsework piles are used to
temporarily support a construction component in place until
construction is sufficiently advanced to where the new construction can
support itself. All falsework piles will be installed using a vibratory
pile driver only and will be extracted with a vibratory pile driver at
the conclusion of construction.
Permanent Piles. As shown in Table 1 permanent piles installed
include 203 36-inch (90 cm) diameter steel pipe, 50 24-inch (60 cm)
diameter steel fender, and 103 18-inch (45 cm) diameter concrete piles.
Driving of the steel support piles will use a combination of vibratory
(primary) and impact methods and will require up to 125 days of pile
driving. When impact driving steel pipe piles, a bubble curtain or
other noise attenuation device would be employed for all pile strikes
with the possible exception of short periods when the device is turned
off to test the effectiveness of the noise attenuation device. Driving
of the concrete piles will use impact methods only, and will require up
to 35 days of pile driving and would occur for a maximum of 45 minutes
a day. Vibratory pile driving
[[Page 10691]]
activity in a day will last a maximum of 5 hours, and impact pile
driving (if required) will last less than 45 minutes for a total of
less than 5 hours and 45 minutes of pile driving activity in a day. All
pile driving will be completed in a 12- month period crossing two in-
water work periods.
Table 1--In-Water Pile Driving Methods, Pile Characteristics, and Driving Durations
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Maximum
Pile size and activity
SPE project feature Method type Number duration within Maximum days
24-hour period
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Pile Removal from Existing Vibratory....... 15-inch (38 cm) 36 5 hours........ 125 days.
Wave Screen and Pier. to 18-inch (45
cm) creosote-
treated timber.
Temporary Falsework.......... Vibratory 36-inch (90 cm) 27 5 hours........
installation steel.
and removal.
Small Craft Mooring and Vibratory, with 24-inch (60 cm) 50 5 hours ...............
Dolphins. proofing. steel. vibratory and
up to 45
minutes impact.
Pier and Wave Screen Vibratory, with 36-inch (90 cm) 203 5 hours
Attachment. proofing. steel. vibratory and
up to 45
minutes impact.
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Fender Piles................. Impact.......... 18-inch (45 cm) 103 0.75 hour...... 35 days
concrete. (following
completion of
timber removal
and steel pile
installation).
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Key: cm = centimeters; SPE = Service Pier Extension.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see ``Proposed
Mitigation'' and ``Proposed Monitoring and Reporting'').
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history, of the potentially affected species.
Additional information regarding population trends and threats may be
found in NMFS's Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., physical
and behavioral descriptions) may be found on NMFS's website
(www.nmfs.noaa.gov/pr/species/mammals/).
Table 2 lists all species with expected potential for occurrence in
Hood Canal and summarizes information related to the population or
stock, including regulatory status under the MMPA and ESA and potential
biological removal (PBR), where known. An expected potential was
defined as species with any regular occurrence in Hood Canal since
1995. Note that while not observed on a consistent basis, west coast
transient killer whales have been recorded intermittently in Hood Canal
with the most recent sightings occurring in 2016 as described below.
They have also been recorded remaining in the area for extended
periods. As such, they have been listed as one of the species for which
authorized take has been requested. For taxonomy, we follow Committee
on Taxonomy (2017). PBR is 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 (as described in NMFS's SARs). While no
mortality is anticipated or authorized here, PBR and annual serious
injury and mortality from anthropogenic sources are included here as
gross indicators of the status of the species and other threats.
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 or survey area.
All managed stocks in this region are assessed in NMFS's U.S. Pacific
Marine Mammal SARs (Carretta et al., 2016) or Alaska Marine Mammal SARs
(Muto et al., 2016). All values presented in Table 2 are the most
recent available at the time of publication and are available in the
2016 SARs (Carretta et al., 2016, Muto et al., 2016) (available online
at: http://www.nmfs.noaa.gov/pr/sars/species.htm).
Table 2--Species Proposed for Authorized Take
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ESA/ MMPA Stock abundance (CV,
status; Nmin, most recent Annual M/
Species Scientific name Stock strategic (Y/ abundance survey) PBR SI \3\
N) \1\ \2\
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Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Killer whale.................. Orcinus orca........ West coast transient............. -; N 243 (n/a; 243, 2009) 2.4 0
\4\.
Family Phocoenidae (porpoises):
Harbor porpoise............... Phocoena phocoena Washington inland waters......... -; N 11,233 (0.37; 8,308; 66 >=7.2
vomerina. 2015).
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[[Page 10692]]
Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
California sea lion........... Zalophus U.S.............................. -; N 296,750 (n/a; 9,200 389
californianus. 153,337; 2011).
Steller sea lion.............. Eumetopias jubatus Eastern U.S...................... -; N 41,638 (n/a; 41,638; 2,498 108
monteriensis. 2015).
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Family Phocidae (earless seals):
Harbor seal................... Phoca vitulina Hood Canal....................... -; N 1,088 (0.15; unk; unk 0.2
richardii. 1999) \4\.
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\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 online 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.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ Abundance estimates for these stocks are greater than eight years old and are therefore not considered current. PBR is 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.
The following species have been sighted in Hood Canal but are not
likely to be found in the activity area and therefore are not analyzed
for noise exposure. Humpback whales (Megaptera novaeangliae) have been
detected year-round in small numbers in Puget Sound; in Hood Canal,
after an absence of sightings for over 15 years, an individual was seen
over a 1-week period in early 2012, with additional sightings in 2015
and 2016 (Orca Network, 2016). Because these sightings are exceptions
to the normal occurrence of the species in Washington inland waters,
the species is not included in the analysis in this application. Gray
whales (Eschrichtius robustus) have been infrequently documented in
Hood Canal waters over the past decade. These sightings are an
exception to the normal seasonal occurrence of gray whales in Puget
Sound feeding areas. Because gray whales are unlikely to be present in
Hood Canal, the species is not included in this analysis. The Southern
Resident killer whale stock is resident to the inland waters of
Washington State and British Columbia; however, it has not been seen in
Hood Canal in over 20 years and was therefore excluded from further
analysis. Dall's porpoise (Phocoenoides dalli) has only been documented
once in Hood Canal and is not included in the analysis.
Killer Whale, West Coast Transient Stock
Among the genetically distinct assemblages of killer whales in the
northeastern Pacific, the West Coast Transient stock, which occurs from
California to southeastern Alaska, is one of two stocks that may occur
in Puget Sound. The other is the Southern Resident killer whale
population, which has not been detected in Hood Canal since 1995.
The geographical range of the West Coast Transient stock of killer
whales includes waters from California through southeastern Alaska with
a preference for coastal waters of southern Alaska and British Columbia
(Krahn et al., 2002). Transient killer whales in the Pacific Northwest
spend most of their time along the outer coast of British Columbia and
Washington, but visit inland waters in search of harbor seals, sea
lions, and other prey. Some studies have shown seasonal trends: Morton
(1990) found bimodal peaks in occurrence during the spring (March) and
fall (September to November) on the central coast of British Columbia,
and Baird and Dill (1995) noted variability in occurrence and behavior
seasonally and between pods with an increase in sightings near harbor
seal haulouts off southern Vancouver Island during August and
September--the peak period for weaning through post-weaning of harbor
seal pups. More recently (2004-2010), another bimodal trend was
detected with transient killer whales occurring most frequently in
Washington inland waters in April-May and August-September (Houghton et
al., 2015). However, transient killer whales may occur in inland waters
in any month (Orca Network, 2015), with their habitat use from one day
to the next being highly unpredictable. These changes in use are likely
related to their stealthy predation behaviors and reduce the chances of
detection by their various prey species within the inland waters.
There are few data to describe the transient killer whale habitat
use within Hood Canal. Killer whales were historically documented in
Hood Canal by sound recordings in 1958 (Ford, 1991), a photograph from
1973, sound recordings in 1995 (Unger, 1997), and also anecdotal
accounts of historical use. More recently, there have been sightings
data ranging from intermittent observations of one or two animals, to
the lengthy stays that were recorded in 2003 of 11 transients that
remained for nearly 2 months (59 days), and in 2005 of a group of six
that were sighted over a nearly 4-month period. In 2005, transients
were documented in the region for a total of 172 days between January
and July (London, 2006). There is about a 10-year data gap for Hood
Canal transient killer whale use with the sightings reported to the
Orca Network in March 2016, when there were sightings over 2 days.
Following this, there was a report from 1 day in April 2016 and 8 days
in May 2016, with whales in Dabob Bay at least one of the days (Orca
Network, 2016). As the sightings in early 2016 were discontinuous, it
is likely that the whales were using Hood Canal as part of a larger
area moving in and out of Hood Canal. It is not known how large an area
these animals were using; it is also unknown if these sightings were
all of the same group of transient killer whales, or if animals were
using the same areas. However, the temporally discontinuous data
suggest a high degree of variability in the habitat use
[[Page 10693]]
and localized relative abundances of transient killer whales in Hood
Canal. It is also likely that longer periods of more continuous
sightings are anomalous, and that the usual use of Hood Canal reflects
the typical transient killer whale behavior of short-term occupancy for
foraging in a small localized area, then dispersing to other parts of
their range.
West Coast Transient killer whales most often travel in small pods
of up to four individuals (Baird and Dill, 1996). From 2004-2010 in the
Salish Sea, the most frequently observed group size was four whales
(Houghton et al., 2015). The most commonly observed group size in Puget
Sound through South Puget Sound and north to Skagit Bay from 2004 to
2010 was six whales (mode = 6, mean = 6.88) (Navy, 2017).
Harbor Porpoise
NMFS conservatively recognizes two stocks in Washington waters: The
Oregon/Washington Coast stock and the Washington Inland Waters stock
(Carretta et al., 2013). Individuals from the Washington Inland Waters
stock are expected to occur in Puget Sound.
In Washington Inland waters, harbor porpoise are known to occur in
the Strait of Juan de Fuca and the San Juan Island area year-round
(Calambokidis and Baird, 1994; Osmek et al., 1996; Carretta et al.,
2012). Harbor porpoises were historically one of the most commonly
observed marine mammals in Puget Sound (Scheffer and Slipp, 1948);
however, there was a significant decline in sightings beginning in the
1940s (Everitt et al., 1979; Calambokidis et al., 1992). Only a few
sightings were reported between the 1970s and 1980s (Calambokidis et
al., 1992; Osmek et al., 1996; Suryan and Harvey, 1998), and no harbor
porpoise sightings were recorded during multiple ship and aerial
surveys conducted in Puget Sound (including Hood Canal) in 1991 and
1994 (Calambokidis et al., 1992; Osmek et al., 1996). Incidental
sightings of marine mammals during aerial bird surveys conducted as
part of the Puget Sound Ambient Monitoring Program (PSAMP) detected few
harbor porpoises in Puget Sound between 1992 and 1999 (Nysewander et
al., 2005). However, these sightings may have been negatively biased
due to the low elevation of the plane, which may have caused an
avoidance behavior. Since 1999, PSAMP data, stranding data, and aerial
surveys conducted from 2013 to 2015 documented increasing numbers of
harbor porpoise in Puget Sound (Nysewander, 2005; WDFW, 2008; Jeffries,
2013; Jefferson et al., 2016).
Sightings in Hood Canal north of the Hood Canal Bridge have
increased in recent years (Navy 2017). During line transect vessel
surveys conducted in the Hood Canal in 2011 for the TPP near Naval Base
Kitsap Bangor and Dabob Bay (HDR Inc., 2012), an average of six harbor
porpoises were sighted per day in the deeper waters. Group sizes ranged
from 1 to 10 individuals (HDR Inc., 2012). Aerial surveys conducted
throughout 2013 to 2015 in Puget Sound indicated density in Puget Sound
was 0.91 individuals/square kilometers (km\2\)) (95% CI = 0.72-1.10,
all seasons pooled) and density in Hood Canal was 0.47/km\2\ (95% CI =
0.29-0.75, all seasons pooled) (Jefferson et al., 2016). Mean group
size of harbor porpoises in Puget Sound in the 2013-2015 surveys was
1.7 in Hood Canal.
Steller Sea Lion
In the North Pacific, NMFS has designated two Steller sea lion
stocks: (1) The western U.S. stock consisting of populations at and
west of Cape Suckling, Alaska (144 degrees West longitude); and (2) the
Eastern U.S. stock, consisting of populations east of Cape Suckling,
Alaska. The western U.S. stock is listed as depleted under the MMPA and
endangered under the ESA. Although there is evidence of mixing between
the two stocks (Jemison et al., 2013), animals from the western U.S.
stock are not present in Puget Sound. Individuals that occur in Puget
Sound are of the Eastern Distinct Population Segment (Allen and
Angliss, 2013). The Eastern Distinct Population Segment (stock) was
removed from listing under the ESA in 2013 because it was stable or
increasing throughout the northern portion of its range (Southeast
Alaska and British Columbia) and stable or increasing slowly in the
central portion of its range (Oregon through northern California) (78
FR 66140; NMFS, 2012a).
The eastern stock of Steller sea lions is found along the coasts of
southeast Alaska to northern California where they occur at rookeries
and numerous haulout locations along the coastline (Jeffries et al.,
2000; Scordino, 2006). Along the northern Washington coast, up to 25
pups are born annually (Jeffries, 2013). Male Steller sea lions often
disperse widely outside of the breeding season from breeding rookeries
in northern California (St. George Reef) and southern Oregon (Rogue
Reef) (Scordino, 2006; Wright et al., 2010). Based on mark recapture
sighting studies, males migrate back into these Oregon and California
locations from winter feeding areas in Washington, British Columbia,
and Alaska (Scordino, 2006).
In Washington, Steller sea lions use haulout sites primarily along
the outer coast from the Columbia River to Cape Flattery, as well as
along the Vancouver Island side of the Strait of Juan de Fuca (Jeffries
et al., 2000). A major winter haulout is located in the Strait of Juan
de Fuca at Race Rocks, British Columbia, Canada (Canadian side of the
Strait of Juan de Fuca) (Edgell and Demarchi, 2012). Numbers vary
seasonally in Washington, with peak numbers present during the fall and
winter months and a decline in the summer months that corresponds to
the breeding season at coastal rookeries (approximately late May to
early June) (Jeffries et al., 2000). In Puget Sound, Jeffries (Navy
2017) identified five winter haulout sites used by adult and subadult
(immature or pre-breeding animals) Steller sea lions, ranging from
immediately south of Port Townsend (near Admiralty Inlet) to Olympia in
southern Puget Sound (Figure 4-1). Numbers of animals observed at these
sites ranged from a few to less than 100 (Navy 2017). In addition,
Steller sea lions (one to two animals have been observed)
opportunistically haul out on various navigational buoys in Admiralty
Inlet south through southern Puget Sound near Olympia (Navy 2017).
Surveys at Naval Base Kitsap Bangor indicate Steller sea lions
begin arriving in September and depart by the end of May (Navy, 2016b)
California Sea Lion
NMFS has defined one stock for California sea lions (U.S. Stock),
with five genetically distinct geographic populations: (1) Pacific
Temperate, (2) Pacific Subtropical, (3) Southern Gulf of California,
(4) Central Gulf of California, and (5) Northern Gulf of California.
The Pacific Temperate population includes rookeries within U.S. waters
and the Coronados Islands just south of the U.S./Mexico border. Animals
from the Pacific Temperate population range north into Canadian waters,
and movement of animals between U.S. waters and Baja California waters
has been documented (Carretta et al., 2013).
During the summer, California sea lions breed on islands from the
Gulf of California to the Channel Islands and seldom travel more than
about 31 mi (50 km) from the islands. The primary rookeries are located
on the California Channel Islands of San Miguel, San Nicolas, Santa
Barbara, and San Clemente. Their distribution shifts to the northwest
in fall and to the southeast during winter and spring, probably in
response to changes in prey availability. In the nonbreeding season,
adult and subadult males migrate
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northward along the coast to central and northern California, Oregon,
Washington, and Vancouver Island, and return south in the spring. They
are occasionally sighted hundreds of miles offshore. Primarily male
California sea lions migrate into northwest waters with most adult
females with pups remaining in waters near their breeding rookeries off
the coasts of California and Mexico. Females and juveniles tend to stay
closer to the rookeries. California sea lions also enter bays, harbors,
and river mouths and often haul out on man-made structures such as
piers, jetties, offshore buoys, and oil platforms.
Jeffries et al. (2000) and Jeffries (Navy 2017) identified
dedicated, regular haulouts used by adult and subadult California sea
lions in Washington inland waters (Figure 4-1). Main haulouts occur at
Naval Base Kitsap Bangor, Naval Base Kitsap Bremerton, and Naval
Station (NAVSTA) Everett, as well as in Rich Passage near Manchester,
Seattle (Shilshole Bay), south Puget Sound (Commencement Bay, Budd
Inlet), and numerous navigation buoys south of Whidbey Island to
Olympia in south Puget Sound (Jeffries et al., 2000) (Figure 4-1). Race
Rocks, British Columbia, Canada (Canadian side of the Strait of Juan de
Fuca) has been identified as a major winter haulout for California sea
lions (Edgell and Demarchi, 2012).
California sea lions are typically present most of the year except
for mid-June through July in Washington inland waters, with peak
abundance numbers between October and May (NMFS, 1997; Jeffries et al.,
2000). California sea lions would be expected to forage within the
area, following local prey availability. During summer months and
associated breeding periods, the inland waters would not be considered
a high-use area by California sea lions, as they would be returning to
rookeries in California waters. However, California sea lions have been
documented during shore-based surveys at Naval Base Kitsap Bangor in
Hood Canal since 2008 in all survey months, with as many as 122
individuals observed at one time (November 2013) hauled out on
submarines at Delta Pier and on PSB floats (Navy, 2016b, Appendix A).
Relatively few individuals (< nine sighted per survey) were present
during these surveys from June through August.
Harbor Seal
Three harbor seal stocks occur in Washington's inland waters:
Hood Canal;
Northern Inland Waters; and
Southern Puget Sound stocks.
Based on radiotelemetry results, interchange between inland and
coastal stocks is unlikely (Jeffries et al., 2003).
Harbor seals are a coastal species, rarely found more than 12 mi
(19 km) from shore, and frequently occupy bays, estuaries, and inlets
(Baird, 2001). Individual seals have been observed several miles
upstream in coastal rivers (Baird, 2001). Ideal harbor seal habitat
includes haulout sites, shelter during the breeding periods, and
sufficient food (Bj[oslash]rge, 2002). Haulout areas can include
intertidal and subtidal rock outcrops, sandbars, sandy beaches, peat
banks in salt marshes, and man-made structures such as log booms,
docks, and recreational floats (Wilson, 1978; Prescott, 1982; Schneider
and Payne, 1983, Gilbert and Guldager, 1998; Jeffries et al., 2000;
Lambourn et al., 2010). Harbor seals do not make extensive pelagic
migrations, though some long distance movement of tagged animals in
Alaska (108 mi (174 km)) and along the U.S. west coast (up to 342 mi
(550 km)) have been recorded (Brown and Mate, 1983; Womble and Gende,
2013). Harbor seals have also displayed strong fidelity to haulout
sites.
Harbor seals are the most common, widely distributed marine mammal
found in Washington marine waters and are frequently observed in the
nearshore marine environment. They occur year-round and breed in
Washington. Numerous harbor seal haulouts occur in Washington inland
waters. Numbers of individuals at haulouts range from a few to between
100 and 500 individuals (Jeffries et al., 2000).
Harbor seals are expected to occur year-round at Naval Base Kitsap
Bangor. In Hood Canal, where Naval Base Kitsap Bangor is located, known
haulouts occur on the west side of Hood Canal at the mouth of the
Dosewallips River and on the western and northern shorelines in Dabob
Bay, located approximately 8.1 miles away from the Navy's installation
(Figure 4-1). Vessel-based surveys conducted from 2007 to 2010 at Naval
Base Kitsap Bangor observed harbor seals in every month of surveys
(Agness and Tannenbaum, 2009; Tannenbaum et al., 2009, 2011). Harbor
seals were routinely seen during marine mammal monitoring for two
construction projects, the Test Pile Project and EHW-2 construction
projects (HDR Inc., 2012; Hart Crowser, 2013, 2014, 2015). Small
numbers of harbor seals have been documented hauling out on the PSB
floats, wavescreen at Carderock Pier, buoys, barges, marine vessels,
and logs (Agness and Tannenbaum, 2009; Tannenbaum et al., 2009, 2011;
Navy, 2016b) and on man-made floating structures near KB Dock and Delta
Pier. Incidental surveys by a Navy biologist in August and September
2016 recorded as many as 28 harbor seals hauled out under Marginal
Wharf or swimming in adjacent waters. On two occasions, four to six
individuals were observed hauled out near Delta Pier. The repeated
sightings of harbor seals in this area suggest a high degree of
tolerance by these individuals for the anthropogenic activity
associated with Naval Base Kitsap Bangor. It is also likely that these
are sightings of the same individuals, rather than different animals
being observed at the same locations.
Past IHA applications for Naval Base Kitsap Bangor indicated a few
observations of harbor seal births or neonates. In 2014, the Navy's
knowledge of harbor seal births increased due to increased pinniped
surveys on the waterfront and increased contact with waterfront
personnel who have had lengthy careers at Bangor (Navy, 2016b). Known
harbor seal births include one on the Carderock wave screen in August
2011; at least one on a small 10 x 10 ft (3 x 3 m) floating dock at
EHW-2 in fall 2013, as reported by EHW-2 construction crew; and
afterbirth on a float at Magnetic Silencing Facility with an unknown
date. In addition, Navy biologists learned that harbor seal pupping has
occurred on a section of the Service Pier since approximately 2001,
according to the Port Operations vessel crews. Harbor seal mother and
pup sets were observed in 2014 hauled out on the Carderock wavescreen
and swimming in nearby waters, and swimming in the vicinity of Delta
Pier (Navy, 2016b).
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 mysticetes
(i.e., low-frequency
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cetaceans). Subsequently, NMFS (2016) described generalized hearing
ranges for these marine mammal hearing groups. Generalized hearing
ranges were chosen based on the approximately 65 decibel (dB) threshold
from the normalized composite audiograms, with the exception for lower
limits for low-frequency cetaceans where the lower bound was deemed to
be biologically implausible and the lower bound from Southall et al.
(2007) retained. 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):
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Generalized hearing is estimated to occur
between approximately 150 hertz (Hz) and 160 kilohertz (kHz);
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; including two members
of the genus Lagenorhynchus, on the basis of recent echolocation data
and genetic data): Generalized hearing is estimated to occur between
approximately 275 Hz and 160 kHz;
Pinnipeds in water; Phocidae (true seals): Generalized
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
and
Pinnipeds in water; Otariidae (eared seals): Generalized
hearing is estimated to occur between 60 Hz and 39 kHz.
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).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2016) for a review of available information.
Five marine mammal species (two cetacean and three pinniped (two
otariid and 1 phocid) species) have the reasonable potential to co-
occur with the proposed survey activities. Of the cetacean species that
may be present, killer whales are classified as mid-frequency cetaceans
and harbor porpoises are classified as high-frequency cetaceans.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The ``Estimated Take by Incidental Harassment'' section
later in this document includes a quantitative analysis of the number
of individuals that are expected to be taken by this activity. The
``Negligible Impact Analysis and Determination'' section considers 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 these activities on the
reproductive success or survivorship of individuals and how those
impacts on individuals are likely to impact marine mammal species or
stocks.
Description of Sound Sources
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 Hz or cycles per second. Wavelength is the distance
between two peaks of a sound wave; lower frequency sounds have longer
wavelengths than higher frequency sounds and attenuate (decrease) more
rapidly in shallower water. Amplitude is the height of the sound
pressure wave or the `loudness' of a sound and is typically measured
using the dB scale. A dB is the ratio between a measured pressure (with
sound) and a reference pressure (sound at a constant pressure,
established by scientific standards). It is a logarithmic unit that
accounts for large variations in amplitude; therefore, relatively small
changes in dB ratings correspond to large changes in sound pressure.
When referring to sound pressure levels (SPLs; the sound force per unit
area), sound is referenced in the context of underwater sound pressure
to 1 micro pascal ([mu]Pa). One pascal is the pressure resulting from a
force of one newton exerted over an area of one square meter. The
source level (SL) represents the sound level at a distance of 1 m from
the source (referenced to 1 [mu]Pa). The received level is the sound
level at the listener's position. Note that all underwater sound levels
in this document are referenced to a pressure of 1 [micro]Pa and all
airborne sound levels in this document are referenced to a pressure of
20 [micro]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.
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 all
directions away from the source (similar to ripples on the surface of a
pond), except in cases where the source is directional. 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.,
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds
produced by marine mammals, fish, and invertebrates), and anthropogenic
sound (e.g., vessels, dredging, aircraft, construction). 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 noise 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 noise 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 noise at
frequencies above 500 Hz, and possibly down to 100 Hz during quiet
times;
Biological: Marine mammals can contribute significantly to
ambient noise levels, as can some fish and shrimp. The frequency band
for biological
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contributions is from approximately 12 Hz to over 100 kHz; and
Anthropogenic: Sources of ambient noise related to human
activity include transportation (surface vessels and aircraft),
dredging and construction, oil and gas drilling and production, seismic
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise
typically dominates the total ambient noise 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 (Richardson et al., 1995). 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
shipping 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.
In-water construction activities associated with the project would
include impact pile driving, vibratory pile driving and vibratory pile
extraction. The sounds produced by these activities fall into one of
two general sound types: Pulsed and non-pulsed (defined in the
following paragraphs). 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,
impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986; Harris, 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, 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.
Impact hammers operate by repeatedly dropping a heavy piston onto a
pile to drive the pile into the substrate. Sound generated by impact
hammers is characterized by rapid rise times and high peak levels, a
potentially injurious combination (Hastings and Popper 2005). Vibratory
hammers install piles by vibrating them and allowing the weight of the
hammer to push them into the sediment. Vibratory hammers produce
significantly less sound than impact hammers. Peak SPLs may be 180 dB
or greater, but are generally 10 to 20 dB lower than SPLs generated
during impact pile driving of the same-sized pile (Oestman et al.,
2009). Rise time is slower, reducing the probability and severity of
injury, and sound energy is distributed over a greater amount of time
(Nedwell and Edwards 2002).
Acoustic Impacts
Please refer to the information given previously (Description of
Sound 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). 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. In this section, we first describe specific
manifestations of acoustic effects before providing discussion specific
to the proposed construction activities in the next section.
Permanent Threshold Shift--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, 2005). 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).
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 dB 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
[[Page 10697]]
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 six 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).
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.
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 (Tursiops truncatus), beluga whale (Delphinapterus
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena
asiaeorientalis)); and three species of pinnipeds (northern elephant
seal (Mirounga angustirostris), 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), Finneran and
Jenkins (2012), and Finneran (2015).
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 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,
2003). 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
[[Page 10698]]
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
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.
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
[[Page 10699]]
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).
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). 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 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.
Non-Auditory Physiological Effects--Non-auditory physiological
effects or injuries that theoretically might occur in marine mammals
exposed to strong underwater sound include stress, neurological
effects, bubble formation, resonance effects, and other types of organ
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies
examining such effects are limited. In general, little is known about
the potential for pile driving to cause auditory impairment or other
physical effects in marine mammals. Available data suggest that such
effects, if they occur at all, would presumably be limited to short
distances from the sound source, where SLs are much higher, and to
activities that extend over a prolonged period. The available data do
not allow identification of a specific exposure level above which non-
auditory effects can be expected (Southall et al., 2007) or any
meaningful quantitative predictions of the numbers (if any) of marine
mammals that might be affected in those ways. However, the proposed
activities do not involve the use of devices such as explosives or mid-
frequency active sonar that are associated with these types of effects.
Therefore, non-auditory physiological impacts to marine mammals are
considered unlikely.
Underwater Acoustic Effects From the Proposed Activities
Potential Effects of Pile Driving Sound--The effects of sounds from
pile driving might include one or more of the following: Temporary or
permanent hearing impairment, non-auditory physical or physiological
effects, and behavioral disturbance (Richardson et al., 1995; Gordon et
al., 2003; Nowacek et al., 2007; Southall et al., 2007). The effects of
pile driving on marine mammals are dependent on several factors,
including the type and depth of the animal; the pile size and type, and
the intensity and duration of the pile driving sound; the substrate;
the standoff distance between the pile and the animal; and the sound
propagation properties of the environment. Impacts to marine mammals
from pile driving activities are expected to result primarily from
acoustic pathways. As such, the degree of effect is intrinsically
related to the frequency, received level, and duration of the sound
exposure, which are in turn influenced by the distance between the
animal and the source. The further away from the source, the less
intense the exposure should be. The substrate and depth of the habitat
affect the sound propagation properties of the environment. In
addition, substrates that are soft (e.g.,
[[Page 10700]]
sand) would absorb or attenuate the sound more readily than hard
substrates (e.g., rock) which may reflect the acoustic wave. Soft
porous substrates would also likely require less time to drive the
pile, and possibly less forceful equipment, which would ultimately
decrease the intensity of the acoustic source.
Hearing Impairment and Other Physical Effects--Marine mammals
exposed to high intensity sound repeatedly or for prolonged periods can
experience hearing threshold shifts. PTS constitutes injury, but TTS
does not (Southall et al., 2007). Based on the best scientific
information available, the SPLs for the proposed construction
activities may exceed the thresholds that could cause TTS or the onset
of PTS based on NMFS' new acoustic guidance (NMFS, 2016).
Disturbance Reactions--Responses to continuous sound, such as
vibratory pile installation, have not been documented as well as
responses to pulsed sounds. With both types of pile driving, it is
likely that the onset of pile driving could result in temporary, short
term changes in an animal's typical behavior and/or avoidance of the
affected area. Specific behavioral changes that may result from this
proposed project include changing durations of surfacing and dives,
moving direction and/or speed; changing/cessation of certain behavioral
activities (such as socializing or feeding); visible startle response
or aggressive behavior (such as tail/fluke slapping or jaw clapping);
and avoidance of areas where sound sources are located. If a marine
mammal responds to a stimulus by changing its behavior (e.g., through
relatively minor changes in locomotion direction/speed or vocalization
behavior), the response may or may not constitute taking at the
individual level, and is unlikely to affect the stock or the species as
a whole. However, if a sound source displaces marine mammals from an
important feeding or breeding area for a prolonged period, potential
impacts on the stock or species could potentially be significant if
growth, survival and reproduction are affected (e.g., Lusseau and
Bejder, 2007; Weilgart, 2007). Note that the significance of many of
these behavioral disturbances is difficult to predict, especially if
the detected disturbances appear minor.
Local observations of marine mammals at Naval Base Kitsap Bangor
during a Test Pile Project (TPP) concluded that pinniped (harbor seal
and California sea lion) foraging behaviors decreased slightly during
construction periods involving impact and vibratory pile driving, and
both pinnipeds and harbor porpoise were more likely to change direction
while traveling during construction (HDR Inc., 2012). Pinnipeds were
more likely to dive and sink when closer to pile driving activity, and
a greater variety of other behaviors were observed with increasing
distance from pile driving. Relatively few observations of cetacean
behaviors were obtained during pile driving. Most harbor porpoises were
observed swimming or traveling through the project area, and no obvious
behavioral changes were associated with pile driving.
Three years of marine mammal monitoring were conducted to support
vibratory and impact pile driving for the construction of Explosives
Handling Wharf #2 (EHW-2) at Kitsap Bangor (Hart Crowser, 2013; 2014;
2015). Over the 3 years of monitoring, harbor seals, California sea
lions, and Steller sea lions were detected within the shutdown and
behavioral disturbance zones (Primary Surveys). Results from monitoring
varied slightly year to year, but in general, it has been found that
marine mammals were equally observed moving away from (or swimming
parallel to) the pile or having no motion during vibratory pile
driving. During impact driving, animals were most frequently observed
moving away (or moving parallel to) or having no relative motion to the
pile (Hart Crowser, 2013; 2014; 2015). Harbor porpoises' predominant
behavior during construction (vibratory pile driving) was swimming or
traveling through the project area. During pre-construction monitoring,
marine mammal observers also reported harbor porpoise foraging. Marine
mammal observers did not detect adverse reactions to TPP or EHW-2
construction activities consistent with distress, injury, or high speed
withdrawal from the area, nor did they report obvious changes in less
acute behaviors.
Auditory Masking--Natural and artificial sounds can disrupt
behavior by masking. Given that the energy distribution of pile driving
covers a broad frequency spectrum, sound from these sources would
likely be within the audible range of marine mammals present in the
project area. Impact pile driving activity is relatively short-term,
and mostly for proofing, with rapid pulses occurring for only a few
minutes per pile. The probability for impact pile driving resulting
from this proposed action masking acoustic signals important to the
behavior and survival of marine mammal species is low. Vibratory pile
driving is also relatively short-term. It is possible that vibratory
pile driving resulting from this proposed action may mask acoustic
signals important to the behavior and survival of marine mammal
species, but the short-term duration and limited affected area would
result in insignificant impacts from masking. Any masking event that
could possibly rise to Level B harassment under the MMPA would occur
concurrently within the zones of behavioral harassment already
estimated for vibratory and impact pile driving, and which have already
been taken into account in the exposure analysis.
Airborne Acoustic Effects From the Proposed Activities--Pinnipeds
that occur near the project site could be exposed to airborne sounds
associated with pile driving that have the potential to cause
behavioral harassment, depending on their distance from pile driving
activities. Cetaceans are not expected to be exposed to airborne sounds
that would result in harassment as defined under the MMPA.
Airborne noise will primarily be an issue for pinnipeds that are
swimming or hauled out near the project site within the range of noise
levels elevated above the acoustic criteria. We recognize that
pinnipeds in the water could be exposed to airborne sound that may
result in behavioral harassment when looking with heads above water.
Most likely, airborne sound would cause behavioral responses similar to
those discussed above in relation to underwater sound. However, these
animals would previously have been ``taken'' as a result of exposure to
underwater sound above the behavioral harassment thresholds, which are
in all cases larger than those associated with airborne sound. Thus,
the behavioral harassment of these animals is already accounted for in
these estimates of potential take. Multiple instances of exposure to
sound above NMFS' thresholds for behavioral harassment are not believed
to result in increased behavioral disturbance, in either nature or
intensity of disturbance reaction. Therefore, we do not believe that
authorization of incidental take resulting from airborne sound for
pinnipeds is warranted, and airborne sound is not discussed further
here.
Potential Pile Driving Effects on Prey--Construction activities
would produce continuous (i.e., vibratory pile driving) sounds and
pulsed (i.e., impact driving) sounds. Fish react to sounds that are
especially strong and/or intermittent low-frequency sounds. Short
duration, sharp sounds can cause overt or subtle changes in fish
behavior and local distribution. Hastings and Popper (2005) identified
several studies
[[Page 10701]]
that suggest fish may relocate to avoid certain areas of sound energy.
Additional studies have documented effects of pile driving on fish,
although several are based on studies in support of large, multiyear
bridge construction projects (e.g., Scholik and Yan, 2001, 2002; Popper
and Hastings, 2009). Sound pulses at received levels of 160 dB may
cause subtle changes in fish behavior. SPLs of 180 dB may cause
noticeable changes in behavior (Pearson et al., 1992; Skalski et al.,
1992). SPLs of sufficient strength have been known to cause injury to
fish and fish mortality.
The most likely impact to fish from pile driving activities at the
project area would be temporary behavioral avoidance within an
undetermined portion of the affected area. The duration of fish
avoidance of this area after pile driving stops is unknown, but a rapid
return to normal recruitment, distribution and behavior is anticipated.
In general, impacts to marine mammal prey species from the proposed
project are expected to be minor and temporary due to the relatively
short timeframe of pile driving and extraction.
Effects to Foraging Habitat--Pile installation may temporarily
impact foraging habitat by increasing turbidity resulting from
suspended sediments. Any increases would be temporary, localized, and
minimal. The Navy must comply with state water quality standards during
these operations by limiting the extent of turbidity to the immediate
project area. In general, turbidity associated with pile installation
is localized to about a 25-foot radius around the pile (Everitt et al.
1980). Cetaceans are not expected to be close enough to the project
pile driving areas to experience effects of turbidity, and any
pinnipeds will be transiting the area and could avoid localized areas
of turbidity. Therefore, the impact from increased turbidity levels is
expected to be discountable to marine mammals.
Impacts to salmonid and forage fish populations, including ESA-
listed species, will be minimized by adhering to the designated in-
water work period. These work periods are designated when out-migrating
juvenile salmonids are least likely to occur. Some habitat degradation
is expected during construction, but the impacts to fish species and
their habitats will be temporary and localized. The presence, shading
potential, and associated artificial lighting of the larger Service
Pier structure, because it would exist in offshore waters of at least
30 feet below MLLW, is not anticipated to alter the behavior of
juvenile salmonids using the nearshore migratory pathway. Adult
salmonids would not experience a substantial barrier effect, and there
would be little or no overall delay in their movements. The numbers of
marine mammals affected by impacts to prey populations will be small;
therefore, the impact will be insignificant in the context of marine
mammal populations.
It is important to note that pile driving and removal activities at
the project site will not obstruct movements or migration of marine
mammals.
In summary, given the relatively short and intermittent nature of
sound associated with individual pile driving and extraction events and
the relatively small area that would be affected, pile driving
activities associated with the proposed action are not likely to have a
permanent, adverse effect on any fish habitat, or populations of fish
species. Thus, any impacts to marine mammal habitat are not expected to
cause significant or long-term consequences for individual marine
mammals or their populations.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of whether the number of takes is ``small'' and the
negligible impact determination.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of 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).
Authorized takes would primarily be by Level B harassment, as pile
driving has the potential to result in disruption of behavioral
patterns for individual marine mammals. There is also some potential
for auditory injury (Level A harassment) to result for the harbor seal,
due to larger predicted auditory injury zones and regular presence
around the waterfront area. Auditory injury is unlikely to occur for
mid-frequency cetaceans or otariid species due to small predicted
zones. The proposed mitigation and monitoring measures are expected to
minimize the severity of such taking to the extent practicable.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the take is estimated.
Described in the most basic way, we estimate take by considering:
(1) Acoustic thresholds above which NMFS believes the best available
science indicates marine mammals will be behaviorally harassed or incur
some degree of permanent hearing impairment; (2) the area or volume of
water that will be ensonified above these levels in a day; (3) the
density or occurrence of marine mammals within these ensonified areas;
and, (4) and the number of days of activities. Below, we describe these
components in more detail and present the proposed take estimate.
Acoustic Thresholds
NMFS uses acoustic thresholds that identify the received level of
underwater sound above which exposed marine mammals would be reasonably
expected to be behaviorally harassed (equated to Level B harassment) or
to incur PTS of some degree (equated to Level A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source (e.g., frequency, predictability, duty cycle), the environment
(e.g., bathymetry), and the receiving animals (hearing, motivation,
experience, demography, behavioral context) and can be difficult to
predict (Southall et al., 2007, Ellison et al., 2011). NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. NMFS predicts that marine mammals are
likely to be behaviorally affected in a manner we consider Level B
harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g.
vibratory pile-driving) and above 160 dB re 1 [mu]Pa (rms) for non-
explosive impulsive (e.g., impact pile driving).
Level A Harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Technical
Guidance, 2016) identifies dual criteria to assess auditory injury
(Level A harassment) to five different marine mammal groups (based on
hearing sensitivity) as a result of exposure to noise from two
different types of sources (impulsive or non-impulsive). The Navy's
proposed activity includes the use of impulsive (impact pile
[[Page 10702]]
driving) and non-impulsive (vibratory pile driving and extraction)
sources.
These thresholds were developed by compiling and synthesizing the
best available science and soliciting input multiple times from both
the public and peer reviewers to inform the final product, and are
provided in Table 3. The references, analysis, and methodology used in
the development of the thresholds are described in NMFS 2016 Technical
Guidance, which may be accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
[GRAPHIC] [TIFF OMITTED] TN12MR18.003
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds.
Pile driving will generate underwater noise that potentially could
result in disturbance to marine mammals swimming by the project area.
Transmission loss (TL) underwater is the decrease in acoustic intensity
as an acoustic pressure wave propagates out from a source until the
source becomes indistinguishable from ambient sound. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. A standard sound propagation model, the Practical
Spreading Loss model, was used to estimate the range from pile driving
activity to various expected SPLs at potential project structures. This
model follows a geometric propagation loss based on the distance from
the driven pile, resulting in a 4.5 dB reduction in level for each
doubling of distance from the source. In this model, the SPL at some
distance away from the source (e.g., driven pile) is governed by a
measured source level, minus the TL of the energy as it dissipates with
distance. The TL equation is:
TL = 15log10(R1/R2)
Where:
TL is the transmission loss in dB,
R1 is the distance of the modeled SPL from the driven
pile, and
R2 is the distance from the driven pile of the initial
measurement.
The degree to which underwater noise propagates away from a noise
source is dependent on a variety of factors, most notably by the water
bathymetry and presence or absence of reflective or absorptive
conditions including the sea surface and sediment type. The TL model
described above was used to calculate the expected noise propagation
from both impact and vibratory pile driving, using representative
source levels to estimate
[[Page 10703]]
the zone of influence (ZOI) or area exceeding the noise criteria.
Source Levels
For the analyses that follow, the TL model described above was used
to calculate the expected noise propagation from pile driving, using an
appropriate representative source level from Table 4 to estimate the
area exceeding the noise criteria. The source levels were derived from
the Navy's document titled Proxy source sound levels and potential
bubble curtain attenuation for acoustic modeling of nearshore marine
pile driving at Navy installations in Puget Sound (Navy 2015). In that
document the Navy reviewed relevant data available for various types
and sizes of piles typically used for pile driving and recommend proxy
source values for Navy installations in Puget Sound. This document may
be found as Appendix B in the Navy's application. Acoustic monitoring
was conducted during previous pile driving projects at this location.
Results were used to establish proxy sound source levels for 36-in
steel piles.
Table 4--Underwater Noise Source Levels Modeled for Impact and Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
Installation RMS (dB re 1 Peak (dB re 1 SEL (dB re 1
Pile type method Pile diameter [mu]Pa) [mu]Pa) [mu]Pa\2\ sec)
----------------------------------------------------------------------------------------------------------------
Timber....................... Vibratory....... 15-18 in (38-45 \1\155 N/A N/A
cm).
Concrete..................... Impact.......... 18 in (45 cm).. 170 184 159
Steel........................ Impact.......... 24 in (60 cm).. 193 210 181
36 (90 cm)..... 194 211 181
Vibratory....... 24 (60 cm)..... 161 N/A N/A
36 (90 cm)..... 166 N/A N/A
----------------------------------------------------------------------------------------------------------------
\1\ Navy opted to use conservative value of 155 dB for project.
Key: cm = centimeter; dB re 1 [mu]Pa = decibels referenced at 1 micropascal; N/A = not applicable; RMS = root
mean square; SEL = sound exposure level.
For vibratory pile driving distances to the PTS thresholds, the TL
model described above incorporated the auditory weighting functions for
each hearing group using a single frequency as described in the NMFS
Optional Spreadsheet (NMFS, 2016b). When NMFS' Technical Guidance
(2016) was published, in recognition of the fact that ensonified area/
volume could be more technically challenging to predict because of the
duration component in the new thresholds, we developed a User
Spreadsheet that includes tools to help predict a simple isopleth that
can be used in conjunction with marine mammal density or occurrence to
help predict takes. We note that because of some of the assumptions
included in the methods used for these tools, we anticipate that
isopleths produced are typically going to be overestimates of some
degree, which may result in some degree of overestimate of Level A
take. However, these tools offer the best way to predict appropriate
isopleths when more sophisticated 3D modeling methods are not
available. NMFS continues to develop ways to quantitatively refine
these tools, and will qualitatively address the output where
appropriate. For stationary sources, including pile driving, NMFS User
Spreadsheet predicts the closest distance at which a marine mammal, if
it remained beyond that distance the whole duration of the activity,
would not incur PTS.
For impact pile driving distances to the cumulative PTS thresholds
for 36-inch (90 cm) and 24-inch (60 cm) steel and concrete pile, the TL
model described above incorporated frequency weighting adjustments by
applying the auditory weighting function over the entire 1-second SEL
spectral data sets from impact pile driving. The Navy believes, and
NMFS concurs, that this methodology provides a closer estimate than
applying the weighting function at a single frequency as suggested in
the NMFS Spreadsheet. The NMFS Spreadsheet is considered to be a
conservative method that typically results in higher estimates of the
PTS onset distance from the pile driving activity. The Navy analysis
focused on the data provided from the Naval Kitsap Bangor Test Pile
Program (steel piles) and the Puget Sound Naval Shipyard Intermediate
Maintenance Facility Pier 6 Fender Pile Replacement Project (concrete
piles) (Grebner et al., 2016). This analysis is described in more
detail in Appendix C.
An unconfined bubble curtain will be used during impact driving of
steel piles, since the project is located in an area without high
currents. While bubble curtain performance is variable, data from the
Bangor Naval Base Test Pile Program indicated an average peak SPL
reduction of 8 dB to 10 dB at 10 meters was achieved for impact driving
of 36- and 48-inch steel pipes (Navy 2015). However, for the SPE
project, a reduction of 8 dB was utilized as shown in Table 5.
Table 5--Inputs for Determining Distances to Cumulative PTS Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
18'' Concrete 24'' Steel 36'' Steel
36'' Steel impact 24'' Steel impact impact vibratory vibratory Timber
--------------------------------------------------------------------------------------------------------------------------------------------------------
INPUTS
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............ (E.1-2) Impact (E.1-2) Impact (E.1-2) Impact (A.1) Vibratory (A.1) Vibratory (A.1) Vibratory
pile driving. pile driving. pile driving. pile driving. pile driving. pile driving.
Source Level (Single Strike/shot 173 dB (assumes 8 173 dB (assumes 8 159 dB............
SEL). dB attenuation) *. dB attenuation) *.
Source Level (RMS SPL).......... .................. .................. .................. 161 dB............ 166 dB............ 155.
Weighting Factor Adjustment Weighting override Weighting override Weighting override 2.5............... 2.5............... 2.5.
(kHz) **. (Grebner et al. (Grebner et al. (Grebner et al.
2016). 2016). 2016).
Number of strikes per day....... 1,600............. 1,600............. 1,600.............
Number of piles per day within 2................. 1................. 3.................
24-h period.
Duration of sound Production .................. .................. .................. 300............... 300............... 300.
(minutes).
Propagation (xLogR)............. 15................ 15................ 15................ 15................ 15................ 15.
[[Page 10704]]
Distance of source level 10................ 10................ 10................ 10................ 10................ 10.
measurement (meters).
--------------------------------------------------------------------------------------------------------------------------------------------------------
* 8 dB reduction from use of unconfined bubble curtain during steel pipe impact driving.
** For impact driving, the TL model described above incorporated frequency weighting adjustments by applying the auditory weighting function over the
entire 1-second SEL spectral data sets.
Table 6--Calculated Radial Distances (Meters) to Underwater Marine Mammal Impact Pile Driving Noise Thresholds--
SELCUM Isopleths \1\
----------------------------------------------------------------------------------------------------------------
Level A isopleths--impact driving \2\
---------------------------------------------------------------
Source type High-
Mid-frequency frequency Phocid Otariid
cetaceans cetaceans pinnipeds pinnipeds
----------------------------------------------------------------------------------------------------------------
18-in concrete \3\.............................. 2 74 19 1
24-in steel \4\................................. 5 253 34 2
36-in steel \4\................................. 14 740 217 12
----------------------------------------------------------------------------------------------------------------
Notes:
1. Calculations based on SELCUM threshold criteria shown in Table 3.
Calculated values were rounded up the nearest meter.
2. Representative spectra were used to calculate the distances to the injury (PTS onset) thresholds for each
functional hearing group for 24-inch and 36-inch steel pile and 24-inch (60 cm) concrete pile. Distances for
18-inch (45 cm) concrete piles assumed to be the same as 24-inch (60 cm) concrete piles.
3. No bubble curtain proposed for concrete pile.
4. Bubble curtain will be used for 24-inch (60 cm) and 36-inch (90 cm) steel piles, and calculations include 8
dB attenuation.
Table 7--Calculated Radial Distances (Meters) to Level A Underwater Marine Mammal Vibratory Pile Driving Noise
Isopleths
----------------------------------------------------------------------------------------------------------------
Level A isopleths--Vibratory driving \1\
-------------------------------------------------------------------------------
Source type High-
Low-frequency Mid-frequency frequency Phocid Otariid
cetaceans cetaceans cetaceans pinnipeds pinnipeds
----------------------------------------------------------------------------------------------------------------
15-18-in timber................. 8 <1 12 5 <1
24-in steel..................... 20 2 30 12 1
36-in steel..................... 43 4 64 26 1.8
----------------------------------------------------------------------------------------------------------------
Notes:
1. Distances to the injury (PTS onset) thresholds calculated using National Marine Fisheries Service calculator
with default Weighting Factor Adjustment of 2.5 (NMFS, 2016b).
Calculated values were rounded up the nearest meter.
Tables 6 and 7 show the radial distances to impact and vibratory
Level A isopleths. Based on the dual criteria provided in the NMFS
Spreadsheet, the cumulative SEL was selected over peak threshold to
calculate injury thresholds because the ensonified distances were
larger.
Using the same source level and transmission loss inputs discussed
above the Level B isopleths were calculated for impact and vibratory
driving (Table 8). Note that these attenuation distances are based on
sound characteristics in open water. The actual attenuation distances
are constrained by numerous land features and islands; these actual
distances are reflected in the ensonified areas given below.
Table 8--Level B Impact and Vibratory Pile Driving Exposure Distances and Ensonified Areas
----------------------------------------------------------------------------------------------------------------
Pile type Attenuation distance Area *
----------------------------------------------------------------------------------------------------------------
Impact (160 dB)
----------------------------------------------------------------------------------------------------------------
18-in concrete.................................... 46 m......................... 6.64 m\2\.
24-in steel....................................... 464 m........................ 0.62 km\2\.
36-in steel....................................... 541 m........................ 0.78 km\2\.
----------------------------------------------------------------------------------------------------------------
Vibratory (120 dB)
----------------------------------------------------------------------------------------------------------------
15-18-in timber................................... 2.2 km....................... 6.8 km\2\.
24-in steel....................................... 5.4 km....................... 26.1 km\2\.
36-in steel....................................... 11.7 km...................... 49.6 km\2\.
----------------------------------------------------------------------------------------------------------------
* Areas were adjusted wherever land masses are encountered prior to reaching the full extent of the radius
around the driven pile.
[[Page 10705]]
Marine Mammal Occurrence
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations.
Transient killer whales are rare in Hood Canal and there are few
data to describe transient killer whale abundance within Hood Canal.
There have been anecdotal accounts of the whales in Hood Canal for
decades. There was a report from 1 day in April 2016 and 8 days in May
2016 of whales Dabob Bay (Orca Network, 2016). It is likely that the
whales were using Hood Canal as part of a larger area moving in and out
of Hood Canal. It is not known how large an area these animals were
using; it is also unknown if these sightings were all of the same group
of transient killer whales, or if animals were using the same areas.
However, the temporally discontinuous data suggest a high degree of
variability in the habitat use and localized relative abundances of
transient killer whales in Hood Canal. Given that whales were observed
on eight days, in May 2016, NMFS will assume that whales could be
observed on up to 8 days during the SPE project. The most commonly
observed group size in Puget Sound from 2004 to 2010 was 6 whales (Navy
2017).
Harbor porpoises may be present in Puget Sound year-round typically
in groups of one to five individuals and are regularly detected in Hood
Canal. Aerial surveys conducted throughout 2013 to 2015 in Puget Sound
indicated density in Puget Sound was 0.91 individuals/km\2\) (95% CI =
0.72-1.10, all seasons pooled) and density in Hood Canal was 0.47/km\2\
(95% CI = 0.29-0.75, all seasons pooled) (Jefferson et al., 2016).
However, after reviewing the most recent data the Navy has estimated
that harbor porpoise density in Hood Canal is 0.44 animals/km\2\
(Smultea et al., 2017). Mean group size of harbor porpoises in Puget
Sound in the 2013-2015 surveys was 1.7 in Hood Canal.
Steller sea lions are routinely seen hauled out on submarines at
Naval Base Kitsap. The Navy relied on monitoring data from 2012 to 2016
to determine the average of the maximum count of hauled out Steller sea
lions for each month in the in-water work window (Appendix A). The
average of the monthly maximum counts during the in-water work window
was 3.14, rounded to 3 exposures per day.
California sea lions can occur at Naval Base Kitsap Bangor in any
month, although numbers are low from June through August (Appendix A in
the application).
California sea lions peak abundance occurs between October and May
(NMFS, 1997; Jeffries et al., 2000) but animals can occur at Naval Base
Kitsap Bangor in any month. The Navy relied on monitoring data from
2012 to 2016 to determine the average of the maximum count of hauled
out California sea lions for each month (Appendix A). The Navy
determined abundance of California sea lions based on the average
monthly maximum counts during the in-water work window (Appendix A),
respectively, for an average maximum count of 48.85, rounded to 49
exposures per day.
Boat-based surveys and monitoring indicate that harbor seals
regularly swim in the waters at Naval Base Kitsap Bangor (Appendix A in
Application). Hauled-out adults, mother/pup pairs, and neonates have
been documented occasionally, but quantitative data are limited.
Incidental surveys in August and September 2016 recorded as many as 28
harbor seals hauled out under Marginal Wharf or swimming in adjacent
waters. Additional animals were likely present at other locations
during the same time of the surveys. To be conservative, the Navy
estimated that an additional 7 animals were present based on typical
sightings at the other piers at Bangor. Therefore, the Navy and NMFS
assume that up to 35 seals could occur near the SPE project area on any
given day.
Take Calculation and Estimation
Here we describe how the information provided above is brought
together to produce a quantitative take estimate.
To quantitatively assess exposure of marine mammals to noise levels
from pile driving over the NMFS threshold guidance, one of three
methods was used depending on the species spatial and temporal
occurrence. For species with rare or infrequent occurrence during the
in-water work window, the likelihood of occurrence was reviewed based
on the information in Chapter 3 of the application and the potential
maximum duration of work days and total work days. Only one species was
in this category, transient killer whale, and it had the potential to
linger for multiple days based on historical information. The
calculation was:
(1) Exposure estimate = Probable abundance during construction x
Probable duration
Where:
Probable abundance = maximum expected group size
Probable duration = probable duration of animal(s) presence at
construction sites during in-water work window
For species that regularly occur in Puget Sound, but for which
local abundance data are not available, marine mammal density estimates
were used when available to determine the number of animals potentially
exposed in a ZOI on any one day of pile driving or extraction. Only
harbor porpoise was in this category.
The equation for this species with only a density estimate and no
site-specific abundance was:
(2) Exposure estimate = N x ZOI x maximum days of pile driving
Where:
N = density estimate used for each species
ZOI = Zone of Influence; the area where noise exceeds the noise
threshold value
For species with site-specific surveys available, exposures were
estimated by:
(3) Exposure estimate = Abundance x maximum days of pile driving
Where:
Abundance = average monthly maximum over the time period when pile
driving will occur for sea lions, and estimated total abundance for
harbor seals
All three pinniped species were in this category. Average monthly
maximum counts of Steller sea lions and California sea lions (see
Appendix A for abundance data of these species) were averaged over the
in-water work window. The maximum number of animals observed during the
month(s) with the highest number of animals present on a survey day was
used in the analysis. For harbor seals, an abundance estimate for the
Bangor waterfront was used.
The following assumptions were used to calculate potential
exposures to impact and vibratory pile driving noise for each
threshold.
For formulas (2) and (3), each species will be assumed to
be present in the project area each day during construction. The
timeframe for takings would be one potential take (Level B harassment
exposure) per individual, per 24 hours.
The pile type, size, and installation method that produce
the largest ZOI were used to estimate exposure of marine mammals to
noise impacts. Vibratory installation of 36-inch (90 cm) steel piles
created the largest ZOI, so the exposure analysis calculates marine
mammal exposures based on 36- inch steel piles for the 125 days when
steel piles would be installed. For the estimated 35 days when concrete
fender piles would be installed, impact driving was the only
installation method and only 18-inch piles were proposed, so the
exposure analysis calculated marine mammal exposures based on impact
driving 18-inch concrete piles.
[[Page 10706]]
All pilings will have an underwater noise disturbance
distance equal to the pile that causes the greatest noise disturbance
(i.e., the piling farthest from shore) installed with the method that
has the largest ZOI. If vibratory pile driving would occur, the largest
ZOI will be produced by vibratory driving. In this case, the ZOI for an
impact hammer will be encompassed by the larger ZOI from the vibratory
driver. Vibratory driving was assumed to occur on all 125 days of steel
pile driving, but not the 35 days of concrete fender pile installation.
Days of pile driving were conservatively based on a
relatively slow daily production rate, but actual daily production
rates may be higher, resulting in fewer actual pile driving days. The
pile driving days are used solely to assess the number of days during
which pile driving could occur if production was delayed due to
equipment failure, safety, etc. In a real construction situation, pile
driving production rates would be maximized when possible.
Transient Killer Whale
Using the first calculation described in the above section,
exposures to underwater pile driving were calculated using the average
group size times the 8 days transient killer whales would be
anticipated in the Hood Canal during pile driving activities. The Navy
assumed that the average pod size was six individuals.
Using this rationale, 48 potential Level B exposures of transient
killer whales from vibratory pile driving are estimated (six animals
times 8 days of exposure). Based on this analysis, the Navy requests
and NMFS proposes 48 Level B incidental takes for behavioral
harassment. Concrete and steel ZOIs from impact driving will be fully
monitorable (maximum distances to behavioral thresholds of 46 m and 541
m, respectively, and maximum distance to injury thresholds is 14 m), so
no killer whale behavioral or injury takes are expected from impact
driving.
Harbor Porpoise
Applying formula (2) to the animal density (0.44animals/km \2\),
the largest ZOI for Level B exposure (49.6 km \2\) and the estimated
days of steel pile driving (125), the Navy requests and NMFS proposes
2,728 Level B incidental takes of harbor porpoises. The 49.6 km \2\ ZOI
excludes the area behind the PSB because harbor porpoise have never
been observed within the barrier. Harbor porpoise can be visually
detected to a distance of about 200 m by experienced observers in
conditions up to Beaufort 2 (Navy 2017). Therefore, the concrete ZOIs
will be fully monitorable (maximum distance of 46 m), so no takes were
calculated for the estimated 35 days of concrete fender pile
installation.
Steller Sea Lion
Concrete ZOIs will be fully monitorable, so no takes were
calculated for the estimated 35 days of concrete fender pile
installation. Formula (3) as described in the previous section was used
with site-specific abundance data to calculate potential exposures of
Steller sea lions during steel pile driving for the SPE project.
Animals could be exposed when traveling, resting, and foraging. Because
a Level A injury shut-down zone will be implemented, Level A harassment
is not expected to occur.
The Navy conservatively assumes that any Steller sea lion that
hauls out at Bangor could swim into the behavioral harassment zone each
day during pile driving because this zone extends across Hood Canal and
up to 11.7 km from the driven pile. The Navy estimated 3 animals could
be exposed to harassment per day. These values provide a worst case
assumption that on all 125 days of pile driving, all animals would be
in the water each day during pile driving. Applying formula (3) to this
abundance and the 125 steel pile driving days, the Navy requests and
NMFS proposes the take of up to 375 Steller sea lions. If project work
occurs during months when Steller sea lions are less likely to be
present, actual exposures would be less. Additionally, if daily pile
driving duration is short, exposure would be expected to be less
because some animals would remain hauled out for the duration of pile
driving. Any exposure of Steller sea lions to pile driving noise will
be minimized to short-term behavioral harassment.
California Sea Lion
Concrete ZOIs will be fully monitorable (maximum distance of 46 m),
so no takes were calculated for the estimated 35 days of concrete
fender pile installation (Figure 6-3 in application). Formula (3) was
used with site-specific abundance data to calculate potential exposures
of California sea lions during pile driving for the SPE project.
Because a Level A injury shut-down zone will be implemented, no
exposure to Level A noise levels will occur at any location. Based on
site-specific data regarding the average maximum counts, the Navy
assumes that 49 exposures per day could occur over 125 planned steel
pile driving days. Therefore, NMFS proposes authorizing 6,125 Level B
takes.
Harbor Seal
The Navy calculated up to 35 harbor seals may be present per day
during summer and early fall months. Exposure of harbor seals to pile
driving noise will be primarily in the form of short-term behavioral
harassment (Level B) during steel pile driving. Concrete ZOIs will be
fully monitorable (maximum distance of 46 m), so no takes were
calculated for the estimated 35 days of concrete fender pile
installation (Figure 6-3 in application). Formula (3) was used with
site-specific abundance data to calculate potential exposures of harbor
seals due to pile driving for the SPE.
The Navy assumes that any harbor seal that hauls out at Bangor
could swim into the behavioral harassment zone each day during impact
pile driving. The largest ZOI for behavioral disturbance (Level B)
would be 11.7 km for vibratory driving and extraction of 36-inch steel
piles. Applying formula (3) to the abundance of this species (35
individuals) and the 125 pile driving days, the Navy requests and NMFS
proposes the Level A and Level B take of up to 4,375 harbor seals
during pile driving for the SPE. The largest ZOI for Level A injury
will be 217 m for impact driving (with bubble curtain) of 36-inch steel
piles. A monitors' ability to observe the entire 217 m injury zone may
be difficult because construction barges and the current Service Pier
structure and associated mooring floats and vessels will interfere with
a monitors' ability to observe the entire injury zone. Some individuals
could enter, and remain in, the injury zone undetected by monitors,
resulting in potential PTS. It is estimated that one of the 35
individuals present on the Bangor waterfront would enter, and remain
in, the injury zone without being detected by marine mammal monitors
each day during steel impact driving. Therefore, with 125 steel pile
driving days and one individual per day being exposed to Level A noise
levels, 125 Level A takes of harbor seals are proposed by NMFS.
Subtracting 125 Level A takes from the estimated total of 4,375 takes
would result in 4,250 Level B takes. It should be noted that Level A
takes of harbor seals would likely be multiple exposures of the same
individuals, rather than single exposures of unique individuals. This
request overestimates the likely Level A exposures because: (1) Seals
are unlikely to remain in the Level A zone underwater long enough to
accumulate sufficient exposure to noise resulting in PTS, and (2) the
estimate assumes that new seals are in the Level A ZOI every day during
pile driving. No Level A
[[Page 10707]]
takes are requested for vibratory pile driving because the maximum
harbor seal injury zone is 15 m and is within a practicable shutdown
distance. It is important to note that the estimate of potential Level
A harassment of harbor seals is expected to be an overestimate, since
the planned project is not expected to occur near Marginal Wharf--the
location where most harbor seal activity occurs.
Table 9 provides a summary of proposed authorized Level A and Level
B takes as well as the percentage of a stock or population proposed for
take.
Table 9--Proposed Authorized Take and Percentage of Stock or Population
----------------------------------------------------------------------------------------------------------------
Proposed authorized take
Species -------------------------------- Percent
Level A Level B population
----------------------------------------------------------------------------------------------------------------
Killer whale.................................................... 0 48 19.7
Harbor porpoise................................................. 0 2,728 24.3
Steller sea lion................................................ 0 375 0.9
California sea lion............................................. 0 6,125 2.0
Harbor seal..................................................... 125 4,250 n/a
----------------------------------------------------------------------------------------------------------------
Proposed Mitigation
In order to issue an IHA under Section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to such
activity, and other means of effecting the least practicable 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 taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting such
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned) the likelihood of effective implementation (probability
implemented as planned) and;
(2) the practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
In addition to the specific measures described later in this
section, the Navy would conduct briefings between construction
supervisors and crews, marine mammal monitoring team, and Navy staff
prior to the start of all pile driving activity, and when new personnel
join the work, in order to explain responsibilities, communication
procedures, marine mammal monitoring protocol, and operational
procedures.
Use of Vibratory Installation--The Navy will employ vibratory
installation to the greatest extent possible when driving steel piles
to minimize high sound pressure levels associated with impact pile
driving. Impact driving of steel piles will only occur when required by
geotechnical conditions or to ``proof'' load-bearing piles driven by
vibratory methods.
Timing Restrictions--To minimize the number of fish exposed to
underwater noise and other construction disturbance, in-water work will
occur during the in-water work window previously described when ESA-
listed salmonids are least likely to be present (USACE, 2015), July 16-
January 15.
All in-water construction activities will occur during daylight
hours (sunrise to sunset) except from July 16 to September 15, when
impact pile driving will only occur starting 2 hours after sunrise and
ending 2 hours before sunset, to protect foraging marbled murrelets
during the nesting season (April 15-September 23). Sunrise and sunset
are to be determined based on National Oceanic and Atmospheric
Administration data, which can be found at http://www.srrb.noaa.gov/highlights/sunrise/sunrise.html.
Use of Bubble Curtain--A bubble curtain or other noise attenuation
device that achieves an average of at least 8 dB of noise attenuation
will be employed during impact installation or proofing of steel piles
where water depths are greater than 0.67 m (2 ft). A noise attenuation
device is not required during vibratory pile driving. If a bubble
curtain or similar measure is used, it will distribute air bubbles
around 100 percent of the piling perimeter for the full depth of the
water column. Any other attenuation measure must provide 100 percent
coverage in the water column for the full depth of the pile. The lowest
bubble ring shall be in contact with the mudline for the full
circumference of the ring. The weights attached to the bottom ring
shall ensure 100 percent mudline contact. No parts of the ring or other
objects shall prevent full mudline contact.
A performance test of the noise attenuation device shall be
conducted prior to initial use for impact pile driving. If a bubble
curtain or similar measure is utilized, the performance test shall
confirm the calculated pressures and flow rates at each manifold ring.
The contractor shall also train personnel in the proper balancing of
air flow to the bubblers. The contractor shall submit an inspection/
performance report to the Navy for approval within 72 hours following
the performance test. Corrections to the noise attenuation device to
meet the performance stands shall occur prior to use for impact
driving.
If the U.S. Fish and Wildlife Service concurs that turning off the
noise attenuation will not negatively impact marbled murrelets,
baseline sound measurements of steel pile driving will occur prior to
the implementation of noise attenuation to evaluate the performance of
a noise attenuation device. Impact pile driving without
[[Page 10708]]
noise attenuation will be limited to the number of piles necessary to
obtain an adequate sample size for each project.
Soft-Start--The use of a soft start procedure is believed to
provide additional protection to marine mammals by warning or providing
a chance to leave the area prior to the hammer operating at full
capacity, and typically involves a requirement to initiate sound from
the hammer at reduced energy followed by a waiting period. A soft-start
procedure will be used for impact pile driving at the beginning of each
day's in-water pile driving or any time impact pile driving has ceased
for more than 30 minutes.
The Navy will start the bubble curtain prior to the initiation of
impact pile driving. The contractor will provide an initial set of
strikes from the impact hammer at reduced energy, followed by a 30-
second waiting period, then two subsequent sets. (The reduced energy of
an individual hammer cannot be quantified because it varies by
individual drivers. Also, the number of strikes will vary at reduced
energy because raising the hammer at less than full power and then
releasing it results in the hammer ``bouncing'' as it strikes the pile,
resulting in multiple ``strikes.'')
Establishment of Shutdown Zones and Disturbance Zones--For all
impact and vibratory pile driving of steel piles, shutdown and
disturbance zones will be established and monitored. The Navy will
focus observations within 1,000 m for all species during these
activities but will record all observations. During impact driving of
concrete piles the Navy will focus on monitoring within 100 m but will
record all observations. The Navy will monitor and record marine mammal
observations within zones and extrapolate these values across the
entirety of the Level B zone as part of the final monitoring report. To
the extent possible, the Navy will record and report on any marine
mammal occurrences, including behavioral disturbances, beyond 1,000 m
for steel pile installation and 100 m for concrete pile installation.
The shutdown zones are based on the distances from the source
predicted for each threshold level. Although different functional
hearing groups of cetaceans and pinnipeds were evaluated, the threshold
levels used to develop the disturbance zones were selected to be
conservative for cetaceans (and therefore at the lowest levels); as
such, the disturbance zones for cetaceans were based on the high
frequency threshold (harbor porpoise). The shutdown zones are based on
the maximum calculated Level A radius for pinnipeds and cetaceans
during installation of 36-inch steel and concrete piles with impact
techniques, as well as during vibratory pile installation and removal.
These actions serve to protect marine mammals, allow for practical
implementation of the Navy's marine mammal monitoring plan and reduce
the risk of a take. The shutdown zone during any non-pile driving
activity will always be a minimum of 10 m (33 ft) to prevent injury
from physical interaction of marine mammals with construction
equipment.
During all pile driving, the shutdown, Level A, and Level B zones
as shown in Tables 10, 11, and 12 will be monitored out to the greatest
extent possible with a focus on monitoring within 1,000 m for steel
pile and 100 m for concrete pile installation.
For steel pile impact pile driving, monitors would initiate
shutdown when harbor seals approach or enter the zone. However, because
of the size of the zone and the inherent difficulty in monitoring
harbor seals, a highly mobile species, it may not be practical, which
is why Level A take is requested.
The isopleths delineating shutdown, Level A, and Level B zones
during impact driving of all steel piles are shown in Table 10. Note
that the Level A isopleth is larger than the Level B isopleth for
harbor porpoises.
Table 10--Shutdown, Level A, and Level B Isopleths During Impact Driving of Steel Piles
----------------------------------------------------------------------------------------------------------------
Level B Level A
Marine mammal group isopleth isopleth Shutdown zone
(meters) (meters) (meters)
----------------------------------------------------------------------------------------------------------------
Cetaceans (Harbor Porpoise)..................................... 541 740 1,000
Harbor Seal..................................................... 541 217 220
Sea Lions....................................................... 541 12 220
----------------------------------------------------------------------------------------------------------------
The isopleths for the shutdown, Level A, and Level B zones during
vibratory driving of all steel piles are shown in Table 11.
Table 11--Shutdown, Level A, Level B Isopleths During Vibratory Driving of Steel Piles
----------------------------------------------------------------------------------------------------------------
Level B Level A
Marine mammal group isopleth isopleth Shutdown zone
(meters) (meters) (meters)
----------------------------------------------------------------------------------------------------------------
Cetaceans (Harbor Porpoise)..................................... 11,700 64 100
Harbor Seal..................................................... 11,700 26 30
Sea Lions....................................................... 11,700 1.8 30
----------------------------------------------------------------------------------------------------------------
The shutdown, Level A, and Level B isopleths for implementation
during impact driving of concrete piles are shown in Table 12. Given
that the shutdown zone for all authorized species is larger than the
Level A and Level B isopleths there should be no take recorded during
concrete pile driving.
[[Page 10709]]
Table 12--Shutdown, Level A, and Level B Isopleths During Impact Driving of Concrete Piles
----------------------------------------------------------------------------------------------------------------
Level B Level A
Marine mammal group isopleth isopleth Shutdown zone
(meters) (meters) (meters)
----------------------------------------------------------------------------------------------------------------
Cetaceans (Harbor Porpoise)..................................... 46 74 100
Harbor Seal..................................................... 46 19 50
Sea Lions....................................................... 46 1 50
----------------------------------------------------------------------------------------------------------------
Note that the radii of the disturbance zones may be adjusted if in-
situ acoustic monitoring is conducted by the Navy to establish actual
distances to the thresholds for a specific pile type and installation
method. However, any proposed acoustical monitoring plan must be pre-
approved by NMFS. The results of any acoustic monitoring plan must be
reviewed and approved by NMFS before the radii of any disturbance zones
may be revised.
The mitigation measures described above should reduce marine
mammals' potential exposure to underwater noise levels which could
result in injury or behavioral harassment. Based on our evaluation of
the applicant's proposed measures, as well as other measures considered
by NMFS, NMFS has preliminarily determined that the proposed mitigation
measures provide the means effecting the least practicable impact on
the affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, Section 101(a)(5)(D) 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
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. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (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: 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 marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring will include the following proposed
requirements.
Marine Mammal Observers (MMOs) will be positioned at the best
practicable vantage points, taking into consideration security, safety,
and space limitations. During pile driving, one MMO will be stationed
in a vessel, and at least four will be stationed on the pier, along the
shore, or on the pile driving barge to maximize observation coverage.
Each MMO location will have a minimum of one dedicated MMO (not
including boat operators). The exact number of MMOs and the observation
locations are to be determined based upon site accessibility and line
of sight for adequate coverage. It is expected that a minimum of four
MMOs will be required, with additional MMOs added into the protocol as
deemed necessary for effective coverage. Additional standards required
for visual monitoring include:
(a) Independent observers (i.e., not construction personal) are
required;
(b) At least one observer must have prior experience working as an
observer;
(c) Other observers may substitute education (undergraduate degree
in biological science or related field) or training for experience;
(d) Where a team of three or more observers are required, one
observer should be designated as lead observer or monitoring
coordinator. The lead observer must have prior experience working as an
observer; and
(e) We will require submission and approval of observer CVs.
Monitoring will be conducted by qualified observers, who will
monitor for marine mammals and implement shutdown/delay procedures when
applicable by calling for the shutdown to the hammer operator.
Qualified observers are trained biologists, with the following minimum
qualifications:
(a) Visual acuity in both eyes (correction is permissible)
sufficient for discernment of moving targets at the water's surface
with ability to estimate target size and distance; use of binoculars
may be necessary to correctly identify the target;
(b) Advanced education in biological science or related field
(undergraduate degree or higher required);
(c) Experience and ability to conduct field observations and
collect data according to assigned protocols (this may include academic
experience);
(d) Experience or training in the field identification of marine
mammals, including the identification of behaviors;
(e) Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
(f) Writing skills sufficient to prepare a report of observations
including but not limited to the number and species of marine mammals
observed; dates and times when in-water construction activities were
conducted; dates and times when in-water construction activities were
suspended to avoid potential incidental injury from construction sound
of marine mammals observed within a defined shutdown zone; and marine
mammal behavior; and
[[Page 10710]]
(g) Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
MMOs will survey the disturbance zone 15 minutes prior to
initiation of pile driving through 30 minutes after completion of pile
driving to ensure there are no marine mammals present. In case of
reduced visibility due to weather or sea state, the MMOs must be able
to see the shutdown zones or pile driving will not be initiated until
visibility in these zones improves to acceptable levels. Marine Mammal
Observation Record forms (Appendix A of the application) will be used
to document observations. Survey boats engaged in marine mammal
monitoring will maintain speeds equal to or less than 10 knots.
MMOs will use binoculars and the naked eye to search continuously
for marine mammals and will have a means to communicate with each other
to discuss relevant marine mammal information (e.g., animal sighted but
submerged with direction of last sighting). MMOs will have the ability
to correctly measure or estimate the animals distance to the pile
driving equipment such that records of any takes are accurate relevant
to the pile size and type.
Shutdown shall occur if a species for which authorization has not
been granted or for which the authorized numbers of takes have been
met. The Navy shall then contact NMFS within 24 hours.
If marine mammal(s) are present within or approaching a shutdown
zone prior to pile driving, the start of these activities will be
delayed until the animal(s) have left the zone voluntarily and have
been visually confirmed beyond the shutdown zone, or 15 minutes has
elapsed without re-detection of the animal.
If animal is observed within or entering the Level B zone during
pile driving, a take would be recorded, behaviors documented. However,
that pile segment would be completed without cessation, unless the
animal approaches or enters the shutdown Zone, at which point all pile
driving activities will be halted. The MMOs shall immediately radio to
alert the monitoring coordinator/construction contractor. This action
will require an immediate ``all-stop'' on pile operations. Once a
shutdown has been initiated, pile driving will be delayed until the
animal has voluntarily left the Shutdown Zone and has been visually
confirmed beyond the Shutdown Zone, or 15 minutes have passed without
re-detection of the animal (i.e., the zone is deemed clear of marine
mammals).
All marine mammals observed within the disturbance zones during
pile driving activities will be recorded by MMOs. These animals will be
documented as Level A or Level B takes as appropriate. Additionally,
all shutdowns shall be recorded. For vibratory driving activities, this
data will be extrapolated across the full extent of the Level B
ensonified zone (i.e. 11.7 km radii) to provide total estimated take
numbers.
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities. It will include an overall description of work completed, a
narrative regarding marine mammal sightings, and associated marine
mammal observation data sheets. Specifically, the report must include
information as described in the Marine Mammal Monitoring Report
(Appendix D of the application).
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
In the unanticipated event that: (1) The specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury, serious injury or mortality; (2) an
injured or dead animal is discovered and cause of death is known; or
(3) an injured or dead animal is discovered and cause of death is not
related to the authorized activities, the Navy will follow the
protocols described in the Section 3 of Marine Mammal Monitoring Report
(Appendix D of the application).
Negligible Impact Analysis and Preliminary Determination
NMFS has defined negligible impact 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'' (50 CFR 216.103).
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'' through harassment, NMFS considers other factors, such as the
likely nature of any responses (e.g., intensity, duration), the context
of any responses (e.g., critical reproductive time or location,
migration), as well as effects on habitat, and the likely effectiveness
of the mitigation. We also assess the number, intensity, and context of
estimated takes by evaluating this information relative to population
status. Consistent with the 1989 preamble for NMFS's implementing
regulations (54 FR 40338; September 29, 1989), the impacts from other
past and ongoing anthropogenic activities are incorporated into this
analysis 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, ongoing sources of human-caused mortality, or
ambient noise levels).
Pile driving and extraction associated with the Navy SPE project as
outlined previously have the potential to injure, disturb or displace
marine mammals. Specifically, the specified activities may result in
Level B harassment (behavioral disturbance) for five marine mammal
species authorized for take from underwater sound generated during pile
driving operations. Level A harassment in the form of PTS may also
occur to limited numbers of one species. Level A harassment was
conservatively authorized for harbor seals since seals can occur in
high numbers near the project area, can be difficult to spot, and MMO's
ability to observe the entire 217 m injury zone may be slightly
impaired because of construction barges and vessels. Potential takes
could occur if marine mammals are present in the Level A or Level B
ensonified zones when pile driving and removal occurs.
No serious injury or mortality is anticipated given the nature of
the activities and measures designed to minimize the possibility of
injury to marine mammals. The potential for injury is minimized through
the construction method and the implementation of the planned
mitigation measures. Specifically, vibratory driving will be the
primary method of installation. This driving method decreases the
potential for injury due to relatively low source levels and lack of
potentially injurious source characteristics. Only piles that cannot be
driven to their desired depths using the vibratory hammer will be
impact driven for the remainder of their required driving depth. Noise
attenuating devices (i.e., bubble curtain) will be used during impact
hammer operations for steel piles. During impact driving,
implementation of soft start and shutdown zones significantly reduces
any possibility of injury. Given
[[Page 10711]]
sufficient ``notice'' through use of soft start (for impact driving),
marine mammals are expected to move away from a sound source that is
annoying prior to it becoming potentially injurious. Given the number
of MMOs that will be employed, observers should have a relatively clear
view of the shutdown zones, although under limited circumstances the
presence of barges and vessels may impair observation of small portions
of shutdown zones. This will enable a high rate of success in
implementation of shutdowns to avoid injury.
The Navy's planned activities are highly localized. Only a
relatively small portion of Hood Canal may be affected. The project is
not expected to have significant adverse effects on marine mammal
habitat. No important feeding and/or reproductive areas for marine
mammals are known to be near the project area. Impacts to salmonid and
forage fish populations, including ESA-listed species, will be
minimized by adhering to the designated in-water work period. Project-
related activities may cause some fish to leave the area of
disturbance, thus temporarily impacting marine mammals' foraging
opportunities in a limited portion of the foraging range, but because
of the relatively small area of the habitat range utilized by each
species that may be affected, the impacts to marine mammal habitat are
not expected to cause significant or long-term negative consequences.
Exposures to elevated sound levels produced during pile driving
activities may cause behavioral responses by an animal, but they are
expected to be mild and temporary. Effects on individuals that are
taken by Level B harassment, on the basis of reports in the literature
as well as monitoring from other similar activities, will likely be
limited to reactions such as increased swimming speeds, increased
surfacing time, or decreased foraging (if such activity were occurring)
(e.g., Thorson and Reyff, 2006; Lerma, 2014). Most likely, individuals
will simply move away from the sound source and be temporarily
displaced from the areas of pile driving, although even this reaction
has been observed primarily only in association with impact pile
driving. These reactions and behavioral changes are expected to subside
quickly when the exposures cease. The pile driving activities analyzed
here are similar to, or less impactful than, numerous construction
activities conducted in other similar locations including Hood Canal,
which have taken place with no reported injuries or mortality to marine
mammals, and no known long-term adverse consequences from behavioral
harassment. Repeated exposures of individuals to levels of sound that
may cause Level B harassment are unlikely to result in permanent
hearing impairment or to significantly disrupt foraging behavior. Level
B harassment will be reduced through use of mitigation measures
described herein.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or
stocks through effects on annual rates of recruitment or survival:
No mortality or serious injury is anticipated or
authorized;
The area of potential impacts is highly localized;
No adverse impacts to marine mammal habitat;
The absence of any significant habitat within the project
area, including rookeries, or known areas or features of special
significance for foraging or reproduction;
Anticipated incidences of Level A harassment would be in
the form of a small degree of PTS to a limited number of animals;
Anticipated incidents of Level B harassment consist of, at
worst, temporary modifications in behavior;
The anticipated efficacy of the required mitigation
measures in reducing the effects of the specified activity.
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 monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under Section 101(a)(5)(D) of the MMPA for specified
activities other than military readiness activities. The MMPA does not
define small numbers and so, in practice, where estimated numbers are
available, NMFS compares the number of individuals taken to the most
appropriate estimation of abundance of the relevant species or stock in
our determination of whether an authorization is limited to small
numbers of marine mammals. Additionally, other qualitative factors may
be considered in the analysis, such as the temporal or spatial scale of
the activities.
Table 9 depicts the number of animals that could be exposed to
Level A and Level B harassment from work associated with the SPE
project. With the exception of harbor seals, the analysis provided
indicates that authorized takes account for no more than 24.3 percent
of the populations of the stocks that could be affected. These are
small numbers of marine mammals relative to the sizes of the affected
species and population stocks under consideration.
For the affected stock of harbor seals, no valid abundance estimate
is available. The most recent abundance estimates for harbor seals in
Washington inland waters are from 1999, and it is generally believed
that harbor seal populations have increased significantly during the
intervening years (e.g., Mapes, 2013). However, we anticipate that
takes estimated to occur for harbor seals are likely to occur only
within some portion of the relevant populations, rather than to animals
from the stock as a whole. For example, takes anticipated to occur at
NBK Bangor would be expected to accrue to the same individual seals
that routinely occur on haulouts at these locations, rather than
occurring to new seals on each construction day. In summary, harbor
seals taken as a result of the specified activities are expected to
comprise only a limited portion of individuals comprising the overall
relevant stock abundance. Therefore, we preliminarily find that small
numbers of marine mammals will be taken relative to the population size
of the Hood Canal stock of harbor seal.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals will be taken relative to the population size
of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
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)
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it
[[Page 10712]]
authorizes, funds, or carries out is not likely to jeopardize the
continued existence of any endangered or threatened species or result
in the destruction or adverse modification of designated critical
habitat.
No incidental take of ESA-listed species is proposed for
authorization or expected to result from this activity. Therefore, NMFS
has determined that formal consultation under section 7 of the ESA is
not required for this action.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the Navy for conducting vibratory and impact pile
driving associated with the proposed Service Pier Extension (SPE) at
Naval Base Kitsap Bangor, Washington from October 1, 2018, to September
30, 2019, provided the previously mentioned mitigation, monitoring, and
reporting requirements are incorporated. This section contains a draft
of the IHA itself. The wording contained in this section is proposed
for inclusion in the IHA (if issued).
1. This Incidental Harassment Authorization (IHA) is valid from
October 1, 2018 through September 30, 2019. This IHA is valid only for
pile driving and extraction activities associated with the Naval Base
Kitsap Bangor SPE project.
2. General Conditions.
(a) A copy of this IHA must be in the possession of the Navy, its
designees, and work crew personnel operating under the authority of
this IHA.
(b) The species authorized for taking are the killer whale (Orcinus
orca; transient only), harbor porpoise (Phocoena phocoena vomerina),
California sea lion (Zalophus californianus), Steller sea lion
(Eumetopias jubatus monteriensis), and harbor seal (Phoca vitulina
richardii).
(c) The taking, by Level A and Level B harassment, is limited to
the species listed in condition 2(b). See Table 11 for numbers of Level
A and Level B take authorized.
(d) The take of any other species not listed in condition 2(b) of
marine mammal is prohibited and may result in the modification,
suspension, or revocation of this IHA.
(e) The Navy shall conduct briefings between construction
supervisors and crews, marine mammal monitoring team, acoustical
monitoring team prior to the start of all pile driving activities, and
when new personnel join the work, in order to explain responsibilities,
communication procedures, marine mammal monitoring protocol, and
operational procedures.
3. Mitigation Measures.
The holder of this Authorization is required to implement the
following mitigation measures:
(a) Time Restrictions--For all in-water pile driving activities,
the Navy shall operate only during daylight hours.
(b) Use of Bubble Curtain.
(i) The Navy shall employ a bubble curtain (or other sound
attenuation device with proven typical performance of at least 8 dB
effective attenuation) during impact pile driving of steel piles in
water depths greater than 2 feet. In addition, the Navy shall implement
the following performance standards.
(ii) The bubble curtain must distribute air bubbles around 100
percent of the piling perimeter for the full depth of the water column.
(iii) The lowest bubble ring shall be in contact with the mudline
for the full circumference of the ring, and the weights attached to the
bottom ring shall ensure 100 percent mudline contact. No parts of the
ring or other objects shall prevent full mudline contact.
(iv) The Navy shall require that construction contractors train
personnel in the proper balancing of air flow to the bubblers, and
shall require that construction contractors submit an inspection/
performance report for approval by the Navy within 72 hours following
the performance test. Corrections to the attenuation device to meet the
performance standards shall occur prior to impact driving.
(c) Use of Soft-Start.
(i) The project shall utilize soft start techniques for impact pile
driving.
(ii) The Navy shall conduct an initial set of three strikes from
the impact hammer at 40 percent energy, followed by a 1-minute waiting
period, then two subsequent three strike sets.
(iii) Soft start shall be required for any impact driving,
including at the beginning of the day, and at any time following a
cessation of impact pile driving of 30 minutes or longer.
(d) Establishment of Shutdown Zones.
(i) The shutdown zones pertaining specific species during impact
driving and vibratory driving are shown on Tables 10, 1, and 12.
(ii) If a marine mammal comes within or approaches the shutdown
zone, pile driving operations shall cease.
(iii) Pile driving and removal operations shall restart once the
marine mammal is visibly seen leaving the zone or after 15 minutes have
passed with no sightings.
(iii) For in-water heavy machinery work other than pile driving
(using, e.g.,standard barges, tug boats), if a marine mammal comes
within 10 m, operations shall cease and vessels shall reduce speed to
the minimum level required to maintain steerage and safe working
conditions.
(iv) Shutdown shall occur if a species for which authorization has
not been granted or for which the authorized numbers of takes have been
met approaches or is observed within the pertinent take zone. The Navy
shall then contact NMFS within 24 hours.
(d) Establishment of Level A and B Harassment Zones.
(i) The Level A and Level B zones pertaining to specific species
during impact driving and vibratory driving are shown on Tables 12, 13,
and 14.
(e) Pile driving activities shall not be conducted when weather/
observer conditions do not allow for adequate sighting of marine
mammals within the disturbance zone (e.g. lack of daylight/fog).
(i) In the event of conditions that prevent the visual detection of
marine mammals, impact pile driving already underway shall be
curtailed, but vibratory driving may continue if driving has already
been initiated on a given pile.
4. Monitoring.
The holder of this Authorization is required to conduct visual
marine mammal monitoring during pile driving activities.
(a) Visual Marine Mammal Observation--The Navy shall collect
sighting data and behavioral responses to pile driving for marine
mammal species observed in the region of activity during the period of
activity. Visual monitoring shall include the following:
(i) Marine Mammal Observers (MMOs) shall be positioned at the best
practicable vantage points, taking into consideration security, safety,
and space limitations. The MMOs shall be stationed in a location that
shall provide adequate visual coverage for the shutdown zones.
(ii) During pile driving, one MMO shall be stationed in a vessel,
and at least four additional MMOs shall be stationed on the pier, along
the shore, or on the pile driving barge to maximize observation
coverage
(iii) Monitoring shall be conducted by trained observers, who shall
have no other assigned tasks during monitoring periods. Trained
observers shall be placed at the best vantage point(s) practicable to
monitor for marine mammals and implement shutdown or delay procedures
when applicable through communication with the equipment operator. The
Navy shall adhere to the following additional observer qualifications:
[[Page 10713]]
(1) Independent observers (i.e., not construction personnel) are
required.
(2) At least one observer must have prior experience working as an
observer.
(3) Other observers may substitute education (degree in biological
science or related field) or training for experience.
(iv) Where a team of three or more observers are required, one
observer shall be designated as lead observer or monitoring
coordinator. The lead observer must have prior experience working as an
observer.
(v) The Navy shall submit observer CVs for approval by NMFS.
(vi) Monitoring shall take place from 15 minutes prior to
initiation of pile driving activity through 30 minutes post-completion
of pile driving activity.
(b) Hydroacoustic Monitoring.
(i) If approved by the U.S. Fish and Wildlife Service, baseline
sound measurements of steel pile driving shall occur prior to the
implementation of noise attenuation. Impact pile driving without noise
attenuation shall be limited to the number of piles necessary to obtain
an adequate sample size.
(ii) If the Navy elects to conduct in-situ acoustic monitoring to
establish actual distances to the thresholds for a pile type and
installation method, the radii of the pertaining zones may be adjusted
according to collected data.
(iii) Any proposed acoustical monitoring plan and any proposed
revisions to zone radii must be pre-approved by NMFS.
(iv) A final acoustic monitoring report shall be submitted to NMFS
within 30 days of completing the monitoring.
5. Reporting.
(a) A draft marine mammal monitoring report shall be submitted to
NMFS within 90 days after the completion of pile driving and removal
activities or a minimum of 60 days prior to any subsequent IHAs. A
final report shall be prepared and submitted to the NMFS within 30 days
following receipt of comments on the draft report from the NMFS. A If
no comments are received from NMFS within 30 days, the draft final
report shall constitute the final report. If comments are received, a
final report addressing NMFS comments must be submitted within 30 days
after receipt of comments.
(i) The report shall include an overall description of work
completed, a narrative regarding marine mammal sightings, and
associated marine mammal observation data sheets.
(ii) The report shall include all items identified in information
described in Section 4 of the Marine Mammal Monitoring Plan (Appendix D
of the application.)
(b) Reporting injured or dead marine mammals:
(i) In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by this IHA,
such as serious injury, or mortality, the Navy shall immediately cease
the specified activities and report the incident to the Office of
Protected Resources, NMFS, and the West Coast Regional Stranding
Coordinator, NMFS. The report must include the following information:
(1) Time and date of the incident;
(2) Description of the incident;
(3) Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
(4) Description of all marine mammal observations and active sound
source use in the 24 hours preceding the incident;
(5) Species identification or description of the animal(s)
involved;
(6) Fate of the animal(s); and
(7) Photographs or video footage of the animal(s). Activities shall
not resume until NMFS is able to review the circumstances of the
prohibited take. NMFS shall work with the Navy to determine what
measures are necessary to minimize the likelihood of further prohibited
take and ensure MMPA compliance. The Navy may not resume their
activities until notified by NMFS.
(ii) In the event that the Navy discovers an injured or dead marine
mammal, and the lead observer 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), the Navy shall immediately
report the incident to the Office of Protected Resources, NMFS, and the
West Coast Regional Stranding Coordinator, NMFS. The report must
include the same information identified in 5(b)(i) of this IHA.
Activities may continue while NMFS reviews the circumstances of the
incident. NMFS shall work with the Navy to determine whether additional
mitigation measures or modifications to the activities are appropriate.
(iii) In the event that the Navy discovers an injured or dead
marine mammal, and the lead observer determines that the injury or
death is not associated with or related to the activities authorized in
the IHA (e.g., previously wounded animal, carcass with moderate to
advanced decomposition, or scavenger damage), the Navy shall report the
incident to the Office of Protected Resources, NMFS, and the West Coast
Regional Stranding Coordinator, NMFS, within 24 hours of the discovery.
The Navy shall provide photographs or video footage or other
documentation of the stranded animal sighting to NMFS.
6. This Authorization may be modified, suspended or withdrawn if
the holder fails to abide by the conditions prescribed herein, or if
NMFS determines the authorized taking is having more than a negligible
impact on the species or stock of affected marine mammals.
Request for Public Comments
We request comment on our analyses, the draft authorization, and
any other aspect of this Notice of Proposed IHA for the proposed
Service Pier Extension project. Please include with your comments any
supporting data or literature citations to help inform our final
decision on the request for MMPA authorization.
On a case-by-case basis, NMFS may issue a one-year renewal IHA
without additional notice when (1) another year of identical or nearly
identical activities as described in the Specified Activities section
is planned, or (2) the activities would not be completed by the time
the IHA expires and renewal would allow completion of the activities
beyond that described in the Dates and Duration section, provided all
of the following conditions are met:
A request for renewal is received no later than 60 days
prior to expiration of the current IHA; and
The request for renewal must include the following:
(1) An explanation that the activities to be conducted beyond the
initial dates either are identical to the previously analyzed
activities or include changes so minor (e.g., reduction in pile size)
that the changes do not affect the previous analyses, take estimates,
or mitigation and monitoring requirements;
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for renewal, the status of the
affected species or stocks, and any other pertinent information, NMFS
determines that there are no more than minor changes in the activities,
the mitigation and monitoring measures remain the same and appropriate,
and the original findings remain valid.
Dated: March 6, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2018-04857 Filed 3-9-18; 8:45 am]
BILLING CODE 3510-22-P