[Federal Register Volume 81, Number 64 (Monday, April 4, 2016)]
[Notices]
[Pages 19326-19352]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-07308]



[[Page 19325]]

Vol. 81

Monday,

No. 64

April 4, 2016

Part III





Department of Commerce





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National Oceanic and Atmospheric Administration





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Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to a Pier Construction and Support Facilities 
Project, Port Angeles, WA; Notice

  Federal Register / Vol. 81 , No. 64 / Monday, April 4, 2016 / 
Notices  

[[Page 19326]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XE297


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Pier Construction and Support 
Facilities Project, Port Angeles, WA

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for 
authorization to take marine mammals incidental to construction 
activities as part of a pier construction and support facilities 
project. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is 
requesting comments on its proposal to issue an incidental harassment 
authorization (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 May 4, 
2016.

ADDRESSES: Comments on the application should be addressed to Jolie 
Harrison, Supervisor, Incidental Take Program, 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.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: Laura McCue, 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.htm. In case of problems accessing these documents, 
please call the contact listed above (see FOR FURTHER INFORMATION 
CONTACT).

National Environmental Policy Act (NEPA)

    The Navy has prepared a draft Environmental Assessment (Pier and 
Support Facilities for Transit Protection System at U.S. Coast Guard 
Air Station/Sector Field Office Port Angeles, WA) in accordance with 
the National Environmental Policy Act (NEPA) and the regulations 
published by the Council on Environmental Quality. It is posted at the 
aforementioned site. 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 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 
this 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 Finding of No Significant 
Impact (FONSI), prior to a final decision on the incidental take 
authorization request.

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 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; 
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.'' The former is termed Level A harassment and 
the latter is termed Level B harassment.

Summary of Request

    On September 11, 2015, we received a request from the Navy for 
authorization to take marine mammals incidental to pile driving 
associated with the construction of a pier and support facilities at 
the U.S. Coast Guard (USCG) Air Station/Sector Field Office Port 
Angeles (AIRSTA/SFO Port Angeles), located in Port Angeles Harbor on 
the Ediz Hook peninsula, Port Angeles. The Navy submitted a revised 
version of the request on February 19, 2016, which we deemed adequate 
and complete on February 22, 2016.
    The Navy proposes to initiate this multi-year project, involving 
impact and

[[Page 19327]]

vibratory pile driving conducted within the approved in-water work 
windows. The proposed activity would occur from November 1, 2016 to 
October 31, 2017. In water work is expected to begin on November 1, 
2016 in order to minimize impacts to an Atlantic Salmon net pen farm 
located in close proximity to the project area. In water work will 
conclude on February 15, 2017, and begin again from July 16 to October 
31, 2017.
    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. Take, by Level B Harassment 
only, has been requested for individuals of five species of marine 
mammals (harbor porpoise [Phocoena phocoena], harbor seal [Phoca 
vitulina], Northern elephant seal [Mirounga angustirostris], Steller 
sea lion [Eumatopias jubatus], and California sea lion [Zalophus 
californianus]).

Description of the Specified Activity

Overview

    The Navy has increased security for in-transit Fleet Ballistic 
Missile Submarines (SSBNs) in inland marine waters of northern 
Washington by establishing a Transit Protection System (TPS) that 
relies on the use of multiple escort vessels. The purpose of the Pier 
and Support Facilities for TPS project is to provide a staging location 
for TPS vessels and crews that escort incoming and outgoing SSBNs 
between dive/surface points in the Strait of Juan de Fuca and Naval 
Base (NAVBASE) Kitsap Bangor.
    Specific activities that can be expected to result in the 
incidental taking of marine mammals are limited to the driving of steel 
piles used for installation of the trestle/fixed pier/floating docks, 
and the removal of existing piles.
    Vibratory pile driving is the preferred method for production piles 
and would be the initial starting point for each installation; however, 
impact pile driving methods may be necessary based on substrate 
conditions. Once a pile hits ``refusal,'' which is where hard solid or 
dense substrate (e.g., gravel, boulders) prevents further pile movement 
by vibratory methods, impact pile driving is used to drive the pile to 
depth.
    All piles would be driven with a vibratory hammer for their initial 
embedment depths, while select piles may be finished with an impact 
hammer for proofing, as necessary. There would be no concurrent pile 
driving or multiple hammers operating simultaneously. Proofing involves 
striking a driven pile with an impact hammer to verify that it provides 
the required load-bearing capacity, as indicated by the number of 
hammer blows per foot of pile advancement. Sound attenuation measures 
(i.e., bubble curtain) would be used during all impact hammer 
operations.

Dates and Duration

    Under the proposed action, in-water construction is anticipated to 
begin in 2016 and require two in-water work window seasons. The 
allowable season for in-water work, including pile driving, at AIRSTA/
SFO Port Angeles is November 1, 2016 through February 15, 2017, and 
July 16, 2017 through October 31, 2017, a window established by the 
Washington Department of Fish and Wildlife in coordination with NMFS 
and the U.S. Fish and Wildlife Service (USFWS) to protect juvenile 
salmon (Oncorhynchus spp.) and bull trout (Salvelinus confluentus). 
Overall, a maximum of 75 days of pile driving are anticipated within 
these in-water work windows. All in-water construction activities will 
occur during daylight hours (sunrise to sunset) except from July 16 to 
February 15 when impact pile driving/removal will only occur starting 2 
hours after sunrise and ending 2 hours before sunset, to protect 
foraging marbled murrelets (an Endangered Species Act [ESA]-listed bird 
under the jurisdiction of USFWS) during nesting season (April 1-
September 23). Other construction (not in-water) may occur between 7 
a.m. and 10 p.m., year-round.

Specific Geographic Region

    AIRSTA/SFO Port Angeles is located in the Strait of Juan de Fuca, 
approximately 62 miles (100 km) east of Cape Flattery, and 63 miles 
(102 km) northwest of Seattle, Washington on the Olympic Peninsula (see 
Figure 1-1 in the Navy's application). The Strait of Juan de Fuca is a 
wide waterway stretching from the Pacific Ocean to the Salish Sea. The 
strait is 95 miles (153-km) long, 15.5 miles (25 km) wide, and has 
depths ranging from 180 m to 250 m on the pacific coast and 55 m at the 
sill. Please see Section 2 of the Navy's application for detailed 
information about the specific geographic region, including physical 
and oceanographic characteristics.

Detailed Description of Activities

    The purpose of the Pier and Support Facilities for TPS project (the 
project) is to provide a staging location for TPS vessels and crews 
that escort incoming and outgoing SSBNs between dive/surface points in 
the Strait of Juan de Fuca and Naval Base (NAVBASE) Kitsap Bangor. The 
Navy has increased security for in-transit Fleet Ballistic Missile 
Submarines (SSBNs) in inland marine waters of northern Washington by 
establishing a Transit Protection System (TPS) that relies on the use 
of multiple escort vessels. Construction of the pier and support 
facilities is grouped into three broad categories: (1) Site Work 
Activities (2) Construction of Upland Facilities (Alert Forces Facility 
[AFF] and Ready Service Armory [RSA]), and (3) Construction of Trestle/
Fixed Pier/Floating Docks.
    The trestle, fixed pier, and floating docks would result in a 
permanent increase in overwater coverage of 25,465 square-feet (ft\2\) 
(2,366 square meters [m\2\]). An estimated 745 ft\2\ (69 m\2\) of 
benthic seafloor would be displaced from the installation of the 144 
permanent steel piles. The fixed pier will lie approximately 354 ft 
(108 m) offshore at water depths between -40 ft (-12 m) and -63 ft (19 
m) mean lower low water (MLLW). It would be constructed of precast 
concrete and be approximately 160 feet long and 42 feet wide (49 m by 
13 m). The fixed pier would have two mooring dolphins that connect to 
the fixed pier via a catwalk, and would be supported by 87 steel piles 
and result in 10,025 ft\2\ (931 m\2\) of permanent overwater coverage. 
The floating docks including brows would be supported by 21 steel piles 
and result in 5,380 ft\2\ (500 m\2\) of permanent overwater coverage. 
The trestle would provide vehicle and pedestrian access to the pier and 
convey utilities to the pier. It would be installed between +7 ft (2 m) 
MLLW and -45 ft (-14 m) MLLW. The trestle would be approximately 355 
feet long (108 m) long and 24 feet (7 m) wide and constructed of 
precast concrete. The trestle would be designed to support a 50 pound 
per square foot (psf) (244 kilograms [kg] per square m) live load or a 
utility trailer with a total load of 3,000 pounds (1,360 kg), and would 
be supported by 36 steel piles and result in 10,060 ft\2\ (935 m\2\) of 
permanent overwater coverage.
    For the entire project, pile installation would include the 
installation and removal of 80 temporary indicator piles, installation 
of 60 permanent sheet piles, and installation of 144 permanent steel 
piles (Table 1). The indicator piles are required to determine if 
required bearing capacities will be achieved with the production piles, 
and to assess whether the correct vibratory and impact hammers are 
being used. The process will be to vibrate the piles to within 5 ft 
(1.5 m) of the target embedment depth required for the

[[Page 19328]]

project, let the piles rest in place for a day, and then impact drive 
the piles the final 5 ft (1.5 m). If the indicator piles cannot be 
successfully vibrated in, then a larger hammer will be used for the 
production piles. The impact driving will also provide an indication of 
bearing capacity via proofing. Each indicator pile would then be 
vibratory extracted (removed) using a vibratory hammer.
    A maximum of 75 days of pile driving may occur. Table 1 summarizes 
the number and nature of piles required for the entire project.

        Table 1--Summary of Piles Required for Pier Construction
                               [In total]
------------------------------------------------------------------------
                  Feature                         Quantity and size
------------------------------------------------------------------------
Total number of in-water piles............  Up to 284.*
Indicator temporary.......................  24-in: 80.
Sheet pile wall...........................  PZC13 Steel sheet piles: 60.
Trestle...................................  18-in: 16, 24-in: 12, 36-in:
                                             8.
Fixed pier piles..........................  24-in: 28, 30-in: 49, 36-in:
                                             10.
Floating docks............................  24-in: 3, 30-in: 6, 36-in:
                                             12.
Maximum pile driving duration.............  75 days (under one-year
                                             IHA).
------------------------------------------------------------------------
* Pile installation would include the installation and removal of 80
  temporary indicator piles, installation of 60 permanent sheet piles,
  and installation of 144 permanent steel piles.

    Pile installation will utilize vibratory pile drivers to the 
greatest extent possible, and the Navy anticipates that most piles will 
be able to be vibratory driven to within several feet of the required 
depth. Pile drivability is, to a large degree, a function of soil 
conditions and the type of pile hammer. Most piles should be able to be 
driven with a vibratory hammer to proper embedment depth. However, 
difficulties during pile driving may be encountered as a result of 
obstructions, such as rocks or boulders, which may exist throughout the 
project area. If difficult driving conditions occur, increased usage of 
an impact hammer will occur.
    Pile production rates are dependent upon required embedment depths, 
the potential for encountering difficult driving conditions, and the 
ability to drive multiple piles without a need to relocate the driving 
rig. If difficult subsurface driving conditions (e.g., cobble/boulder 
zones) are encountered that cause refusal with the vibratory equipment, 
it may be necessary to use an impact hammer to drive some piles for the 
remaining portion of their required depth. The worst-case scenario is 
that a pile would be driven for its entire length using an impact 
hammer. Given the uncertainty regarding the types and quantities of 
boulders or cobbles that may be encountered, and the depth at which 
they may be encountered, the number of strikes necessary to drive a 
pile its entire length would vary. All piles driven or struck with an 
impact hammer would be surrounded by a bubble curtain over the full 
water column to minimize in-water sound. Pile production rate (number 
of piles driven per day) is affected by many factors: Size, type 
(vertical versus angled), and location of piles; weather; number of 
driver rigs operating; equipment reliability; geotechnical (subsurface) 
conditions; and work stoppages for security or environmental reasons 
(such as presence of marine mammals).

Description of Marine Mammals in the Area of the Specified Activity

    There are eleven marine mammal species with recorded occurrence in 
the Strait of Juan de Fuca, including seven cetaceans and four 
pinnipeds. Of these eleven species, only five are expected to have a 
reasonable potential to be in the vicinity of the project site. These 
species are harbor porpoise (Phocoena phocoena), harbor seal (Phoca 
vitulina), Northern elephant seal (Mirounga angustirostris), Steller 
sea lion (Eumatopias jubatus), and California sea lion (Zalophus 
californianus). Harbor seals occur year round throughout the nearshore 
inland waters of Washington. Harbor seals are expected to occur year 
round in Port Angeles Harbor, with a nearby haul-out site on a log boom 
located approximately 1.7 miles (2.7 km) west of the project site and 
another haul-out site 1.3 miles (2.1 km) south of the project. Steller 
sea lions and California sea lions may occur in the area, but there are 
no site-specific surveys on these species. Harbor porpoises and 
Northern elephant seal are rare through the project area. The Dall's 
porpoise (Phocoenoides dalli dalli), humpback whale (Megaptera 
novaeangliae), minke whale (Balaenoptera acutorostrata), gray whale 
(Eschrichtius robustus), Pacific white-sided dolphin (Lagenorhynchus 
obliquidens), and killer whales (Orcinus orca) are extremely rare in 
Port Angeles Harbor, and we do not believe there is a reasonable 
likelihood of their occurrence in the project area during the proposed 
period of validity for this IHA.
    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 Strait of Juan de 
Fuca (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 February 1, 
2016).
    Table 2 lists the eleven marine mammal species with expected 
potential for occurrence in the vicinity of AIRSTA/SFO Port Angeles 
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, Northern elephant seal, Dall's porpoise, Pacific white-sided 
dolphins, harbor porpoise, southern resident killer whale, humpback 
whale, minke whale, and gray whale are addressed in the Pacific SARs 
(e.g., Carretta et al., 2015), while the Steller sea lion and West 
coast transient killer whale are treated in the Alaska SARs (e.g., Muto 
and Angliss, 2015).
    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.

[[Page 19329]]



                                 Table 2--Marine Mammals Potentially Present in the Vicinity of AIRSTA/SFO Port Angeles
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                                                                                     Stock abundance  (CV,                        Relative occurrence in
                                                               ESA/MMPA  status;       Nmin, most recent               Annual M/     Strait of Juan de
              Species                         Stock            Strategic  (Y/N) 1     abundance survey) 2    PBR \3\      SI 4       Fuca;  season of
                                                                                                                                        occurrence
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                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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                                                             Family Phocoenidae (porpoises)
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Harbor porpoise....................  Washington inland       -; N                   10,682 (0.38; 7,841;           63      >=2.2  Possible regular
                                      waters 5.                                      2003).                                        presence in the
                                                                                                                                   Strait of Juan de
                                                                                                                                   Fuca, but unlikely
                                                                                                                                   near PAH; year-round.
Dall's porpoise....................  CA/OR/WA..............  -; N                   42,000 (0.33; 32,106;         257       >0.4  Rare.
                                                                                     2008).
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                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Family Delphinidae (dolphins)
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Pacific white-sided dolphin........  CA/OR/WA..............  -; N                   26,930 (0.28; 21,406;         171       17.8  Rare.
                                                                                     2008).
Killer whale.......................  West coast transient..  -; N                   243 (n/a; 243; 2009)..        2.4          0  Unlikely.
                                     Southern resident.....  E; S                   78 (n/a; 78; 2014)....       0.14          0  ......................
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                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Family Balaenopteridae
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Humpback whale.....................  CA/OR/WA..............  E; S                   1,918 (0.03; 1,855;            11       >5.5  Unlikely.
                                                                                     2011).
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Minke whale........................  CA/OR/WA..............  -; N                   478 (1.36; 202; 2008).          2          0  Unlikely.
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                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Family Eschrichtiidae
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Gray whale.........................  Eastern N. Pacific....  -; N                   20,990 (0.05; 20,125;         624        132  Unlikely.
                                                                                     2011).
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                                                         Order Carnivora--Superfamily Pinnipedia
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                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion................  U.S...................  -; N                   296,750 (n/a; 153,337;      9,200        389  Seasonal/common; Fall
                                                                                     2011).                                        to late spring (Aug
                                                                                                                                   to Jun).
Steller sea lion...................  Eastern U.S...........  -; S                   60,131- 74,448 (n/a;      7 1,645       92.3  Seasonal/occasional;
                                                                                     36,551; 2013) 6.                              Fall to late spring
                                                                                                                                   (Sep to May).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal 8......................  Washington inland       -; N                   11,036 (0.15; n/a;            n/a        9.8  Common; Year-round
                                      waters 5.                                      1999).                                        resident.
Northern elephant seal.............  California breeding     -; N                   179,000 (n/a; 81,368;       4,882        8.8  Seasonal/rare: Spring
                                      stock.                                         2010).                                        to late fall (Apr to
                                                                                                                                   Nov).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 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 specie's (or similar species') life history to arrive at a best abundance estimate; therefore, there is no associated CV. In these cases, the
  minimum abundance may represent actual counts of all animals ashore.
\3\ 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 2015 SARs (www.nmfs.noaa.gov/pr/sars/draft.htm) except harbor seals. See comment 8.
\5\ 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.
\6\ 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).
\7\ PBR is calculated for the U.S. portion of the stock only (excluding animals in British Columbia) and assumes that the stock is not within its OSP.
  If we assume that the stock is within its OSP, PBR for the U.S. portion increases to 2,069.
\8\ Values for harbor seal presented here are from the 2013 SAR.


[[Page 19330]]

    Although the humpback whale (Megaptera novaeangliae), minke whale 
(Balaenoptera acutorostrata), gray whale (Eschrichtius robustus), 
killer whale (Orcinus orca), Dall's porpoise (Phocoenoides dalli), and 
Pacific white-sided dolphin (Lagenorhynchus obliquidens) occur in the 
Strait of Juan de Fuca, these marine mammals species are an extremely 
rare occurrence in Port Angeles Harbor. Characteristics of Port Angeles 
Harbor that inhibit or deter use by these marine mammals include the 
semi-enclosed embayment with no through access and high volume of 
vessel traffic that include tankers, dry bulk cargo carriers, barges, 
tugs, fishing boats, leisure craft, Puget Sound Pilots craft, and ferry 
service, as well as USCG and Navy vessels. The smaller Dall's porpoise 
and Pacific white-sided dolphin are considered offshore, deep water 
species and would likely avoid the embayment of Port Angeles Harbor. 
This species also exhibit fidelity to foraging areas, and there are no 
known foraging areas in the behavioral harassment zone. In addition, 
the larger sized whales are highly visible and more likely to be 
detected outside of behavioral harassment zones (see Section 6.3.1 
Underwater Sound Propagation) by marine mammal observers (protected 
species observers [PSOs]); therefore, exposure, and possibly behavioral 
harassment could be avoided. These six species are not carried forward 
for further analysis beyond this section. The five species for which 
occurrence in/near Port Angeles harbor is likely are described further 
below.

Harbor Porpoise

    Harbor porpoises are found primarily in inshore and relatively 
shallow coastal waters (<100 m) from Point Barrow (Alaska) to Point 
Conception (California). Various genetic analyses and investigation of 
pollutant loads indicate a low mixing rate for harbor porpoises along 
the west coast of North America and likely fine-scale geographic 
structure along an almost continuous distribution from California to 
Alaska (e.g., Osmek et al., 1994; Chivers et al., 2002, 2007). However, 
stock boundaries are difficult to draw because any rigid line is 
generally arbitrary from a biological perspective. On the basis of 
genetic data and density discontinuities identified from aerial 
surveys, eight stocks have been identified in the eastern North 
Pacific, including northern Oregon/Washington coastal and inland 
Washington stocks (Carretta et al., 2013a). The Washington inland 
waters stock includes individuals found east of Cape Flattery and is 
the only stock that may occur in the project area.
    The Washington inland waters stock has a population estimate of 
10,682 animals (Caretta et al., 2015). A recent aerial survey from 
April, 2015 provided an estimate of harbor porpoise in the Strait of 
Juan de Fuca of 647 individuals (Smultsea, et al., 2015). The status of 
this stock relative to its Optimum Sustainable Population (OSP) level 
and population trends is unknown (Caretta et al., 2015). The stock is 
not considered ``depleted'' or listed as a ``strategic stock'' under 
the MMPA and is not listed as ``threatened'' or ``endangered'' under 
the ESA.
    Within the Exclusive Economic Zone (EEZ) boundaries of the coastal 
waters of northern Oregon and Washington, harbor porpoise deaths are 
known to occur in the northern Washington marine set gillnet tribal 
fishery. Fishing effort in the coastal marine set gillnet tribal 
fishery has declined since 2004. A mean annual mortality of 3.0 harbor 
porpoise was calculated in 2007-2011 from stranding data. Since these 
deaths could not be attributed to a particular fishery, and were the 
only confirmed fishery-related deaths in this area in 2007-2011, they 
are noted in unknown West Coast fisheries (Caretta et al., 2013). In 
2006, a UME was declared for harbor porpoises throughout Oregon and 
Washington, and a total of 114 strandings were reported in 2006-07. The 
cause of the UME has not been determined and several factors, including 
contaminants, genetics, and environmental conditions, are still being 
investigated (Carretta et al., 2013a).
    In Washington inland waters, harbor porpoise are known to occur in 
the Strait of Juan de Fuca and the San Juan Island area year round 
(Calambokidis and Baird 1994; Osmek et al., 1998; Carretta et al., 
2012). Recent aerial surveys from April, 2015 reported that harbor 
porpoise was the most commonly sighted species in the Strait of Juan de 
Fuca, with 154 groups sighted over 4 days (Smultsea et al., 2015). In 
the Strait of Juan de Fuca, harbor porpoise are seasonally localized in 
relatively small areas during the reproductive season (April-October). 
More densely localized aggregations and increased seasonal densities 
have been reported in the Strait of Juan de Fuca, near Victoria (Hall 
et al., 2002). A photo-identification study in the San Juan Islands 
also provides evidence for local, discrete subpopulations (Flaherty and 
Stark 1982) with a high degree of site fidelity (Hall 2009). Harbor 
porpoise tend to occupy an ecological niche consisting of relatively 
shallow water, generally less than 650 ft (200 m) deep (Hall 1996; 
Lockyer et al. 2001; Hall 2004). No site-specific information is 
available for Port Angeles Harbor. Harbor porpoise could forage within 
Port Angeles Harbor, following local prey availability, but because of 
the strong site fidelity and lack of sightings in the harbor, use of 
the project area would be rare.

Northern Elephant Seal

    Northern elephant seals that may occur in the activity area would 
belong to the California breeding stock. The current best abundance 
estimate for the California breeding stock of Northern elephant seal is 
179,000 individuals (Caretta et al., 2015). This stock of Northern 
elephant seal is not designated as ``depleted'' under the MMPA nor are 
they listed as ``threatened'' or ``endangered'' under the ESA. The 
level of human-caused mortality and serious injury is not known to 
exceed the PBR, which is 4,882. This stock of Northern elephant seals 
is not classified as a strategic stock (Allen and Angliss 2014). The 
population continues to grow, with most births occurring at southern 
California rookeries (Lowry et al. 2014). There are no known habitat 
issues that are of concern for this stock. However, expanding pinniped 
populations in general have resulted in increased human-caused serious 
injury and mortality, due to shootings, entrainment in power plants, 
interactions with recreational hook and line fisheries, separation of 
mothers and pups due to human disturbance, dog bites, and vessel and 
vehicle strikes (Carretta et al. 2014).
    The northern elephant seal occurs almost exclusively in the eastern 
and central North Pacific. Rookeries are located from central Baja 
California, Mexico, to northern California (Stewart and Huber 1993). 
Recent aerial surveys from April, 2015 reported no sighting of elephant 
seals in the Strait of Juan de Fuca (Smultsea et al., 2015). Adult 
elephant seals engage in two long migrations per year, one following 
the breeding season, and another following the annual molt (Stewart and 
DeLong 1995; Robinson et al., 2012). Between the two foraging periods, 
they return to land to molt, with females returning earlier than males 
(March through April versus July through August). After the molt, 
adults return to their northern feeding areas until the next winter 
breeding season. Breeding occurs from December to March (Stewart and 
Huber 1993). Juvenile elephant seals typically leave the rookeries in 
April or May and head north, traveling an average of 559 to 621 miles 
(900 to 1,000 km). Most elephant seals return to their natal

[[Page 19331]]

rookeries when they start breeding (Huber et al. 1991). Their foraging 
range extends thousands of miles offshore into the central North 
Pacific. Adults tend to stay offshore, but juveniles and subadults are 
often seen along the coasts of Oregon, Washington, and British Columbia 
(Condit and Le Boeuf 1984; Stewart and Huber 1993).
    Small numbers of juvenile elephant seals haul out and go through 
their molting process in Washington State. Molting is a natural 
condition that takes 4 to 5 weeks to complete. In Washington inland 
waters, there are regular haul-out sites at Smith and Minor Islands, 
Dungeness Spit, and Protection Island in the Strait of Juan de Fuca 
that are thought to be used year round (Jeffries et al., 2000). 
Juvenile elephant seals haul out along the shoreline for several weeks, 
occasionally entering the water and returning to the same area again. 
Hauling out allows the skin to warm up and help speed up the molting 
process. WDFW surveys in 2013 reported two haul-out sites with two 
individuals present (WDFW 2015). The closest documented haul-out is at 
Dungeness Spit, 11 miles (18 km) east of the project where one elephant 
seal was last reported in 2006 (WDFW 2015). Northern elephant seals are 
not expected to occur within Port Angeles Harbor because there are no 
known haul-outs and they typically use the same sites repeatedly; 
however, it is possible a juvenile could haul out near the project site 
and once on shore would likely stay for the duration of the project. In 
addition, elephant seals could forage within Port Angeles Harbor, 
following local prey availability.

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 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 near Port Angeles 
Harbor.
    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 percent 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). Because the counts of eastern Steller sea lions have 
steadily increased over a 30+ year period, this stock is likely within 
its OSP; however, no determination of its status relative to OSP has 
been made (Allen and Angliss, 2014).
    Between 2008 and 2012, a minimum total of 64 animals from the 
eastern Steller sea lion stock were reported taken. The annual average 
take for subsistence harvest in Alaska was 11 individuals in 2004-08 
(Muto and Angliss, 2015). Data on community subsistence harvests is no 
longer being collected, and this average is retained as an estimate for 
current and future subsistence harvest. Sea lion deaths are also known 
to occur because of illegal shooting, vessel strikes, or capture in 
research gear and other traps (Muto and Angliss, 2015). The mean 
average human-caused mortality and serious injury of eastern Steller 
sea lions for 2008-2012 from sources other than fisheries and Alaska 
Native harvest is 29.4.
    The population is estimated to be within the range of 60,131 and 
74,448 animals. This stock is not listed as ``depleted'' under the 
MMPA, and is not listed as ``threatened'' or ``endangered'' under the 
ESA (Alaska SAR). It is considered a strategic stock under the MMPA.
    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 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). Recent aerial surveys from April, 2015 reported seven 
groups of Steller sea lions sighted in the Strait of Juan de Fuca 
(Smultsea et al., 2015).
    There are no known Steller sea lions haul-outs in Port Angeles 
Harbor (WDFW, 2015). The nearest haul-out to the project site is 
approximately 12.5 miles (20 kilometers) across the Strait of Juan de 
Fuca at Race Rocks and identified to have an annual maximum number of 
greater than 100 animals (Wiles, 2015). Animal censuses at the Race 
Rocks Ecological Reserve between January 2014 and January 2016 
indicated a peak abundance in September to December, with numbers that 
ranged from 200 to 500 individuals (Race Rocks Ecological Reserve Web 
site 2016). The Steller sea lions at Race Rocks are mainly bachelor 
bulls or juvenile yearlings. This is not a breeding colony, and mature 
females are not usually present (Race Rocks Ecological Reserve Web site 
2016). In contrast, a haul-out about 30 miles (48 km) east of the 
project at Point Wilson was surveyed November 2013 with one Steller sea 
lion (WDFW, 2015). Steller sea lions could forage within Port Angeles 
Harbor, following local prey availability, but because haul-outs are 
far away, use of the area is likely limited.

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 et al., 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., 2013a). Multiple stocks

[[Page 19332]]

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). Only the Washington inland waters 
stock may be found in the project area.
    Recent genetic evidence suggests that harbor seals of Washington 
inland waters may have sufficient population structure to warrant 
division into multiple distinct stocks (Huber et al., 2010, 2012). 
Within U.S. west coast waters, five stocks of harbor seals are 
recognized: (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); (3) Hood Canal; (4) Oregon/Washington Coast; 
and (5) California. Until this stock structure is accepted, we consider 
a single Washington inland waters stock.
    In 1999, the mean count of harbor seals occurring in Washington's 
inland waters was 7,213 (CV = 0.14) in Washington Northern Inland 
Waters (Caretta, et al., 2015). The most recent population estimate 
available for the Washington inland waters stock comes from the 2013 
SAR, which reported 11,036 animals. The draft 2015 SAR (Caretta et al., 
2015) currently lists the population size as unknown and PBR as 
undetermined. 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).
    Harbor seals occur year round throughout the nearshore inland 
waters of Washington. Harbor seals are expected to occur year round in 
Port Angeles Harbor, with a nearby haul-out site on a log boom located 
approximately 1.7 miles (2.7 km) west of the project site that was last 
surveyed in March 2013 and had a total count of 73 harbor seals (WDFW 
2015). Another haulout site is 1.3 miles (2.1 km) south of the project 
but is across the harbor that was last surveyed in July 2010 and had a 
total count of 87 harbor seals (WDFW 2015). The level of use of these 
haul-outs during the fall and winter is unknown, but is expected to be 
much less as air temperatures become colder than water temperatures, 
resulting in seals in general hauling out less (Pauli and Terhune 
1987). Harbor seals may also use other undocumented haul-out sites near 
the project site. Recent aerial surveys from April, 2015 reported that 
harbor seals were the most commonly sighted pinniped in the Strait of 
Juan de Fuca, with nearly 1400 individuals sighted in 286 groups 
(Smultsea et al., 2015).

California Sea Lion

    California sea lions range from the Gulf of California north to the 
Gulf of 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., 2013a). The maximum population growth rate was 9.2 percent when 
pup counts from the El Ni[ntilde]o years were removed. This stock has 
an estimated population abundance of 296,750 animals. California sea 
lions in the U.S. are not listed as ``endangered'' or ``threatened'' 
under the Endangered Species Act or as ``depleted'' under the MMPA 
(Caretta et al., 2015).
    The average annual commercial fishery mortality is 331 animals per 
year. Total human-caused mortality of this stock is at least 389 
animals per year. In addition, a summary of stranding database records 
for 2005-09 shows an annual average of 65 such events, which is likely 
a gross underestimate because most carcasses are not recovered. 
California sea lions may also be removed because of predation on 
endangered salmonids (seventeen per year, 2008-10) or incidentally 
captured during scientific research (three per year, 2005-09) (Carretta 
et al., 2013a). Sea lion mortality has also 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 was an Unusual Mortality Event (UME) 
declaration in effect for California sea lions from 2013-2015. 
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 January 29, 2016).
    An estimated 3,000 to 5,000 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 (Jeffries et al., 2000) and return south the following spring 
(Mate, 1975; Bonnell et al., 1983). Peak numbers of up to 1,000 
California sea lions occur in Puget Sound (including Hood Canal) during 
this time period (Jeffries et al., 2000).
    During the summer, California sea lions breed on islands from the 
Gulf of California to the Channel Islands and seldom travel more than 
about 31 miles (50 km) from the islands. The primary rookeries are 
located on the California Channel Islands of San Miguel, San Nicolas, 
Santa Barbara, and San Clemente, probably in response to changes in 
prey availability. In the nonbreeding season, adult and subadult males 
migrate north along the coast to central and northern California, 
Oregon, Washington, and Vancouver Island, and return south in the 
spring. Their distribution shifts to the northwest in fall and to the 
southeast during winter and spring. Recent aerial surveys from April, 
2015 reported 12 sightings of California sea lions in the Strait of 
Juan de Fuca representing 13 individuals (Smultsea et al., 2015). 
California sea lions are occasionally sighted hundreds of miles 
offshore. The animals found in northwest waters are typically males; 
most adult females with pups remain in waters near their breeding 
rookeries off the coasts of California and Mexico. Females and 
juveniles tend to stay closer to the rookeries. California sea lions 
also enter bays, harbors, and river

[[Page 19333]]

mouths and often haul out on man-made structures such as piers, 
jetties, offshore buoys, and oil platforms.
    Dedicated, regular haul-outs used by adult and subadult California 
sea lions in Washington inland waters have been identified (Jeffries et 
al., 2000). There are no known California sea lion haul-outs in Port 
Angeles Harbor (WDFW 2015). The nearest haul-out is about 40 miles (64 
km) east of the project site near Admiralty Inlet (Jeffries et al., 
2000). California sea lions are typically present between August and 
June in Washington inland waters, with peak abundance numbers occurring 
between October and May (NMFS 1997; Jeffries et al., 2000). California 
sea lions could forage within Port Angeles Harbor, following local prey 
availability, but because haul-outs are far away, use of the project 
area is likely limited. During the summer months and associated 
breeding periods, the inland waters would not be considered a high-use 
area by California sea lions, because they would be returning to 
rookeries in California waters. However, surveys at Navy facilities, 
primarily located in Hood Canal, indicate that a few individuals are 
present through mid-June to July, with some arrivals in August and in 
some cases individuals present year round (U.S. Department of the Navy 
2015). The limited number of California sea lions observed during these 
surveys suggests that a few individual animals could be moving through 
the Strait Juan de Fuca and may use the activity area before heading to 
established haul-out sites to the east within the inland waters of 
Puget Sound.

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity (e.g. sound produced by pile 
driving), including mitigation, may impact marine mammals and their 
habitat. The ``Estimated Take by Incidental Harassment'' section later 
in this document will include a quantitative analysis of the number of 
individuals that are expected to be taken by this activity. The 
``Negligible Impact Analysis'' section will include 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, and the ``Proposed Mitigation'' section to draw 
conclusions regarding the likely impacts of this activity on the 
reproductive success or survivorship of individuals and from that on 
the affected marine mammal populations or stocks.
    In the following discussion, we 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 [mu]Pa and all airborne sound levels in 
this document are referenced to a pressure of 20 [mu]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    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

[[Page 19334]]

noise for frequencies between 20 and 300 Hz. In general, the 
frequencies of anthropogenic sounds are below 1 kHz and, if higher 
frequency sound levels are created, they attenuate rapidly (Richardson 
et al., 1995). Sound from identifiable anthropogenic sources other than 
the activity of interest (e.g., a passing vessel) is sometimes termed 
background sound, as opposed to ambient sound.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the project would 
include impact pile driving 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 lower levels of 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 intense 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). Note that no direct measurements of hearing ability have been 
successfully completed for low-frequency cetaceans. The functional 
groups and the associated frequencies are indicated below (note that 
these frequency ranges correspond to the range for the composite group, 
with the entire range not necessarily reflecting the capabilities of 
every species within that group):
     Low-frequency cetaceans (mysticetes): Functional hearing 
is estimated to occur between approximately 7 Hz and 25 kHz (up to 30 
kHz in some species), with best hearing estimated to be from 100 Hz to 
8 kHz (Watkins, 1986; Ketten, 1998; Houser et al., 2001; Au et al., 
2006; Lucifredi and Stein, 2007; Ketten et al., 2007; Parks et al., 
2007a; Ketten and Mountain, 2009; Tubelli et al., 2012);
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Functional hearing is estimated to occur 
between approximately 150 Hz and 160 kHz, with best hearing from 10 to 
less than 100 kHz (Johnson, 1967; White, 1977; Richardson et al., 1995; 
Szymanski et al., 1999; Kastelein et al., 2003; Finneran et al., 2005a, 
2009; Nachtigall et al., 2005, 2008; Yuen et al., 2005; Popov et al., 
2007; Au and Hastings, 2008; Houser et al., 2008; Pacini et al., 2010, 
2011; Schlundt et al., 2011);
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, including the hourglass dolphin, on the 
basis of recent echolocation data and genetic data [May-Collado and 
Agnarsson, 2006; Kyhn et al. 2009, 2010; Tougaard et al. 2010]): 
Functional hearing is estimated to occur between approximately 200 Hz 
and 180 kHz (Popov and Supin, 1990a,b; Kastelein et al., 2002; Popov et 
al., 2005); and
     Pinnipeds in water; Phocidae (true seals): Functional 
hearing is estimated to occur between approximately 75 Hz to 100 kHz, 
with best hearing between 1-50 kHz (M[oslash]hl, 1968; Terhune and 
Ronald, 1971, 1972; Richardson et al., 1995; Kastak and Schusterman, 
1999; Reichmuth, 2008; Kastelein et al., 2009);
     Pinnipeds in water; Otariidae (eared seals): Functional 
hearing is estimated to occur between 100 Hz and 48 kHz for Otariidae, 
with best hearing between 2-48 kHz (Schusterman et al., 1972; Moore and 
Schusterman, 1987; Babushina et al., 1991; Richardson et al., 1995; 
Kastak and Schusterman, 1998; Kastelein et al., 2005a; Mulsow and 
Reichmuth, 2007; Mulsow et al., 2011a, b).

[[Page 19335]]

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    There are five marine mammal species (one cetacean and four 
pinniped [two otariid and two phocid] species) with expected potential 
to co-occur with Navy construction activities. Please refer to Table 2. 
The harbor porpoise is classified as a high-frequency cetacean.
    Potential effects of underwater sound--Please refer to the 
information given previously (Description of Sound Sources) regarding 
sound, characteristics of sound types, and metrics used in this 
document. Anthropogenic sounds cover a broad range of frequencies and 
sound levels and can have a range of highly variable impacts on marine 
life, from none or minor to potentially severe responses, depending on 
received levels, duration of exposure, behavioral context, and various 
other factors. The potential effects of underwater sound from active 
acoustic sources can potentially result in one or more of the 
following: Temporary or permanent hearing impairment, non-auditory 
physical or physiological effects, behavioral disturbance, stress, and 
masking (Richardson et al., 1995; Gordon et al., 2004; Nowacek et al., 
2007; Southall et al., 2007; Gotz et al., 2009). The degree of effect 
is intrinsically related to the signal characteristics, received level, 
distance from the source, and duration of the sound exposure. In 
general, sudden, high level sounds can cause hearing loss, as can 
longer exposures to lower level sounds. Temporary or permanent loss of 
hearing will occur almost exclusively for noise within an animal's 
hearing range. We first describe specific manifestations of acoustic 
effects before providing discussion specific to the Navy's construction 
activities.
    Richardson et al. (1995) described zones of increasing intensity of 
effect that might be expected to occur, in relation to distance from a 
source and assuming that the signal is within an animal's hearing 
range. First is the area within which the acoustic signal would be 
audible (potentially perceived) to the animal, but not strong enough to 
elicit any overt behavioral or physiological response. The next zone 
corresponds with the area where the signal is audible to the animal and 
of sufficient intensity to elicit behavioral or physiological 
responsiveness. Third is a zone within which, for signals of high 
intensity, the received level is sufficient to potentially cause 
discomfort or tissue damage to auditory or other systems. Overlaying 
these zones to a certain extent is the area within which masking (i.e., 
when a sound interferes with or masks the ability of an animal to 
detect a signal of interest that is above the absolute hearing 
threshold) may occur; the masking zone may be highly variable in size.
    We describe the more severe effects (i.e., permanent hearing 
impairment, certain non-auditory physical or physiological effects) 
only briefly as we do not expect that there is a reasonable likelihood 
that the Navy's activities may result in such effects (see below for 
further discussion). Marine mammals exposed to high-intensity sound, or 
to lower-intensity sound for prolonged periods, can experience hearing 
threshold shift (TS), which is the loss of hearing sensitivity at 
certain frequency ranges (Kastak et al., 1999; Schlundt et al., 2000; 
Finneran et al., 2002, 2005b). TS can be permanent (PTS), in which case 
the loss of hearing sensitivity is not fully recoverable, or temporary 
(TTS), in which case the animal's hearing threshold would recover over 
time (Southall et al., 2007). Repeated sound exposure that leads to TTS 
could cause PTS. In severe cases of PTS, there can be total or partial 
deafness, while in most cases the animal has an impaired ability to 
hear sounds in specific frequency ranges (Kryter, 1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals--PTS data exists only for a single harbor seal 
(Kastak et al., 2008)--but are assumed to be similar to those in humans 
and other terrestrial mammals. PTS typically occurs at exposure levels 
at least several decibels above (a 40-dB threshold shift approximates 
PTS onset; e.g., Kryter et al., 1966; Miller, 1974) that inducing mild 
TTS (a 6-dB threshold shift approximates TTS onset; e.g., Southall et 
al. 2007). Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS thresholds for impulse sounds (such as 
impact pile driving pulses as received close to the source) are at 
least 6 dB higher than the TTS threshold on a peak-pressure basis and 
PTS cumulative sound exposure level thresholds are 15 to 20 dB higher 
than TTS cumulative sound exposure level thresholds (Southall et al., 
2007). Given the higher level of sound or longer exposure duration 
necessary to cause PTS as compared with TTS, it is considerably less 
likely that PTS could occur.
    Non-auditory physiological effects or injuries that theoretically 
might occur in marine mammals exposed to high level underwater sound or 
as a secondary effect of extreme behavioral reactions (e.g., change in 
dive profile as a result of an avoidance reaction) caused by exposure 
to sound include neurological effects, bubble formation, resonance 
effects, and other types of organ or tissue damage (Cox et al., 2006; 
Southall et al., 2007; Zimmer and Tyack, 2007). The Navy's activities 
do not involve the use of devices such as explosives or mid-frequency 
active sonar that are associated with these types of effects.
    When a live or dead marine mammal swims or floats onto shore and is 
incapable of returning to sea, the event is termed a ``stranding'' (16 
U.S.C. 1421h(3)). Marine mammals are known to strand for a variety of 
reasons, such as infectious agents, biotoxicosis, starvation, fishery 
interaction, ship strike, unusual oceanographic or weather events, 
sound exposure, or combinations of these stressors sustained 
concurrently or in series (e.g., Geraci et al., 1999). However, the 
cause or causes of most strandings are unknown (e.g., Best, 1982). 
Combinations of dissimilar stressors may combine to kill an animal or 
dramatically reduce its fitness, even though one exposure without the 
other would not be expected to produce the same outcome (e.g., Sih et 
al., 2004). For further description of stranding events see, e.g., 
Southall et al., 2006; Jepson et al., 2013; Wright et al., 2013.
    1. Temporary threshold shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to sound (Kryter, 1985). 
While experiencing TTS, the hearing threshold rises, and a sound must 
be at a higher level in order to be heard. In terrestrial and marine 
mammals, TTS can last from minutes or hours to days (in cases of strong 
TTS). In many cases, hearing sensitivity recovers rapidly after 
exposure to the sound ends. Few data on sound levels and durations 
necessary to elicit mild TTS have been obtained for marine mammals, and 
none of the data published at the time of this writing concern TTS 
elicited by exposure to multiple pulses of sound.

[[Page 19336]]

    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to 
serious. For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS in a non-critical frequency 
range that occurs during a time where ambient noise is lower and there 
are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin [Tursiops truncatus], beluga whale [Delphinapterus 
leucas], harbor porpoise, and Yangtze finless porpoise [Neophocoena 
asiaeorientalis]) and three species of pinnipeds (northern elephant 
seal, harbor seal, and California sea lion) exposed to a limited number 
of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (e.g., Finneran et al., 2002; Nachtigall et al., 
2004; Kastak et al., 2005; Lucke et al., 2009; Popov et al., 2011). In 
general, harbor seals (Kastak et al., 2005; Kastelein et al., 2012a) 
and harbor porpoises (Lucke et al., 2009; Kastelein et al., 2012b) have 
a lower TTS onset than other measured pinniped or cetacean species. 
Additionally, the existing marine mammal TTS data come from a limited 
number of individuals within these species. There are no data available 
on noise-induced hearing loss for mysticetes. For summaries of data on 
TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007) and Finneran and Jenkins 
(2012).
    2. Behavioral effects--Behavioral disturbance may include a variety 
of effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. Behavioral responses to sound are highly 
variable and context-specific and any reactions depend on numerous 
intrinsic and extrinsic factors (e.g., species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day), as well as the interplay between factors (e.g., 
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007; 
Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not 
only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al., 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). 
Please see Appendices B-C of Southall et al. (2007) for a review of 
studies involving marine mammal behavioral responses to sound.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance (Bejder et al., 2009). The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. As noted, behavioral state may affect the type of response. 
For example, animals that are resting may show greater behavioral 
change in response to disturbing sound levels than animals that are 
highly motivated to remain in an area for feeding (Richardson et al., 
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with 
captive marine mammals have showed pronounced behavioral reactions, 
including avoidance of loud sound sources (Ridgway et al., 1997; 
Finneran et al., 2003). Observed responses of wild marine mammals to 
loud pulsed sound sources (typically seismic airguns or acoustic 
harassment devices) have been varied but often consist of avoidance 
behavior or other behavioral changes suggesting discomfort (Morton and 
Symonds, 2002; see also Richardson et al., 1995; Nowacek et al., 2007).
    Available studies show wide variation in response to underwater 
sound; therefore, it is difficult to predict specifically how any given 
sound in a particular instance might affect marine mammals perceiving 
the signal. If a marine mammal does react briefly to an underwater 
sound by changing its behavior or moving a small distance, the impacts 
of the change are unlikely to be significant to the individual, let 
alone the stock or population. However, if a sound source displaces 
marine mammals from an important feeding or breeding area for a 
prolonged period, impacts on individuals and populations could be 
significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 
2005). However, there are broad categories of potential response, which 
we describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing, 
interference with or alteration of vocalization, avoidance, and flight.
    Changes in dive behavior can vary widely, and may consist of 
increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive (e.g., Frankel 
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et 
al., 2004; Goldbogen et al., 2013a,b). Variations in dive behavior may 
reflect interruptions in biologically significant activities (e.g., 
foraging) or they may be of little biological significance. The impact 
of an alteration to dive behavior resulting from an acoustic exposure 
depends on what the animal is doing at the time of the exposure and the 
type and magnitude of the response.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that

[[Page 19337]]

respiration rates may either be unaffected or could increase, depending 
on the species and signal characteristics, again highlighting the 
importance in understanding species differences in the tolerance of 
underwater noise when determining the potential for impacts resulting 
from anthropogenic sound exposure (e.g., Kastelein et al., 2001, 2005b, 
2006; Gailey et al., 2007).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007b). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors, and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from seismic surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006).
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996). The result of a flight response could range from 
brief, temporary exertion and displacement from the area where the 
signal provokes flight to, in extreme cases, marine mammal strandings 
(Evans and England, 2001). However, it should be noted that response to 
a perceived predator does not necessarily invoke flight (Ford and 
Reeves, 2008), and whether individuals are solitary or in groups may 
influence the response.
    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In 
addition, chronic disturbance can cause population declines through 
reduction of fitness (e.g., decline in body condition) and subsequent 
reduction in reproductive success, survival, or both (e.g., Harrington 
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    3. Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle, 1950; 
Moberg, 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha, 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker, 2000; 
Romano et al., 2002b) and, more rarely, studied in wild populations 
(e.g., Romano et al., 2002a).

[[Page 19338]]

For example, Rolland et al. (2012) found that noise reduction from 
reduced ship traffic in the Bay of Fundy was associated with decreased 
stress in North Atlantic right whales. These and other studies lead to 
a reasonable expectation that some marine mammals will experience 
physiological stress responses upon exposure to acoustic stressors and 
that it is possible that some of these would be classified as 
``distress.'' In addition, any animal experiencing TTS would likely 
also experience stress responses (NRC, 2003).
    4. Auditory masking--Sound can disrupt behavior through masking, or 
interfering with, an animal's ability to detect, recognize, or 
discriminate between acoustic signals of interest (e.g., those used for 
intraspecific communication and social interactions, prey detection, 
predator avoidance, navigation) (Richardson et al., 1995). Masking 
occurs when the receipt of a sound is interfered with by another 
coincident sound at similar frequencies and at similar or higher 
intensity, and may occur whether the sound is natural (e.g., snapping 
shrimp, wind, waves, precipitation) or anthropogenic (e.g., shipping, 
sonar, seismic exploration) in origin. The ability of a noise source to 
mask biologically important sounds depends on the characteristics of 
both the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007b; Di Iorio and Clark, 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore, 2014). Masking can be tested 
directly in captive species (e.g., Erbe, 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand, 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking.
    Potential Effects of Pile Driving Sound--The effects of sounds from 
pile driving might include one or more of the following: Temporary or 
permanent hearing impairment, non-auditory physical or physiological 
effects, behavioral disturbance, and masking (Richardson et al., 1995; 
Gordon et al., 2003; Nowacek et al., 2007; Southall et al., 2007). The 
effects of pile driving on marine mammals are dependent on several 
factors, including the type and depth of the animal; the pile size and 
type, and the intensity and duration of the pile driving sound; the 
depth of the water column; the substrate; the standoff distance between 
the pile and the animal; and the sound propagation properties of the 
environment. Impacts to marine mammals from pile driving activities are 
expected to result primarily from acoustic pathways. As such, the 
degree of effect is intrinsically related to the frequency, received 
level, and duration of the sound exposure, which are in turn influenced 
by the distance between the animal and the source. The further away 
from the source, the less intense the exposure should be. The substrate 
and depth of the habitat affect the sound propagation properties of the 
environment. In addition, substrates that are soft (e.g., 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 could be 
expected to include physiological and behavioral responses to the 
acoustic signature (Viada et al., 2008). Potential effects from 
impulsive sound sources like pile driving can range in severity from 
effects such as behavioral disturbance to temporary or permanent 
hearing impairment (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 shifts. 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. PTS constitutes injury, but TTS does not (Southall et 
al., 2007). Based on the best scientific information available, the 
SPLs for the construction activities in this project are far below the 
thresholds that could cause TTS or the onset of PTS: 180 dB re 1 [mu]Pa 
rms for odontocetes and 190 dB re 1 [mu]Pa rms for pinnipeds (Table 3).
    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

[[Page 19339]]

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 thresholds are 160 dB for 
impulsive sources is 120 dB for continuous sources (Table 3). 
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). 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).
    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 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);
     Longer-term habitat abandonment due to loss of desirable 
acoustic environment; and
     Longer-term 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. 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. 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 low. 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 behavioral thresholds 
are 90 dB for harbor seals, and 100 dB for all other pinnipeds (Table 
3). 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 the 
area and move further from the source.

Anticipated Effects on Marine Mammal Habitat

    The proposed activities at AIRSTA/SFO Port Angeles 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 only rookeries or major 
haul-out sites in close proximity to the project site are harbor seal 
haul-outs located approximately 1.7 miles (2.7 km) west, and another 
1.3 miles (2.1 km) south of the project site. The next closest rookery 
or major haul-out site is 11.2 miles (18 km) away. The nearest Steller 
sea lion haul-out to the project site is approximately 12.5 miles (20 
km) across the Strait of Juan de Fuca at Race Rocks. There are no ocean 
bottom structures of significant biological importance to marine 
mammals that may be present in the marine waters in the vicinity of the 
project area. Therefore, the main impact 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 
AIRSTA/SFO Port Angeles and minor impacts to the immediate substrate 
during installation and removal of piles during the wharf construction 
project. Temporary and localized reduction in water quality could occur 
as a result of in-water construction activities during

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the installation and removal of piles when bottom sediments are 
disturbed. Effects on turbidity and sedimentation are expected to be 
short-term and not result in any measurable effects on marine mammals 
and their habitat.

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 
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 wharf construction project. However, adverse impacts 
may occur to a few species of rockfish and salmon, 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. Impacts to 
these species could result from potential impacts to their eggs and 
larvae; however, impacts are not anticipated to be permanent or 
significant.

Pile Driving Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in the Port Angeles Harbor. 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 Port Angeles Harbor and 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. 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.
    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 Port Angeles 
harbor. 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.

Mitigation 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 180/190 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. Modeled distances for shutdown zones (the 
area in which SPLs equal or exceed the 180/190 dB rms) are shown in 
Table 6. However, during impact pile driving, the Navy would implement 
a minimum shutdown zone of 30 m radius for cetaceans and 10 m radius 
for pinnipeds around all pile driving activity. The modeled injury 
threshold distances are approximately 29 m and 6 m, respectively. 
During vibratory driving, the shutdown zone would be 10 m distance from 
the source for all animals. These precautionary measures are intended 
to further reduce any possibility of acoustic injury, as well as to 
account for any undue reduction in the modeled zones stemming from the 
assumption of 6 dB attenuation from use of a bubble curtain (see 
discussion later in this section).
    Disturbance Zone--Disturbance zones are the areas in which SPLs 
equal or exceed 160 and 120 dB rms (for pulsed and non-pulsed 
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 6. Given the size of 
the disturbance zone for vibratory pile driving, it is impossible to 
guarantee that all animals would be observed or to make comprehensive 
observations of fine-scale behavioral reactions to sound, and only a 
portion of the zone will be monitored.
    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. The received level may be estimated on the basis of past or

[[Page 19341]]

subsequent acoustic monitoring. It may then be determined whether the 
animal was exposed to sound levels constituting incidental harassment 
in post-processing of observational data, and a precise accounting of 
observed incidents of harassment created. Therefore, although the 
predicted distances to behavioral harassment thresholds are useful for 
estimating harassment for purposes of authorizing levels of incidental 
take, actual take may be determined in part through the use of 
empirical data. That information may then be used to extrapolate 
observed takes to reach an approximate understanding of actual total 
takes.
    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 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 Marine Mammal Monitoring Plan (available at www.nmfs.noaa.gov/pr/permits/incidental.htm), developed by the Navy with our approval, 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.

Sound Attenuation Devices

    Sound levels can be greatly reduced during impact pile driving 
using sound attenuation devices. There are several types of sound 
attenuation devices including bubble curtains, cofferdams, and 
isolation casings (also called temporary noise attenuation piles 
[TNAP]), and cushion blocks. The Navy proposes to use bubble curtains, 
which create a column of air bubbles rising around a pile from the 
substrate to the water surface. The air bubbles absorb and scatter 
sound waves emanating from the pile, thereby reducing the sound energy. 
Bubble curtains may be confined or unconfined. An unconfined bubble 
curtain may consist of a ring seated on the substrate and emitting air 
bubbles from the bottom. An unconfined bubble curtain may also consist 
of a stacked system, that is, a series of multiple rings placed at the 
bottom and at various elevations around the pile. Stacked systems may 
be more effective than non-stacked systems in areas with high current 
and deep water (Oestman et al., 2009).
    A confined bubble curtain contains the air bubbles within a 
flexible or rigid sleeve made from plastic, cloth, or pipe. Confined 
bubble curtains generally offer higher attenuation levels than 
unconfined curtains because they may physically block sound waves and 
they prevent air bubbles from migrating away from the pile. For this 
reason, the confined bubble curtain is commonly used in areas with high 
current velocity (Oestman et al., 2009).
    Both environmental conditions and the characteristics of the sound 
attenuation device may influence the effectiveness of the device. 
According to Oestman et al. (2009):
     In general, confined bubble curtains attain better sound 
attenuation levels in areas of high current than unconfined bubble 
curtains. If an unconfined device is used, high current velocity may 
sweep bubbles away from the pile, resulting in reduced levels of sound 
attenuation.
     Softer substrates may allow for a better seal for the 
device, preventing leakage of air bubbles and escape of sound waves. 
This increases the effectiveness of the device. Softer substrates also 
provide additional attenuation of sound traveling through the 
substrate.
     Flat bottom topography provides a better seal, enhancing 
effectiveness of the sound attenuation device, whereas sloped or 
undulating terrain reduces or eliminates its effectiveness.
     Air bubbles must be close to the pile; otherwise, sound 
may propagate into the water, reducing the effectiveness of the device.
     Harder substrates may transmit ground-borne sound and 
propagate it into the water column.
    The literature presents a wide array of observed attenuation 
results for bubble curtains (e.g., Oestman et al., 2009; Coleman, 2011; 
see Table 3-2 in

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Appendix A of the Navy's application). The variability in attenuation 
levels is due to variation in design, as well as differences in site 
conditions and difficulty in properly installing and operating in-water 
attenuation devices. As a general rule, reductions of greater than 10 
dB cannot be reliably predicted. For 36-in piles the average rms 
reduction with use of the bubble curtain was nine dB, where the 
averages of all bubble-on and bubble-off data were compared. For 48-in 
piles, the average SPL reduction with use of a bubble curtain was seven 
dB for average rms values (see Table 3-1 in Appendix A of the Navy's 
application).
    To avoid loss of attenuation from design and implementation errors, 
the Navy has required specific bubble curtain design specifications, 
including testing requirements for air pressure and flow prior to 
initial impact hammer use, and a requirement for placement on the 
substrate. Bubble curtains shall be used during all impact pile 
driving. The device will distribute air bubbles around 100 percent of 
the piling perimeter for the full depth of the water column, and the 
lowest bubble ring shall be in contact with the mudline for the full 
circumference of the ring. We considered eight dB as potentially the 
best estimate of average SPL (rms) reduction, assuming appropriate 
deployment and no problems with the equipment. Therefore, an eight dB 
reduction was used in the Navy's analysis of pile driving noise in the 
environmental analyses.

Timing Restrictions

    In Port Angeles Harbor, designated timing restrictions exist for 
pile driving activities to avoid in-water work when salmonids and other 
spawning forage fish are likely to be present. The in-water work window 
is November 1, 2016-February 15, 2017, and July 16-October 31, 2017. 
All in-water construction activities will occur during daylight hours 
(sunrise to sunset) except from July 16 to February 15 when impact pile 
driving/removal will only occur starting 2 hours after sunrise and 
ending 2 hours before sunset, to protect foraging marbled murrelets 
during nesting season (April 1-September 23). Other construction (not 
in-water) may occur between 7 a.m. and 10 p.m., year-round.

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 vibratory hammers for 
fifteen seconds at reduced energy followed by a thirty-second waiting 
period. This procedure is repeated two additional times.
    Implementation of soft start for vibratory pile driving during 
previous pile driving work for the Explosives Handling Wharf at Fort 
Hood Navy Base Kitsap Bangor led to equipment failure and serious human 
safety concerns, which resulted in discontinuation of the soft-start 
procedure for vibratory pile driving. The Marine Mammal Commission has 
stated that the soft-start is a viable, effective component of a 
mitigation plan designed to effect the least practicable impact on 
marine mammals. In response to this concern, NMFS formed a working 
group with the Navy in April 2014 to address the soft-start procedures. 
At this time, the EHW-2 project is the only project where the procedure 
has been waived.
    For this proposed IHA, as a result of this potential low risk to 
human safety, we have determined vibratory soft start to be 
practicable, but if unsafe working conditions during soft-starts are 
reported by the contractor and verified by an independent safety 
inspection, the Navy may elect to discontinue vibratory soft-starts.
    For impact driving, soft start will be required, and contractors 
will provide an initial set of strikes from the impact hammer at 
reduced energy, followed by a thirty-second waiting period, then two 
subsequent reduced energy strike sets. The reduced energy of an 
individual hammer cannot be quantified because of variation in 
individual drivers. 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.'' Soft start for impact driving will be required at 
the beginning of each day's pile driving work and at any time following 
a cessation of impact 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, 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)

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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 accomplish one or 
more of the following general goals:
    1. An increase in the probability of detecting marine mammals, both 
within defined zones of effect (thus allowing for more effective 
implementation of the mitigation) and in general to generate more data 
to contribute to the analyses mentioned below;
    2. An increase in our understanding of how many marine mammals are 
likely to be exposed to stimuli that we associate with specific adverse 
effects, such as behavioral harassment or hearing threshold shifts;
    3. An increase in our understanding of how marine mammals respond 
to stimuli expected to result in incidental take and how anticipated 
adverse effects on individuals may impact the population, stock, or 
species (specifically through effects on annual rates of recruitment or 
survival) through any of the following methods:
     Behavioral observations in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict pertinent information, e.g., received level, 
distance from source);
     Physiological measurements in the presence of stimuli 
compared to observations in the absence of stimuli (need to be able to 
accurately predict pertinent information, e.g., received level, 
distance from source);
     Distribution and/or abundance comparisons in times or 
areas with concentrated stimuli versus times or areas without stimuli;
    4. An increased knowledge of the affected species; or
    5. An increase in our understanding of the effectiveness of certain 
mitigation and monitoring measures.
    The Navy submitted a marine mammal monitoring plan as part of the 
IHA application for this project. It can be found on the Internet at 
www.nmfs.noaa.gov/pr/permits/incidental.htm. The plan may be modified 
or supplemented based on comments or new information received from the 
public during the public comment period.

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 Marine 
Mammal Monitoring Plan would implement the following procedures for 
pile driving:
     A minimum of three Marine Mammal Observers (protected 
species observers [PSOs]) would be present during both impact and 
vibratory pile driving/removal and 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 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.
    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;
     Locations of all marine mammal observations; and
     Other human activity in the area.

Reporting

    A draft report would be submitted within ninety calendar days of 
the completion of the in-water work window. 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 problems encountered in deploying sound attenuating devices, 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.

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

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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.
    Low level responses to sound (e.g., short-term avoidance of an 
area, short-term changes in locomotion or vocalization) are less likely 
to result in fitness effects on individuals that would ultimately 
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 individual animals could potentially be 
significant and could potentially translate to affects on annual rates 
of recruitment or survival (e.g., Lusseau and Bejder, 2007; Weilgart, 
2007). Specific understanding of the activity and the effected species 
are necessary to predict the severity of impacts and the likelihood of 
fitness impacts, however, we start with the estimated number of takes, 
understanding that additional analysis is needed to understand what 
those takes mean. 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, taking the duration of the activity into consideration. 
This practice provides a good sense of the number of instances of take, 
but potentially overestimates the numbers of individual marine mammals 
taken. 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. 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, harbor seals, 
Northern elephant seals, and harbor porpoises in Port Angeles Harbor 
that may result from pile driving during construction activities 
associated with the pier construction and support facilities project 
described previously in this document. 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 incidences 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 (Table 3). 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 should be considered 
guidelines for estimating when harassment may occur (i.e., when an 
animal is exposed to levels equal to or exceeding the relevant 
criterion) in specific contexts; however, useful contextual information 
that may inform our assessment of effects is typically lacking and we 
consider these thresholds as step functions. NMFS is currently revising 
these acoustic guidelines; for more information on that process, please 
visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. Vibratory pile 
driving produces continuous noise and impact pile driving produces 
impulsive noise.

               Table 3--Current Acoustic Exposure Criteria
------------------------------------------------------------------------
           Criterion                 Definition           Threshold
------------------------------------------------------------------------
Level A harassment (underwater)  Injury (PTS--any    180 dB (cetaceans)/
                                  level above that    190 dB (pinnipeds)
                                  which is known to   (rms).
                                  cause TTS).
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).
------------------------------------------------------------------------
* NMFS has not established any formal criteria for harassment resulting
  from exposure to airborne sound. However, these thresholds represent
  the best available information regarding the effects of pinniped
  exposure to such sound and NMFS' practice is to associate exposure at
  these levels with Level B harassment.

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

[[Page 19345]]

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 Port Angeles Harbor, 
where water increases with depth as the receiver moves away from the 
shoreline, 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. A large 
quantity of literature regarding SPLs recorded from pile driving 
projects is available for consideration. In order to determine 
reasonable SPLs and their associated effects on marine mammals that are 
likely to result from pile driving at AIRSTA/SFO Port Angeles, studies 
with similar properties to the specified activity were evaluated. SPLs 
from driving of 12-, 18-, 24-, 30-, and 36-in piles by impact and 
vibratory hammers were measured (Tables 4 and 5). All projects were 
located in California, Oregon, and Washington, but projects in marine 
waters of Puget Sound including the San Juan Islands were favored over 
those in the San Francisco Bay area, the mouth of the Columbia River, 
or coastal bays because they were more similar to the conditions at 
Port Angeles harbor. Overall, studies which met the following 
parameters were considered: (1) Pile size and materials: Steel pipe 
piles (24- to 36-in diameter), concrete piles (18- to 24-in diameter), 
timber piles (12-in diameter), steel sheet piles (24-in); (2) Hammer 
machinery: Vibratory and impact hammer; and (3) Physical environment: 
Shallow depth (less than 5 m to 15 m), similar substrate type to 
project area (sand/silt to sand/silt/cobbles overlying glacial till or 
hard clay layers).

  Table 4--Underwater SPLs From Monitored Construction Activities Using
                             Impact Hammers
------------------------------------------------------------------------
                                                             Range of
                                             Number of      average rms
                Pile size                    projects       (n-weighted
                                            considered     pile average)
                                                          dB re 1 [mu]Pa
------------------------------------------------------------------------
                                  Steel
------------------------------------------------------------------------
24-inch.................................               2   181-198 (193)
30-inch.................................               3   192-196 (195)
36-inch (all projects)..................               3   185-196 (192)
36-inch (Bangor only)...................               1   185-196 (194)
All 24/30/36-inch.......................               7   181-198 (193)
------------------------------------------------------------------------
                                Concrete
------------------------------------------------------------------------
<18-inch................................               3   158-173 (170)
24-inch.................................               7   167-179 (174)
------------------------------------------------------------------------

    The tables presented here detail representative pile driving SPLs 
that have been recorded from similar construction activities in recent 
years. Due to the similarity of these actions and the Navy's proposed 
action, these values represent reasonable SPLs which could be 
anticipated, and which were used in the acoustic modeling and analysis. 
Table 4 displays SPLs measured during pile installation using an impact 
hammer and Table 5 displays SPLs measured during pile installation 
using a vibratory hammer. For impact driving, average RMS values over 
24-, 30-, and 36-in piles ranged from 181 dB to 198 dB. A source value 
of 193 dB rms at 10 m was the average value reported from the listed 
studies. For vibratory pile driving, source levels ranged depending on 
pile type and size. At 10 m, source values of 161 dB (16- to 24-in 
steel pipe pile), 167 dB (30- to 36-in steel pipe pile), were used.

             Table 5--Underwater SPLs From Monitored Construction Activities Using Vibratory Hammers
----------------------------------------------------------------------------------------------------------------
         Project and location             Pile size and type          Water depth             Measured SPLs
----------------------------------------------------------------------------------------------------------------
Vashon Terminal, WA \1\..............  30-in steel pipe.......  6 m....................  165 dB (rms) at 11 m.
Keystone Terminal, WA \2\............  30-in steel pipe.......  8 m....................  165 dB (rms) at 10 m.
Edmonds Ferry Terminal, WA \3\.......  36-in steel pipe.......  5.8 m..................  162-163 dB (rms) at 10
                                                                                          m.
Anacortes Ferry Terminal, WA \4\.....  36-in steel pipe.......  12.7 m.................  168-170 dB (rms) at 10
                                                                                          m.
California \5\.......................  36-in steel pipe.......  5 m....................  170 dB/175 dB (rms) at
                                                                                          10 m.\8\
Test Pile Program, NBKB \6\..........  36-in steel pipe.......  13.7-26.8 m............  154-169 dB (rms) at 10
                                                                                          m.
EHW-2, Year 1, NBKB \7\..............  36-in steel pipe.......  Avg of mid- and deep-    169 dB (rms) at 10 m.
                                                                 depth.
Test Pile Program, NBKB \6\..........  48-in steel pipe.......  13.7-26.8 m............  172 dB (rms) at 10 m.
California \3\.......................  72-in steel pipe.......  5 m....................  170 dB/180 dB (rms) at
                                                                                          10 m.\8\
----------------------------------------------------------------------------------------------------------------
Sources: \1\ Laughlin, 2010a; \2\ Laughlin, 2010b; \3\ Loughlin, 2011; \4\ Loughlin, 2012; \5\ Caltrans, 2012;
  \6\ Illingworth & Rodkin, 2012; \7\ Illingworth & Rodkin, 2013 (See Navy application).
\8\ Specific location/project unknown. Summary value possibly comprising multiple events rather than a single
  event. Average and maximum values presented.

    All calculated distances to, and the total area encompassed by, the 
marine mammal sound thresholds are provided in Table 6. Although radial 
distance and area associated with the zone ensonified to 160 dB (the 
behavioral harassment threshold for pulsed sounds, such as those 
produced by impact driving) are presented in Table 6, this zone would 
be

[[Page 19346]]

subsumed by the 120-dB zone produced by vibratory driving. Thus, 
behavioral harassment of marine mammals associated with impact driving 
is not considered further here. Since the 160-dB threshold and the 120-
dB threshold both indicate behavioral harassment, pile driving effects 
in the two zones are equivalent. Although not considered as a likely 
construction scenario, if only the impact driver was operated on a 
given day incidental take on that day would likely be lower because the 
area ensonified to levels producing Level B harassment would be smaller 
(although actual take would be determined by the numbers of marine 
mammals in the area on that day).

Table 6--Calculated Distance(s) to and Area Encompassed by Underwater Marine Mammal Sound Thresholds During Pile
                                                  Installation
----------------------------------------------------------------------------------------------------------------
               Threshold                      Steel pile size                  Distance            Area  (km\2\)
----------------------------------------------------------------------------------------------------------------
Impact driving, pinniped injury (190    24-inch....................  5 m........................        0.000078
 dB).
                                        30-inch....................  6 m........................         0.00011
                                        36-inch....................  4 m........................         0.00005
Impact driving, cetacean injury (180    24-inch....................  22 m.......................          0.0015
 dB).
                                        30-inch....................  29 m.......................          0.0026
                                        36-inch....................  18 m.......................           0.001
Impact driving, disturbance (160 dB)..  24-inch....................  464 m......................            0.43
                                        30-inch....................  631 m......................            0.75
                                        36-inch....................  398 m......................            0.33
Vibratory driving, disturbance (120     24-inch....................  6,310 m....................            20.4
 dB).
                                        30-inch....................  13,594 m...................            29.9
                                        36-inch....................  13,594 m...................            29.9
----------------------------------------------------------------------------------------------------------------

    Port Angeles Harbor does not represent open water, or free field, 
conditions. Therefore, sounds would attenuate as they encounter land 
masses or bends in the canal. As a result, the calculated distance and 
areas of impact for the 120-dB threshold cannot actually be attained at 
the project area. See Figure 6-1 of the Navy's application for a 
depiction of the size 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 a result, 
the Navy analyzed the potential for pinnipeds hauled out or swimming at 
the surface near AIRSTA/SFO Port Angeles to be exposed to airborne SPLs 
that could result in Level B behavioral harassment. 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.
    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. In order to determine reasonable airborne 
SPLs and their associated effects on marine mammals that are likely to 
result from pile driving at AIRSTA/SFO Port Angeles, studies with 
similar properties to the proposed action, as described previously, 
were evaluated. Table 7 details representative pile driving activities 
that have occurred in recent years. Due to the similarity of these 
actions and the Navy's proposed action, they represent reasonable SPLs 
which could be anticipated.

                           Table 7--Airborne SPLs From Similar Construction Activities
----------------------------------------------------------------------------------------------------------------
      Project and location         Pile size and type         Method                  Measured SPLs \5\
----------------------------------------------------------------------------------------------------------------
Cape Disappointment Boat Launch   12-in steel pipe...  Impact.............  89 A-weighted.
 Facility, Wave Barrier Project
 \1\.
Bangor Test Pile Program........  24-in steel pipe...  Impact.............  110 dB Lmax at 15 m
                                                                            95 dB Lmax at 122 m.
SR 520 Bridge Replacement Test    24-in steel pipe...  Impact.............  95-100 dB Lmax at 11-15 m.
 Pile \2\.
SR 520 Bridge Replacement Test    30-in steel pipe...  Impact.............  103-106 dB Lmax at 11-15 m.
 Pile \2\.
Bangor Test Pile Program \3\....  36-in steel pipe...  Impact.............  109 dB Lmax at 15 m.
Wahkiakum Ferry Terminal \4\....  18-in steel pipe...  Vibratory..........  87.5 dB Lmax at 15 m.
Bangor Test Pile Program........  24-in steel pipe...  Vibratory..........  92 dB Leq at 15 m
                                                                            78 dB Leq at 122 m.
SR 520 Bridge Replacement Test    24-in steel pipe...  Vibratory..........  88 dB Leq at 11 m.
 Pile \2\.
Keystone Ferry Terminal, WA \4\.  30-in steel pipe...  Vibratory..........  95 dB rms at 15 m.
Vashon Ferry Terminal Test Pile   30-in steel pipe...  Vibratory..........  83-85 ** dB Leq at 15 m*.
 Project 4 5.
Bangor Test Pile Program \3\....  36-in steel pipe...  Vibratory..........  93 dB Leq at 15 m.
----------------------------------------------------------------------------------------------------------------
Sources: \1\ WSDOT, 2006; \2\ WSDOT, 2010f; \3\ Navy, 2012; \4\ WSDOT, 2010g; \5\ WSDOT, 2010d.
* Sound pressure levels standardized to 50 ft range. Measurements made at 11 meters.
** Converted to C-weighted from A-weighted measurements to approximate unweighted sound level, reported at a
  distance of 26 to 36 feet.


[[Page 19347]]

    Based on these values and the assumption of spherical spreading 
loss, distances to relevant thresholds and associated areas of 
ensonification are presented in Table 8. See Figure 6-6 of the Navy's 
application for a depiction of the size of areas in which each airborne 
sound threshold is predicted to occur at the project area due to pile 
driving.

  Table 8--Distances to Relevant Sound Thresholds and Areas of Ensonification for Airborne Sound, Using 36-Inch
                                                   Steel Piles
----------------------------------------------------------------------------------------------------------------
                                                                                   Distance to threshold (m) and
                                                                                        associated area of
                    Group                                  Threshold                  ensonification (km\2\)
                                                                                 -------------------------------
                                                                                     Vibratory        Impact
----------------------------------------------------------------------------------------------------------------
Harbor seals................................  90 dB.............................        27, 0.11       192, 0.11
Other pinnipeds.............................  100 dB............................         9, 0.01        61, 0.01
----------------------------------------------------------------------------------------------------------------

Marine Mammal Densities

    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 considered the best available information for Washington 
inland waters, except where specific local abundance information is 
available. Here, we rely on NMSDD density information for the Steller 
sea lions and California see lions, and use local abundance data for 
harbor seals. For species without a predictable occurrence, like the 
harbor porpoise and Northern elephant seal, estimates are based on 
historical likelihood of encounter. Please see Appendix A of the Navy's 
application for more information on the NMSDD information.
    For all species, the most appropriate information available was 
used to estimate the number of potential incidences of take. For harbor 
porpoise and Northern elephant seals, this involved reviewing 
historical occurrence and numbers, as well as group size to develop a 
realistic estimate of potential exposure. For Steller sea lion and 
California sea lions, this involved NMSDD data. For harbor seals, this 
involved site-specific data from published literature describing harbor 
seal research conducted in Washington and Oregon, including counts from 
haul-outs near Port Angeles Harbor (WDFW, 2015). Therefore, density was 
calculated as the maximum number of individuals expected to be present 
at a given time (Houghton et al., 2015) divided by the area of Port 
Angeles Harbor.

Description of Take Calculation

    The take calculations presented here rely on the best data 
currently available for marine mammal populations in the Port Angeles 
Harbor. The formula was developed for calculating take due to pile 
driving activity and applied to each group-specific sound impact 
threshold. The formula is founded on the following assumptions:
     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 75 total days of in-water activity and 
the largest ZOI equals 29.9 km\2\;
     Exposure modeling assumes that one impact pile driver and 
three vibratory pile drivers are operating concurrently; and,
     Exposures to sound levels above the relevant thresholds 
equate to take, as defined by the MMPA.
    The calculation for marine mammal takes is estimated by:

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 the estimated range of impact to the sound 
criteria. The relevant distances specified in Table 6 were used to 
calculate ZOIs around each pile. The ZOI impact area took into 
consideration the possible affected area of Port Angeles harbor from 
the pile driving site furthest from shore with attenuation due to land 
shadowing from bends in the shoreline. Because of the close proximity 
of some of the piles to the shore, the narrowness of the harbor at the 
project area, and the maximum fetch, the ZOIs for each threshold are 
not necessarily spherical and may be truncated.
    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. Acoustic monitoring has demonstrated that 
Level B harassment zones for vibratory pile driving are likely to be 
smaller than the zones estimated through modeling based on measured 
source levels and practical spreading loss. Also of note is the fact 
that the effectiveness of mitigation measures in reducing takes is 
typically not quantified in the take estimation process. See Table 9 
for total estimated incidents of take.

Airborne Sound

    Pinnipeds that occur near the project site could be exposed to 
airborne sounds associated with pile driving that have the potential to 
cause behavioral harassment, depending on their distance from pile 
driving activities. Cetaceans are not expected to be exposed to 
airborne sounds that would result in harassment as defined under the 
MMPA.
    Airborne noise will primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria in Table 7. We recognize 
that pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with heads above water. 
However, these animals would previously have been `taken' as a result 
of exposure to underwater sound above the behavioral harassment 
thresholds, which are in all cases larger than those associated with 
airborne sound. Thus, the behavioral harassment of these animals is 
already accounted for in these estimates of potential take. Multiple 
incidents of exposure to sound above NMFS' thresholds for behavioral 
harassment are not believed to result in

[[Page 19348]]

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.
    Harbor Porpoise--In Washington inland waters, harbor porpoises are 
most abundant in the Strait of Juan de Fuca, San Juan Island area, and 
Admiralty Inlet. Although harbor porpoise occur year round in the 
Strait of Juan de Fuca, harbor porpoises are a rare occurrence in Port 
Angeles Harbor, and density-based analysis does not adequately account 
for their unique temporal and spatial distributions. Estimates are 
based on historical likelihood of encounter. Based on the assumption 
that 3 harbor porpoise may be present intermittently in the ZOI (Hall, 
2004), a total of 225 harbor porpoise exposures were estimated over 75 
days of construction. These exposures would be a temporary behavioral 
harassment and would not impact the long-term health of individuals; 
the viability of the population, species, or stocks would remain 
stable.
    California Sea Lion--The California sea lion is most common in the 
Strait of Juan de Fuca from fall to late spring. California sea lion 
haul-outs are greater than 30 miles (48 km) away. Animals could be 
exposed when traveling, resting, or foraging. Primarily only male 
California sea lions migrate through the Strait of Juan de Fuca 
(Jeffries et al., 2000). Based on the NMSDD data showing that 0.676 
California sea lions per km\2\ may be present intermittently in the 
ZOI, 1,516 exposures were estimated for this species. These exposures 
would be a temporary behavioral harassment. It is assumed that this 
number would include multiple behavioral harassments of the same 
individual(s).
    Steller Sea Lion--Steller sea lions occur seasonally in the Strait 
of Juan de Fuca from September through May. Steller sea lion haul-outs 
are 13 miles (21 km) away. Based on the NMSDD data showing that 0.935 
Steller sea lion per km\2\ may be present intermittently in the ZOI, 
2,097 exposures were estimated for this species. These exposures would 
be a temporary behavioral harassment. It is assumed that this number 
would include multiple behavioral harassments of the same 
individual(s).
    Harbor Seal--Harbor seals are present year round with haul-outs in 
Port Angeles Harbor. Prior Navy IHAs have successfully used density-
based estimates; however, in this case, density estimates were not 
appropriate because there is a haul-out nearby on a log boom 
approximately 1.7 miles (2.7 km) west of the project site that was last 
surveyed in March 2013 and had a total count of 73 harbor seals (WDFW 
2015). Another haul-out site is 1.3 miles (2.1 km) south of the project 
but is across the harbor that was last surveyed in July 2010 and had a 
total count of 87 harbor seals (WDFW 2015). Density was calculated as 
the maximum number of individuals expected to be present at a given 
time (160 animals), times the number of days of pile activity. Based on 
the assumption that there could be 160 harbors seals hauled out in 
proximity to the ZOI, 12,000 exposures were estimated for this stock 
over 75 days of construction.
    We recognize that over the course of the day, while the proportion 
of animals in the water may not vary significantly, different 
individuals may enter and exit the water. Therefore, an instantaneous 
estimate of animals in the water at a given time may not produce an 
accurate assessment of the number of individuals that enter the water 
over the daily duration of the activity. However, no data exist 
regarding fine-scale harbor seal movements within the project area on 
time durations of less than a day, thus precluding an assessment of 
ingress or egress of different animals through the action area. As 
such, it is impossible, given available data, to determine exactly what 
number of individuals may potentially be exposed to underwater sound.
    A typical pile driving day (in terms of the actual time spent 
driving) is somewhat shorter than may be assumed (i.e., 8-15 hours) as 
a representative pile driving day based on daylight hours. Construction 
scheduling and notional production rates in concert with typical delays 
mean that hammers are active for only some fraction of time on pile 
driving ``days.''
    Harbor seals are not likely to have a uniform distribution as is 
assumed through use of a density estimate, but are likely to be 
relatively concentrated near areas of interest such as the haul-outs or 
foraging areas. The estimated 160 harbor seals is the maximum number of 
animals at haul-outs outside of the airborne Level B behavioral 
harassment zone; the number of exposures to individual harbor seals 
foraging in the underwater behavioral harassment zone would likely be 
much lower.
    This tells us that (1) there are likely to be significantly fewer 
harbor seals in the majority of the action area than the take estimate 
suggests; and (2) pile driving actually occurs over a limited timeframe 
on any given day (i.e., less total time per day than would be assumed 
based on daylight hours and non-continuously), reducing the amount of 
time over which new individuals might enter the action area within a 
given day. These factors lead us to believe that the approximate number 
of seals that may be found in the action area (160) is more 
representative of the number of animals exposed than the number of 
takes requested for this species, and only represents 1.5 percent of 
the most recent estimate of this stock of harbor seals. Moreover, 
because the Navy is typically unable to determine from field 
observations whether the same or different individuals are being 
exposed, each observation is recorded as a new take, although an 
individual theoretically would only be considered as taken once in a 
given day.
    Northern elephant seal--Northern elephant seals are rare visitors 
to the Strait of Juan de Fuca. However, individuals, primarily 
juveniles, have been known to sporadically haul out to molt on 
Dungeness Spit about 12 miles (19 km) from Port Angeles. One elephant 
seal was observed hauled-out at Dungeness Spit in each of the following 
years: 2000, 2002, 2004, 2005, and 2006 (WDFW 2015). Elephant seals are 
primarily present during spring and summer months. If a northern 
elephant seal was in the ZOI, it would likely be a solitary juvenile. 
Northern elephant seals are a rare occurrence in Port Angeles Harbor, 
and density-based analysis does not adequately account for their unique 
temporal and spatial distributions; therefore, estimates are based on 
historical likelihood of encounter. Based on the assumption that one 
elephant seal may be present intermittently in the ZOI, 75 exposures 
were calculated for this species. These exposures would be a temporary 
behavioral harassment.

[[Page 19349]]



  Table 9--Number of Potential Incidental Instances of Take of Marine Mammals Within Various Acoustic Threshold
                                                      Zones
----------------------------------------------------------------------------------------------------------------
                                                                            Underwater
                                                                 --------------------------------
                Species                          Density                           Level B  (120    % of stock
                                                                      Level A         dB) \1\
----------------------------------------------------------------------------------------------------------------
California sea lion...................  0.676 animal/sq. km *...               0           1,516             0.5
Steller sea lion......................  0.935 animals/sq. km *..               0           2,097               4
Harbor seal...........................  160 \2\.................               0  \4\ 12,000/160         100/1.5
Northern elephant seal................  1 \3\...................               0              75            0.04
Harbor porpoise.......................  3 \3\...................               0             225               2
----------------------------------------------------------------------------------------------------------------
\1\ The 160-dB acoustic harassment zone associated with impact pile driving would always be subsumed by the 120-
  dB harassment zone produced by vibratory driving. Therefore, takes are not calculated separately for the two
  zones.
* For species with associated density, density was multiplied by largest ZOI (i.e., 29.9 km\2\). The resulting
  value was rounded to the nearest whole number and multiplied by the 75 days of activity. For species with
  abundance only, that value was multiplied directly by the 75 days of activity. We assume for reasons described
  earlier that no takes would result from airborne noise.
\2\ For this species, site-specific data was used from published literature describing research conducted in
  Washington and Oregon, including counts from haul-outs near Port Angeles Harbor. Therefore, density was
  calculated as the maximum number of individuals expected to be present at a given time.
\3\ Figures presented are abundance numbers, not density, and are calculated as the average of average daily
  maximum numbers per month (see Section 6.6 in application). Abundance numbers are rounded to the nearest whole
  number for take estimation.
\4\ The maximum number of harbor seal anticipated to be in the vicinity to be exposed to the sound levels is 160
  animals based on counts from the two nearby haul out sites. This small number of individuals is expected to be
  the same animals exposed repeatedly, instead of new individuals being exposed each day. These animals, to
  which any incidental take would accrue, represent 1.5 percent of the most recent estimate of the stock
  abundance from the 2013 SAR.

Analyses and Preliminary Determinations

Negligible Impact Analysis

    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 
(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 of our analyses applies to all the species listed in 
Table 9, given that the anticipated effects of this activity on these 
different marine mammal stocks are expected to be similar. There is no 
information about the nature or severity of the impacts, or the size, 
status, or structure of any of these species or stocks that would lead 
to a different analysis for this activity.
    Pile driving activities associated with the pier construction 
project, 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, which is likely 
to occur because (1) harbor seals are frequently observed in Port 
Angeles harbor in two known haul-out locations; or (2) cetaceans or 
pinnipeds transit the outer edges of the larger Level B harassment zone 
outside of the harbor.
    No injury, serious injury, or mortality is anticipated given the 
methods of installation 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, 
vibratory hammers will be the primary method of installation, and this 
activity does not have significant potential to cause injury to marine 
mammals due to the relatively low source levels produced (likely less 
than 180 dB rms) and the lack of potentially injurious source 
characteristics. Impact pile driving produces short, sharp pulses with 
higher peak levels and much sharper rise time to reach those peaks. 
When impact driving is necessary, required measures (use of a sound 
attenuation system, which reduces overall source levels as well as 
dampening the sharp, potentially injurious peaks, and implementation of 
shutdown zones) significantly reduce any possibility of injury. Given 
sufficient ``notice'' through use of soft start, marine mammals are 
expected to move away from a sound source that is annoying prior to it 
becoming potentially injurious. The likelihood that marine mammal 
detection ability by trained observers is high under the environmental 
conditions described for Port Angeles harbor further enables the 
implementation of shutdowns to avoid injury, serious injury, or 
mortality.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature, will likely be limited to reactions 
such as increased swimming speeds, increased surfacing time, or 
decreased foraging (if such activity were occurring). 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. 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 
fitness to those 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

[[Page 19350]]

likely to simply avoid the project area while the activity is 
occurring.
    For pinnipeds, no rookeries are present in the project area, but 
there are two haul-outs within 2.5 mi (4 km) of the project site. 
However, the project area is not known to provide foraging habitat of 
any special importance (other than is afforded by the known migration 
of salmonids). No cetaceans are expected within the harbor.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of injury, serious injury, or 
mortality may reasonably be considered discountable; (2) the 
anticipated incidences of Level B harassment consist of, at worst, 
temporary modifications in behavior; (3) the absence of any major 
rookeries and only a few haul-out areas near or adjacent to the project 
site; (4) the absence of cetaceans within the harbor and generally 
sporadic occurrence outside of the ensonified area; (5) the absence of 
any other known areas or features of special significance for foraging 
or reproduction within the project area; and (6) the presumed efficacy 
of the planned mitigation measures in reducing the effects of the 
specified activity to the level of least practicable impact. In 
addition, none of these stocks are listed under the ESA or designated 
as depleted under the MMPA. In combination, we believe that these 
factors, as well as the available body of evidence from other similar 
activities, including those conducted in nearby locations, demonstrate 
that the potential effects of the specified activity will have only 
short-term effects on individuals. The specified activity is not 
expected to impact rates of recruitment or survival and will therefore 
not result in population-level impacts. 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 Navy's pier 
construction activities will have a negligible impact on the affected 
marine mammal species or stocks.

Small Numbers Analysis

    The numbers of animals authorized to be taken for harbor porpoise, 
Northern elephant seal, and Steller and California sea lions would be 
considered small relative to the relevant stocks or populations (less 
than one percent for Northern elephant seal and California sea lion, 
less than four percent for Steller sea lion, and less than two percent 
for harbor porpoise) even if each estimated taking occurred to a new 
individual--an extremely unlikely scenario. For pinnipeds occurring in 
the nearshore areas, there will almost certainly be some overlap in 
individuals present day-to-day. Further, for the pinniped species, 
these takes could potentially occur only within some small portion of 
the overall regional stock. For example, of the estimated 296,750 
California sea lions, only certain adult and subadult males--believed 
to number approximately 3,000-5,000 by Jeffries et al. (2000)--travel 
north during the non-breeding season. That number has almost certainly 
increased with the population of California sea lions--the 2000 SAR for 
California sea lions reported an estimated population size of 204,000-
214,000 animals--but likely remains a relatively small portion of the 
overall population.
    For harbor seals, takes are likely to occur only within some 
portion of the population, rather than to animals from the Washington 
inland waters stock as a whole. It is estimated that, based on counts 
from the two nearby haul out sites, 160 harbor seals could potentially 
be in the vicinity to be exposed to the sound levels. This small number 
of individuals is expected to be the same animals exposed repeatedly, 
instead of new individuals being exposed each day. These animals, to 
which any incidental take would accrue, represent 1.5 percent of the 
most recent estimate of the stock abundance from the 2013 SAR.
    As summarized here, the estimated numbers of potential incidents of 
harassment for these species are likely much higher than will 
realistically occur. This is because (1) we use the maximum possible 
number of days (75) in estimating take, despite the fact that multiple 
delays and work stoppages are likely to result in a lower number of 
actual pile driving days; and (2) sea lion estimates rely on the 
averaged maximum daily abundances per month, rather than simply an 
overall average which would provide a much lower abundance figure. In 
addition, potential efficacy of mitigation measures in terms of 
reduction in numbers and/or intensity of incidents of take has not been 
quantified. Therefore, these estimated take numbers are likely to be 
overestimates of individuals. 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 this action. Therefore, we have determined that the total taking of 
affected species or stocks would not have an unmitigable adverse impact 
on the availability of such species or stocks for taking for 
subsistence purposes.

Endangered Species Act (ESA)

    No marine mammal species listed under the ESA are expected to be 
affected by these activities. Therefore, we have determined that a 
section 7 consultation under the ESA is not required.

National Environmental Policy Act (NEPA)

    In compliance with the NEPA of 1969 (42 U.S.C. 4321 et seq.), as 
implemented by the regulations published by the Council on 
Environmental Quality (CEQ; 40 CFR parts 1500-1508), the Navy prepared 
an Environmental Assessment (EA) for this project. In compliance with 
NEPA, the CEQ regulations, and NOAA Administrative Order 216-6, we will 
independently evaluate the Navy's EA and determine whether or not to 
adopt it. We may prepare a separate NEPA analysis and incorporate 
relevant portions of Navy's EA by reference. 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 Finding of No 
Significant Impact (FONSI), prior to a final decision on the incidental 
take authorization request. The 2015 NEPA documents are available for 
review at http://www.nmfs.noaa.gov/pr/permits/incidental.htm.

Proposed Authorization

    As a result of these preliminary determinations, we propose to 
issue an IHA to the Navy for conducting the described pier and support 
facilities for the transit protection system U.S. Coast Guard Air 
Station/Sector Field Office Port Angeles, Washington from November 1, 
2016 through February 15, 2017, and July 16 through October 31, 2017 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. The proposed IHA language is provided 
next.
    This section contains a draft of the IHA itself. The wording 
contained in this section is proposed for inclusion in the IHA (if 
issued).

[[Page 19351]]

    1. This Incidental Harassment Authorization (IHA) is valid for one 
year from the date of issuance.
    2. This IHA is valid only for pile driving and removal activities 
associated with construction of pier and support facilities for the 
transit protection system U.S. Coast Guard Air Station/Sector Field 
Office Port Angeles, 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), Northern elephant seal (Mirounga angustirostris), California 
sea lion (Zalophus californianus), Steller sea lion (Eumetopias 
jubatus), and harbor porpoise (Phocoena phocoena).
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b). See Table 1 below for numbers of take 
authorized.

                    Table 1--Authorized Take Numbers
------------------------------------------------------------------------
                                                  Authorized take
                 Species                 -------------------------------
                                              Level A         Level B
------------------------------------------------------------------------
Harbor seal.............................               0          12,000
Northern elephant seal..................               0              75
California sea lion.....................               0           1,516
Steller sea lion........................               0           2,097
Harbor porpoise.........................               0             225
                                         -------------------------------
    Total...............................               0          15,913
------------------------------------------------------------------------

    (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, 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.
    (f) Prior to the start of pile driving or removal, the Navy will 
contact the Orca Network and/or Center for Whale Research to determine 
the location of the nearest marine mammal sightings. Daily sighting 
information reported on the Orca Network Twitter site (https://twitter.com/orcanetwork) will be checked several times a day. In 
addition, the SeaSound Remote Sensing Network will be monitored for 
real-time information on the presence or absence of whales before 
starting any pile driving or removal.
    4. Mitigation Measures
    In order to ensure the least practicable impact on the species 
listed in condition 3(b), the holder of this Authorization is required 
to implement the following mitigation measures:
    (a) During impact pile driving, the Navy shall implement a minimum 
shutdown zone of 10 m radius around the pile, to be effective for all 
species of pinniped, and a minimum shutdown zone of 30 m radius around 
the pile, to be effective for all species of cetacean. If a marine 
mammal comes within the relevant zone, operations shall cease.
    (b) During vibratory pile driving and removal, the Navy shall 
implement a minimum shutdown zone of 10 m radius around the pile for 
marine mammals. If a marine mammal comes within this zone, such 
operations shall cease.
    (c) The Navy shall similarly avoid direct interaction with marine 
mammals during in-water heavy machinery work other than pile driving 
that may occur in association with the wharf construction project. If a 
marine mammal comes within 10 m of such activity, operations shall 
cease and vessels shall reduce speed to the minimum level required to 
maintain steerage and safe working conditions, as appropriate.
    (d) The Navy shall establish monitoring locations as described in 
the Marine Mammal Monitoring Plan. For all pile driving activities, a 
minimum of three PSOs will be present during all impact and vibratory 
pile driving/removal. PSOs would be positioned at the best practicable 
vantage points, taking into consideration security, safety, and space 
limitations at USCG AIRSTA/SFO Port Angeles. A minimum of three PSOs 
would be present during both impact and vibratory pile driving/removal. 
Both the injury and behavioral harassment zones would be monitored in 
order to remain in compliance with the MMPA. 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.
    (e) Monitoring shall take place from 15 minutes prior to initiation 
of pile driving activity through 30 minutes post-completion of pile 
driving activity. Pre-activity monitoring shall be conducted for 15 
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.
    (f) 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 at a specific location 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 15 minutes have passed without re-detection 
of the animal.
    (g) 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.
    (h) Approved sound attenuation devices shall be used during impact 
pile driving operations. The Navy shall implement the necessary 
contractual

[[Page 19352]]

requirements to ensure that such devices are capable of achieving 
optimal performance, and that deployment of the device is implemented 
properly such that no reduction in performance may be attributable to 
faulty deployment.
    (i) The Navy shall use soft start techniques recommended by NMFS 
for pile driving.
    i. For impact pile driving, the soft start requires contractors to 
provide an initial set of strikes from the impact hammer at reduced 
energy, followed by a 30-second waiting period, then two subsequent 
reduced energy strike sets. Soft start shall be implemented at the 
start of each day's impact pile driving and at any time following 
cessation of impact pile driving for a period of 30 minutes or longer.
    ii. For vibratory pile driving, if a variable moment driver can be 
used, the contractor will initiate noise from vibratory drivers for 15 
seconds at reduced energy, followed by a 30-second waiting period. The 
procedure shall be repeated two additional times. However, if a 
variable moment hammer proves infeasible for use with this project, or 
if unsafe working conditions during soft starts are reported by the 
contractor, the Navy may discontinue use of the vibratory soft start 
measure. The Navy will inform NMFS Office of Protected Resources if the 
soft-start procedure is discontinued.
    (j) 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 marine mammal monitoring conducted 
under the IHA within 90 calendar days of the end of the in-water work 
period. A final report shall be prepared and submitted within 30 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 www.nmfs.noaa.gov/pr/permits/incidental/construction.htm).
    (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.
    i. 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.
    ii. 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 analysis, the draft authorization, and 
any other aspect of this Notice of Proposed IHA for Navy's wharf 
construction 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: March 28, 2016.
Wanda Cain,
Acting Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2016-07308 Filed 4-1-16; 8:45 am]
BILLING CODE 3510-22-P