[Federal Register Volume 80, Number 142 (Friday, July 24, 2015)]
[Notices]
[Pages 44033-44057]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-18145]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XE055
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Two Pier Maintenance Projects
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; two proposed incidental harassment authorizations;
request for comments.
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SUMMARY: NMFS has received two requests from the U.S. Navy (Navy) for
authorization to take marine mammals incidental to construction
activities as part of two separate pier maintenance projects at Naval
Base Kitsap Bremerton. Pursuant to the Marine Mammal Protection Act
(MMPA), NMFS is requesting comments on its proposal to issue incidental
harassment authorizations (IHA) to the Navy to incidentally take marine
mammals, by Level B Harassment only, during the specified activity.
DATES: Comments and information must be received no later than August
24, 2015.
ADDRESSES: Comments on the applications 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 to the Internet 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: Ben Laws, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
An electronic copy of the Navy's application and supporting
documents, as well as a list of the references cited in this document,
may be obtained by visiting the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing
these documents, please call the contact listed above.
National Environmental Policy Act (NEPA)
Pier 6 Maintenance Project
The Navy prepared an Environmental Assessment (EA; 2013) for this
project. We subsequently adopted the EA and signed our own Finding of
No Significant Impact (FONSI) prior to issuing the first IHA for this
project, in accordance with NEPA and the regulations published by the
Council on Environmental Quality. Information in the Navy's
application, the Navy's EA, and this notice collectively provide the
environmental information related to proposed issuance of this IHA for
public review and comment. All documents are available at the
aforementioned Web site. We will review all comments submitted in
response to this notice as we complete the NEPA process, including a
decision of whether to reaffirm the existing FONSI, prior to a final
decision on the incidental take authorization request.
Pier 4 Maintenance Project
The Navy prepared an EA to consider the direct, indirect and
cumulative effects to the human environment resulting from the
maintenance project. NMFS has reviewed the EA and believes it
appropriate to adopt the EA in order to assess the impacts to the human
environment of issuance of an IHA to the Navy and subsequently sign our
own FONSI. Information in the Navy's application, the Navy's EA, and
this notice collectively provide the environmental information related
to proposed issuance of this IHA for public review and comment.
For both proposed IHAs, all documents are available at the
aforementioned Web site. We will review all comments submitted in
response to this notice as we complete the NEPA processes, including a
final decision of whether to reaffirm the existing FONSI or adopt the
Navy's EA and sign a FONSI (for the Pier 6 and Pier 4 IHAs,
respectively), prior to a final decision on the incidental take
authorization requests.
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request by U.S.
citizens who engage in a specified activity (other than commercial
fishing) within a specified area, the incidental, but not intentional,
taking of small numbers of marine mammals, providing that certain
findings are made and the necessary prescriptions are established.
The incidental taking of small numbers of marine mammals may be
allowed only if NMFS (through authority delegated by the Secretary)
finds that the total taking by the specified activity during the
specified time period will (i) have a negligible impact on the species
or stock(s) and (ii) not have an unmitigable adverse impact on the
availability of the species or stock(s) for subsistence uses (where
relevant). Further, the permissible methods of taking and requirements
pertaining to the mitigation, monitoring and reporting of such taking
must be set forth, either in specific regulations or in an
authorization.
The allowance of such incidental taking under section 101(a)(5)(A),
by harassment, serious injury, death, or a combination thereof,
requires that regulations be established. Subsequently, a Letter of
Authorization may be issued pursuant to the prescriptions established
in such regulations, providing that the level of taking will be
consistent with the findings made for the total taking allowable under
the specific regulations. Under section 101(a)(5)(D), NMFS may
authorize such incidental taking by harassment only, for periods of not
more
[[Page 44034]]
than one year, pursuant to requirements and conditions contained within
an IHA. The establishment of prescriptions through either specific
regulations or an authorization requires notice and opportunity for
public comment.
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``. . .
an impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.'' Except with respect to certain activities
not pertinent here, 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].''
Summary of Requests
On April 14, 2015, we received two requests from the Navy for
authorization to take marine mammals incidental to pile driving and
removal associated with the Pier 6 and Pier 4 maintenance projects at
Naval Base Kitsap Bremerton, WA (NBKB). Hereafter, it may be assumed
that use of the generic term ``pile driving'' refers to both pile
driving and removal unless referring specifically to pile installation.
The Navy submitted revised versions of the requests on May 20 and June
12, 2015, the latter of which we deemed adequate and complete. This is
expected to be the third and final year of in-water work associated
with the Pier 6 project. The Pier 4 project is expected to require only
one year to complete in-water work. Each section of this notice is
either separated into project-specific subsections or indicates whether
the discussion to follow applies to both projects or applies to both
projects except where indicated.
The use of both vibratory and impact pile driving is expected to
produce underwater sound at levels that have the potential to result in
behavioral harassment of marine mammals. Species with the expected
potential to be present during all or a portion of the in-water work
windows include the Steller sea lion (Eumetopias jubatus monteriensis),
California sea lion (Zalophus californianus), and harbor seal (Phoca
vitulina richardii). All of these species may be present during the
proposed periods of validity for these IHAs.
For Pier 6, this would be the third such IHA, if issued, following
the IHAs issued effective from December 1, 2013, through March 1, 2014
(78 FR 69825) and from October 1, 2014, through March 1, 2015 (79 FR
59238). Monitoring reports associated with these previous IHAs are
available on the Internet at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm and provide environmental information related to
proposed issuance of these IHAs for public review and comment.
Description of the Specified Activities
In this section, we provide a mixed discussion with project-
specific portions indicated.
Overview
NBKB serves as the homeport for a nuclear aircraft carrier and
other Navy vessels and as a shipyard capable of overhauling and
repairing all types and sizes of ships. Other significant capabilities
include alteration, construction, deactivation, and dry-docking of
naval vessels. Both Pier 6 and Pier 4, originally constructed in 1926
and 1922, respectively, require substantial maintenance to maintain
readiness. Over the course of the entire Pier 6 project, the Navy will
remove 400 deteriorating creosoted timber (380) and steel (20) fender
piles and replace them with 330 new pre-stressed concrete fender piles.
For Pier 4, the Navy plans to remove eighty deteriorating creosoted
timber fender piles and replace them with eighty new steel fender
piles.
Dates and Duration
For both projects, in-water work would occur only during approved
work windows established to protect bull trout and migrating salmon;
however, the two projects would operate under different requirements
pursuant to separate agreements with the U.S. Fish and Wildlife Service
(FWS). Under a 2013 agreement with FWS, in-water work associated with
the Pier 6 project may be conducted from June 15 to March 1 of any
year. In 2015, FWS requested that Navy operate under a more restrictive
work window related to bull trout (Salvelinus confluentus) occurrence
in the project area, and in-water work associated with the Pier 4
project may occur from July 16 to February 15.
Pier 6--The total three-year project is expected (on the basis of
assumed production rates) to require fifty days of vibratory pile
removal and 135 days of impact pile driving (total of 185 days of in-
water pile driving work), although it appears that better-than-expected
production rates will result in a reduced number of total days. Under
the proposed action--which includes only the portion of the project
that would be completed under this proposed IHA--a maximum of sixty
pile driving days would occur. The Navy proposes to conduct fifteen
days of vibratory pile removal and 45 days of pile installation with an
impact hammer. Either type of pile driving may occur on any day during
the proposed period of validity. The proposed Pier 6 IHA covers only
the third year (in-water work window) of the project, and would be
valid from September 1, 2015, through March 1, 2016.
Pier 4--The Navy expects to require thirty days of total work,
including approximately ten days of vibratory pile removal and twenty
days of vibratory pile driving. Either type of pile driving may occur
on any day during the proposed period of validity (within approved work
window). The proposed Pier 4 IHA would be valid for one year, from
December 1, 2015, through November 30, 2016. The Navy requested a one-
year period of validity for this proposed IHA due to uncertainty
regarding the project start date. However, the proposed in-water work
would occur within only a single work window; i.e., would occur from
December 1, 2015, through February 15, 2016, or would occur from July
16, 2016, through November 30, 2016.
Specific Geographic Region
NBKB is located on the north side of Sinclair Inlet in Puget Sound
(see Figures 1-1 and 2-1 of the Navy's applications). Sinclair Inlet,
an estuary of Puget Sound extending 3.5 miles southwesterly from its
connection with the Port Washington Narrows, connects to the main basin
of Puget Sound through Port Washington Narrows and then Agate Pass to
the north or Rich Passage to the east. Sinclair Inlet has been
significantly modified by development activities. Fill associated with
transportation, commercial, and residential development of NBKB, the
City of Bremerton, and the local ports of Bremerton and Port Orchard
has resulted in significant changes to the shoreline. The area
surrounding both Pier 6 and Pier 4 is industrialized, armored and
adjacent to railroads and highways. Sinclair Inlet is also the
receiving body for a wastewater treatment plant located just west of
NBKB. Sinclair Inlet is relatively shallow and does not flush fully
despite freshwater stream inputs. The action area is essentially the
same for both projects, and is referred to generally as
[[Page 44035]]
the project area hereafter. Pier 4 and Pier 6 are co-located
approximately 300 m apart on the NBKB waterfront. Please see Figure 4-1
of the Navy's applications.
Detailed Description of Activities
Pier 6--The Navy plans to remove deteriorated timber and steel
fender piles at Pier 6 and replace them with prestressed concrete
piles. The entire project calls for the removal of 380 12-in diameter
creosoted timber piles and twenty 12-in steel pipe piles. These would
be replaced with 240 18-in square concrete piles and ninety 24-in
square concrete piles. It is not possible to specify accurately the
number of piles that might be installed or removed in any given work
window, due to various delays that may be expected during construction
work and uncertainty inherent to estimating production rates. The Navy
assumes a notional production rate of sixteen piles per day (removal)
and four piles per day (installation) in determining the number of days
of pile driving expected, and scheduling (as well as exposure analysis)
is based on this assumption.
All piles are planned for removal via vibratory driver. The driver
is suspended from a barge-mounted crane and positioned on top of a
pile. Vibration from the activated driver loosens the pile from the
substrate. Once the pile is released, the crane raises the driver and
pulls the pile from the sediment. Vibratory extraction is expected to
take approximately 5-30 minutes per pile. If piles break during
removal, the remaining portion may be removed via direct pull or with a
clamshell bucket. Replacement piles would be installed via impact
driver and would require approximately 15-60 minutes of driving time
per pile, depending on subsurface conditions. Impact driving or
vibratory removal could occur on any work day during the period of the
proposed IHA.
Description of Work Accomplished, Pier 6--During the first in-water
work season for the Pier 6 project, the contractor completed
installation of two concrete piles, on two separate days. During the
second in-water work season, 282 piles were removed by vibratory
extraction or direct pull. The contractor found that the direct pull
method was very effective in pile removal and approximately fifty
percent of the piles that were removed during Year 2, including three
steel piles, were pulled without the use of the vibratory driver. A
total of 168 new concrete piles were installed using an impact hammer.
Therefore, approximately 118 piles remain to be removed and 160 to be
installed. The Navy's monitoring reports are available on the Internet
at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
Pier 4--The Navy plans to remove eighty deteriorated 14-in timber
fender piles at Pier 4 and replace them with eighty new 12 to 14-in
steel fender piles. Here, due to slightly different geotechnical
conditions, the Navy assumes a notional production rate of eight piles
per day (removal) and four piles per day (installation) in determining
the number of days of pile driving expected, and scheduling (as well as
exposure analysis) is based on this assumption. All pile driving and
removal would be accomplished with a vibratory driver (except where
removal is accomplished by direct pull or other mechanical means, e.g.,
clamshell, cutting). Expected per-pile time for removal and
installation is similar to that described for Pier 6.
Neither project would employ more than one pile driving rig.
Therefore, there would not be concurrent pile driving specific to
either project. In addition, due to scheduling differences, it is
unlikely that in-water work associated with the two projects would
occur concurrently, meaning that it is highly unlikely that there would
be more than one pile driving rig in operation at NBKB at any time even
considering both projects. Pile driving would occur only during
daylight hours.
Description of Marine Mammals in the Area of the Specified Activity
There are five marine mammal species with records of occurrence in
waters of Sinclair Inlet in the action area. These are the California
sea lion, harbor seal, Steller sea lion, gray whale (Eschrichtius
robustus), and killer whale (Orcinus orca). The harbor seal is a year-
round resident of Washington inland waters, including Puget Sound,
while the sea lions are absent for portions of the summer. For the
killer whale, both transient (west coast stock) and resident (southern
stock) animals have occurred in the area. However, southern resident
animals are known to have occurred only once, with the last confirmed
sighting from 1997 in Dyes Inlet. A group of 19 whales from the L-25
subpod entered and stayed in Dyes Inlet, which connects to Sinclair
Inlet northeast of NBKB, for thirty days. Dyes Inlet may be reached
only by traversing from Sinclair Inlet through the Port Washington
Narrows, a narrow connecting body that is crossed by two bridges, and
it was speculated at the time that the whales' long stay was the result
of a reluctance to traverse back through the Narrows and under the two
bridges. There is one other unconfirmed report of a single southern
resident animal occurring in the project area, in January 2009. Of
these stocks, the southern resident killer whale is listed (as
endangered) under the Endangered Species Act (ESA).
An additional seven species have confirmed occurrence in Puget
Sound, but are considered rare to extralimital in Sinclair Inlet and
the surrounding waters. These species--the humpback whale (Megaptera
novaeangliae), minke whale (Balaenoptera acutorostrata scammoni),
Pacific white-sided dolphin (Lagenorhynchus obliquidens), harbor
porpoise (Phocoena phocoena vomerina), Dall's porpoise (Phocoenoides
dalli dalli), and northern elephant seal (Mirounga angustirostris)--
along with the southern resident killer whale, are considered extremely
unlikely to occur in the action area or to be affected by the specified
activities, and are not considered further in this document. A review
of sightings records available from the Orca Network
(www.orcanetwork.org; accessed July 13, 2015) confirms that there are
no recorded observations of these species in the action area (with the
exception of the southern resident sightings described above).
We have reviewed the Navy's detailed species descriptions,
including life history information, for accuracy and completeness and
refer the reader to sections 3 and 4 of the Navy's application instead
of reprinting the information here. Please also refer to NMFS' Web site
(www.nmfs.noaa.gov/pr/species/mammals) for generalized species accounts
and to the Navy's Marine Resource Assessment for the Pacific Northwest,
which documents and describes the marine resources that occur in Navy
operating areas of the Pacific Northwest, including Puget Sound (DoN,
2006). The document is publicly available at www.navfac.navy.mil/products_and_services/ev/products_and_services/marine_resources/marine_resource_assessments.html (accessed July 13, 2015).
Table 1 lists the marine mammal species with expected potential for
occurrence in the vicinity of NBKB during the project timeframe and
summarizes key information regarding stock status and abundance.
Taxonomically, we follow Committee on Taxonomy (2014). Please see NMFS'
Stock Assessment Reports (SAR), available at www.nmfs.noaa.gov/pr/sars,
for more detailed accounts of these stocks' status and abundance. The
harbor seal, California sea lion, and gray
[[Page 44036]]
whale are assessed in the Pacific SARs (e.g., Carretta et al., 2014),
while the Steller sea lion and transient killer whale are considered in
the Alaska SARs (e.g., Allen and Angliss, 2014).
In the species accounts provided here, we offer a brief
introduction to the species and relevant stock as well as available
information regarding population trends and threats, and describe any
information regarding local occurrence.
Table 1--Marine Mammals Potentially Present in the Vicinity of NBKB
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ESA/MMPA Stock abundance
status; (CV, Nmin, most Relative occurrence in
Species Stock Strategic (Y/ recent abundance PBR \3\ Annual M/SI \4\ Sinclair Inlet; season of
N) \1\ survey) \2\ occurrence
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)...................................................................................
Family Eschrichtiidae...................................................................................................................................
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Gray whale................... Eastern North --; N.......... 20,990 (0.05; 624................. \10\ 132 Rare; year-round.
Pacific \5\. 20,125; 2010-11)
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)........................................................................................
Family Delphinidae......................................................................................................................................
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Killer whale................. West coast --; N.......... 243 (n/a; 2009) 2.4................. 0 Rare; year-round.
transient \6\.
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Order Carnivora--Superfamily Pinnipedia.................................................................................................................
Family Otariidae (eared seals and sea lions)............................................................................................................
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California sea lion.......... U.S............. --; N.......... 296,750 (n/a; 9,200............... 389 Common; year-round
153,337; 2011) (excluding July).
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Steller sea lion............. Eastern U.S.\5\. --; N \8\...... 60,131-74,448 (n/ 1,645............... 92.3 Occasional/seasonal; Oct-
a; 36,551; 2008- May.
13)\9\
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Family Phocidae (earless seals).........................................................................................................................
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Harbor seal.................. Washington --; N.......... 11,036 (0.15; undetermined........ >2.8 Common; year-round.
northern inland 7,213; 1999)
waters \7\.
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\1\ 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 (see
footnote 3) 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\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For killer whales, the
abundance values represent direct counts of individually identifiable animals; therefore there is only a single abundance estimate with no associated
CV. For certain stocks of pinnipeds, abundance estimates are based upon observations of animals (often pups) ashore multiplied by some correction
factor derived from knowledge of the species (or similar species) life history to arrive at a best abundance estimate; therefore, there is no
associated CV. In these cases, the minimum abundance may represent actual counts of all animals ashore. The most recent abundance survey that is
reflected in the abundance estimate is presented; there may be more recent surveys that have not yet been incorporated into the estimate.
\3\ Potential biological removal, 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 size (OSP).
\4\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value. All
values presented here are from the draft 2014 SARs (www.nmfs.noaa.gov/pr/sars/draft.htm).
\5\ Abundance estimates (and resulting PBR values) for these stocks are new values presented in the draft 2014 SARs. This information was made available
for public comment and is currently under review and therefore may be revised prior to finalizing the 2014 SARs. However, we consider this information
to be the best available for use in this document.
\6\ The abundance estimate for this stock includes only animals from the ``inner coast'' population occurring in inside waters of southeastern Alaska,
British Columbia, and Washington--excluding animals from the ``outer coast'' subpopulation, including animals from California--and therefore should be
considered a minimum count. For comparison, the previous abundance estimate for this stock, including counts of animals from California that are now
considered outdated, was 354.
\7\ 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
and PBR values, as these represent the best available information for use in this document.
\8\ The eastern distinct population segment of the Steller sea lion, previously listed under the ESA as threatened, was delisted on December 4, 2013 (78
FR 66140; November 4, 2013).
\9\ Best abundance is calculated as the product of pup counts and a factor based on the birth rate, sex and age structure, and growth rate of the
population. A range is presented because the extrapolation factor varies depending on the vital rate parameter resulting in the growth rate (i.e.,
high fecundity or low juvenile mortality).
\10\ Includes annual Russian subsistence harvest of 127 whales.
Steller Sea Lion
Steller sea lions are distributed mainly around the coasts to the
outer continental shelf along the North Pacific rim from northern
Hokkaido, Japan through the Kuril Islands and Okhotsk Sea, Aleutian
Islands and central Bering Sea, southern coast of Alaska and south to
California (Loughlin et al., 1984). Based on distribution, population
response, and phenotypic and genotypic data, two separate stocks of
Steller sea
[[Page 44037]]
lions are recognized within U. S. waters, with the population divided
into western and eastern distinct population segments (DPS) at
144[deg]W (Cape Suckling, Alaska) (Loughlin, 1997). The eastern DPS
extends from California to Alaska, including the Gulf of Alaska, and is
the only stock that may occur in Sinclair Inlet.
According to NMFS' recent status review (NMFS, 2013), the best
available information indicates that the overall abundance of eastern
DPS Steller sea lions has increased for a sustained period of at least
three decades while pup production has also increased significantly,
especially since the mid-1990s. Johnson and Gelatt (2012) provided an
analysis of growth trends of the entire eastern DPS from 1979-2010,
indicating that the stock increased during this period at an annual
rate of 4.2 percent (90% CI 3.7-4.6). Most of the overall increase
occurred in the northern portion of the range (southeast Alaska and
British Columbia), but pup counts in Oregon and California also
increased significantly (e.g., Merrick et al., 1992; Sease et al.,
2001; Olesiuk and Trites, 2003; Fritz et al. 2008; Olesiuk, 2008; NMFS,
2008, 2013). In Washington, Pitcher et al. (2007) reported that Steller
sea lions, presumably immature animals and non-breeding adults,
regularly used four haul-outs, including two ``major'' haul-outs (>50
animals). The same study reported that the numbers of sea lions counted
between 1989 and 2002 on Washington haul-outs increased significantly
(average annual rate of 9.2 percent) (Pitcher et al., 2007). Although
the stock size has increased, its status relative to OSP size is
unknown. However, the consistent long-term estimated annual rate of
increase may indicate that the stock is reaching OSP size (Allen and
Angliss, 2014).
The eastern stock breeds in rookeries located in southeast Alaska,
British Columbia, Oregon, and California. There are no known breeding
rookeries in Washington (Allen and Angliss, 2014) but eastern stock
Steller sea lions are present year-round along the outer coast of
Washington, including immature animals or non-breeding adults of both
sexes. In 2011, the minimum count for Steller sea lions in Washington
was 1,749 (Allen and Angliss, 2014), up from 516 in 2001 (Pitcher et
al., 2007). In Washington, Steller sea lions primarily occur at haul-
out sites along the outer coast from the Columbia River to Cape
Flattery and in inland waters sites along the Vancouver Island
coastline of the Strait of Juan de Fuca (Jeffries et al., 2000; Olesiuk
and Trites, 2003; Olesiuk, 2008). Numbers vary seasonally in Washington
waters with peak numbers present during the fall and winter months
(Jeffries et al., 2000). More recently, five winter haul-out sites used
by adult and subadult Steller sea lions have been identified in Puget
Sound (see Figure 4-2 of the Navy's applications). Numbers of animals
observed at all of these sites combined were less than 200 individuals.
The closest haul-out, with approximately 30 to 50 individuals near the
Navy's Manchester Fuel Depot, occurs approximately 6.5 mi from the
project site but is physically separated by various land masses and
waterways. However, one Steller sea lion was observed hauled out on the
floating security barrier at NBKB in November 2012. No permanent haul-
out has been identified in the project area and Steller sea lion
presence is considered to be rare and seasonal.
Harbor Seal
Harbor seals inhabit coastal and estuarine waters and shoreline
areas of the northern hemisphere from temperate to polar regions. The
eastern North Pacific subspecies is found from Baja California north to
the Aleutian Islands and into the Bering Sea. Multiple lines of
evidence support the existence of geographic structure among harbor
seal populations from California to Alaska (e.g., O'Corry-Crowe et al.,
2003; Temte, 1986; Calambokidis et al., 1985; Kelly, 1981; Brown, 1988;
Lamont, 1996; Burg, 1996). Harbor seals are generally non-migratory,
and analysis of genetic information suggests that genetic differences
increase with geographic distance (Westlake and O'Corry-Crowe, 2002).
However, because stock boundaries are difficult to meaningfully draw
from a biological perspective, three separate harbor seal stocks are
recognized for management purposes along the west coast of the
continental U.S.: (1) Inland waters of Washington (including Hood
Canal, Puget Sound, and the Strait of Juan de Fuca out to Cape
Flattery), (2) outer coast of Oregon and Washington, and (3) California
(Carretta et al., 2014). Multiple stocks are recognized in Alaska.
Samples from Washington, Oregon, and California demonstrate a high
level of genetic diversity and indicate that the harbor seals of
Washington inland waters possess unique haplotypes not found in seals
from the coasts of Washington, Oregon, and California (Lamont et al.,
1996).
Recent genetic evidence suggests that harbor seals of Washington
inland waters have sufficient population structure to warrant division
into multiple distinct stocks (Huber et al., 2010, 2012). Based on
studies of pupping phenology, mitochondrial DNA, and microsatellite
variation, Carretta et al. (2014) divide the Washington inland waters
stock into three new populations, and present these as stocks: (1)
Southern Puget Sound (south of the Tacoma Narrows Bridge); (2)
Washington northern inland waters (including Puget Sound north of the
Tacoma Narrows Bridge, the San Juan Islands, and the Strait of Juan de
Fuca); and (3) Hood Canal. Only the northern inland waters stock of
harbor seals is expected to occur in the action area.
The best available abundance estimate was derived from aerial
surveys of harbor seals in Washington conducted during the pupping
season in 1999, during which time the total numbers of hauled-out seals
(including pups) were counted (Jeffries et al., 2003). Radio-tagging
studies conducted at six locations collected information on harbor seal
haul-out patterns in 1991-92, resulting in a pooled correction factor
(across three coastal and three inland sites) of 1.53 to account for
animals in the water which are missed during the aerial surveys (Huber
et al., 2001), which, coupled with the aerial survey counts, provides
the abundance estimate (see Table 1).
Harbor seal counts in Washington State increased at an annual rate
of six percent from 1983-96, increasing to ten percent for the period
1991-96 (Jeffries et al., 1997). The population is thought to be
stable, and the Washington inland waters stock is considered to be
within its OSP size (Jeffries et al., 2003).
Harbor seal numbers increase from January through April and then
decrease from May through August as the harbor seals move to adjacent
bays on the outer coast of Washington for the pupping season. From
April through mid-July, female harbor seals haul out on the outer coast
of Washington at pupping sites to give birth. Harbor seals are expected
to occur in Sinclair Inlet and NBKB at all times of the year. No
permanent haul-out has been identified at NBKB. The nearest known haul-
outs are along the south side of Sinclair Inlet on log breakwaters at
several marinas in Port Orchard, approximately one mile from Pier 6. An
additional haul-out location in Dyes Inlet, approximately 8.5 km north
and west (shoreline distance), was believed to support less than 100
seals (Jeffries et al., 2000). Please see Figure 4-2 of the Navy's
application.
California Sea Lion
California sea lions range from the Gulf of California north to the
Gulf of
[[Page 44038]]
Alaska, with breeding areas located in the Gulf of California, western
Baja California, and southern California. Five genetically distinct
geographic populations have been identified: (1) Pacific temperate, (2)
Pacific subtropical, and (3-5) southern, central, and northern Gulf of
California (Schramm et al., 2009). Rookeries for the Pacific temperate
population are found within U.S. waters and just south of the U.S.-
Mexico border, and animals belonging to this population may be found
from the Gulf of Alaska to Mexican waters off Baja California. For
management purposes, a stock of California sea lions comprising those
animals at rookeries within the U.S. is defined (i.e., the U.S. stock
of California sea lions) (Carretta et al., 2014). Pup production at the
Coronado Islands rookery in Mexican waters is considered an
insignificant contribution to the overall size of the Pacific temperate
population (Lowry and Maravilla-Chavez, 2005).
Trends in pup counts from 1975 through 2008 have been assessed for
four rookeries in southern California and for haul-outs in central and
northern California. During this time period counts of pups increased
at an annual rate of 5.4 percent, excluding six El Nino years when pup
production declined dramatically before quickly rebounding (Carretta et
al., 2014). The maximum population growth rate was 9.2 percent when pup
counts from the El Ni[ntilde]o years were removed. There are
indications that the California sea lion may have reached or is
approaching carrying capacity, although more data are needed to confirm
that leveling in growth persists (Carretta et al., 2014).
Sea lion mortality has been linked to the algal-produced neurotoxin
domoic acid (Scholin et al., 2000). Future mortality may be expected to
occur, due to the sporadic occurrence of such harmful algal blooms.
There is currently an Unusual Mortality Event (UME) declaration in
effect for California sea lions. Beginning in January 2013, elevated
strandings of California sea lion pups have been observed in southern
California, with live sea lion strandings nearly three times higher
than the historical average. Findings to date indicate that a likely
contributor to the large number of stranded, malnourished pups was a
change in the availability of sea lion prey for nursing mothers,
especially sardines. The causes and mechanisms of this UME remain under
investigation (www.nmfs.noaa.gov/pr/health/mmume/californiasealions2013.htm; accessed July 13, 2015).
California sea lions were not recorded in Puget Sound until
approximately 1979 (Steiger and Calambokidis, 1986). Everitt et al.
(1980) reported the initial occurrence of large numbers in northern
Puget Sound in the spring of that year. Similar sightings and increases
in numbers were documented throughout the region after the initial
sighting (Steiger and Calambokidis 1986), including urbanized areas
such as Elliot Bay near Seattle and heavily used areas of central Puget
Sound (Gearin et al., 1986). California sea lions now use haul-out
sites within all regions of Washington inland waters (Jeffries et al.,
2000). California sea lions migrate northward along the coast to
central and northern California, Oregon, Washington, and Vancouver
Island during the non-breeding season from September to May and return
south the following spring (Mate, 1975; Bonnell et al., 1983). Jeffries
et al. (2000) estimated that 3,000 to 5,000 individuals make this trip,
with peak numbers of up to 1,000 occurring in Puget Sound during this
time period. The California sea lion population has grown
substantially, and it is likely that the numbers migrating to
Washington inland waters have increased as well.
Occurrence in Puget Sound is typically between September and June
with peak abundance between September and May. During summer months
(June through August) and associated breeding periods, California sea
lions are largely returning to rookeries in California and are not
present in large numbers in Washington inland waters. They are known to
utilize a diversity of man-made structures for hauling out (Riedman,
1990) and, although there are no regular California sea lion haul-outs
known within Sinclair Inlet (Jeffries et al., 2000), they are
frequently observed hauled out at several opportune areas at NBKB
(e.g., floating security fence; see Figures 4-1 and 4-2 of the Navy's
application). The next nearest recorded haul-outs are navigation buoys
and net pens in Rich Passage, approximately 10 km east of NBKB
(Jeffries et al., 2000).
Killer Whale
Killer whales are one of the most cosmopolitan marine mammals,
found in all oceans with no apparent restrictions on temperature or
depth, although they do occur at higher densities in colder, more
productive waters at high latitudes and are more common in nearshore
waters (Leatherwood and Dahlheim, 1978; Forney and Wade, 2006). Killer
whales are found throughout the North Pacific, including the entire
Alaska coast, in British Columbia and Washington inland waterways, and
along the outer coasts of Washington, Oregon, and California. On the
basis of differences in morphology, ecology, genetics, and behavior,
populations of killer whales have largely been classified as
``resident'', ``transient'', or ``offshore'' (e.g., Dahlheim et al.,
2008). Several studies have also provided evidence that these ecotypes
are genetically distinct, and that further genetic differentiation is
present between subpopulations of the resident and transient ecotypes
(e.g., Barrett-Lennard, 2000). The taxonomy of killer whales is
unresolved, with expert opinion generally following one of two lines:
Killer whales are either (1) a single highly variable species, with
locally differentiated ecotypes representing recently evolved and
relatively ephemeral forms not deserving species status, or (2)
multiple species, supported by the congruence of several lines of
evidence for the distinctness of sympatrically occurring forms (Krahn
et al., 2004). Resident and transient whales are currently considered
to be unnamed subspecies (Committee on Taxonomy, 2014).
The resident and transient populations have been divided further
into different subpopulations on the basis of genetic analyses,
distribution, and other factors. Recognized stocks in the North Pacific
include Alaska residents; northern residents; southern residents; Gulf
of Alaska, Aleutian Islands, and Bering Sea transients; and west coast
transients, along with a single offshore stock. See Allen and Angliss
(2014) for more detail about these stocks. West coast transient killer
whales, which occur from California through southeastern Alaska, are
the only type expected to potentially occur in the project area.
It is thought that the stock grew rapidly from the mid-1970s to
mid-1990s as a result of a combination of high birth rate, survival, as
well as greater immigration of animals into the nearshore study area
(DFO, 2009). The rapid growth of the population during this period
coincided with a dramatic increase in the abundance of the whales'
primary prey, harbor seals, in nearshore waters. Population growth
began slowing in the mid-1990s and has continued to slow in recent
years (DFO, 2009). Population trends and status of this stock relative
to its OSP level are currently unknown. Analyses in DFO (2009)
estimated a rate of increase of about six percent per year from 1975 to
2006, but this included recruitment of non-calf whales into the
population.
[[Page 44039]]
Transient occurrence in inland waters appears to peak during August
and September which is the peak time for harbor seal pupping, weaning,
and post-weaning (Baird and Dill, 1995). The number of west coast
transients in Washington inland waters at any one time was considered
likely to be fewer than twenty individuals by Wiles (2004), although
more recent information (2004-10) suggests that transient use of inland
waters has increased, possibly due to increasing prey abundance
(Houghton et al., in prep.). However, Sinclair Inlet is a shallow bay
located approximately eight miles through various waterways from the
main open waters of Puget Sound, where killer whales occur more
frequently, and killer whale occurrence in Sinclair Inlet is uncommon.
From December 2002 to June 2014, there were two reports of transient
killer whales transiting through the area around NBKB, with both
reports occurring in May (a group of up to twelve in 2004 and a group
of up to five in 2012; www.orcanetwork.org).
Gray Whale
Gray whales are found in shallow coastal waters, migrating between
summer feeding areas in the north and winter breeding areas in the
south. Gray whales were historically common throughout the northern
hemisphere but are now found only in the Pacific, where two populations
are recognized, Eastern and Western North Pacific (ENP and WNP). ENP
whales breed and calve primarily in areas off Baja California and in
the Gulf of California. From February to May, whales typically migrate
northbound to summer/fall feeding areas in the Chukchi and northern
Bering Seas, with the southbound return to calving areas typically
occurring in November and December. WNP whales are known to feed in the
Okhotsk Sea and off of Kamchatka before migrating south to poorly known
wintering grounds, possibly in the South China Sea.
The two populations have historically been considered
geographically isolated from each other; however, recent data from
satellite-tracked whales indicates that there is some overlap between
the stocks. Two WNP whales were tracked from Russian foraging areas
along the Pacific rim to Baja California (Mate et al., 2011), and, in
one case where the satellite tag remained attached to the whale for a
longer period, a WNP whale was tracked from Russia to Mexico and back
again (IWC, 2012). Between 22-24 WNP whales are known to have occurred
in the eastern Pacific through comparisons of ENP and WNP photo-
identification catalogs (IWC, 2012; Weller et al., 2011; Burdin et al.,
2011), and WNP animals comprised 8.1 percent of gray whales identified
during a recent field season off of Vancouver Island (Weller et al.,
2012). In addition, two genetic matches of WNP whales have been
recorded off of Santa Barbara, CA (Lang et al., 2011a). More recently,
Urban et al. (2013) compared catalogs of photo-identified individuals
from Mexico with photographs of whales off Russia and reported a total
of 21 matches. Therefore, a portion of the WNP population is assumed to
migrate, at least in some years, to the eastern Pacific during the
winter breeding season. However, no WNP whales are known to have
occurred in Washington inland waters. The likelihood of any gray whale
being exposed to project sound to the degree considered in this
document is already low, given the uncommon occurrence of gray whales
in the project area. In the event that a gray whale did occur in the
project area, it is extremely unlikely that it would be one of the
approximately twenty WNP whales that have been documented in the
eastern Pacific (less than one percent probability). The WNP population
is listed as endangered under the ESA and depleted under the MMPA as a
foreign stock; however, the likelihood that a WNP whale would be
present in the action area is insignificant and discountable.
In addition, recent studies provide new information on gray whale
stock structure within the ENP, with emphasis on whales that feed
during summer off the Pacific coast between northern California and
southeastern Alaska, occasionally as far north as Kodiak Island, Alaska
(Gosho et al., 2011). These whales, collectively known as the Pacific
Coast Feeding Group (PCFG), are a trans-boundary population with the
U.S. and Canada and are defined by the International Whaling Commission
(IWC) as follows: Gray whales observed between June 1 to November 30
within the region between northern California and northern Vancouver
Island (from 41[deg]N to 52[deg]N) and photo-identified within this
area during two or more years (Carretta et al., 2013). Photo-
identification and satellite tagging studies provide data on abundance,
population structure, and movements of PCFG whales (Calambokidis et
al., 2010; Mate et al.; 2010; Gosho et al., 2011). These data in
conjunction with genetic studies (e.g., Frasier et al., 2011; Lang et
al., 2011b) indicate that the PCFG may be a demographically distinct
feeding aggregation, and may warrant consideration as a distinct stock
(Carretta et al., 2014). It is unknown whether PCFG whales would be
encountered in Washington inland waters. Here, we consider only a
single stock of ENP whales.
The ENP population of gray whales, which is managed as a stock, was
removed from ESA protection in 1994, is not currently protected under
the ESA, and is not listed as depleted under the MMPA. Punt and Wade
(2010) estimated the ENP population was at 91 percent of carrying
capacity and at 129 percent of the maximum net productivity level and
therefore within the range of its optimum sustainable population. The
estimated annual rate of increase from 1967-88, based on a revised
abundance time series from Laake et al. (2009), is 3.2 percent (Punt
and Wade, 2010), and the population size of the ENP gray whale stock
has been increasing over the past several decades despite a west coast
UME from 1999-2001. It is likely that oceanographic factors limited
food availability (LeBouef et al., 2000; Moore et al., 2001; Minobe,
2002; Gulland et al., 2005), with resulting declines in survival rates
of adults (Punt and Wade, 2012). The population has recovered to levels
seen prior to the UME (Carretta et al., 2014).
Gray whales generally migrate southbound past Washington in late
December and January, and transit past Washington on the northbound
return in March to May. Gray whales do not generally make use of
Washington inland waters, but have been observed in certain portions of
those waters in all months of the year, with most records occurring
from March through June (Calambokidis et al., 2010;
www.orcanetwork.org) and associated with regular feeding areas. Usually
fewer than twenty gray whales visit the inner marine waters of
Washington and British Columbia beginning in about January, with some
staying until summer. Six to ten of these are PCFG whales that return
most years to feeding sites near Whidbey and Camano Islands in northern
Puget Sound. The remaining individuals occurring in any given year
generally appear unfamiliar with feeding areas, often arrive emaciated,
and commonly die of starvation (WDFW, 2012). From December 2002 to June
2014, the Orca Network sightings database reports four occurrences of
gray whales in the project area during the in-water work window
(www.orcanetwork.org). Three sightings occurred during the winter of
2008-09, and one stranding was reported in January 2013. The necropsy
of the whale indicated that it was a juvenile
[[Page 44040]]
male in poor nutritional health. Two other strandings have been
recorded in the project area, in May 2005 and July 2011.
Potential Effects of the Specified Activity on Marine Mammals
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals. This
discussion also includes reactions that we consider to rise to the
level of a take and those that we do not consider to rise to the level
of a take (for example, with acoustics, we may include a discussion of
studies that showed animals not reacting at all to sound or exhibiting
barely measurable avoidance). This section is intended as a background
of potential effects and does not consider either the specific manner
in which this activity will be carried out or the mitigation that will
be implemented, and how either of those will shape the anticipated
impacts from this specific activity. The Estimated Take by Incidental
Harassment section later in this document will include a quantitative
analysis of the number of individuals that are expected to be taken by
this activity. The Negligible Impact Analyses section will include the
analysis of how this specific activity will impact marine mammals and
will consider the content of this section, the Estimated Take by
Incidental Harassment section, the Proposed Mitigation section, and the
Anticipated Effects on Marine Mammal Habitat section to draw
conclusions regarding the likely impacts of this activity on the
reproductive success or survivorship of individuals and from that on
the affected marine mammal populations or stocks. In the following
discussion, we provide general background information on sound and
marine mammal hearing before considering potential effects to marine
mammals from sound produced by vibratory and impact pile driving.
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 hertz (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 decibel (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 microPascal ([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 contributions is from approximately 12 Hz to over 100
kHz.
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
[[Page 44041]]
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.
The underwater acoustic environment in Sinclair Inlet is likely to
be dominated by noise from day-to-day port and vessel activities.
Normal port activities include vessel traffic from large ships,
submarines, support vessels, and security boats, and loading and
maintenance operations. Other sources of human-generated underwater
sound in the area are recreational vessels, industrial ship noise, and
ferry traffic at the adjacent Washington State Ferry Terminal. In 2009,
the average broadband (100 Hz-20 kHz) underwater noise level at NBK
Bangor in the Hood Canal was measured at 114 dB (Slater, 2009), which
is within the range of levels reported for a number of sites within the
greater Puget Sound region (95-135 dB; e.g., Carlson et al., 2005;
Veirs and Veirs, 2006). Measurements near ferry terminals in Puget
Sound, such as the Bremerton terminal adjacent to NBKB, resulted in
median noise levels (50% cumulative distribution function) between 106
and 133 dB (Laughlin, 2012). Although no specific measurements have
been made at NBKB, it is reasonable to believe that levels may
generally be higher than at NBK Bangor as there is a greater degree of
activity, that levels periodically exceed the 120-dB threshold and,
therefore, that the high levels of anthropogenic activity in the area
create an environment far different from quieter habitats where
behavioral reactions to sounds around the 120-dB threshold have been
observed (e.g., Malme et al., 1984, 1988).
Known sound levels and frequency ranges associated with
anthropogenic sources similar to those that would be used for this
project are summarized in Table 2. Details of the source types are
described in the following text.
Table 2--Representative Sound Levels of Anthropogenic Sources
----------------------------------------------------------------------------------------------------------------
Frequency Underwater sound
Sound source range (Hz) level Reference
----------------------------------------------------------------------------------------------------------------
Small vessels................ 250-1,000 151 dB rms at 1 Richardson et al., 1995.
m.
Tug docking gravel barge..... 200-1,000 149 dB rms at Blackwell and Greene, 2002.
100 m.
Vibratory driving of 72-in 10-1,500 180 dB rms at 10 Reyff, 2007.
steel pipe pile. m.
Impact driving of 36-in steel 10-1,500 195 dB rms at 10 Laughlin, 2007.
pipe pile. m.
Impact driving of 66-in cast- 10-1,500 195 dB rms at 10 Reviewed in Hastings and Popper, 2005.
in-steel-shell (CISS) pile. m.
----------------------------------------------------------------------------------------------------------------
In-water construction activities associated with the project would
include impact pile driving and vibratory pile driving. The sounds
produced by these activities fall into one of two general sound types:
pulsed and non-pulsed (defined in the following). The distinction
between these two sound types is important because they have differing
potential to cause physical effects, particularly with regard to
hearing (e.g., Ward, 1997 in Southall et al., 2007). Please see
Southall et al., (2007) for an in-depth discussion of these concepts.
Pulsed sound sources (e.g., explosions, gunshots, sonic booms,
impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986; Harris, 1998; NIOSH, 1998; ISO, 2003; ANSI, 2005) and
occur either as isolated events or repeated in some succession. Pulsed
sounds are all characterized by a relatively rapid rise from ambient
pressure to a maximal pressure value followed by a rapid decay period
that may include a period of diminishing, oscillating maximal and
minimal pressures, and generally have an increased capacity to induce
physical injury as compared with sounds that lack these features.
Non-pulsed sounds can be tonal, narrowband, or broadband, brief or
prolonged, and may be either continuous or non-continuous (ANSI, 1995;
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals
of short duration but without the essential properties of pulses (e.g.,
rapid rise time). Examples of non-pulsed sounds include those produced
by vessels, aircraft, machinery operations such as drilling or
dredging, vibratory pile driving, and active sonar systems (such as
those used by the U.S. Navy). The duration of such sounds, as received
at a distance, can be greatly extended in a highly reverberant
environment.
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; Carlson et al., 2005).
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals,
and exposure to sound can have deleterious effects. To appropriately
assess these potential effects, 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
measured or estimated hearing ranges on the basis of available
behavioral data, audiograms derived using auditory evoked potential
techniques, anatomical modeling, and other data. The lower and/or upper
frequencies for some of these functional hearing groups have been
modified from those designated by Southall et al. (2007). The
functional groups and the associated frequencies are indicated below
(note that these frequency ranges do not necessarily correspond to the
range of best hearing, which varies by species):
[[Page 44042]]
Low-frequency cetaceans (mysticetes): Functional hearing
is estimated to occur between approximately 7 Hz and 25 kHz (extended
from 22 kHz; Watkins, 1986; Au et al., 2006; Lucifredi and Stein, 2007;
Ketten and Mountain, 2009; Tubelli et al., 2012);
Mid-frequency cetaceans (larger toothed whales, beaked
whales, and most delphinids): Functional hearing is estimated to occur
between approximately 150 Hz and 160 kHz;
High-frequency cetaceans (porpoises, river dolphins, and
members of the genera Kogia and Cephalorhynchus; now considered to
include two members of the genus Lagenorhynchus on the basis of recent
echolocation data and genetic data [May-Collado and Agnarsson, 2006;
Kyhn et al. 2009, 2010; Tougaard et al. 2010]): Functional hearing is
estimated to occur between approximately 200 Hz and 180 kHz; and
Pinnipeds in water: Functional hearing is estimated to
occur between approximately 75 Hz to 100 kHz for Phocidae (true seals)
and between 100 Hz and 40 kHz for Otariidae (eared seals), with the
greatest sensitivity between approximately 700 Hz and 20 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 et al.,
2013).
There are five marine mammal species (two cetacean and three
pinniped [two otariid and one phocid] species) with expected potential
to co-occur with Navy construction activities. Please refer to Table 1.
Of the two cetacean species that may be present, the killer whale is
classified as mid-frequency and the gray whale is classified as low-
frequency.
Acoustic Effects, Underwater
Potential Effects of Pile Driving Sound--The effects of sounds from
pile driving might result in one or more of the following: Temporary or
permanent hearing impairment, non-auditory physical or physiological
effects, behavioral disturbance, and masking (Richardson et al., 1995;
Gordon et al., 2004; Nowacek et al., 2007; Southall et al., 2007). The
effects of pile driving on marine mammals are dependent on several
factors, including the size, type, and depth of the animal; the depth,
intensity, and duration of the pile driving sound; the depth of the
water column; the substrate of the habitat; 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 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. Shallow environments are typically more structurally
complex, which leads to rapid sound attenuation. In addition,
substrates that are soft (e.g., 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.
In the absence of mitigation, impacts to marine species would be
expected to result from physiological and behavioral responses to both
the type and strength of the acoustic signature (Viada et al., 2008).
The type and severity of behavioral impacts are more difficult to
define due to limited studies addressing the behavioral effects of
impulsive sounds on marine mammals. Potential effects from impulsive
sound sources can range in severity from effects such as behavioral
disturbance or tactile perception to physical discomfort, slight injury
of the internal organs and the auditory system, or mortality (Yelverton
et al., 1973).
Hearing Impairment and Other Physical Effects--Marine mammals
exposed to high intensity sound repeatedly or 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 recoverable, or
temporary (TTS), in which case the animal's hearing threshold would
recover over time (Southall et al., 2007). Marine mammals depend on
acoustic cues for vital biological functions, (e.g., orientation,
communication, finding prey, avoiding predators); thus, TTS may result
in reduced fitness in survival and reproduction. However, this depends
on the frequency and duration of TTS, as well as the biological context
in which it occurs. TTS of limited duration, occurring in a frequency
range that does not coincide with that used for recognition of
important acoustic cues, would have little to no effect on an animal's
fitness. Repeated sound exposure that leads to TTS could cause PTS. PTS
constitutes injury, but TTS does not (Southall et al., 2007). The
following subsections discuss in somewhat more detail the possibilities
of TTS, PTS, and non-auditory physical effects.
Temporary Threshold Shift--TTS is the mildest form of hearing
impairment that can occur during exposure to a strong sound (Kryter,
1985). While experiencing TTS, the hearing threshold rises, and a sound
must be stronger in order to be heard. In terrestrial mammals, TTS can
last from minutes or hours to days (in cases of strong TTS). For sound
exposures at or somewhat above the TTS threshold, hearing sensitivity
in both terrestrial and marine mammals recovers rapidly after exposure
to the sound ends. Few data on sound levels and durations necessary to
elicit mild TTS have been obtained for marine mammals, and none of the
published data concern TTS elicited by exposure to multiple pulses of
sound. Available data on TTS in marine mammals are summarized in
Southall et al. (2007).
Given the available data, the received level of a single pulse
(with no frequency weighting) might need to be approximately 186 dB re
1 [mu]Pa\2\-s (i.e., 186 dB sound exposure level [SEL] or approximately
221-226 dB p-p [peak]) in order to produce brief, mild TTS. Exposure to
several strong pulses that each have received levels near 190 dB rms
(175-180 dB SEL) might result in cumulative exposure of approximately
186 dB SEL and thus slight TTS in a small odontocete, assuming the TTS
threshold is (to a first approximation) a function of the total
received pulse energy.
The above TTS information for odontocetes is derived from studies
on the bottlenose dolphin (Tursiops truncatus) and beluga whale
(Delphinapterus leucas). There is no published TTS information for
other species of cetaceans. However, preliminary evidence from a harbor
porpoise exposed to pulsed sound suggests that its TTS threshold may
have been lower (Lucke et al., 2009). As summarized above, data that
are now available imply that TTS is unlikely to occur unless
odontocetes are exposed to pile driving pulses stronger than 180 dB re
1 [mu]Pa rms.
Permanent Threshold Shift--When PTS occurs, there is physical
damage to the sound receptors in the ear. In severe cases, there can be
total or partial
[[Page 44043]]
deafness, while in other cases the animal has an impaired ability to
hear sounds in specific frequency ranges (Kryter, 1985). There is no
specific evidence that exposure to pulses of sound can cause PTS in any
marine mammal. However, given the possibility that mammals close to a
sound source might incur TTS, there has been further speculation about
the possibility that some individuals might incur PTS. Single or
occasional occurrences of mild TTS are not indicative of permanent
auditory damage, but repeated or (in some cases) single exposures to a
level well above that causing TTS onset might elicit PTS.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals but are assumed to be similar to those in humans and
other terrestrial mammals. PTS might occur at a received sound level at
least several decibels above that inducing mild TTS if the animal were
exposed to strong sound pulses with rapid rise time. Based on data from
terrestrial mammals, a precautionary assumption is that the PTS
threshold for impulse sounds (such as pile driving pulses as received
close to the source) is at least 6 dB higher than the TTS threshold on
a peak-pressure basis and probably greater than 6 dB (Southall et al.,
2007). On an SEL basis, Southall et al. (2007) estimated that received
levels would need to exceed the TTS threshold by at least 15 dB for
there to be risk of PTS. Thus, for cetaceans, Southall et al. (2007)
estimate that the PTS threshold might be an M-weighted SEL (for the
sequence of received pulses) of approximately 198 dB re 1 [mu]Pa\2\-s
(15 dB higher than the TTS threshold for an impulse). Given the higher
level of sound necessary to cause PTS as compared with TTS, it is
considerably less likely that PTS could occur.
Measured source levels from impact pile driving can be as high as
214 dB rms. Although no marine mammals have been shown to experience
TTS or PTS as a result of being exposed to pile driving activities,
captive bottlenose dolphins and beluga whales exhibited changes in
behavior when exposed to strong pulsed sounds (Finneran et al., 2000,
2002, 2005). The animals tolerated high received levels of sound before
exhibiting aversive behaviors. Experiments on a beluga whale showed
that exposure to a single watergun impulse at a received level of 207
kPa (30 psi) p-p, which is equivalent to 228 dB p-p, resulted in a 7
and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, respectively.
Thresholds returned to within 2 dB of the pre-exposure level within
four minutes of the exposure (Finneran et al., 2002). Although the
source level of pile driving from one hammer strike is expected to be
much lower than the single watergun impulse cited here, animals being
exposed for a prolonged period to repeated hammer strikes could receive
more sound exposure in terms of SEL than from the single watergun
impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in the aforementioned
experiment (Finneran et al., 2002). However, in order for marine
mammals to experience TTS or PTS, the animals have to be close enough
to be exposed to high intensity sound levels for a prolonged period of
time. Based on the best scientific information available, these SPLs
are far below the thresholds that could cause TTS or the onset of PTS.
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 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. Marine mammals that show behavioral avoidance
of pile driving, including some odontocetes and some pinnipeds, are
especially unlikely to incur auditory impairment or non-auditory
physical effects.
Disturbance Reactions
Disturbance includes a variety of effects, including subtle changes
in behavior, more conspicuous changes in activities, and displacement.
Behavioral responses to sound are highly variable and context-specific
and reactions, if any, depend on species, state of maturity,
experience, current activity, reproductive state, auditory sensitivity,
time of day, and many other factors (Richardson et al., 1995; Wartzok
et al., 2003; Southall et al., 2007).
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. 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. Behavioral state may affect the type of response as well. 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 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 guns or acoustic harassment devices, but also
including pile driving) have been varied but often consist of avoidance
behavior or other behavioral changes suggesting discomfort (Morton and
Symonds, 2002; Thorson and Reyff, 2006; see also Gordon et al., 2004;
Wartzok et al., 2003; Nowacek et al., 2007). 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. These
behavioral changes may include (Richardson et al., 1995): Changing
durations of surfacing and dives, number of blows per surfacing, or
moving direction and/or speed; reduced/increased vocal activities;
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); avoidance of
areas where sound sources are located; and/or flight responses (e.g.,
pinnipeds flushing into water from haul-outs or rookeries). Pinnipeds
may increase their haul-out time, possibly to avoid in-water
disturbance (Thorson and Reyff, 2006).
The biological significance of many of these behavioral
disturbances is difficult to predict, especially if the detected
disturbances appear minor. However, the consequences of behavioral
modification could be expected to be biologically significant if the
change affects growth, survival, or reproduction. Significant
behavioral modifications that could potentially
[[Page 44044]]
lead to effects on growth, survival, or reproduction include:
Drastic changes in diving/surfacing patterns (such as
those thought to cause beaked whale stranding due to exposure to
military mid-frequency tactical sonar);
Habitat abandonment due to loss of desirable acoustic
environment; and
Cessation of feeding or social interaction.
The onset of behavioral disturbance from anthropogenic sound
depends on both external factors (characteristics of sound sources and
their paths) and the specific characteristics of the receiving animals
(hearing, motivation, experience, demography) and is difficult to
predict (Southall et al., 2007).
Auditory Masking
Natural and artificial sounds can disrupt behavior by masking, or
interfering with, a marine mammal's ability to hear other sounds.
Masking occurs when the receipt of a sound is interfered with by
another coincident sound at similar frequencies and at similar or
higher levels. Chronic exposure to excessive, though not high-
intensity, sound could cause masking at particular frequencies for
marine mammals, which utilize sound for vital biological functions.
Masking can interfere with detection of acoustic signals such as
communication calls, echolocation sounds, and environmental sounds
important to marine mammals. Therefore, under certain circumstances,
marine mammals whose acoustical sensors or environment are being
severely masked could also be impaired from maximizing their
performance fitness in survival and reproduction. If the coincident
(masking) sound were man-made, it could be potentially harassing if it
disrupted hearing-related behavior. 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. Because sound
generated from in-water pile driving is mostly concentrated at low
frequency ranges, it may have less effect on high frequency
echolocation sounds made by porpoises. However, lower frequency man-
made sounds are more likely to affect detection of communication calls
and other potentially important natural sounds such as surf and prey
sound. It may also affect communication signals when they occur near
the sound band and thus reduce the communication space of animals
(e.g., Clark et al., 2009) and cause increased stress levels (e.g.,
Foote et al., 2004; Holt et al., 2009).
Masking has the potential to impact species at the population or
community levels as well as at individual levels. Masking affects both
senders and receivers of the signals and can potentially have long-term
chronic effects on marine mammal species and populations. Recent
research suggests that 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, and that most of
these increases are from distant shipping (Hildebrand, 2009). All
anthropogenic sound sources, such as those from vessel traffic, pile
driving, and dredging activities, contribute to the elevated ambient
sound levels, thus intensifying masking.
The most intense underwater sounds in the proposed action are those
produced by impact pile driving. 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, with rapid pulses occurring for approximately fifteen
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 likely to be
negligible. Vibratory pile driving is also relatively short-term, with
rapid oscillations occurring for approximately one and a half hours per
pile. 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.
Acoustic Effects, Airborne
Marine mammals that occur in the project area could be exposed to
airborne sounds associated with pile driving that have the potential to
cause harassment, depending on their distance from pile driving
activities. Airborne pile driving sound would have less impact on
cetaceans than pinnipeds because sound from atmospheric sources does
not transmit well underwater (Richardson et al., 1995); thus, airborne
sound would only be an issue for pinnipeds either hauled-out or looking
with heads above water in the project area. Most likely, airborne sound
would cause behavioral responses similar to those discussed above in
relation to underwater sound. For instance, anthropogenic sound could
cause hauled-out pinnipeds to exhibit changes in their normal behavior,
such as reduction in vocalizations, or cause them to temporarily
abandon their habitat and move further from the source. Studies by
Blackwell et al. (2004) and Moulton et al. (2005) indicate a tolerance
or lack of response to unweighted airborne sounds as high as 112 dB
peak and 96 dB rms.
Anticipated Effects on Habitat
The proposed activities associated with both projects at NBKB would
not result in permanent impacts to habitats used directly by marine
mammals, such as haul-out sites, but may have potential short-term
impacts to food sources such as forage fish and salmonids. The proposed
activities could also affect acoustic habitat (see masking discussion
above), but this is unlikely given the existing conditions at the
project site (see previous discussion of acoustic environment under
Description of Sound Sources above). There are no rookeries or major
haul-out sites, no known foraging hotspots, or other ocean bottom
structure of significant biological importance to marine mammals
present in the marine waters in the vicinity of the project area.
Therefore, the main impact issue associated with the proposed activity
would be temporarily elevated sound levels and the associated direct
effects on marine mammals, as discussed previously in this document.
The most likely impact to marine mammal habitat occurs from pile
driving effects on likely marine mammal prey (i.e., fish) near NBKB and
minor impacts to the immediate substrate during installation and
removal of piles during the pier maintenance project.
Pile Driving Effects on Potential Prey
Construction activities would produce both pulsed (i.e., impact
pile driving) and continuous (i.e., vibratory pile driving) sounds.
Fish react to sounds which 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
[[Page 44045]]
Popper (2005) identified several studies 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 of the 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 are expected to be minor and temporary due to the short
timeframe for the project. However, adverse impacts may occur to a few
species of fish which may still be present in the project area despite
operating in a reduced work window in an attempt to avoid important
fish spawning time periods.
Pile Driving Effects on Potential Foraging Habitat
The area likely impacted by the project is relatively small
compared to the available habitat in inland waters in the region.
Avoidance by potential prey (i.e., fish) of the immediate area due to
the temporary loss of this foraging habitat is also possible. 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. Any behavioral avoidance by fish of the
disturbed area would still leave significantly large areas of fish and
marine mammal foraging habitat in the nearby vicinity.
In summary, given the short daily duration of sound associated with
individual pile driving events and the relatively small areas being
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. The area around NBKB, including the
adjacent ferry terminal and nearby marinas, is heavily altered with
significant levels of industrial and recreational activity, and is
unlikely to harbor significant amounts of forage fish. Thus, any
impacts to marine mammal habitat are not expected to cause significant
or long-term consequences for individual marine mammals or their
populations.
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. Here we provide a single description of proposed
mitigation measures, as we propose to require similar measures for both
the Pier 6 and Pier 4 IHAs. The only differences would be related to
the difference between impact and vibratory driving, as described
below. The Pier 4 project does not involve impact driving and measures
specific to that technique are not relevant for the Pier 4 project.
Please see Proposed Authorizations, below, for requirements specific to
each proposed IHA.
Measurements from similar pile driving events were coupled with
practical spreading loss to estimate zones of influence (ZOI; see
Estimated Take by Incidental Harassment); these values were used to
develop mitigation measures for pile driving activities at NBKB. The
ZOIs effectively represent the mitigation zone that would be
established around each pile to prevent Level A harassment to marine
mammals, while providing estimates of the areas within which Level B
harassment might occur. 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.
Monitoring and Shutdown for Pile Driving
The following measures would apply to the Navy's mitigation through
shutdown and disturbance zones:
Shutdown Zone--For all pile driving activities, the Navy will
establish a shutdown zone intended to contain the area in which SPLs
equal or exceed the 190 dB rms acoustic injury criteria. The purpose of
a shutdown zone is to define an area within which shutdown of activity
would occur upon sighting of a marine mammal (or in anticipation of an
animal entering the defined area), thus preventing injury of marine
mammals (as described previously under Potential Effects of the
Specified Activity on Marine Mammals, serious injury or death are
unlikely outcomes even in the absence of mitigation measures). Modeled
radial distances for shutdown zones are shown in Table 5. However, a
minimum shutdown zone of 10 m (which is larger than the maximum
predicted injury zone) will be established during all pile driving
activities, regardless of the estimated zone. Vibratory pile driving
activities are not predicted to produce sound exceeding the 190-dB
Level A harassment threshold, but these precautionary measures are
intended to prevent the already unlikely possibility of physical
interaction with construction equipment and to further reduce any
possibility of acoustic injury.
Disturbance Zone--Disturbance zones are the areas in which SPLs
equal or exceed 160 and 120 dB rms (for impulse and continuous sound,
respectively). Disturbance zones provide utility for monitoring
conducted for mitigation purposes (i.e., shutdown zone monitoring) by
establishing monitoring protocols for areas adjacent to the shutdown
zones. Monitoring of disturbance zones enables observers to be aware of
and communicate the presence of marine mammals in the project area but
outside the shutdown zone and thus prepare for potential shutdowns of
activity. However, the primary purpose of disturbance zone monitoring
is for documenting incidents of Level B harassment; disturbance zone
monitoring is discussed in greater detail later (see Proposed
Monitoring and Reporting). Nominal radial distances for disturbance
zones are shown in Table 5.
In order to document observed incidents of harassment, monitors
record all marine mammal observations, regardless of location. The
observer's location, as well as the location of the pile being driven,
is known from a GPS. The location of the animal is estimated as a
distance from the observer, which is then compared to the location from
the pile. It may then be estimated whether the animal was exposed to
sound levels constituting incidental harassment on the basis of
predicted distances to relevant thresholds in post-processing of
observational and acoustic data, and a precise accounting of observed
incidences of harassment created. This information may then be used to
extrapolate observed takes to reach an approximate understanding of
actual total takes.
[[Page 44046]]
Monitoring Protocols--Monitoring would be conducted before, during,
and after pile driving activities. In addition, observers shall record
all incidents of marine mammal occurrence, regardless of distance from
activity, and shall document any behavioral reactions in concert with
distance from piles being driven. Observations made outside the
shutdown zone will not result in shutdown; that pile segment would be
completed without cessation, unless the animal approaches or enters the
shutdown zone, at which point all pile driving activities would be
halted. Monitoring will take place from fifteen minutes prior to
initiation through thirty minutes post-completion of pile driving
activities. Pile driving activities include the time to install or
remove a single pile or series of piles, as long as the time elapsed
between uses of the pile driving equipment is no more than thirty
minutes. Please see the project-specific Monitoring Plans (Appendix C
in both the Pier 4 and Pier 6 applications; www.nmfs.noaa.gov/pr/permits/incidental/construction.htm), developed by the Navy in
agreement with NMFS, for full details of the monitoring protocols.
The following additional measures apply to visual monitoring:
(1) Monitoring will be conducted by qualified observers, who will
be placed at the best vantage point(s) practicable to 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:
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;
Advanced education in biological science or related field
(undergraduate degree or higher required);
Experience and ability to conduct field observations and
collect data according to assigned protocols (this may include academic
experience);
Experience or training in the field identification of
marine mammals, including the identification of behaviors;
Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
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
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.
(2) Prior to the start of pile driving activity, the shutdown zone
will be monitored for fifteen minutes to ensure that it is clear of
marine mammals. Pile driving will only commence once observers have
declared the shutdown zone clear of marine mammals; animals will be
allowed to remain in the shutdown zone (i.e., must leave of their own
volition) and their behavior will be monitored and documented. The
shutdown zone may only be declared clear, and pile driving started,
when the entire shutdown zone is visible (i.e., when not obscured by
dark, rain, fog, etc.). In addition, if such conditions should arise
during impact pile driving that is already underway, the activity would
be halted.
(3) If a marine mammal approaches or enters the shutdown zone
during the course of pile driving operations, activity will be halted
and delayed until either the animal has voluntarily left and been
visually confirmed beyond the shutdown zone or fifteen minutes have
passed without re-detection of the animal. Monitoring will be conducted
throughout the time required to drive a pile.
Special Conditions
The Navy has not requested the authorization of incidental take for
killer whales or gray whales (see discussion below in Estimated Take by
Incidental Harassment). Therefore, shutdown would be implemented in the
event that either of these species is observed in the vicinity, prior
to entering the defined disturbance zone. As described later in this
document, we believe that occurrence of these species during the in-
water work window would be uncommon and that the occurrence of an
individual or group would likely be highly noticeable and would attract
significant attention in local media and with local whale watchers and
interested citizens.
Prior to the start of pile driving on any day, the Navy would
contact and/or review the latest sightings data from the Orca Network
and/or Center for Whale Research to determine the location of the
nearest marine mammal sightings. The Orca Sightings Network consists of
a list of over 600 residents, scientists, and government agency
personnel in the U.S. and Canada, and includes passive acoustic
detections. The presence of a killer whale or gray whale in the
southern reaches of Puget Sound would be a notable event, drawing
public attention and media scrutiny. With this level of coordination in
the region of activity, the Navy should be able to effectively receive
real-time information on the presence or absence of whales, sufficient
to inform the day's activities. Pile driving would not occur if there
was the risk of incidental harassment of a species for which incidental
take was not authorized.
During vibratory pile driving, one land-based observer would be
positioned at the pier work site. Additionally, one vessel-based
observer will travel through the monitoring area, completing an entire
loop approximately every thirty minutes (please see Figure 1 of
Appendix C in the Navy's applications). If any killer whales or gray
whales are detected, activity would not begin or would shut down.
Timing Restrictions
In the project area, designated timing restrictions exist to avoid
in-water work when salmonids and other spawning forage fish are likely
to be present. The in-water work window is June 15-March 1 for Pier 6
and July 16-February 15 for Pier 4. All in-water construction
activities would occur only during daylight hours (sunrise to sunset).
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. This procedure is repeated two
additional times. It is difficult to specify the reduction in energy
for any given hammer because of variation across drivers and, for
impact hammers, the actual number of strikes at reduced energy will
vary because operating the hammer at less than full power results in
``bouncing'' of the hammer as it strikes the pile, resulting in
multiple ``strikes.'' The pier maintenance project will utilize soft
start techniques for both impact and vibratory pile driving. We require
the Navy to initiate sound from vibratory hammers for fifteen seconds
at reduced energy followed by a thirty-second
[[Page 44047]]
waiting period, with the procedure repeated two additional times. For
impact driving, we require an initial set of three strikes from the
impact hammer at reduced energy, followed by a thirty-second waiting
period, then two subsequent three strike sets. Soft start will be
required at the beginning of each day's pile driving work and at any
time following a cessation of pile driving of thirty minutes or longer.
We have carefully evaluated the Navy's proposed mitigation measures
and considered their effectiveness in past implementation to
preliminarily determine whether they are likely to effect the least
practicable impact on the affected marine mammal species and stocks and
their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another: (1)
The manner in which, and the degree to which, the successful
implementation of the measure is expected to minimize adverse impacts
to marine mammals, (2) the proven or likely efficacy of the specific
measure to minimize adverse impacts as planned; and (3) the
practicability of the measure for applicant implementation.
Any mitigation measure(s) we prescribe should be able to
accomplish, have a reasonable likelihood of accomplishing (based on
current science), or contribute to the accomplishment of one or more of
the general goals listed below:
(1) Avoidance or minimization of injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may contribute to this goal).
(2) A reduction in the number (total number or number at
biologically important time or location) of individual marine mammals
exposed to stimuli expected to result in incidental take (this goal may
contribute to 1, above, or to reducing takes by behavioral harassment
only).
(3) A reduction in the number (total number or number at
biologically important time or location) of times any individual marine
mammal would be exposed to stimuli expected to result in incidental
take (this goal may contribute to 1, above, or to reducing takes by
behavioral harassment only).
(4) A reduction in the intensity of exposure to stimuli expected to
result in incidental take (this goal may contribute to 1, above, or to
reducing the severity of behavioral harassment only).
(5) Avoidance or minimization of adverse effects to marine mammal
habitat, paying particular attention to the prey base, blockage or
limitation of passage to or from biologically important areas,
permanent destruction of habitat, or temporary disturbance of habitat
during a biologically important time.
(6) For monitoring directly related to mitigation, an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation.
Based on our evaluation of the Navy's proposed measures, as well as
any other potential measures that may be relevant to the specified
activity, we have preliminarily determined that the proposed mitigation
measures provide the means of effecting the least practicable impact on
marine mammal 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
incidental take authorizations must include the suggested means of
accomplishing the necessary monitoring and reporting that will result
in increased knowledge of the species and of the level of taking or
impacts on populations of marine mammals that are expected to be
present in the proposed action area.
Any monitoring requirement we prescribe should improve our
understanding of one or more of the following:
Occurrence of marine mammal species in action area (e.g.,
presence, abundance, distribution, density).
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
Affected species (e.g., life history, dive patterns); (3) Co-occurrence
of marine mammal species with the action; or (4) Biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
Individual responses to acute stressors, or impacts of
chronic exposures (behavioral or physiological).
How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of an individual; or (2) Population,
species, or stock.
Effects on marine mammal habitat and resultant impacts to
marine mammals.
Mitigation and monitoring effectiveness.
With the exception of acoustic monitoring required for the Pier 6
project (see below), monitoring requirements are the same for both Pier
4 and Pier 6 projects, and a single discussion is provided here.
Monitoring requirements specific to impact pile driving are only
applicable to the Pier 6 project. The Navy marine mammal monitoring
plans can be found as Appendix C of both applications, on the Internet
at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
Acoustic Monitoring
Specific to the Pier 6 project, the Navy will implement a sound
source level verification study during the specified activities. Data
will be collected in order to estimate airborne and underwater source
levels for vibratory removal of timber piles and impact driving of
concrete piles, with measurements conducted for ten piles of each type.
Monitoring will include one underwater and one airborne monitoring
position. These exact positions will be determined in the field during
consultation with Navy personnel, subject to constraints related to
logistics and security requirements. Reporting of measured sound level
signals will include the average, minimum, and maximum rms value and
frequency spectra for each pile monitored. Please see section 11.4.4 of
the Navy's Pier 6 application for details of the Navy's acoustic
monitoring plan. This acoustic monitoring program was included with
requirements under Year 2 of the Pier 6 project, but could not be
conducted due to changes to the project schedule.
Visual Marine Mammal Observations
The Navy will collect sighting data and behavioral responses to
construction for marine mammal species observed in the region of
activity during the period of activity. All observers will be trained
in marine mammal identification and behaviors and are required to have
no other construction-related tasks while conducting monitoring. The
Navy will monitor the shutdown zone and disturbance zone before,
during, and after pile driving, with observers located at the best
practicable vantage points. Based on our requirements, the Navy would
implement the following procedures for pile driving:
MMOs would be located at the best vantage point(s) in
order to properly see the entire shutdown zone and as much of the
disturbance zone as possible.
During all observation periods, observers will use
binoculars and the
[[Page 44048]]
naked eye to search continuously for marine mammals.
If the shutdown zones are obscured by fog or poor lighting
conditions, pile driving at that location will not be initiated until
that zone is visible. Should such conditions arise while impact driving
is underway, the activity would be halted.
The shutdown and disturbance zones around the pile will be
monitored for the presence of marine mammals before, during, and after
any pile driving or removal activity.
During vibratory pile driving, two observers would be deployed as
described under Proposed Mitigation, including one land-based observer
and one-vessel-based observer traversing the extent of the Level B
harassment zone. We previously required (for Years 1-2 of the Pier 6
project) the deployment of four land-based observers (in addition to
one vessel-based observer) during vibratory driving. This additional
monitoring effort served to confirm that our assumptions relating to
marine mammal occurrence in the action area were accurate, and we do
not believe it necessary to continue with two shore-based observers in
the far-field, in addition to the far-field vessel-based observer, to
accomplish the required monitoring of incidental take. During impact
driving, one observer would be positioned at or near the pile to
observe the much smaller disturbance zone.
Individuals implementing the monitoring protocol will assess its
effectiveness using an adaptive approach. Monitoring biologists will
use their best professional judgment throughout implementation and seek
improvements to these methods when deemed appropriate. Any
modifications to protocol will be coordinated between NMFS and the
Navy.
Data Collection
We require that observers use approved data forms. Among other
pieces of information, the Navy will record detailed information about
any implementation of shutdowns, including the distance of animals to
the pile and description of specific actions that ensued and resulting
behavior of the animal, if any. In addition, the Navy will attempt to
distinguish between the number of individual animals taken and the
number of incidents of take. We require that, at a minimum, the
following information be collected on the sighting forms:
Date and time that monitored activity begins or ends;
Construction activities occurring during each observation
period;
Weather parameters (e.g., percent cover, visibility);
Water conditions (e.g., sea state, tide state);
Species, numbers, and, if possible, sex and age class of
marine mammals;
Description of any observable marine mammal behavior
patterns, including bearing and direction of travel and distance from
pile driving activity;
Distance from pile driving activities to marine mammals
and distance from the marine mammals to the observation point;
Description of implementation of mitigation measures
(e.g., shutdown or delay).
Locations of all marine mammal observations; and
Other human activity in the area.
Reporting
A draft report would be submitted to NMFS within 45 days of the
completion of marine mammal monitoring, or sixty days prior to the
issuance of any subsequent IHA for these projects (if required),
whichever comes first. The report will include marine mammal
observations pre-activity, during-activity, and post-activity during
pile driving days, and will also provide descriptions of any behavioral
responses to construction activities by marine mammals and a complete
description of all mitigation shutdowns and the results of those
actions and an extrapolated total take estimate based on the number of
marine mammals observed during the course of construction. A final
report must be submitted within thirty days following resolution of
comments on the draft report.
Monitoring Results From Previously Authorized Activities
The Navy complied with the mitigation and monitoring required under
the previous authorizations for the Pier 6 project. Marine mammal
monitoring occurred before, during, and after each pile driving event.
During the course of these activities, the Navy did not exceed the take
levels authorized under the IHAs. In accordance with the 2013 and 2014
IHAs, the Navy submitted monitoring reports (available at:
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm).
Under the 2013 IHA, the Navy anticipated a total of 65 pile driving
days; however, only a limited program of test pile driving actually
took place. Pile driving occurred on only two days, with a total of
only two piles driven (both impact-driven concrete piles). The only
species observed was the California sea lion. A total of 24 individuals
were observed within the defined Level B harassment zone, but all were
hauled-out on port security barrier floats outside of the defined Level
B harassment zone for airborne sound. Therefore, no take of marine
mammals occurred incidental to project activity under the year one IHA.
Under the 2014 IHA, the Navy anticipated a total of sixty pile
driving days, but actually conducted a total of 32 pile driving days.
This total included sixteen days each of impact driving and pile
removal; however, only approximately fifty percent of pile removal
required use of the vibratory driver and there were a total of 24
monitoring days. Only two species, the California sea lion and harbor
seal, were observed. Total observed incidents of take were 275 for
California sea lions (151 during vibratory removal and 124 during
impact driving) and ten for harbor seals (nine during vibratory removal
and one during impact driving). Given the extensive far-field
monitoring required, no extrapolation of observed takes to unobserved
area was necessary.
Observed behaviors were typical for pinnipeds and included
foraging, milling, and traveling. Numerous California sea lions use the
port security floats as a haul-out. No reactions indicative of
disturbance were observed.
Estimated Take by Incidental Harassment
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].''
All anticipated takes would be by Level B harassment resulting from
vibratory and impact pile driving and involving temporary changes in
behavior. The proposed mitigation and monitoring measures are expected
to minimize the possibility of injurious or lethal takes such that take
by Level A harassment, serious injury, or mortality is considered
discountable. However, it is unlikely that injurious or lethal takes
would occur even in the absence of the planned mitigation and
monitoring measures.
If a marine mammal responds to a stimulus by changing its behavior
(e.g., through relatively minor changes in locomotion direction/speed
or
[[Page 44049]]
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,
impacts on animals or on the stock or species could potentially be
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007). Given the
many uncertainties in predicting the quantity and types of impacts of
sound on marine mammals, it is common practice to estimate how many
animals are likely to be present within a particular distance of a
given activity, or exposed to a particular level of sound. In practice,
depending on the amount of information available to characterize daily
and seasonal movement and distribution of affected marine mammals, it
can be difficult to distinguish between the number of individuals
harassed and the instances of harassment and, when duration of the
activity is considered, it can result in a take estimate that
overestimates the number of individuals harassed. In particular, for
stationary activities, it is more likely that some smaller number of
individuals may accrue a number of incidences of harassment per
individual than for each incidence to accrue to a new individual,
especially if those individuals display some degree of residency or
site fidelity and the impetus to use the site (e.g., because of
foraging opportunities) is stronger than the deterrence presented by
the harassing activity.
The project area is not believed to be particularly important
habitat for marine mammals, nor is it considered an area frequented by
marine mammals, although harbor seals may be present year-round and sea
lions are known to haul-out on man-made objects at the NBKB waterfront.
Sightings of other species are rare. Therefore, behavioral disturbances
that could result from anthropogenic sound associated with these
activities are expected to affect only a relatively small number of
individual marine mammals, although those effects could be recurring
over the life of the project if the same individuals remain in the
project vicinity.
The Navy has requested authorization for the incidental taking of
small numbers of Steller sea lions, California sea lions, and harbor
seals in Sinclair Inlet and nearby waters that may result from pile
driving during construction activities associated with the pier
maintenance projects described previously in this document. The
available information, and the most appropriate way to use that
information in estimating take by incidental harassment, is general to
Sinclair Inlet. Therefore, we provide a single discussion of exposure
analyses that is applicable to both the Pier 4 and Pier 6 projects.
In order to estimate the potential incidents of take that may occur
incidental to the specified activity, we must first estimate the extent
of the sound field that may be produced by the activity and then
consider in combination with information about marine mammal density or
abundance in the project area. We first provide information on
applicable sound thresholds for determining effects to marine mammals
before describing the information used in estimating the sound fields,
the available marine mammal density or abundance information, and the
method of estimating potential incidents of take.
Sound Thresholds
We use generic sound exposure thresholds to determine when an
activity that produces sound might result in impacts to a marine mammal
such that a take by harassment might occur. To date, no studies have
been conducted that explicitly examine impacts to marine mammals from
pile driving sounds or from which empirical sound thresholds have been
established. These thresholds (Table 3) are used to estimate when
harassment may occur (i.e., when an animal is exposed to levels equal
to or exceeding the relevant criterion) in specific contexts; however,
useful contextual information that may inform our assessment of effects
is typically lacking and we consider these thresholds as step
functions. NMFS is working to revise these acoustic guidelines; for
more information on that process, please visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
Table 3--Current Acoustic Exposure Criteria
------------------------------------------------------------------------
Criterion Definition Threshold
------------------------------------------------------------------------
Level A......................... Injury (PTS--any 180 dB (cetaceans)/
harassment (underwater)......... level above that 190 dB
which is known to (pinnipeds)
cause TTS). (rms).
Level B harassment (underwater). Behavioral 160 dB (impulsive
disruption. source)/120 dB
(continuous
source) (rms).
Level B harassment (airborne)... Behavioral 90 dB (harbor
disruption. seals)/100 dB
(other pinnipeds)
(unweighted).
------------------------------------------------------------------------
Distance to Sound Thresholds
Underwater Sound Propagation Formula--Pile driving generates
underwater noise that can potentially result in disturbance to marine
mammals in the project area. Transmission loss (TL) is the decrease in
acoustic intensity as an acoustic pressure wave propagates out from a
source. TL parameters vary with frequency, temperature, sea conditions,
current, source and receiver depth, water depth, water chemistry, and
bottom composition and topography. The general formula for underwater
TL is:
TL = B * log10(R1/R2),
Where
R1 = the distance of the modeled SPL from the driven
pile, and
R2 = the distance from the driven pile of the initial
measurement.
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive conditions including in-water structures and
sediments. Spherical spreading occurs in a perfectly unobstructed
(free-field) environment not limited by depth or water surface,
resulting in a 6 dB reduction in sound level for each doubling of
distance from the source (20*log[range]). Cylindrical spreading occurs
in an environment in which sound propagation is bounded by the water
surface and sea bottom, resulting in a reduction of 3 dB in sound level
for each doubling of distance from the source (10*log[range]). A
practical spreading value of fifteen is often used under conditions,
such as Sinclair Inlet, where water increases with depth as the
receiver moves away from the shoreline,
[[Page 44050]]
resulting in an expected propagation environment that would lie between
spherical and cylindrical spreading loss conditions. Practical
spreading loss (4.5 dB reduction in sound level for each doubling of
distance) is assumed here.
Underwater Sound--The intensity of pile driving sounds is greatly
influenced by factors such as the type of piles, hammers, and the
physical environment in which the activity takes place. However, a
limited quantity of literature is available for consideration regarding
SPLs recorded from pile driving projects similar to the Navy's activity
(i.e., impact-driven concrete piles and vibratory pile removal). In
order to determine reasonable SPLs and their associated effects on
marine mammals that are likely to result from pile driving at NBKB,
studies with similar properties to the specified activity were
evaluated, and are displayed in Table 4.
Table 4--Summary of Proxy Measured Underwater SPLs
----------------------------------------------------------------------------------------------------------------
Pile size and
Location Method material Measured SPLs
----------------------------------------------------------------------------------------------------------------
Berth 22, Port of Oakland \1\...... Impact................ 24-in concrete....... 176 dB at 10 m.
Mad River Slough, CA \1\........... Vibratory............. 13-in steel pipe..... 155 dB at 10 m.
Port Townsend, WA \2\.............. Vibratory (removal)... 12-in timber......... 150 dB at 16 m.
----------------------------------------------------------------------------------------------------------------
Sources: \1\ Caltrans, 2012; \2\ Laughlin, 2011.
We consider the values presented in Table 4 to be representative of
SPLs that may be produced by impact driving of concrete piles,
vibratory driving of steel piles, and vibratory removal of timber
piles, respectively. The value from Berth 22 was selected as
representative of the largest concrete pile size to be installed and
may be conservative when smaller concrete piles are driven. The value
from Mad River Slough is for vibratory installation and would likely be
conservative when applied to vibratory extraction, which would be
expected to produce lower SPLs than vibratory installation of same-
sized piles. All calculated distances to and the total area encompassed
by the marine mammal sound thresholds are provided in Table 5.
Table 5--Distances to Relevant Sound Thresholds and Areas of Ensonification, Underwater
----------------------------------------------------------------------------------------------------------------
Distance to threshold (m) and associated area of ensonification (km\2\)
Description ---------------------------------------------------------------------------
190 dB 180 dB 160 dB 120 dB
----------------------------------------------------------------------------------------------------------------
Concrete piles, impact.............. 1.2, <0.0001 5.4, 0.0001 117, 0.04 n/a
Steel piles, vibratory.............. 0 0 n/a 2,154\2\, 7.5
Timber piles, vibratory............. 0 0 n/a 1,585; 5.0
----------------------------------------------------------------------------------------------------------------
\1\ SPLs used for calculations were: 191 dB for impact driving, 170 dB for vibratory removal of steel piles, and
168 dB for vibratory removal of timber piles.
\2\ Areas presented take into account attenuation and/or shadowing by land. Please see Appendix B in the Navy's
applications.
Sinclair Inlet does not represent open water, or free field,
conditions. Therefore, sounds would attenuate according to the
shoreline topography. Distances shown in Table 5 are estimated for
free-field conditions, but areas are calculated per the actual
conditions of the action area. See Appendix B of the Navy's
applications for a depiction of areas in which each underwater sound
threshold is predicted to occur at the project area due to pile
driving.
Airborne Sound--Pile driving can generate airborne sound that could
potentially result in disturbance to marine mammals (specifically,
pinnipeds) which are hauled out or at the water's surface. As was
discussed for underwater sound from pile driving, the intensity of pile
driving sounds is greatly influenced by factors such as the type of
piles, hammers, and the physical environment in which the activity
takes place. As before, measured values from other studies were used as
proxy values to determine reasonable airborne SPLs and their associated
effects on marine mammals that might result from pile driving at NBKB.
There are no measurements known for unweighted airborne sound from
either impact driving of concrete piles or for vibratory driving of
timber piles. A spherical spreading loss model (i.e., 6 dB reduction in
sound level for each doubling of distance from the source), in which
there is a perfectly unobstructed (free-field) environment not limited
by depth or water surface, is appropriate for use with airborne sound
and was used to estimate the distance to the airborne thresholds.
Table 6--Summary of Proxy Measured Airborne SPLs
----------------------------------------------------------------------------------------------------------------
Pile size and
Location Method material Measured SPLs
----------------------------------------------------------------------------------------------------------------
Test Pile Program, Hood Canal \1\. Impact............... 24-in steel pipe..... 89 dB at 15 m.
Wahkiakum Ferry Terminal, WA \2\.. Vibratory............ 18-in steel pipe..... 87.5 dB at 15 m.
----------------------------------------------------------------------------------------------------------------
Sources: \1\ Illingworth & Rodkin, 2012; \2\ Laughlin, 2010.
Steel piles generally produce louder source levels than do
similarly sized concrete or timber piles. Similarly, the value shown
here for the larger steel piles (18-in) would likely be louder than
smaller steel piles or timber piles. Therefore, these values will
likely overestimate the distances to relevant thresholds. Based on
these values and the assumption of spherical spreading loss, distances
to relevant thresholds and associated areas of ensonification
[[Page 44051]]
are presented in Table 7; these areas are depicted in Appendix B of the
Navy's applications.
Table 7--Distances to Relevant Sound Thresholds and Areas of
Ensonification, Airborne
------------------------------------------------------------------------
Distance to threshold (m) and
associated area of
ensonification (m\2\)
Group -------------------------------
Vibratory
Impact driving driving
------------------------------------------------------------------------
Harbor seals............................ 13, 169 11, 121
Sea lions............................... 5, 25 4, 16
------------------------------------------------------------------------
\1\SPLs used for calculations were: 112.5 dB for impact driving and 111
dB for use of a vibratory hammer.
However, because there are no regular haul-outs within such a small
area around the site of proposed pile driving activity, we believe that
incidents of incidental take resulting solely from airborne sound are
unlikely. In particular, the zones for sea lions are within the minimum
shutdown zone defined for underwater sound, and the zones for harbor
seals are only slightly larger. It is extremely unlikely that any
structure would be available as a haul-out opportunity within these
zones, or that an animal would haul out in such close proximity to pile
driving activity. There is a remote possibility that an animal could
surface in-water, but with head out, within one of the defined zones
and thereby be exposed to levels of airborne sound that we associate
with harassment, but any such occurrence would likely be accounted for
in our estimation of incidental take from underwater sound.
In summary, we generally recognize that pinnipeds occurring within
an estimated airborne harassment zone, whether in the water or hauled
out, could be exposed to airborne sound that may result in behavioral
harassment. However, any animal exposed to airborne sound above the
behavioral harassment threshold is likely to also be exposed to
underwater sound above relevant thresholds (which are typically in all
cases larger zones than those associated with airborne sound). Thus,
the behavioral harassment of these animals is already accounted for in
these estimates of potential take. Multiple incidents 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.
Marine Mammal Densities
For all species, the best scientific information available was
considered for use in the marine mammal take assessment calculations.
The Navy has developed, with input from regional marine mammal experts,
estimates of marine mammal densities in Washington inland waters for
the Navy Marine Species Density Database (NMSDD). A technical report
(Hanser et al., 2015) describes methodologies and available information
used to derive these densities, which are generally based upon the best
available information for Washington inland waters, except where
specific local abundance information is available.
At NBKB, the Navy began collecting opportunistic observational data
of animals hauled-out on the floating security barrier. These surveys
began in February 2010 and have been conducted approximately monthly
from September 2010 through December 2014 (DoN, 2014). In addition, the
Washington State Department of Transportation (WSDOT) recently
conducted in-water pile driving over the course of multiple work
windows as part of the Manette Bridge construction project in the
nearby Port Washington Narrows. WSDOT conducted required marine mammal
monitoring as part of this project (WSDOT, 2011, 2012; Rand, 2011).
Here, we considered NMSDD density information for all five species we
believe to have the potential for occurrence in the project area, but
determined it most appropriate to use local abundance data for the
three pinniped species. Density information is shown in Table 8; see
Hanser et al. (2015) for descriptions of how the densities were
derived. That document is publicly available on the Internet at
nwtteis.com/DocumentsandReferences/NWTTDocuments/SupportingTechnicalDocuments.aspx (accessed July 13, 2015). See below
for discussion of gray whale and killer whale.
Description of Take Calculation
The following assumptions are made when estimating potential
incidences of take:
All marine mammal individuals potentially available are
assumed to be present within the relevant area, and thus incidentally
taken;
An individual can only be taken once during a 24-h period;
There were will be sixty total days of activity for the
Pier 6 project and thirty total days for the Pier 4 project; and,
Exposures to sound levels at or above the relevant
thresholds equate to take, as defined by the MMPA.
The estimation of marine mammal takes typically uses the following
calculation:
Exposure estimate = (n * ZOI) * days of total activity
Where:
n = density estimate used for each species/season.
ZOI = sound threshold ZOI area; the area encompassed by all
locations where the SPLs equal or exceed the threshold being
evaluated.
n * ZOI produces an estimate of the abundance of animals that could
be present in the area for exposure, and is rounded to the nearest
whole number before multiplying by days of total activity.
The ZOI impact area is estimated using the relevant distances in
Table 5, taking into consideration the possible affected area due to
topographical constraints of the action area (i.e., radial distances to
thresholds are not always reached). When local abundance is the best
available information, in lieu of the density-area method described
above, we may simply multiply some number of animals (as determined
through counts of animals hauled-out) by the number of days of
activity, under the assumption that all of those animals will be
present and incidentally taken on each day of activity.
There are a number of reasons why estimates of potential incidents
of take may be conservative, assuming that available density or
abundance estimates and estimated ZOI areas are accurate. We assume, in
the absence of information supporting a more refined conclusion, that
the output of the calculation represents the number of individuals that
may be taken by the specified activity. In fact, in the context of
stationary activities such as pile driving and in areas where resident
animals may be present, this number more realistically represents the
number of incidents of take that may accrue to a smaller number of
individuals. While pile driving can occur any day throughout the in-
water work window, and the analysis is conducted on a per day basis,
only a fraction of that time (typically a matter of hours on any given
day) is actually spent pile driving. The potential effectiveness of
mitigation measures in reducing the number of takes is typically not
quantified in the take estimation process. For these reasons, these
take estimates may be conservative. See Table 8 for total estimated
incidents of take.
[[Page 44052]]
Harbor Seal--While no harbor seal haul-outs are present in the
action area or in the immediate vicinity of NBKB, haul-outs are present
elsewhere in Sinclair Inlet and in other nearby waters and harbor seals
may haul out on available objects opportunistically. Marine mammal
monitoring conducted during pile driving work on the Manette Bridge
showed variable numbers of harbor seals (but generally greater than
indicated by the uncorrected NMSDD density of 1.219 animals/km\2\).
During the first year of construction (in-water work window only), an
average of 3.7 harbor seals were observed per day of monitoring with a
maximum of 59 observed in October 2011 (WSDOT, 2011; Rand, 2011).
During the most recent construction period (July-November 2012), an
average of eleven harbor seals per monitoring day was observed, though
some animals were likely counted multiple times (WSDOT, 2012). Given
the potential for similar occurrence of harbor seals in the vicinity of
NBKB during the in-water construction period, we determined it
appropriate to use this most recent, local abundance information in the
take assessment calculation.
California Sea Lion--Similar to harbor seals, it is not likely that
use of the NMSDD density value for California sea lions (0.13 animals/
km\2\) would adequately represent their potential occurrence in the
project area, i.e., would result in an underestimate. California sea
lions are commonly observed hauled out on the floating security barrier
which is in close proximity to the piers; counts from 52 surveys
(February 2010-December 2014) showed an average of 48 individuals per
survey day (range 0-219; DoN, 2014). These counts represent the best
local abundance data available and were used in the take assessment
calculation.
Steller Sea Lion--No Steller sea lion haul-outs are present within
or near the action area, and Steller sea lions have not been observed
during Navy waterfront surveys or during monitoring associated with the
Manette Bridge construction project. It is assumed that the possibility
exists that a Steller sea lion could occur in the project area, but
there is no known attractant in Sinclair Inlet, which is a relatively
muddy, industrialized area, and the floating security barrier that
California sea lions use as an opportunistic haul-out cannot generally
accommodate the larger adult Steller sea lions (juveniles could haul-
out on the barrier). Use of the NMSDD density estimate (0.037 animals/
km\2\) results in an estimate of zero exposures, and there are no
existing data to indicate that Steller sea lions would occur more
frequently locally. However, as a precaution and to account for the
possibility that a Steller sea lion could occur in the project area, we
assume that one Steller sea lion could occur per day of activity.
Killer Whale--Transient killer whales are rarely observed in the
project area, with records since 2002 showing one group transiting
through the area in May 2004 and a subsequent, similar observation in
May 2010. No other observations have occurred during Navy surveys or
during project monitoring for Manette Bridge. Use of the NMSDD density
estimate (0.0024 animals/km\2\) results in an estimate of zero
exposures, and there are no existing data to indicate that killer
whales would occur more frequently locally. Therefore, the Navy has not
requested the authorization of incidental take for transient killer
whales and we do not propose such authorization. The Navy would not
begin activity or would shut down upon report of a killer whale present
within or approaching the relevant ZOI.
Gray Whale--Gray whales are rarely observed in the project area,
and the majority of in-water work would occur when whales are
relatively less likely to occur (i.e., outside of March-May). Since
2002 and during the in-water work window, there are observational
records of three whales (all during winter 2008-09) and a stranding
record of a fourth whale (January 2013). No other observations have
occurred during Navy surveys or during project monitoring for Manette
Bridge. Use of the NMSDD density estimate (0.0005 animals/km\2\)
results in an estimate of zero exposures, and there are no existing
data to indicate that gray whales would occur more frequently locally.
Therefore, the Navy has not requested the authorization of incidental
take for gray whales and we do not propose such authorization. The Navy
would not begin activity or would shut down upon report of a gray whale
present within or approaching the relevant ZOI.
Table 8--Calculations for Incidental Take Estimation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total proposed Total proposed
n * ZOI authorized takes, authorized takes,
Species n (animals/km\2\) \1\ (vibratory steel Abundance \3\ Pier 6 (% of Pier 4 (% of
pile removal) \2\ total stock) total stock)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion......................... 0.1266........................ 1 45 2,880 (1.0) 1,440 (0.5)
Steller sea lion............................ 0.0368........................ 0 1 60 (0.1) 30 (0.05)
Harbor seal................................. 1.219 \5\..................... 9 11 660 (6.0) 330 (3.0)
Killer whale (transient).................... 0.0024 (fall)................. 0 n/a 0 0
Gray whale.................................. 0.0005 (winter)............... 0 n/a 0 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Best available species- and season-specific density estimate, with season noted in parentheses where applicable (Hanser et al., 2015).
\2\ Product of density and largest ZOI (7.5 km\2\) rounded to nearest whole number; presented for reference only.
\3\ Best abundance numbers multiplied by expected days of activity (60 and 30 for Pier 6 and Pier 4, respectively) to produce take estimate.
\4\ Totals presented for reference only. Negligible impact and small numbers analyses (below) consider the project-specific numbers in columns to left.
\5\ Uncorrected density; presented for reference only.
Analyses and Preliminary Determinations
Negligible Impact Analyses
NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``. . .
an impact resulting from the specified activity that cannot be
reasonably expected to, and is not reasonably likely to, adversely
affect the species or stock through effects on annual rates of
recruitment or survival.'' A negligible impact finding is based on the
lack of likely adverse effects on annual rates of recruitment or
survival (i.e., population-level effects). An estimate of the number of
Level B harassment 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 behavioral
harassment, we consider other factors, such as the likely nature of any
responses (e.g., intensity, duration), the context of any responses
[[Page 44053]]
(e.g., critical reproductive time or location, migration), as well as
the number and nature of estimated Level A harassment takes, the number
of estimated mortalities, and effects on habitat.
To avoid repetition, the discussion below applies to all the
species listed in Table 8 for which we propose to authorize take, and
to both separately proposed IHAs (i.e., the Navy's planned activities
pursuant to the separate Pier 6 and Pier 4 projects), as the
anticipated effects of both the Pier 6 and Pier 4 maintenance projects
on marine mammals are expected to be relatively similar in nature.
There is no information about the nature or severity of the impacts, or
the size, status, or structure of any species or stock that would lead
to species- or action-specific analyses for these activities.
Pile driving activities associated with the pier maintenance
projects, as outlined previously, have the potential to disturb or
displace marine mammals. Specifically, the specified activities may
result in take, in the form of Level B harassment (behavioral
disturbance) only, from underwater sounds generated from pile driving.
Potential takes could occur if individuals of these species are present
in the ensonified zone when pile driving is happening.
No injury, 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 these
outcomes is minimized through the construction method and the
implementation of the planned mitigation measures. Specifically, piles
would be removed via vibratory means--an activity that does not have
the potential to cause injury to marine mammals due to the relatively
low source levels produced (less than 180 dB) and the lack of
potentially injurious source characteristics--and, while impact pile
driving produces short, sharp pulses with higher peak levels and much
sharper rise time to reach those peaks, only small diameter concrete
piles are planned for impact driving (no impact pile driving would
occur for the Pier 4 project). Predicted source levels for such impact
driving events are significantly lower than those typical of impact
driving of steel piles and/or larger diameter piles. In addition,
implementation of soft start and shutdown zones significantly reduces
any possibility of injury. Given 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 its becoming
potentially injurious. Environmental conditions in Sinclair Inlet are
expected to generally be good, with calm sea states, although Sinclair
Inlet waters may be more turbid than those further north in Puget Sound
or in Hood Canal. Nevertheless, we expect conditions in Sinclair Inlet
would allow a high marine mammal detection capability for the trained
observers required, enabling a high rate of success in implementation
of shutdowns to avoid injury, serious injury, or mortality. In
addition, the topography of Sinclair Inlet should allow for placement
of observers sufficient to detect cetaceans, should any occur (see
Figure 1 of Appendix C in the Navy's applications).
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; HDR, Inc., 2012). 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. The pile driving
activities analyzed here are similar to, or less impactful than,
numerous other construction activities conducted in San Francisco Bay
and in the Puget Sound region, 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 hearing impairment or to significantly disrupt
foraging behavior. Thus, even repeated Level B harassment of some small
subset of the overall stock is unlikely to result in any significant
realized decrease in viability for the affected individuals, and thus
would not result in any adverse impact to the stock as a whole. Level B
harassment will be reduced to the level of least practicable impact
through use of mitigation measures described herein and, if sound
produced by project activities is sufficiently disturbing, animals are
likely to simply avoid the area while the activity is occurring.
In summary, these negligible impact analyses are founded on the
following factors: (1) The possibility of injury, serious injury, or
mortality may reasonably be considered discountable; (2) the
anticipated incidents of Level B harassment consist of, at worst,
temporary modifications in behavior; (3) the absence of any significant
habitat within the project area, including rookeries, significant haul-
outs, or known areas or features of special significance for foraging
or reproduction; (4) the presumed efficacy of the proposed mitigation
measures in reducing the effects of the specified activity to the level
of least practicable impact. In addition, these stocks are not listed
under the ESA or considered depleted under the MMPA. In combination, we
believe that these factors, as well as the available body of evidence
from other similar activities, demonstrate that the potential effects
of the specified activities will have only short-term effects on
individuals. The specified activities are not expected to impact rates
of recruitment or survival and will therefore not result in population-
level impacts. Below, we make separate preliminary findings specific to
each project.
Pier 6--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, we preliminarily find that the
total marine mammal take from the Navy's pier maintenance activities
will have a negligible impact on the affected marine mammal species or
stocks.
Pier 4--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, we preliminarily find that the
total marine mammal take from the Navy's pier maintenance activities
will have a negligible impact on the affected marine mammal species or
stocks.
Small Numbers Analyses
The number of incidents of take proposed for authorization for
these stocks, specific to each separate project, would be considered
small relative to the relevant stocks or populations (one percent or
less for both sea lion stocks and six percent or less for harbor seals;
Table 8) even if each estimated taking occurred to a new individual.
This is an extremely unlikely scenario as, for pinnipeds in estuarine/
inland waters, there is likely to be some overlap in individuals
present day-to-day. Below, we make separate preliminary findings
specific to each project.
Pier 6--Based on the analysis contained herein of the likely
effects of the specified activity on marine mammals and their habitat,
and taking
[[Page 44054]]
into consideration the implementation of the mitigation and monitoring
measures, we preliminarily find that small numbers of marine mammals
will be taken relative to the populations of the affected species or
stocks.
Pier 4--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 mitigation and
monitoring measures, we preliminarily find that small numbers of marine
mammals will be taken relative to the populations of the affected
species or stocks.
Impact on Availability of Affected Species for Taking for Subsistence
Uses
There are no relevant subsistence uses of marine mammals implicated
by these actions. Therefore, relevant to both the Pier 6 and Pier 4
proposed IHAs, we have determined that the total taking of affected
species or stocks would not have an unmitigable adverse impact on the
availability of such species or stocks for taking for subsistence
purposes.
Endangered Species Act (ESA)
No marine mammal species listed under the ESA are expected to be
affected by these activities. Therefore, we have determined that
section 7 consultations under the ESA are not required.
National Environmental Policy Act (NEPA)
Pier 6--In compliance with the National Environmental Policy Act of
1969 (42 U.S.C. 4321 et seq.), as implemented by the regulations
published by the Council on Environmental Quality (40 CFR parts 1500-
1508), the Navy prepared an Environmental Assessment (EA) to consider
the direct, indirect and cumulative effects to the human environment
resulting from the pier maintenance project. NMFS made the Navy's EA
available to the public for review and comment, in relation to its
suitability for adoption by NMFS in order to assess the impacts to the
human environment of issuance of an IHA to the Navy. Also in compliance
with NEPA and the CEQ regulations, as well as NOAA Administrative Order
216-6, NMFS has reviewed the Navy's EA, determined it to be sufficient,
and adopted that EA and signed a Finding of No Significant Impact
(FONSI) on November 8, 2013.
We have reviewed the Navy's application for a renewed IHA for
ongoing construction activities for 2015-16 and the 2014-15 monitoring
report. Based on that review, we have determined that the proposed
action is very similar to that considered in the previous IHA. In
addition, no significant new circumstances or information relevant to
environmental concerns have been identified. Thus, we have determined
preliminarily that the preparation of a new or supplemental NEPA
document is not necessary, and will, after review of public comments
determine whether or not to reaffirm our 2013 FONSI. The 2013 NEPA
documents are available for review at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
Pier 4--The Navy has prepared a Draft EA in accordance with NEPA
and the regulations published by the Council on Environmental Quality.
We have posted it on the NMFS Web site concurrently with the
publication of this proposed IHA. NMFS will independently evaluate the
EA and determine whether or not to adopt it. We may prepare a separate
NEPA analysis and incorporate relevant portions of the Navy's EA by
reference. Information in the Navy's application, EA, and this notice
collectively provide the environmental information related to proposed
issuance of the IHA for public review and comment. We will review all
comments submitted in response to this notice as we complete the NEPA
process, including a decision of whether to sign a FONSI, prior to a
final decision on the IHA request.
Proposed Authorizations
As a result of these preliminary determinations, we propose to
issue two separate IHAs to the Navy for conducting the described pier
maintenance activities in Sinclair Inlet, provided the previously
mentioned mitigation, monitoring, and reporting requirements are
incorporated. Specific language from the proposed IHAs is provided
next.
This section contains drafts of the IHAs. The wording contained in
this section is proposed for inclusion in the IHAs (if issued).
Pier 6
1. This Incidental Harassment Authorization (IHA) is valid from
September 1, 2015 through March 1, 2016.
2. This IHA is valid only for pile driving and removal activities
associated with the Pier 6 Maintenance Project at Naval Base Kitsap
Bremerton, Washington.
3. 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 harbor seal (Phoca
vitulina), California sea lion (Zalophus californianus), and Steller
sea lion (Eumetopias jubatus).
(c) The taking, by Level B harassment only, is limited to the
species listed in condition 3(b). See Table 1 for numbers of take
authorized.
Table 1--Authorized Take Numbers, by Species
------------------------------------------------------------------------
Authorized
Species take
------------------------------------------------------------------------
Harbor seal................................................ 660
California sea lion........................................ 2,880
Steller sea lion........................................... 60
------------------------------------------------------------------------
(d) The taking by injury (Level A harassment), serious injury, or
death of any of the species listed in condition 3(b) of the
Authorization or any taking of any other species 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, acoustic
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.
4. Mitigation Measures.
The holder of this Authorization is required to implement the
following mitigation measures:
(a) For all pile driving, the Navy shall implement a minimum
shutdown zone of 10 m radius around the pile. If a marine mammal comes
within or approaches the shutdown zone, such operations shall cease.
(b) The Navy shall establish monitoring locations as described
below. Please also refer to the Marine Mammal Monitoring Plan
(Monitoring Plan; attached).
i. For all vibratory pile removal activities, a minimum of two
observers shall be deployed. One observer shall be located at the pier
work site, positioned to achieve optimal monitoring of the shutdown
zone and the surrounding waters of Sinclair Inlet. A minimum of one
vessel-based observer shall be deployed and shall conduct regular
transits through the estimated disturbance zone for the duration of the
activity.
ii. For all impact pile driving activities, a minimum of one shore-
based observer shall be located at the pier work site.
[[Page 44055]]
iii. These observers shall record all observations of marine
mammals, regardless of distance from the pile being driven, as well as
behavior and potential behavioral reactions of the animals. If any
killer whales or gray whales are detected, activity must not begin or
must shut down.
iv. All observers shall be equipped for communication of marine
mammal observations amongst themselves and to other relevant personnel
(e.g., those necessary to effect activity delay or shutdown).
(c) Prior to the start of pile driving on any day, the Navy shall
take measures to ensure that no species for which incidental take is
not authorized are located within the vicinity of the action area, and
shall contact and/or review the latest sightings data from the Orca
Network and/or Center for Whale Research, including passive acoustic
detections, to determine the location of the nearest marine mammal
sightings.
(d) Monitoring shall take place from fifteen minutes prior to
initiation of pile driving activity through thirty minutes post-
completion of pile driving activity. Pre-activity monitoring shall be
conducted for fifteen minutes to ensure that the shutdown zone is clear
of marine mammals, and pile driving may commence when observers have
declared the shutdown zone clear of marine mammals. In the event of a
delay or shutdown of activity resulting from marine mammals in the
shutdown zone, animals shall be allowed to remain in the shutdown zone
(i.e., must leave of their own volition) and their behavior shall be
monitored and documented. Monitoring shall occur throughout the time
required to drive a pile. The shutdown zone must be determined to be
clear during periods of good visibility (i.e., the entire shutdown zone
and surrounding waters must be visible to the naked eye).
(e) If a marine mammal approaches or enters the shutdown zone, all
pile driving activities at that location shall be halted. If pile
driving is halted or delayed due to the presence of a marine mammal,
the activity may not commence or resume until either the animal has
voluntarily left and been visually confirmed beyond the shutdown zone
or fifteen minutes have passed without re-detection of the animal.
(f) Monitoring shall be conducted by qualified observers, as
described in the Monitoring Plan. Trained observers shall be placed
from 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.
(g) The Navy shall use soft start techniques recommended by NMFS
for vibratory and impact pile driving. Soft start for vibratory drivers
requires contractors to initiate sound for fifteen seconds at reduced
energy followed by a thirty-second waiting period. This procedure is
repeated two additional times. Soft start for impact drivers requires
contractors to provide an initial set of strikes at reduced energy,
followed by a thirty-second waiting period, then two subsequent reduced
energy strike sets. Soft start shall be implemented at the start of
each day's pile driving and at any time following cessation of pile
driving for a period of thirty minutes or longer. Soft start for impact
drivers must be implemented at any time following cessation of impact
driving for a period of thirty minutes or longer.
(h) Pile driving shall only be conducted during daylight hours.
5. Monitoring.
The holder of this Authorization is required to conduct marine
mammal monitoring during pile driving activity. Marine mammal
monitoring and reporting shall be conducted in accordance with the
Monitoring Plan.
(a) 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. All observers shall be trained
in marine mammal identification and behaviors, and shall have no other
construction-related tasks while conducting monitoring.
(b) For all marine mammal monitoring, the information shall be
recorded as described in the Monitoring Plan.
(c) The Navy shall conduct acoustic monitoring sufficient to
measure underwater and airborne source levels for vibratory removal of
timber piles and impact driving of concrete piles. Minimum requirements
include:
i. Measurements shall be taken for a minimum of ten piles of each
type.
ii. Each hydrophone (underwater) and microphone (airborne) shall be
calibrated prior to the beginning of the project and shall be checked
at the beginning of each day of monitoring activity.
iii. Environmental data shall be collected including but not
limited to: wind speed and direction, wave height, water depth,
precipitation, and type and location of in-water construction
activities, as well other factors that could contribute to influencing
the airborne and underwater sound levels measured (e.g. aircraft,
boats).
iv. The construction contractor shall supply the Navy and
monitoring personnel with an estimate of the substrate condition,
hammer model and size, hammer energy settings and any changes to those
settings during the piles being monitored.
v. Post-analysis of data shall include the average, minimum, and
maximum rms values and frequency spectra for each pile monitored. If
equipment used is able to accommodate such a requirement, average,
minimum, and maximum peak values shall also be provided.
6. Reporting.
The holder of this Authorization is required to:
(a) Submit a draft report on all monitoring conducted under the IHA
within 45 days of the completion of marine mammal and acoustic
monitoring, or sixty days prior to the issuance of any subsequent IHA
for this project, whichever comes first. A final report shall be
prepared and submitted within thirty days following resolution of
comments on the draft report from NMFS. This report must contain the
informational elements described in the Monitoring Plan, at minimum
(see attached), and shall also include:
i. Detailed information about any implementation of shutdowns,
including the distance of animals to the pile and description of
specific actions that ensued and resulting behavior of the animal, if
any.
ii. Description of attempts to distinguish between the number of
individual animals taken and the number of incidences of take, such as
ability to track groups or individuals.
iii. A refined take estimate based on the number of marine mammals
observed during the course of construction activities.
iv. Results of acoustic monitoring, including the information
described in condition 5(c) of this authorization.
(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 an injury (Level A harassment), serious injury, or mortality,
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:
A. Time and date of the incident;
B. Description of the incident;
C. Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
[[Page 44056]]
D. Description of all marine mammal observations in the 24 hours
preceding the incident;
E. Species identification or description of the animal(s) involved;
F. Fate of the animal(s); and
G. 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 will work with Navy to
determine what measures are necessary to minimize the likelihood of
further prohibited take and ensure MMPA compliance. Navy may not resume
their activities until notified by NMFS.
ii. In the event that 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), 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 6(b)(i)
of this IHA. Activities may continue while NMFS reviews the
circumstances of the incident. NMFS will work with Navy to determine
whether additional mitigation measures or modifications to the
activities are appropriate.
iii. In the event that 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, scavenger damage), 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. Navy
shall provide photographs or video footage or other documentation of
the stranded animal sighting to NMFS.
7. This Authorization may be modified, suspended or withdrawn if
the holder fails to abide by the conditions prescribed herein, or if
the authorized taking is having more than a negligible impact on the
species or stock of affected marine mammals.
Pier 4
1. This Incidental Harassment Authorization (IHA) is valid from
December 1, 2015, through November 30, 2016.
2. This IHA is valid only for pile driving and removal activities
associated with the Pier 4 Maintenance Project at Naval Base Kitsap
Bremerton, Washington.
3. 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 harbor seal (Phoca
vitulina), California sea lion (Zalophus californianus), and Steller
sea lion (Eumetopias jubatus).
(c) The taking, by Level B harassment only, is limited to the
species listed in condition 3(b). See Table 1 for numbers of take
authorized.
Table 1--Authorized Take Numbers, by Species
------------------------------------------------------------------------
Authorized
Species take
------------------------------------------------------------------------
Harbor seal................................................ 330
California sea lion........................................ 1,440
Steller sea lion........................................... 30
------------------------------------------------------------------------
(d) The taking by injury (Level A harassment), serious injury, or
death of any of the species listed in condition 3(b) of the
Authorization or any taking of any other species 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, acoustic
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.
4. Mitigation Measures.
The holder of this Authorization is required to implement the
following mitigation measures:
(a) For all pile driving, the Navy shall implement a minimum
shutdown zone of 10 m radius around the pile. If a marine mammal comes
within or approaches the shutdown zone, such operations shall cease.
(b) The Navy shall establish monitoring locations as described
below. Please also refer to the Marine Mammal Monitoring Plan
(Monitoring Plan; attached).
i. For all vibratory pile removal activities, a minimum of two
observers shall be deployed. One observer shall be located at the pier
work site, positioned to achieve optimal monitoring of the shutdown
zone and the surrounding waters of Sinclair Inlet. A minimum of one
vessel-based observer shall be deployed and shall conduct regular
transits through the estimated disturbance zone for the duration of the
activity.
ii. These observers shall record all observations of marine
mammals, regardless of distance from the pile being driven, as well as
behavior and potential behavioral reactions of the animals. If any
killer whales or gray whales are detected, activity must not begin or
must shut down.
iii. All observers shall be equipped for communication of marine
mammal observations amongst themselves and to other relevant personnel
(e.g., those necessary to effect activity delay or shutdown).
(c) Prior to the start of pile driving on any day, the Navy shall
take measures to ensure that no species for which incidental take is
not authorized are located within the vicinity of the action area, and
shall contact and/or review the latest sightings data from the Orca
Network and/or Center for Whale Research, including passive acoustic
detections, to determine the location of the nearest marine mammal
sightings.
(d) Monitoring shall take place from fifteen minutes prior to
initiation of pile driving activity through thirty minutes post-
completion of pile driving activity. Pre-activity monitoring shall be
conducted for fifteen minutes to ensure that the shutdown zone is clear
of marine mammals, and pile driving may commence when observers have
declared the shutdown zone clear of marine mammals. In the event of a
delay or shutdown of activity resulting from marine mammals in the
shutdown zone, animals shall be allowed to remain in the shutdown zone
(i.e., must leave of their own volition) and their behavior shall be
monitored and documented. Monitoring shall occur throughout the time
required to drive a pile. The shutdown zone must be determined to be
clear during periods of good visibility (i.e., the entire shutdown zone
and surrounding waters must be visible to the naked eye).
(e) If a marine mammal approaches or enters the shutdown zone, all
pile driving activities at that location shall be halted. If pile
driving is halted or delayed due to the presence of a marine mammal,
the activity may not commence or resume until either the animal has
voluntarily left and been visually confirmed beyond the shutdown zone
or fifteen minutes have passed without re-detection of the animal.
(f) Monitoring shall be conducted by qualified observers, as
described in the Monitoring Plan. Trained observers shall be placed
from the best vantage point(s) practicable to monitor for
[[Page 44057]]
marine mammals and implement shutdown or delay procedures when
applicable through communication with the equipment operator.
(g) The Navy shall use soft start techniques recommended by NMFS
for vibratory pile driving. Soft start for vibratory drivers requires
contractors to initiate sound for fifteen seconds at reduced energy
followed by a thirty-second waiting period. This procedure is repeated
two additional times. Soft start shall be implemented at the start of
each day's pile driving and at any time following cessation of pile
driving for a period of thirty minutes or longer.
(h) Pile driving shall only be conducted during daylight hours.
5. Monitoring.
The holder of this Authorization is required to conduct marine
mammal monitoring during pile driving activity. Marine mammal
monitoring and reporting shall be conducted in accordance with the
Monitoring Plan.
(a) 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. All observers shall be trained
in marine mammal identification and behaviors, and shall have no other
construction-related tasks while conducting monitoring.
(b) For all marine mammal monitoring, the information shall be
recorded as described in the Monitoring Plan.
6. Reporting.
The holder of this Authorization is required to:
(a) Submit a draft report on all monitoring conducted under the IHA
within 45 days of the completion of marine mammal and acoustic
monitoring, or sixty days prior to the issuance of any subsequent IHA
for this project, whichever comes first. A final report shall be
prepared and submitted within thirty days following resolution of
comments on the draft report from NMFS. This report must contain the
informational elements described in the Monitoring Plan, at minimum
(see attached), and shall also include:
i. Detailed information about any implementation of shutdowns,
including the distance of animals to the pile and description of
specific actions that ensued and resulting behavior of the animal, if
any.
ii. Description of attempts to distinguish between the number of
individual animals taken and the number of incidences of take, such as
ability to track groups or individuals.
iii. A refined take estimate based on the number of marine mammals
observed during the course of construction activities.
(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 an injury (Level A harassment), serious injury, or mortality,
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:
A. Time and date of the incident;
B. Description of the incident;
C. Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
D. Description of all marine mammal observations in the 24 hours
preceding the incident;
E. Species identification or description of the animal(s) involved;
F. Fate of the animal(s); and
G. 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 will work with Navy to
determine what measures are necessary to minimize the likelihood of
further prohibited take and ensure MMPA compliance. Navy may not resume
their activities until notified by NMFS.
ii. In the event that 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), 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 6(b)(i)
of this IHA. Activities may continue while NMFS reviews the
circumstances of the incident. NMFS will work with Navy to determine
whether additional mitigation measures or modifications to the
activities are appropriate.
iii. In the event that 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, scavenger damage), 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. Navy
shall provide photographs or video footage or other documentation of
the stranded animal sighting to NMFS.
7. This Authorization may be modified, suspended or withdrawn if
the holder fails to abide by the conditions prescribed herein, or if
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 authorizations, and
any other aspect of this Notice of Proposed IHAs for Navy's pier
maintenance activities. Please include with your comments any
supporting data or literature citations to help inform our final
decision on Navy's request for an MMPA authorization.
Dated: July 20, 2015.
Perry F. Gayaldo,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2015-18145 Filed 7-23-15; 8:45 am]
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