[Federal Register Volume 87, Number 20 (Monday, January 31, 2022)]
[Notices]
[Pages 4844-4866]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-01833]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB634]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to BNSF Railway Bridge Heavy 
Maintenance Project in King County, Washington

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

ACTION: Notice; proposed incidental harassment authorizations; request 
for comments on proposed authorizations and possible renewals.

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SUMMARY: NMFS has received a request from BNSF Railway (BNSF) for 
authorization to take marine mammals incidental to a Railway Bridge 
Heavy Maintenance Project in King County, Washington. Pursuant to the 
Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue two consecutive incidental harassment authorization 
(IHAs) to incidentally take marine mammals during the specified 
activities. NMFS is also requesting comments on possible one-time, one-
year renewals for each IHA that could be issued under certain 
circumstances and if all requirements are met, as described in Request 
for Public Comments at the end of this notification. NMFS will consider 
public comments prior to making any final decision on the issuance of 
the requested MMPA authorizations and agency responses will be 
summarized in the final notice of our decision.

DATES: Comments and information must be received no later than March 2, 
2022.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Written comments should be submitted 
via email to <a href="/cdn-cgi/l/email-protection#86cfd2d6a8d6e7f3eaefe8e3c6e8e9e7e7a8e1e9f0"><span class="__cf_email__" data-cfemail="93dac7c3bdc3f2e6fffafdf6d3fdfcf2f2bdf4fce5">[email protected]</span></a>.
    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, including all attachments, must 
not exceed a 25-megabyte file size. All comments received are a part of 
the public record and will generally be posted online at 
www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act 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: Robert Pauline, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed incidental harassment authorization is provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of IHAs) with 
respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has 
preliminarily determined that the issuance of the proposed IHAs 
qualifies to be categorically excluded from further NEPA review.
    We will review all comments submitted in response to this 
notification prior to concluding our NEPA process or making a final 
decision on the IHA request.

Summary of Request

    On August 17, 2021, NMFS received a request from BNSF Railway 
(BNSF) for two consecutive IHAs allowing the take of marine mammals 
incidental to the Railway Bridge 0050-0006.3 (Bridge 6.3) Heavy 
Maintenance Project in King County, Washington. The application was 
deemed adequate and complete on November 22, 2021. BNSF's request is 
for take of a small number of seven species of marine mammal by Level B 
harassment and Level A harassment. Neither BNSF nor NMFS expects 
serious injury or mortality to result from this activity and, 
therefore, IHAs are appropriate.

Description of Proposed Activity

Overview

    BNSF is proposing to engage in maintenance activities at Bridge 
6.3, a bridge with a movable deck to allow vessels to pass. The purpose 
of this project is to extend the service life of the existing structure 
by replacing several components of the existing movable span including 
replacing the existing counterweight, counterweight trunnion bearings, 
and rocker frame system of the existing movable span. This work would

[[Page 4845]]

occur over two years, requiring the issuance of two consecutive IHAs.
    In-water activities that could result in take of marine mammals 
include impact pile driving of 36-inch temporary steel piles (which 
will be removed via cutting with Broco Rod which is not likely to cause 
take), vibratory installation and extraction of 14-inch H-piles, 
vibratory installation and extraction of 12-inch timber piles, 
hydraulic clipper cutting and extraction of 12-inch timber piles, 
drilling of 48-inch diameter shafts using oscillator rotator equipment, 
and removing the pile created by filling the drilled shaft and steel 
casing with concrete and removing the casing with a diamond wire saw.
    Bubble curtains will be used during impact pile driving to reduce 
in-water sound levels. The work would occur over two years during July 
16 through February 15 of each year due to the U.S. Army Corp of 
Engineers (USACE) in-water work window restrictions for salmonids.

Dates and Duration

    BSNF anticipates that the project will requires approximately 122 
days of in-water work over 24 months. The proposed IHAs would be 
effective from July 16, 2022 to July 15, 2023 for Year 1, which would 
include 113 days of in-water activities and July 16, 2023 to July 15, 
2024 for Year 2, which would include 9 days of in-water activities.

Specific Geographic Region

    The project activities will occur at BNSF Bridge 6.3, in Ballard, 
WA, which is located in King County at Latitude 47.666784[deg] North by 
Longitude -122.402108[deg] West. The Bridge spans the Lake Washington 
Ship Canal which runs through the city of Seattle and connects the 
fresh water body of Lake Washington with Puget Sound's Shilshole Bay. 
The Bridge is located just west of the Hiram M. Chittenden Locks and is 
the last bridge to span the Lake Washington Ship Canal before it flows 
into Puget Sound 2,500 ft (772 m) to the west. The Bridge is 
approximately 1,144 ft (349 m) long and was built in 1917 (See Figure 
1). The substrate below the ordinary high water mark (OHWM) is composed 
of sandy silt intermixed with gravels and riprap. Approximately 75 
percent of the Canal shoreline is developed with armored bulkheads, 
ship holding areas, and other artificial structures.
    The nearest pinniped haulouts are located 0.82 mi (Shilshole Bay 
Jetty) and 1.42 mi (West Point Buoy) away but not in direct line of 
sight with the construction activity as shown in Figure 6 in the 
Application.
BILLING CODE 3510-22-P

[[Page 4846]]

[GRAPHIC] [TIFF OMITTED] TN31JA22.001

BILLING CODE 3510-22-C

Detailed Description of Specific Activity

    Bridge 6.3 consists of 18 spans supported by 19 piers. Pier 1 is 
the southern abutment, and Pier 19 is the northern abutment. Piers 6 
through 11 are either at the edge of or below the OHWM of the Canal. 
Pier 6 is at the southern shoreline, adjacent to Commodore Park, and 
extends partially below the OHWM. Pier 11 is at the base of a steep 
slope at the northern shoreline and extends partially below the OHWM. 
Piers 7 through 10 are fully within the Canal. Pier 7 is near the 
middle of the Canal, and Piers 8, 9, and 10 are to the north of the 
north guide wall. Span 7 is a movable span (Strauss Heel-Trunnion 
Bascule) that rotates clockwise up when opening for marine vessels that 
cannot pass under the bridge when it is in the closed (down) position. 
(See Appendix A in Application for additional detail).
    Work trestles are required to provide access to the superstructure 
above Piers 8, 9, and 10. Cranes and associated construction equipment 
will be used atop the work trestles to install the temporary drilled 
shafts and then replace the existing counterweight, counterweight 
trunnion bearings, and rocker frame system.

[[Page 4847]]

    The overall construction process can be segmented into following 
primary phases:
    1. Site Mobilization;
    2. Demolish Residential Structures;
    3. Install Work Trestles;
    4. Install Drilled Shafts;
    5. Replace Bascule Span Components;
    6. Remove Work Trestles; and
    7. Site Demobilization
    Only phase 2, 3, 4 and 6 involve in-water work which could result 
in the harassment of marine mammals. Therefore, the other phases will 
not be discussed further, although additional information may be found 
in the application.

Demolish Residential Structures

    Previous owners of an adjacent parcel had expanded their dock/deck, 
float, and shed onto the BNSF right-of-way to the extent that a portion 
of their structure is attached to bridge Pier 11. This dock and shed 
are within the footprint of where the western work trestle will be 
installed and in the general vicinity of where construction barges may 
need to be deployed. These structures are supported by in-water 80 12-
inch timber piles that must be removed prior to installation of the 
work trestles.

Install Work Trestles

    Two temporary work trestles are required to provide construction 
access to the moveable span, as well as a work platform for support 
cranes and associated construction equipment and supplies. Each work 
trestle is composed of a series of large wood planks that rest on steel 
crossbeams that are welded onto the top of steel support pipe piles. 
The number and size of the steel pipe piles required for the project is 
dictated by the anticipated weight of the cranes, counterweight, steel 
beams, trunnion bearings, support equipment, and industry standard 
safety factor. All piles will be proofed to a predetermined loading 
capacity. Each work trestle will be approximately 240 ft (73 m) long by 
45 ft (13.7.m) wide. A total of 170 temporary piles (140 in-water and 
30 above water) are required (Table 1). A 20 percent contingency is 
included in this estimate. Pile types include 136 36-inch steel pipe 
piles and 34 14-inch H-piles.

                             Table 1--Temporary Pile Summary by Construction Purpose
----------------------------------------------------------------------------------------------------------------
        Pile size (inch)               Pile type            Pile use         In-water     Uplands       Total
----------------------------------------------------------------------------------------------------------------
36..............................  Steel Pipe.........  Trestle Support...          116           20          136
14..............................  H-Pile.............  Trestle Approach..            0            8            8
14..............................  H-Pile.............  Turbidity Fencing.           20            0           20
                                                                          --------------------------------------
    Subtotal....................  ...................  ..................          136           28          140
14..............................  H-Pile.............  20% Contingency...            4            2            6
                                                                          --------------------------------------
    Total.......................  ...................  ..................          140           30          170
----------------------------------------------------------------------------------------------------------------

    Trestle approach piles and trestle support piles will be installed 
with an impact hammer from start to finish due to concerns associated 
with movement of the existing bridge. A bubble curtain will be utilized 
during all impact pile driving when water depth is greater than 2 ft 
(0.6 m). In-water 14-inch H-piles for turbidity fencing will be 
installed with a vibratory hammer.
    Concurrent impact driving of 36-inch steel pipes may be utilized, 
but BNSF may select to only utilize one pile-driving crew depending on 
schedule, rate of progress, and number of days remaining in the 
allowable in-water work window.

Install Drilled Shafts

    A total of 22 temporary, 4-foot-diameter drilled shafts may be 
installed, including 11 immediately west and 11 east of Piers 9 and 10. 
Drilled shafts are anticipated to be installed by using oscillator 
rotator equipment with the advanced full-case method. Oscillator 
rotator equipment is used to excavate a circular hole into the ground. 
Since the project area likely includes unstable soils, a casing will be 
used to keep the hole open. The rotator/oscillator method uses 
hydraulic jacks that use pressure/torque to rotate the casing 20 
degrees one direction and then 20 degrees the other direction as it 
pushes the casing into the substrate. The tip of the first or initial 
casing has teeth that cut into the earth as it advances. Once one 
section of casing is installed, another section of casing is connected 
to the previously installed casing by bolting them together with an 
impact wrench. This process continues until the design load depth has 
been reached. Once the casing is fully installed, all the material 
within it is then removed (with a clamshell bucket or other method) 
prior to filling the shafts with concrete. The top of the concrete 
filled shafts or piles are then connected to a platform that will also 
be formed of concrete. The platform and concrete-filled shafts will be 
removed after maintenance has been completed.
    Note BNSF may use 116 36-inch-diameter pipe piles instead of the 
drilled shafts. This contingency for 36-inch diameter pipe piles has 
been included in the estimated total number of 36-inch pipe piles that 
may be used during this project and analyzed below.

Remove Work Trestles and Shafts

    All the temporary work trestle piles will be removed to a depth of 
2 ft (0.6 m) below mudline. The piles will be cut by a diver using the 
Broco Rod cutting method. A diver will make two cuts and then reach/
penetrate inside and cut the pipe pile from the inside diameter 2 ft 
(0.6 m) below mudline. The crane will then be used to snap and lift the 
pile out of the Canal and off the platform. This operation will 
continue to the north shoreline until the crane is on land and has 
removed all the work trestle piles. Drilled shafts will be removed to a 
depth of 2 ft (0.6 m) below the mudline. The concrete-filled shafts may 
be cut with a diamond wire saw. In-water 14-inch H-piles or wood/steel 
posts will be pulled out of the substrate by a crane or vibratory 
hammer removal as necessary.
    During Year 1 12-inch wood piles (12 days) would be extracted while 
36-inch steel pipes (10 days), 14-inch H-piles (3 days), and 48-inch 
drilled shaft casings (88 days) would be installed. During Year 214-
inch H-piles (3 days) and 48-inch (6 days) drilled shaft casings would 
be removed.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information

[[Page 4848]]

regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species or stocks for which take is expected and 
proposed to be authorized for this action, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and potential biological 
removal (PBR), where known. For taxonomy, we follow Committee on 
Taxonomy (2021). PBR is defined by the MMPA as the maximum number of 
animals, not including natural mortalities, that may be removed from a 
marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population (as described in NMFS's SARs). While no 
mortality is anticipated or authorized here, PBR and annual serious 
injury and mortality from anthropogenic sources are included here as 
gross indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. SARs (e.g., Carretta et al., 2021a). All values presented 
in Table 2 are the most recent available at the time of publication and 
are available in the 2020 U.S. Pacific SARs (Carretta et al., 2021a) 
and 2021 draft Pacific and Alaska SARs (Carretta et al., 2021b, Muto et 
al., 2021) available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports.

                                                      Table 2--Species Proposed for Authorized Take
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                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \a\          abundance survey) \b\               SI \c\
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                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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                                                            Family Balaenopteridae (rorquals)
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Minke whale.........................  Balaenoptera             California/Oregon/.....  -, -, N             915 (0.792, 509, 2018)        4.1    >= 0.59
                                       acutorostrata.          Washington.............
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                                                                   Family Delphinidae
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Common Bottlenose Dolphin...........  Tursiops truncatus.....  California/Oregon/       -, -, N             3,477 (0.696, 2,048,        19.70       0.82
                                                                Washington offshore.                         2018).
Long-beaked Common Dolphin..........  Delphinus capensis.....  California.............  -, -, N             83,379 (0.216, 69,636,        668     >=29.7
                                                                                                             2018).
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                                                             Family Phocoenidae (porpoises)
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Harbor porpoise.....................  Phocoena phocoena......  Washington Inland        -, -, N             11,233 (0.37, 8,308,           66      >=7.2
                                                                Waters.                                      2015).
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                                                         Order Carnivora--Superfamily Pinnipedia
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                                                      Family Otariidae (eared seals and sea lions)
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California Sea Lion.................  Zalophus californianus.  United States..........  -, -, N             257,606 (N/A, 233,515,     14,011       >320
                                                                                                             2014).
Steller sea lion....................  Eumetopias jubatus       Eastern U.S............  -, -, N             43,201 \d\ (see SAR,        2,592        113
                                       monteriensis.                                                         43,201, 2017).
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                                                             Family Phocidae (earless seals)
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Harbor seal.........................  Phoca vitulina.........  Washington Northern      -, -, N             1,088 (0.15, UNK,              NA       10.6
                                                                Inland Waters.                               1999) \e\.
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a--ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or designated
  as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or which is
  determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
  automatically designated under the MMPA as depleted and as a strategic stock.
b--NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
c--These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual mortality/serious injury (M/SI) often cannot be determined precisely and is in some cases presented as a minimum value
  or range.
d--Best estimate of pup and non-pup counts, which have not been corrected to account for animals at sea during abundance surveys.
e--The abundance estimate for this stock is greater than eight years old and is therefore not considered current. PBR is considered undetermined for
  this stock, as there is no current minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as
  these represent the best available information for use in this document.

Minke Whale

    Minke whales are the most abundant of the rorquals and the 
population is considered mostly stable globally. In the Pacific, minke 
whales are usually seen over continental shelves (Brueggeman et al., 
1990). In the extreme north, minke whales are believed to be migratory, 
but in inland waters of Washington and in central California they 
appear to establish home ranges (Dorsey et al., 1990). They feed on 
crustaceans,

[[Page 4849]]

plankton, and small schooling fish (like sandlance) through side 
lunging.
    Minke whales are reported in Washington inland waters year-round, 
although few are reported in the winter (Calambokidis and Baird 1994). 
Minke whales are relatively common in the San Juan Islands and Strait 
of Juan de Fuca (especially around several of the banks in both the 
central and eastern Strait), but are relatively rare in Puget Sound.

Common Bottlenose Dolphin

    Bottlenose dolphins are distributed worldwide in tropical and warm-
temperate waters. In many regions, including California, separate 
coastal and offshore populations are known (Walker 1981; Ross and 
Cockcroft 1990; Lowther 2006). They have also been documented in 
offshore waters as far north as about 41 [deg]N and they may range into 
Oregon and Washington waters during warm-water periods. Sighting 
records off California and Baja California (Lee 1993; Mangels and 
Gerrodette 1994) suggest that offshore bottlenose dolphins have a 
continuous distribution in these two regions. There is no apparent 
seasonality in distribution (Forney and Barlow 1998).
    Bottlenose dolphins employ a variety of strategies to feed, 
including both individual and cooperative hunting and techniques such 
as herding and charging schools of fish, passive listening, and 
echolocation. The California/Oregon/Washington offshore stock is the 
one most likely to occur in Washington waters.

Long-Beaked Common Dolphin

    The common dolphin has been observed in the project area. There is 
debate as to whether short-beaked and long-beaked common dolphins are 
the same species; we separate the two based on COT (2021). Only long-
beaked common dolphins have been spotted in central and south Puget 
Sound (Orca Network 2020) and this report addresses only the California 
long-beaked common dolphin stock.
    Long-beaked common dolphins typically inhabit warmer temperate and 
tropical waters and are not usually present north of California; 
however, sightings of live dolphins and dead stranded individuals have 
been increasing in the Salish Sea since the early 2000s. Common 
dolphins were sighted in 2003, 2011-12, and 2016-17, with strandings 
occurring in inland waters in 2012 and 2017. These sighting and 
stranding events are proximal to El Ni[ntilde]o periods. Since June 
2016, several common dolphins have remained in Puget Sound and group 
sizes of 5-20 individuals are often reported (Shuster et al., 2018).

Harbor Porpoise

    Harbor porpoise occur along the U.S. west coast from southern 
California to the Bering Sea (Carretta et al., 2020). They rarely occur 
in waters warmer than 63 degrees Fahrenheit (17 degrees Celsius). The 
Washington Inland Waters stock is found from Cape Flattery throughout 
Puget Sound and the Salish Sea region. In southern Puget Sound, harbor 
porpoise were common in the 1940s, but marine mammal surveys, stranding 
records since the early 1970s, and harbor porpoise surveys in the early 
1990's indicated that harbor porpoise abundance had declined (Carretta 
et al., 2020). Annual winter aerial surveys conducted by the Washington 
Department of Fish and Wildlife from 1995 to 2015 revealed an 
increasing trend in harbor porpoise in Washington inland waters, 
including the return of harbor porpoise to Puget Sound (Carretta et 
al., 2020). Seasonal surveys conducted in spring, summer, and fall 
2013-2015 in Puget Sound and Hood Canal documented substantial numbers 
of harbor porpoise in Puget Sound. Observed porpoise numbers were twice 
as high in spring as in fall or summer, indicating a seasonal shift in 
distribution.
    In most areas, harbor porpoise occur in small groups of just a few 
individuals. Harbor porpoise must forage nearly continuously to meet 
their high metabolic needs (Wisniewska et al., 2016). They consume up 
to 550 small fish (1.2-3.9 inches (3-10 cm); e.g., anchovies) per hour 
at a nearly 90 percent capture success rate (Wisniewska et al., 2016).

California Sea Lion

    California sea lions occur from Vancouver Island, British Columbia, 
to the southern tip of Baja California. They breed on the offshore 
islands of southern and central California from May through July (Heath 
and Perrin, 2008). During the non-breeding season, adult and subadult 
males and juveniles migrate northward along the coast to central and 
northern California, Oregon, Washington, and Vancouver Island 
(Jefferson et al., 1993). They return south the following spring (Heath 
and Perrin 2008, Lowry and Forney, 2005). Females and some juveniles 
tend to remain closer to rookeries (Antonelis et al., 1990; Melin et 
al., 2008).
    Pupping occurs primarily on the California Channel Islands from 
late May until the end of June (Peterson and Bartholomew 1967). Weaning 
and mating occur in late spring and summer during the peak upwelling 
period (Bograd et al., 2009). After the mating season, adult males 
migrate northward to feeding areas as far away as the Gulf of Alaska 
(Lowry et al., 1992), and they remain away until spring (March-May), 
when they migrate back. Adult females generally remain south of 
Monterey Bay, California throughout the year, feeding in coastal waters 
in the summer and offshore waters in the winter, alternating between 
foraging and nursing their pups on shore until the next pupping/
breeding season (Melin and DeLong, 2000; Melin et al., 2008).
    California sea lions regularly occur on rocks, buoys and other 
structures. Occurrence in the project area is expected to be common. 
The California sea lion is the most frequently sighted otariid found in 
Washington waters. Some 3,000 to 5,000 animals are estimated to move 
into Pacific Northwest waters of Washington and British Columbia during 
the fall (September) and remain until the late spring (May) when most 
return to breeding rookeries in California and Mexico (Jeffries et al., 
2000). Peak counts of over 1,000 animals have been made in Puget Sound 
(Jeffries et al., 2000).

Steller Sea Lion

    Steller sea lions range along the North Pacific Rim from northern 
Japan to California, with centers of abundance and distribution in the 
Gulf of Alaska and Aleutian Islands. Large numbers of individuals 
widely disperse when not breeding (late May to early July) to access 
seasonally important prey resources (Muto et al., 2019). Steller sea 
lions were subsequently partitioned into the western and eastern 
Distinct Population Segments (DPSs; western and eastern stocks) in 1997 
(62 FR 24345, May 5, 1997) when they were listed under the ESA. The 
western DPS breeds on rookeries located west of 144 [deg]W in Alaska 
and Russia, whereas the eastern DPS breeds on rookeries in southeast 
Alaska through California. The eastern DPS was delisted from the ESA in 
2013.
    The eastern DPS and MMPA stock is the only population of Steller's 
sea lions thought to occur in the project area. In Washington waters, 
numbers decline during the summer months, which correspond to the 
breeding season at Oregon and British Columbia rookeries (approximately 
late May to early June) and peak during the fall and winter months. 
Steller sea lion abundances vary seasonally with a minimum estimate of 
1,000 to 2,000 individuals present or passing through the Strait of

[[Page 4850]]

Juan de Fuca in fall and winter months (Jeffries et al., 2000).

Harbor Seal

    Harbor seals are found from Baja California to the eastern Aleutian 
Islands of Alaska (Harvey and Goley, 2011). The animals in the project 
area are part of the Southern Puget Sound stock. Harbor seals are the 
most common marine mammal species observed in the project area and are 
the only one that breeds and remains in the inland marine waters of 
Washington year-round (Calambokidis and Baird, 1994).
    Harbor seals are central-place foragers (Orians and Pearson, 1979) 
and tend to exhibit strong site fidelity within season and across 
years, generally forage close to haulout sites, and repeatedly visit 
specific foraging areas (Grigg et al., 2012; Suryan and Harvey, 1998; 
Thompson et al., 1998). Depth, bottom relief, and prey abundance also 
influence foraging location (Grigg et al., 2012).
    Harbor seals molt from May through June. Peak numbers of harbor 
seals haul out during late May to early June, which coincides with the 
peak molt. During both pupping and molting seasons, the number of seals 
and the length of time hauled out per day increase, from an average of 
7 hours per day to 10-12 hours (Harvey and Goley, 2011; Huber et al., 
2001; Stewart and Yochem, 1994).
    Harbor seals tend to forage at night and haul out during the day 
with a peak in the afternoon between 1 p.m. and 4 p.m. (Grigg et al., 
2012; London et al., 2001; Stewart and Yochem, 1994; Yochem et al., 
1987). Tide levels affect the maximum number of seals hauled out, with 
the largest number of seals hauled out at low tide, but time of day and 
season have the greatest influence on haul out behavior (Manugian et 
al., 2017; Patterson and Acevedo-Guti[eacute]rrez, 2008; Stewart and 
Yochem, 1994).
    As indicated above, all 7 species (with 7 managed stocks) in Table 
2 temporally and spatially co-occur with the activity to the degree 
that take is reasonably likely to occur, and we have proposed 
authorizing it.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al., (2007) recommended that marine mammals be 
divided into functional hearing groups based on directly measured or 
estimated hearing ranges on the basis of available behavioral response 
data, audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al., (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 3.

                  Table 3--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
        Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans   7 Hz to 35 kHz.
 (baleen whales).
Mid-frequency (MF) cetaceans   150 Hz to 160 kHz.
 (dolphins, toothed whales,
 beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans  275 Hz to 160 kHz.
 (true porpoises, Kogia,
 river dolphins,
 cephalorhynchid,
 Lagenorhynchus cruciger & L.
 australis).
Phocid pinnipeds (PW)          50 Hz to 86 kHz.
 (underwater) (true seals).
Otariid pinnipeds (OW)         60 Hz to 39 kHz.
 (underwater) (sea lions and
 fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al., (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Seven marine mammal species (four cetacean and three pinniped (two 
otariid and one phocid) species) have the reasonable potential to co-
occur with the proposed survey activities. Please refer to Table 3. 
Minke whales are low frequency cetaceans, long-beaked common dolphins 
and common bottlenose dolphins are mid-frequency cetaceans, harbor 
porpoises are classified as high-frequency cetaceans, Harbor seals are 
in the phocid group, and Steller sea lions and California sea lions are 
otariids.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The Negligible Impact Analysis 
and Determination section considers the content of this section, the 
Estimated Take section, and the Proposed Mitigation section, to draw 
conclusions regarding the likely impacts of these activities on the 
reproductive success or survivorship of individuals and how those 
impacts on individuals are likely to impact marine mammal species or 
stocks.
    Acoustic effects on marine mammals during the specified activity 
can occur from vibratory and impact pile driving and drilling, cutting, 
and clipping. The effects of underwater noise from BNSF's proposed 
activities have the potential to result in Level A and Level B 
harassment of marine mammals in the action area.

[[Page 4851]]

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given place and is usually a composite of sound from many 
sources both near and far. The sound level of an area is defined by the 
total acoustical energy being generated by known and unknown sources. 
These sources may include physical (e.g., waves, wind, precipitation, 
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced 
by marine mammals, fish, and invertebrates), and anthropogenic sound 
(e.g., vessels, dredging, aircraft, construction).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    In-water construction activities associated with the project would 
include impact pile driving, vibratory pile driving, vibratory pile 
removal, drilling by oscillator rotators, cutting with a wire saw, and 
clipping of wood timbers. The sounds produced by these activities fall 
into one of two general sound types: Impulsive and non-impulsive. 
Impulsive sounds (e.g., explosions, gunshots, sonic booms, impact pile 
driving) are typically transient, brief (less than 1 second), 
broadband, and consist of high peak sound pressure with rapid rise time 
and rapid decay (ANSI 1986; NIOSH 1998; ANSI 2005; NMFS 2018a). Non-
impulsive sounds (e.g. aircraft, machinery operations such as drilling 
or dredging, vibratory pile driving, clipping, cutting, and active 
sonar systems) can be broadband, narrowband or tonal, brief or 
prolonged (continuous or intermittent), and typically do not have the 
high peak sound pressure with raid rise/decay time that impulsive 
sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). 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).
    Two types of pile hammers would be used on this project: Impact and 
vibratory. Impact hammers operate by repeatedly dropping a heavy piston 
onto a pile to drive the pile into the substrate. Sound generated by 
impact hammers is characterized by rapid rise times and high peak 
levels, a potentially injurious combination (Hastings and Popper 2005). 
Vibratory hammers install piles by vibrating them and allowing the 
weight of the hammer to push them into the sediment. Vibratory hammers 
produce significantly less sound than impact hammers. Peak sound 
pressure levels (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). Hydraulic pile clippers are placed over the pile and 
lowered to the mudline where they use opposing blades in a horizontal 
motion to cut the existing wood piles. Diamond wire cutting is the 
process of using wire of various diameters and lengths, impregnated 
with diamond dust of various sizes, to cut through drilled shaft 
casing.
    The likely or possible impacts of BNSF's proposed activity on 
marine mammals could involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of the equipment and personnel; however, any impacts to marine 
mammals are expected to primarily be acoustic in nature. Acoustic 
stressors include effects of heavy equipment operation during pile 
installation and removal.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal, drilling, cutting and 
clipping is the primary means by which marine mammals may be harassed 
from BNSF's specified activity. In general, animals exposed to natural 
or anthropogenic sound may experience physical and psychological 
effects, ranging in magnitude from none to severe (Southall et al., 
2007). In general, exposure to pile driving and removal noise has the 
potential to result in auditory threshold shifts and behavioral 
reactions (e.g., avoidance, temporary cessation of foraging and 
vocalizing, changes in dive behavior). Exposure to anthropogenic noise 
can also lead to non-observable physiological responses such an 
increase in stress hormones. Additional noise in a marine mammal's 
habitat can mask acoustic cues used by marine mammals to carry out 
daily functions such as communication and predator and prey detection. 
The effects of drilling, cutting, pile driving and removal noise on 
marine mammals are dependent on several factors, including, but not 
limited to, sound type (e.g., impulsive vs. non-impulsive), the 
species, age and sex class (e.g., adult male vs. mom with calf), 
duration of exposure, the distance between the pile and the animal, 
received levels, behavior at time of exposure, and previous history 
with exposure (Wartzok et al., 2004; Southall et al., 2007). Here we 
discuss physical auditory effects (threshold shifts) followed by 
behavioral effects and potential impacts on habitat.
    NMFS defines a noise-induced threshold shift (TS) as a change, 
usually an increase, in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). The amount of 
threshold shift is customarily expressed in dB. A TS can be permanent 
or temporary. As described in NMFS (2018), there are numerous factors 
to consider when examining the consequence of TS, including, but not 
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough 
duration or to a high enough level to induce a TS, the magnitude of the 
TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how an animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al., 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals

[[Page 4852]]

indicate that a 40 dB threshold shift approximates PTS onset (see Ward 
et al., 1958, 1959; Ward 1960; Kryter et al., 1966; Miller 1974; Ahroon 
et al., 1996; Henderson et al., 2008). PTS levels for marine mammals 
are estimates, as with the exception of a single study unintentionally 
inducing PTS in a harbor seal (Kastak et al., 2008), there are no 
empirical data measuring PTS in marine mammals largely due to the fact 
that, for various ethical reasons, experiments involving anthropogenic 
noise exposure at levels inducing PTS are not typically pursued or 
authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--TTS is a temporary, reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range above a previously established 
reference level (NMFS 2018). Based on data from cetacean TTS 
measurements (see Southall et al., 2007), a TTS of 6 dB is considered 
the minimum threshold shift clearly larger than any day-to-day or 
session-to-session variation in a subject's normal hearing ability 
(Schlundt et al., 2000; Finneran et al., 2000, 2002). As described in 
Finneran (2015), marine mammal studies have shown the amount of TTS 
increases with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, the amount of 
TTS is typically small and the growth curves have shallow slopes. At 
exposures with higher SELcum, the growth curves become steeper and 
approach linear relationships with the noise SEL.
    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 (similar to those discussed in auditory 
masking, below). 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 takes place during a time when the animal 
is traveling through the open ocean, 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. We note that reduced hearing sensitivity as 
a simple function of aging has been observed in marine mammals, as well 
as humans and other taxa (Southall et al., 2007), so we can infer that 
strategies exist for coping with this condition to some degree, though 
likely not without cost.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor 
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis)) 
and five species of pinnipeds exposed to a limited number of sound 
sources (i.e., mostly tones and octave-band noise) in laboratory 
settings (Finneran 2015). TTS was not observed in trained spotted 
(Phoca largha) and ringed (Pusa hispida) seals exposed to impulsive 
noise at levels matching previous predictions of TTS onset (Reichmuth 
et al., 2016). In general, harbor seals and harbor porpoises have a 
lower TTS onset than other measured pinniped or cetacean species 
(Finneran 2015). Additionally, the existing marine mammal TTS data come 
from a limited number of individuals within these species. No data are 
available on noise-induced hearing loss for mysticetes. For summaries 
of data on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al., (2007), Finneran and Jenkins 
(2012), Finneran (2015), and Table 5 in NMFS (2018). Installing piles 
requires a combination of impact pile driving and vibratory pile 
driving. For this project, these activities would not occur at the same 
time and there would be pauses in activities producing the sound during 
each day. Given these pauses and that many marine mammals are likely 
moving through the ensonified area and not remaining for extended 
periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal also has the potential to behaviorally disturb marine mammals. 
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 & Bejder 2007; Weilgart 2007; NRC 2005).
    Disturbance may result in 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. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff 2006). 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). 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). In general, 
pinnipeds seem more tolerant of, or at least habituate more quickly to, 
potentially disturbing underwater sound than do cetaceans, and 
generally seem to be less responsive to exposure to industrial sound 
than most cetaceans. Please see Appendices B-C of Southall et al., 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    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.
    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

[[Page 4853]]

responses, neuroendocrine responses, or immune responses (e.g., Seyle 
1950; Moberg 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker 2000; Romano 
et al., 2002b) and, more rarely, studied in wild populations (e.g., 
Romano et al., 2002a). For example, Rolland et al., (2012) found that 
noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003), however 
distress is an unlikely result of this project based on observations of 
marine mammals during previous, similar projects in the area.
    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., pile driving, 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. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with drilling, 
cutting, clipping, pile driving and removal that have the potential to 
cause behavioral harassment, depending on their distance from the 
activities. Cetaceans are not expected to be exposed to airborne sounds 
that would result in harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels exceeding the acoustic thresholds. We recognize that pinnipeds 
in the water could be exposed to airborne sound that may result in 
behavioral harassment when looking with their heads above water. 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. 
However, these animals would previously have been `taken' because of 
exposure to underwater sound above the behavioral harassment 
thresholds, which are, in all cases, larger than those associated with 
airborne sound. As described above there are no regular haulouts in 
direct line of sight of the project area. Thus, the behavioral 
harassment of these animals is already accounted for in these estimates 
of potential take. Therefore, authorization of incidental take 
resulting from airborne sound for pinnipeds is not warranted, and 
airborne sound is not discussed further here.

Marine Mammal Habitat Effects

    BNSF's construction activities could have localized, temporary 
impacts on marine mammal habitat by increasing in-water sound pressure 
levels and slightly decreasing water quality. Construction activities 
are of short duration and would likely have temporary impacts on marine 
mammal habitat through increases in underwater sound. Increased noise 
levels may affect acoustic habitat (see masking discussion above) and 
adversely affect marine mammal prey in the vicinity of the project area 
(see discussion below). During drilling, cutting, clipping, impact and 
vibratory pile driving, elevated levels of underwater noise would 
ensonify a portion of the Ship Canal and potentially radiate some 
distance into Shilshole Bay depending on the sound source where both 
fish and mammals may occur and could affect foraging success. 
Additionally, marine mammals may avoid the area during construction, 
however, displacement due to noise is expected to be temporary and is 
not expected to result in long-term effects to the individuals or 
populations.
    A temporary and localized increase in turbidity near the seafloor 
would occur in the immediate area surrounding the area where piles or 
shafts are installed (and removed in the case of the temporary piles). 
The sediments on the sea floor will be disturbed during pile

[[Page 4854]]

driving and shaft drilling; however, suspension will be brief and 
localized and is unlikely to measurably affect marine mammals or their 
prey in the area. In general, turbidity associated with pile 
installation is localized to about a 25-foot (7.6-meter) radius around 
the pile (Everitt et al., 1980). Cetaceans are not expected to be close 
enough to the pile driving areas to experience effects of turbidity, 
and any pinnipeds could avoid localized areas of turbidity. Therefore, 
we expect the impact from increased turbidity levels to be discountable 
to marine mammals and do not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals except for the actual 
footprint of the project. The total seafloor area affected by pile 
installation and removal is a very small area compared to the vast 
foraging area available to marine mammals in Puget Sound.
    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 we anticipate a rapid return to normal recruitment, 
distribution and behavior. Any behavioral avoidance by fish of the 
disturbed area would still leave large areas of fish and marine mammal 
foraging habitat in the nearby vicinity in Puget Sound.

Effects on Potential Prey

    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., fishes). Marine mammal 
prey varies by species, season, and location. Here, we describe studies 
regarding the effects of noise on known marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009). 
Depending on their hearing anatomy and peripheral sensory structures, 
which vary among species, fishes hear sounds using pressure and 
particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
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). Several studies have demonstrated that impulse sounds might 
affect the distribution and behavior of some fishes, potentially 
impacting foraging opportunities or increasing energetic costs (e.g., 
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al., 
1992; Santulli et al., 1999; Paxton et al., 2017). However, some 
studies have shown no or slight reaction to impulse sounds (e.g., Pena 
et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman, 2009; Cott 
et al., 2012).
    SPLs of sufficient strength have been known to cause injury to fish 
and fish mortality. However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al., (2012a) showed that a TTS of 4-6 dB was recoverable within 24 
hours for one species. Impacts would be most severe when the individual 
fish is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013).
    The most likely impact to fish from drilling, cutting, clipping, 
and pile driving activities at the project areas would be temporary 
behavioral avoidance of the area. The duration of fish avoidance of an 
area after pile driving stops is unknown, but a rapid return to normal 
recruitment, distribution and behavior is anticipated.
    The area impacted by the project is relatively small compared to 
the available habitat in Shilshole Bay and larger Puget Sound. Any 
behavioral avoidance by fish of the disturbed area would still leave 
significantly large areas of fish and marine mammal foraging habitat in 
the nearby vicinity. Additionally, as noted previously, BNSF will 
adhere to the USACE's in-water work window restrictions on pile 
extraction and installation (July 16 to January 15) to reduce potential 
effects to salmonids, including juvenile ESA-listed salmonids. As 
described in the preceding, the potential for BNSF's construction to 
affect the availability of prey to marine mammals or to meaningfully 
impact the quality of physical or acoustic habitat is considered to be 
insignificant.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the acoustic sources for pile installation and extraction has the 
potential to result in disruption of behavioral patterns for individual 
marine mammals. There is also some potential for auditory injury (Level 
A harassment) to result, primarily for harbor seals, because predicted 
auditory injury zones are large. Auditory injury is unlikely to occur 
for low-frequency cetaceans, mid-frequency cetaceans, high-frequency 
cetaceans, and otariids. The proposed mitigation and monitoring 
measures are expected to minimize the severity of the taking to the 
extent practicable.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best

[[Page 4855]]

available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these basic factors can contribute to a basic calculation to 
provide an initial prediction of takes, additional information that can 
qualitatively inform take estimates is also sometimes available (e.g., 
previous monitoring results or average group size). Below, we describe 
the factors considered here in more detail and present the proposed 
take estimate.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources.
    BNSF's proposed activity includes the use of continuous (vibratory 
pile driving and removal, oscillator rotator equipment, wire saw 
cutting, clipping) and impulsive (impact pile driving) equipment, and 
therefore both the 120- and 160-dB re 1 [mu]Pa (rms) thresholds are 
applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). BNSF's proposed activity includes the use 
of impulsive (impact pile driving) and non-impulsive (vibratory pile 
driving) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The following pile sizes and installation/extraction methods were 
analyzed:
    <bullet> 36-inch steel pipe pile, impact installation, with 5 dB 
bubble curtain source level reduction under two installation scenarios 
(1 pile driver or 2 concurrent pile drivers);
    <bullet> 48-inch steel pipe pile, oscillator installation (drilled 
shaft);
    <bullet> 48-inch steel pipe pile, diamond wire saw cutting;
    <bullet> 14-inch steel H-pile, vibratory installation/extraction;
    <bullet> 12-inch timber pile, vibratory installation/extraction; 
and
    <bullet> 12-inch timber pile, pile clipper extraction.
    Impact pile driver installation of 36-inch steel pipe piles 
analyzed a worst-case scenario consisting of two crews driving 36-inch 
steel pipe piles simultaneously (Scenario 2) in order to provide 
maximum flexibility should multiple crews become necessary during 
construction. It is likely, however, that only one crew will operate at 
one time (Scenario 1). Based on NMFS guidance, decibel addition is not 
considered in the 36-inch steel pipe pile impact analysis since during 
impact hammering or other impulsive sources, it is unlikely that the 
two hammers would strike at the same exact instant

[[Page 4856]]

(or within the 0.1 second average pulse duration). Therefore, the sound 
source levels will not be adjusted regardless of the distance between 
the hammers and each source will be analyzed separately.
    Vibratory pile driving of 14-inch H-piles, and vibratory and pile 
clipper extraction of 12-inch timber piles (residential structures 
demolition) were analyzed in the event these methods become necessary 
(if, for instance, crane weight alone cannot seat the 14-inch H-piles 
for the turbidity screen installation or crane torque alone cannot 
extract timber piles by direct pulling/twisting).
    This analysis uses in-water source sound levels for vibratory and 
impact pile driving from Washington State Department of Transportation 
Biological Assessment Manual (WDSOT 2020), and California Department of 
Transportation Division (Caltrans 2015). Analysis of drilled shaft 
installation used sound source data came from (HDR, 2011. Diamond wire 
saw cutting and hydraulic pile clipper cutting came from the Navy 
(2019). Source sound levels for each analysis were measured at 10m from 
the source and based on other projects with the same pile type and 
size, installation/extraction technique, and similar substrate if no 
project site-specific information is available.
    In cases where multiple sources were provided from the above 
references, the following methodology was used to select in-water 
source sound levels to generate a proxy:
    1. Select first by corresponding pile size and type;
    2. Eliminate those that do not have substrates similar to the 
project site substrate (i.e. sandy silt intermixed with gravels and 
riprap); and
    3. Of the remaining, select highest source sound level to be 
conservative.
    All piles driven and/or proofed with an impact hammer would use a 
bubble curtain. It is estimated that use of a bubble curtain would 
result in a minimum of a 5-dB reduction in underwater sound levels 
during 36-inch pipe pile driving, and this reduction has been included 
in the estimate to account for a reasonably achievable reduction in 
sound during underwater construction activity. Source sound levels are 
summarized in Table 5.

                                      Table 5--In-Water Sound Source Levels
----------------------------------------------------------------------------------------------------------------
                                                                                                       dB single-
Pile size (inch)       Pile type              Source        Construction method   dB peak     dB RMS     strike
                                                                                                          SEL
----------------------------------------------------------------------------------------------------------------
36..............  Steel pipe.........  Caltrans, 2015. 36-  Impact.............        208        190        180
                                        inch steel pipe
                                        pile Table I.2-1.
14..............  H-pile.............  Caltrans, 2015. 12-  Vibratory..........  .........        150  .........
                                        inch steel H-pile
                                        proxy Table I.2-2.
12..............  Timber Pile........  Greenbusch Group,    Vibratory..........  .........        152  .........
                                        2018. 12-inch
                                        timber pile.
12..............  Timber Pile........  NAVFAC SW 2020       Hydraulic Pile       .........        154  .........
                                        Compendium. 13-      Clipper.
                                        inch round
                                        polycarbonate pile.
48..............  Steel Shaft........  HDR Alaska, Inc.,    Oscillator.........  .........      143.8  .........
                                        2011. 144-inch
                                        steel shaft proxy.
48..............  Steel-encased        NAVFAC SW 2020       Diamond bladed wire  .........      161.5  .........
                   Concrete Shaft.      Compendium. 66-      saw.
                                        inch steel encased
                                        concrete- filled
                                        caisson proxy.
----------------------------------------------------------------------------------------------------------------

    Transmission loss (TL), expressed as decibels, is the reduction in 
a specified level between two specified points R1, R2 that are within 
an underwater acoustic field. By convention, R1 is chosen to be closer 
to the source of sound than R2, such that transmission loss is usually 
a positive quantity. 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 * Log<INF>10</INF> (R<INF>2</INF>/R<INF>1</INF>),

where

TL = transmission loss in dB
B = transmission loss coefficient
R<INF>1</INF> = distance from source to distance at which the level 
is estimated (typically 10-m for pile driving)
R<INF>2</INF> = distance from source to the isopleth associated with 
the applicable acoustic threshold

    Absent site-specific acoustical monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient in the above formula. Site-specific 
transmission loss data for BNSF bridge site is not available, therefore 
the default coefficient of 15 is used to determine the distances to the 
Level A and Level B harassment thresholds.
    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources, NMFS User 
Spreadsheet predicts the distance at which, if a marine mammal remained 
at that distance the whole duration of the activity, it would incur 
PTS. Inputs used in the User Spreadsheet are shown in Table 6 and the 
resulting isopleths are reported below in Table 7.

                              Table 6--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  36-inch steel-2  14-inch steel H-   12-inch timber
                                 36-inch steel      concurrent      pile vibratory       vibratory      48-inch steel     48-inch Wire    12-inch timber
                                 (scenario 1)      (scenario 2)         install         extraction        oscillator      saw cutting    clipper cutting
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used.........  (E.1) Impact      (E.1) Impact      (A.1) Vibratory   (A.1) Vibratory   (A) stationary   (A) stationary   (A) stationary
                                pile driving.     pile driving.     pile driving.     pile driving.     source (non-     source (non-     source (non-
                                                                                                        impulsive,       impulsive,       impulsive,
                                                                                                        continuous).     continuous).     continuous)

[[Page 4857]]

 
Source Level (Single Strike/   175 SEL/203 Peak  175 SEL/203 Peak  150 RMS.........  152 RMS.........  143.8 RMS......  161.5 RMS......  154 RMS
 shot SEL) and Peak or RMS.
Weighting Factor Adjustment    2...............  2...............  2.5.............  2.5.............  2.5............  2.5............  2.5
 (kHz).
(a) Number of strikes per      1000............  1000............  ................  ................  ...............  ...............  ...............
 pile.
Number piles or shafts per     6...............  12..............  8...............  10..............  0.25...........  4..............  20
 day.
Duration for single pile       ................  ................  30..............  15..............  1920...........  60.............  4
 (min).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Transmission loss coefficient for all sources is 15 and all source level values quoted are at 10m distance.


                                        Table 7--Calculated Distances to Level A and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                 Level A zone (meters)                         Level B
                                                                           -----------------------------------------------------------------  harassment
                 Pile type, size, and pile driving method                                                                                        zone
                                                                            LF cetacean  MF cetacean  HF cetacean     Phocid      Otariid      (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Scenario 1. 36-inch Steel Pipe Impact Drive (Year 1)......................          966           34        1,150          517           38          464
Scenario 2. 36-inch Steel Pipe Impact Drive (Year 1)......................        1,533           55        1,826          820           60          464
14-inch H-Pile Vibratory (Year 1, Year 2).................................            3            1            5            2            1        1,000
12-inch Timber Vibratory (Year 1).........................................            3            1            5            2            1        1,359
48-inch Drilled Shaft Oscillatory Installation (Year 1)...................          0.2            0          0.2          0.1            0          386
48-inch Concrete-lined Steel Shaft Diamond Wire Saw Removal Year 2).......          1.9          0.2          2.7          1.1          0.1        5,843
12-inch Timber Pile Clipper Year 1).......................................          0.6            0          0.6          0.3            0        1,848
--------------------------------------------------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals and how it is brought 
together to produce a quantitative take estimate.
    Take estimates were calculated using a combination of best 
available data. Best available density data was for the most part from 
the U.S. Department of the Navy's Marine Species Density Database Phase 
III for the Northwest Training and Testing Study Area (Navy 2019) which 
includes seasonal density estimates: Winter (Dec-Feb), Spring (Mar-
May), Summer (Jun-Aug), Fall (Sep-Nov). The project will not work in-
water in the Spring as that season is outside the July 16-February 15 
in-water work season. The most conservative (highest density) seasonal 
estimate from the remaining three seasons was used where seasonal 
overlap exists and densities differ across seasons. Estimated take was 
calculated using density estimates multiplied by the area of each Level 
B harassment zone for each pile type multiplied by the number of days 
of in-water activity for each pile type. In some instances and where 
noted, observation-based data from WSDOT's Seattle Multimodal Project 
at Colman Dock Season Three Marine Mammal Monitoring Report (WSDOT 
2020a) or other observational data was used instead of U.S. Navy data 
when Navy density data was zero or extremely low.
    BNSF proposes to work in-water for 113 days in Year 1 and 9 days in 
Year 2, or approximately 5.5 months assuming a 5-day work week for 23 
weeks in Year 1 and a half a month assuming a 5-day work week for 2 
weeks in Year 2.

Minke Whale

    The estimated take was calculated as described above using the 
Navy's density data which resulted in zero takes of minke whale for 
both Year 1 and Year 2 as shown in Table 8. Therefore, as described 
above, we looked at other observational data. The WSDOT Seattle 
Multimodal Project at Colman Dock Year 3 IHA Monitoring Report observed 
minke whale presence indicates sightings of a single minke whale over 7 
months (WSDOT 2020a). Given this information, BNSF and NMFS 
conservatively assumed that up to one whale per month could be taken by 
harassment.
    A shutdown zone at the full distance of the level A harassment 
isopleths (<= 1533 m) will be applied to avoid take by Level A 
harassment.
    The 113 days of work in Year 1 and 9 days in Year 2, equates to 5.5 
months x 1 minke whale/month = 6 encounters with minke whales in Year 1 
and 0.5 months x 1 Minke whale/month = 1 whale in Year 2. Therefore, 
BNSF has requested and NMFS proposes 6 takes by Level B harassment in 
Year 1 and 1 take by Level B harassment in year in Year 2.

                                                         Table 8--Calculated Take of Minke Whale
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Species
                                            density     Level A    Level B                                      Year 1     Year 1     Year 2     Year 2
                Activity                   (animals/      area       area       Length of activity (days)     estimated  estimated  estimated  estimated
                                             km\2\)     (km\2\)    (km\2\)                                      take A     take B     take A     take B
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact 36-inch Steel Pipe Pile (2           0.0000054      0.376      0.183  10 (Yr 1)......................          0          0  .........  .........
 Concurrent Drivers).

[[Page 4858]]

 
Vibratory 14-inch H-Pile................    0.0000054      0.005      0.235  6 (3 Yr 1, 3 Yr 2).............          0          0          0          0
Vibratory 12-inch Timber Pile...........    0.0000054      0.005      0.286  8 (Yr 1).......................          0          0  .........  .........
Oscillator Install of 4-foot Drilled        0.0000054      0.000      0.169  88 (Yr 1)......................          0          0  .........  .........
 Shaft.
Diamond Wire Saw Removal of 48-inch         0.0000054      0.000      2.290  6 (Yr 2).......................  .........  .........          0          0
 Drilled Shaft.
24-inch Pile Clipper Removal of 12-inch     0.0000054      0.000      0.381  4 (Yr 1).......................          0          0  .........  .........
 Timber Pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Common Bottlenose Dolphin

    Estimated take using the Navy's density estimates for common 
bottlenose dolphins as described above resulted in zero take in both 
Year 1 and Year 2 as shown in Table 9. Therefore, as described above, 
we looked at other observational data. Common bottlenose dolphins have 
been rare visitors to Puget Sound. However, the WSDOT Seattle 
Multimodal Project at Colman Dock Year 3 IHA monitoring report observed 
common bottlenose dolphin at a rate of 6 per month (WSDOT 2020a). In-
water work will occur for 113 days in Year 1 and 9 days in Year 2, 
which would equate to 33 dolphin takes in Year 1 (5.5 months x 6 
dolphins/month) and 3 dolphin takes in Year 2 (0.5 months x 3 dolphins/
month). A shutdown zone at the full distance of the level A harassment 
isopleths (<= 55m) can be effectively applied to avoid Level A take. 
Therefore, BNSF has requested and NMFS proposes to authorize 33 takes 
by Level B harassment in Year 1 and 3 takes by Level B harassment in 
year in Year 2.

                                                     Table 9--Calculated Take of Bottlenose Dolphin
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Species
                                            density     Level A    Level B                                      Year 1     Year 1     Year 2     Year 2
                Activity                   (animals/      area       area       Length of activity (days)     estimated  estimated  estimated  estimated
                                             km\2\)     (km\2\)    (km\2\)                                      take A     take B     take A     take B
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact 36-inch Steel Pipe Pile (2           0.0000054      0.376      0.183  10 (Yr 1)......................          0          0  .........  .........
 Concurrent Drivers).
Vibratory 14-inch H-Pile................    0.0000054      0.005      0.235  6 (3 Yr 1, 3 Yr 2).............          0          0          0          0
Vibratory 12-inch Timber Pile...........    0.0000054      0.005      0.286  8 (Yr 1).......................          0          0  .........  .........
Oscillator Install of 4-foot Drilled        0.0000054      0.000      0.169  88 (Yr 1)......................          0          0  .........  .........
 Shaft.
Diamond Wire Saw Removal of 48-inch         0.0000054      0.000      2.290  6 (Yr 2).......................  .........  .........          0          0
 Drilled Shaft.
24-inch Pile Clipper Removal of 12-inch     0.0000054      0.000      0.381  4 (Yr 1).......................          0          0  .........  .........
 Timber Pile.
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................  ...........  .........  .........  122............................          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------

Long-Beaked Common Dolphin

    Using the Navy's density data, which was zero, estimated take of 
common dolphins was calculated to be zero in Year 1 and Year 2. 
Therefore, as described above, we looked at other observational data. 
Sightings of live dolphins throughout inside waters and Southern Puget 
Sound have been recorded in 2003, 2011-12, and 2016 -17. Group size 
ranged from 2 (in 2003 and 2011-12) to 5-12 (in 2016-2017) (Shuster et 
al. 2017). Since June 2016, several common dolphins have remained in 
Puget Sound, group sizes of 5-20 individuals are often reported and 
some of these groups stayed in the region for several months. Sightings 
of these animals mostly began in summer and early fall sometimes 
extending into winter months. (Shuster et al., 2018). We conservatively 
predict that a group of 20 individuals will be taken on a monthly 
basis. The Level A harassment shutdown zone for mid-frequency hearing 
group will be implemented to minimize the severity of any Level A 
harassment that could occur. The in-water work would occur for 113 days 
in Year 1 and 9 days in Year 2, which would result in 110 takes (5.5 
months x 20 dolphins/month) in Year 1 and 20 takes (1 month x 20 
dolphins/month) in Year 2 by Level B harassment. BNSF has requested and 
NMFS proposes to authorize 110 takes of long-beaked common dolphin by 
Level B harassment in Year 1 and 10 takes by Level B harassment in year 
in Year 2.

Harbor Porpoise

    Harbor porpoise density estimates based on the Navy's data were 
used to calculate requested and proposed take as shown in Table 10. 
Analysis of the size of the level A harassment zones multiplied by 
density associated with harbor porpoise predicted that two porpoises 
could be taken by Level A harassment during the 10 days that concurrent 
driving of 36-in steel piles occurs during year 1. However, take by 
Level A harassment is unlikely given that the threshold and associated 
PTS isopleth is based on the acoustic energy accrued over a specified 
time period and it is unlikely that a highly mobile animal such as the 
harbor porpoise would spend the that amount if time in the Level A 
harassment zone. However, given the larger size of the zone and the 
cryptic nature of harbor porpoises, we have precautionarily proposed to 
authorize 2 takes by Level A harassment for Year 1. The Level A 
harassment shut down zone for high frequency hearing group will be 
implemented to minimize severity of any Level A harassment takes that 
do occur. Since there will be no impact driving during Year 2, the size 
of the Level A harassment zone will not exceed 5 m and, therefore, no 
take by Level A harassment was requested and none has been proposed. 
BNSF has requested and NMFS proposes to authorize 12 takes of harbor 
porpoise by Level B harassment in Year 1 and 8 takes by Level B 
harassment in year in Year 2.

[[Page 4859]]



                                                      Table 10--Calculated Take of Harbor Porpoise
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Species
                                            density     Level A    Level B                                      Year 1     Year 1     Year 2     Year 2
                Activity                   (animals/      area       area       Length of activity (days)     estimated  estimated  estimated  estimated
                                             km\2\)     (km\2\)    (km\2\)                                      take A     take B     take A     take B
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact 36-inch Steel Pipe Pile (2                0.54      0.376      0.183  10 (Yr 1)......................          2          1  .........  .........
 Concurrent Drivers).
Vibratory 14-inch H-Pile................         0.54      0.005      0.235  6 (3 Yr 1, 3 Yr 2).............          0          1          0          1
Vibratory 12-inch Timber Pile...........         0.54      0.005      0.286  8 (Yr 1).......................          0          1  .........  .........
Oscillator Install of 4-foot Drilled             0.54      0.000      0.169  88 (Yr 1)......................          0          8  .........  .........
 Shaft.
Diamond Wire Saw Removal of 48-inch              0.54      0.000      2.290  6 (Yr 2).......................  .........  .........          0          7
 Drilled Shaft.
24-inch Pile Clipper Removal of 12-inch          0.54      0.000      0.381  4 (Yr 1).......................          0          1  .........  .........
 Timber Pile.
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................  ...........  .........  .........  122............................          2         12          0          8
--------------------------------------------------------------------------------------------------------------------------------------------------------

Harbor Seal

    Harbor seal density estimates based on data from the Navy were 
initially used to calculate requested and proposed take (Table 11). 
These estimates, however, do not account for numerous seals feeding on 
migrating salmonids at Ballard Locks, especially during summer (June-
September) months. A new acoustic deterrent device was tested over two 
years to keep seals away from the Locks (Bogaard, Pers. Comm, 2022). A 
study report is currently being developed for publication. Study 
observers were primarily focused on behavioral effects of the deterrent 
on seals and monitored seal behavioral reactions during 30 minute 
observation periods up to eight times per day. Actual seal abundance 
was not recorded. However, observers noted that groups of 5-6 harbor 
seals were very common from late June through September during the 
salmon run, although smaller numbers were present throughout the year. 
It is likely that many of the same animals were observed multiple times 
across daily observation periods. The in-water work window runs from 
July 16, 2022 through February 15, 2023. Given this information, NMFS 
assumed for Year 1 that during the 54 in-water work days between July 
16, 2022 and September 30, 2022, 5 harbor seals would be taken per day 
(270 takes). For the remaining 59 in-water work days between October 1, 
2022 and February 15, 2023, a single harbor seal would be taken per day 
(59) for a total of 329 takes. There are 10 in-water work days that 
include concurrent impact driving of 36-inch piles when the Level A 
harassment isopleth is relatively large (1,826 m) (and also exceeds the 
Level B harassment isopleth (464 m)) so it is possible that Level A 
harassment could occur in some animals. Also, note that the constrained 
design of the lock system means that seals would likely spend extended 
periods in the confined area while feeding. NMFS conservatively assumes 
that all of these 10 in-water work days would occur during salmon 
migration (February 15-Sept 30) and that up to one-third of seals taken 
per day (2) could be exposed to sound energy levels resulting in some 
degree of Level A harassment (20). The estimated takes by Level A 
harassment is subtracted from the Level B harassment take to avoid 
double-counting. Since a smaller number of seals expected to be present 
during non-migratory period and the seals would have little incentive 
to congregate near the locks in the absence of salmon, NMFS does not 
expect any Level A harassment of seals to occur. Therefore, NMFS is 
proposing during Year 1 to authorize 20 takes by Level A harassment and 
309 takes by Level B harassment (329-20).
    For Year 2, NMFS assumed that all 9 in-water work days would occur 
during salmon migration between July 16, 2023 and September 30, 2024 
with up to 6 harbor seals taken per day (54). No Level A take 
harassment is proposed during Year 2 since the largest Level A isopleth 
for all planned activities is 2 m. However, the density-based estimate 
was 57 takes as shown in Table 11. Therefore, NMFS is proposing 57 
takes of harbor seal by Level B harassment during Year 2.

                                                        Table 11--Calculated Take of Harbor Seal
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Species
                                            density     Level A    Level B                                      Year 1     Year 1     Year 2     Year 2
                Activity                   (animals/      area       area       Length of activity (days)     estimated  estimated  estimated  estimated
                                             km\2\)     (km\2\)    (km\2\)                                      take A     take B     take A     take B
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact 36-inch Steel Pipe Pile (2                3.91      0.215      0.183  10 (Yr 1)......................          8          7  .........  .........
 Concurrent Drivers).
Vibratory 14-inch H-Pile................         3.91      0.005      0.235  6 (3 Yr 1, 3 Yr 2).............          0          3          0          3
Vibratory 12-inch Timber Pile...........         3.91      0.005      0.286  8 (Yr 1).......................          0          9  .........  .........
Oscillator Install of 4-foot Drilled             3.91      0.005      0.169  88 (Yr 1)......................          0         58  .........  .........
 Shaft.
Diamond Wire Saw Removal of 48-inch              3.91      0.005      2.290  6 (Yr 2).......................  .........  .........          0         54
 Drilled Shaft.
24-inch Pile Clipper Removal of 12-inch          3.91      0.005      0.381  4 (Yr 1).......................          0          6  .........  .........
 Timber Pile.
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................  ...........  .........  .........  122............................          8         83          0         57
--------------------------------------------------------------------------------------------------------------------------------------------------------

California Sea Lion

    BNSF initially considered California sea lion density estimates to 
calculate requested take, which resulted in relatively low estimates (4 
takes in Year 1 and 3 takes in Year 2 by Level B harassment) as shown 
in Table 12. However, California sea lions are known to frequent the 
Ballard Locks to feed on migrating salmon (KUOW, 2020). While no formal 
research studies have recorded individual numbers of California sea 
lions at Ballard Locks, news articles reported accounts of California 
sea lion sightings which ranged from a few to many more (Hakai 
Magazine, 2018; King 5 News, 2021). Observers associated with the 
acoustic deterrent device study described above, reported that 
California sea lions were less numerous than harbor seals, having been 
seen at a rate of 2-3 per day during peak salmonid migration (Bogaard, 
Pers. Comm. 2022). They were less common during non-migratory seasons. 
Given this information, NMFS assumed for Year 1 that during the 54 in-
water work days between July 16, 2022 and September 30, 2022, 2 
California sea lions would be taken per day (108). For

[[Page 4860]]

the remaining 59 in-water work days between October 1, 2022 and 
February 15, 2023, a single California sea lion would be taken very 
third day (20). Take by Level A harassment is possible, but unlikely, 
given that the largest Level A harassment isopleth is 60 m (with a 10 m 
shutdown zone for otariids) but only during 10 in-water work days which 
would include impact driving during Year 1. The Level A harassment zone 
during all other in-water work days in both Year 1 and Year 2 is 1 m or 
less. A California sea lion would not be expected to remain within the 
injury zone long enough (5.4 hours) to accrue the amount energy that 
would result in take Level A harassment. As such, NMFS is proposing 
during Year 1 to authorize 128 takes by Level B harassment. No takes by 
Level A harassment are proposed.
    For Year 2, NMFS assumed that all 9 in-water work days would occur 
during peak salmon migration between July 16, 2023 and September 30, 
2024 with up to 2 California sea lions taken per day (18). NMFS is 
proposing to authorize 18 takes of California sea lion by Level B 
harassment. No Level A take harassment is proposed.

                                         Table 12--Calculated Take of California Sea Lions by Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Species
                                            density     Level A    Level B                                      Year 1     Year 1     Year 2     Year 2
                Activity                   (animals/      area       area       Length of activity (days)     estimated  estimated  estimated  estimated
                                             km\2\)     (km\2\)    (km\2\)                                      take A     take B     take A     take B
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact 36-inch Steel Pipe Pile (2              0.2211      0.023      0.183  10 (Yr 1)......................          0          0  .........  .........
 Concurrent Drivers).
Vibratory 14-inch H-Pile................       0.2211      0.004      0.235  6 (3 Yr 1, 3 Yr 2).............          0          0          0          0
Vibratory 12-inch Timber Pile...........       0.2211      0.004      0.286  8 (Yr 1).......................          0          1  .........  .........
Oscillator Install of 4-foot Drilled           0.2211      0.000      0.169  88 (Yr 1)......................          0          3  .........  .........
 Shaft.
Diamond Wire Saw Removal of 48-inch            0.2211      0.000      2.290  6 (Yr 2).......................  .........  .........          0          3
 Drilled Shaft.
24-inch Pile Clipper Removal of 12-inch        0.2211      0.000      0.381  4 (Yr 1).......................          0          0  .........  .........
 Timber Pile.
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................  ...........  .........  .........  ...............................  .........          4  .........          3
--------------------------------------------------------------------------------------------------------------------------------------------------------

Stellar Sea Lion

    Stellar sea lion density estimates were initially used to calculate 
requested take as shown in Table 13. Based on the density data, BNSF 
has requested a single take for both Year 1 and Year 2. Given the large 
number of in-water work days in Year 1, NMFS has precautionarily 
increased the proposed Level B harassment to 5 takes while maintaining 
the 1 proposed take by Level B harassment as calculated by density 
estimates in Year 2. Monitors with the acoustic deterrent study did not 
observe any Steller sea lions during the two years that the study was 
underway (Bogaard, Pers. Comm, 2022).

                                          Table 13--Calculated Take of Steller Sea Lions by Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Species
                                            density     Level A    Level B                                      Year 1     Year 1     Year 2     Year 2
                Activity                   (animals/      area       area       Length of activity (days)     estimated  estimated  estimated  estimated
                                             km\2\)     (km\2\)    (km\2\)                                      take A     take B     take A     take B
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact 36-inch Steel Pipe Pile (2              0.0478      0.023      0.183  10 (Yr 1)......................          0          0  .........  .........
 Concurrent Drivers).
Vibratory 14-inch H-Pile................       0.0478      0.004      0.235  6 (3 Yr 1, 3 Yr 2).............          0          0          0          1
Vibratory 12-inch Timber Pile...........       0.0478      0.004      0.286  8 (Yr 1).......................          0          0  .........  .........
Oscillator Install of 4-foot Drilled           0.0478      0.000      0.169  88 (Yr 1)......................          0          1  .........  .........
 Shaft.
Diamond Wire Saw Removal of 48-inch            0.0478      0.000      2.290  6 (Yr 2).......................  .........  .........          0          0
 Drilled Shaft.
24-inch Pile Clipper Removal of 12-inch        0.0478      0.000      0.381  4 (Yr 1).......................          0          0  .........  .........
 Timber Pile.
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................  ...........  .........  .........  ...............................  .........          1  .........          1
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The estimated take by Level A and Level B harassment for all 
authorized species and stocks by year, and percentage take by stock is 
shown in Table 14.

                  Table 14--Estimated Take by Level A and Level B Harassment, by Species, Stock and Year, and Percentage Take by Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   IHA Year 1                            IHA Year 2
                                                                             ----------------------  Total take as ----------------------  Total take as
             Common name                         Stock            Abundance     Take A     Take B    percentage of    Take A     Take B    percentage of
                                                                               request    request        stock       request    request        stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Minke Whale..........................  California/Oregon/                915  .........          6            0.66  .........          1            0.11
                                        Washington.
Common Bottlenose Dolphin............  California/Oregon/              3,477  .........         33            0.95  .........          3            0.09
                                        Washington offshore.
Long-beaked Common Dolphin...........  California..............       83,379  .........        110            0.13  .........         20            0.01
Harbor Porpoise......................  Washington Inland Waters       11,233  .........         12            0.11  .........          8            0.07
Harbor Seal..........................  Washington Northern             1,088         20        309            32.6  .........         57             5.2
                                        Inland Waters.
California Sea Lion..................  United States...........      257,606  .........        108            0.04  .........         20           <0.01
Stellar Sea Lion.....................  Eastern U.S.............       43,201  .........          5            0.01  .........          1           <0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 4861]]

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 the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned); and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    In addition to the measures described later in this section, BNSF 
will employ the following mitigation measures:
    <bullet> BNSF must ensure that construction supervisors and crews, 
the monitoring team, and relevant BNSF staff are trained prior to the 
start of activities subject to these IHAs, so that responsibilities, 
communication procedures, monitoring protocols, and operational 
procedures are clearly understood. New personnel joining during the 
project must be trained prior to commencing work;
    <bullet> Monitoring must take place from 30 minutes prior to 
initiation of pile driving activity (i.e., pre-start clearance 
monitoring) through 30 minutes post-completion of pile driving 
activity;
    <bullet> If a marine mammal is observed entering or within the 
shutdown zones indicated in Table 14, pile driving activity must be 
delayed or halted;
    <bullet> Pile driving activity must be halted upon observation of 
either a species for which incidental take is not authorized or a 
species for which incidental take has been authorized but the 
authorized number of takes has been met, entering or within the 
harassment zone (as shown in Table 14); and
    <bullet> BNSF, construction supervisors and crews, PSOs, and 
relevant BNSF staff must avoid direct physical interaction with marine 
mammals during construction activity. If a marine mammal comes within 
10 meters of such activity, operations must cease and vessels must 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions, as necessary to avoid direct physical 
interaction.
    The following mitigation measures apply to BNSF's in-water 
construction activities:
    <bullet> Establishment of Shutdown Zones--BNSF will establish 
shutdown zones for all pile driving and removal activities. The purpose 
of a shutdown zone is generally to define an area within which shutdown 
of the activity would occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area). Shutdown zones 
will vary based on the activity type and marine mammal hearing group. 
In addition to the shutdown zones listed in Table 15, BNSF will shut 
down construction activity if a humpback or southern resident killer 
whale is observed approaching or within the specified Level B 
harassment zone.
    <bullet> Protected Species Observers--The placement of Protected 
Species Observers (PSOs) during all pile driving and removal activities 
(described in detail in the Proposed Monitoring and Reporting section) 
will ensure that the entire shutdown zone is visible during pile 
driving and removal. Should environmental conditions deteriorate such 
that marine mammals within the entire shutdown zone would not be 
visible (e.g., fog, heavy rain), drilling, cutting, clipping, pile 
driving and removal must be delayed until the PSO is confident marine 
mammals within the shutdown zone could be detected.

    Table 15--Shutdown Zones for Each Hearing Group and Level B Harassment Zones During Pile Installation and
                                                     Removal
                                                    [Meters]
----------------------------------------------------------------------------------------------------------------
                                                                                                       Level B
 Pile type, size, and pile driving       LF           MF           HF         Phocid      Otariid     harassment
              method                                                                                     zone
----------------------------------------------------------------------------------------------------------------
Scenario 1. Single 36-inch Pipe...        1,000           40        1,200           10           10          500
Scenario 2. 2 Concurrent 36-inch          1,600           60        1,900           10           10          500
 Pipe.............................
14-inch H-Pile....................           10           10           10           10           10        1,000
12-inch Timber Vibratory..........           10           10           10           10           10        1,400
48-inch Drilled Shaft Oscillatory            10           10           10           10           10          400
 Installation.....................
48-inch Concrete-lined Steel Shaft           10           10           10           10           10        5,900
 Diamond Wire Saw Removal.........
12-inch Timber Pile Clipper.......           10           10           10           10           10        1,900
----------------------------------------------------------------------------------------------------------------

    <bullet> Monitoring for Level A and Level B Harassment--BNSF will 
monitor the Level B harassment zones to the extent practicable and the 
entire Level A harassment zones. Monitoring zones provide utility for 
observing by establishing monitoring protocols for areas adjacent to 
the shutdown zones. Monitoring zones enable observers to be aware of 
and communicate the presence of marine mammals in the project area 
outside the shutdown zone and thus prepare for a potential cessation of 
activity should the animal enter the shutdown zone. At least three PSOs

[[Page 4862]]

would monitor harassment zones during all in-water construction 
activities. PSO monitoring stations are described below in the Proposed 
Monitoring and Reporting section.
    <bullet> Pre-activity Monitoring--Prior to the start of daily in-
water construction activity, or whenever a break in drilling, clipping, 
cutting, pile driving/removal of 30 minutes or longer occurs, PSOs will 
observe the shutdown and monitoring zones for a period of 30 minutes. 
The shutdown zone will be considered cleared when a marine mammal has 
not been observed within the zone for that 30-minute period. If a 
marine mammal is observed within the shutdown zone, a soft-start cannot 
proceed until the animal has left the zone or has not been observed for 
15 minutes. When a marine mammal for which Level B harassment take is 
authorized is present in the Level B harassment zone, activities may 
begin and Level B harassment take will be recorded. If the entire Level 
B harassment zone is not visible at the start of construction, pile 
driving activities can begin. If work ceases for more than 30 minutes, 
the pre-activity monitoring of the shutdown zones will commence.
    <bullet> Soft Start--Soft-start procedures are believed to provide 
additional protection to marine mammals by providing warning and/or 
giving marine mammals a chance to leave the area prior to the hammer 
operating at full capacity. For impact pile driving, contractors will 
be required to provide an initial set of three strikes from the hammer 
at reduced energy, followed by a 30-second waiting period. This 
procedure will be conducted three times before impact pile driving 
begins. Soft start will 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.
    <bullet> Bubble Curtain--BNSF will use a marine pile-driving energy 
attenuator (i.e., air bubble curtain system) during impact pile 
driving. The use of sound attenuation will reduce SPLs and the size of 
the zones of influence for Level A harassment and Level B harassment. 
Bubble curtains will meet the following requirements:
    [cir] The bubble curtain must distribute air bubbles around 100 
percent of the piling circumference for the full depth of the water 
column;
    [cir] The lowest bubble ring must be in contact with the substrate 
for the full circumference of the ring, and the weights attached to the 
bottom ring shall ensure 100 percent substrate contact. No parts of the 
ring or other objects shall prevent full substrate contact; and
    [cir] Air flow to the bubblers must be balanced around the 
circumference of the pile.
    Based on our evaluation of BNSF's proposed measures, NMFS has 
preliminarily determined that the proposed mitigation measures provide 
the means effecting the least practicable impact on the affected 
species or stocks and their habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    <bullet> Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
Marine Mammal Monitoring Plan found in Appendix E in the application. 
Marine mammal monitoring during drilling, clipping, cutting, pile 
driving and removal must be conducted by NMFS-approved PSOs in a manner 
consistent with the following:
    <bullet> Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods must be used;
    <bullet> At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
    <bullet> Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field), or training 
for prior experience performing the duties of a PSO during construction 
activity pursuant to a NMFS-issued incidental take authorization; and
    <bullet> PSOs must be approved by NMFS prior to beginning any 
activity subject to this IHA.
    PSOs must have the following additional qualifications:
    <bullet> Ability to conduct field observations and collect data 
according to assigned protocols;
    <bullet> Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    <bullet> Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    <bullet> 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, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
    <bullet> 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;
    A minimum of three PSOs located at positions designated in Figure 1 
and Figure 2 of the Marine Mammal Monitoring Plan found in Appendix E 
of

[[Page 4863]]

the Application must monitor harassment zones during all in-water 
construction activities. One PSO would be stationed in close proximity 
to the construction site. A second PSO would be stationed at Bay 
Terrace Road which is located east of the Bridge 6.3 on the southern 
side of the Ship Canal. This location would provide views of ensonified 
areas radiating into Shilshole Bay as well as waters east of the mouth 
of the Ship Canal. A third PSO would be located on the north side of 
the Ship Canal at the Northwest 60th Street Viewpoint west of Bridge 
6.3. This location provides views westward towards the mouth of the 
Ship Canal. A fourth PSO must be on a boat positioned in Puget Sound 
when a wire saw is being utilized to monitor the extended Level B 
harassment zone associated with this equipment. A wire saw would be 
employed on approximately 6 in-water work days. If hydroacoustic 
monitoring results of diamond wire saw cutting activities show that the 
entirety of the Level B harassment zone may be viewed by from land-
based PSOs, then the PSO on the boat may not be deployed. All results 
from hydroacoustic monitoring, described in the next section, must be 
submitted to NMFS. NMFS must approve the removal of the boat-based PSO 
and modification of the new harassment isopleth.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after drilling, clipping, cutting, pile driving/removal 
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 or removed. Drilling, clipping, cutting, Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the 
drilling, clipping, cutting, pile driving equipment is no more than 30 
minutes.

Hydroacoustic Monitoring

    Hydroacoustic monitoring will be conducted during in-water pile-
driving and wire saw activities and recorded source levels will be 
compared to the reported sound levels employed as part of this 
application to determine harassment isopleths modeled in this 
application. Information about methods, data collection, and reporting 
are described in the Acoustic Monitoring Plan in Appendix F of the 
Application. The following representative subsets will be measured:
    <bullet> A minimum of 15, 36-inch impact driven piles for the 
Project in the following subsets:
    1. A minimum of 5 piles towards the beginning of pile driving 
activity;
    2. A minimum of 5 piles towards the middle of pile driving 
activity;
    3. A minimum of 5 piles towards the latter pile driving activity.
    <bullet> A minimum of 4, 48-inch drilled shafts oscillated for the 
Project in the following subsets:
    1. A minimum of 2 drilled shafts towards the beginning of the 
activity;
    2. A minimum of 2 drilled shafts towards the end of the activity.
    <bullet> A minimum of 2 48-inch drilled shafts will be monitored 
when cut with a wire saw.

Reporting

    BNSF must submit its draft reports on all monitoring conducted 
under the IHAs within 90 calendar days of the completion of monitoring 
or 60 calendar days prior to the requested issuance of any subsequent 
IHA for construction activity at the same location, whichever comes 
first. A final report must be prepared and submitted within 30 calendar 
days following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of receipt of 
the draft report, the report shall be considered. The report will 
include an overall description of work completed, a narrative regarding 
marine mammal sightings, and associated PSO data sheets. Specifically, 
the report must include:
    <bullet> Dates and times (begin and end) of all marine mammal 
monitoring;
    <bullet> Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
driven or removed and by what method: Drilling, cutting, clipping, 
impact driving, and vibratory driving and removal; duration of driving 
time for each pile (vibratory) and number of strikes per pile (impact 
driving);
    <bullet> PSO locations during marine mammal monitoring;
    <bullet> Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
    <bullet> Name of PSO who sighted the animal(s) and PSO location and 
activity at time of sighting;
    <bullet> Time of sighting;
    <bullet> Identification of the animal(s) (e.g., genus/species, 
lowest possible taxonomic level, or unidentified), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    <bullet> Distance and location of each observed marine mammal 
relative to the pile being driven for each sighting;
    <bullet> Estimated number of animals (min/max/best estimate);
    <bullet> Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, etc.);
    <bullet> Animal's closest point of approach and estimated time 
spent within the harassment zone;
    <bullet> Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching);
    <bullet> Number of marine mammals detected within the harassment 
zones, by species; and
    <bullet> Detailed information about implementation of any 
mitigation (e.g., shutdowns and delays), a description of specific 
actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    The acoustic monitoring report must contain the informational 
elements described in the Acoustic Monitoring Plan and, at minimum, 
must include:
    <bullet> Hydrophone equipment and methods: Recording device, 
sampling rate, distance (m) from the pile where recordings were made; 
depth of water and recording device(s);
    <bullet> Type and size of pile being driven or cut, substrate type, 
method of driving or cutting during recordings (e.g., hammer model and 
energy), and total pile driving or cutting duration;
    <bullet> Whether a sound attenuation device is used and, if so, a 
detailed description of the device used and the duration of its use per 
pile;
    <bullet> For impact pile driving (per pile): Number of strikes; 
depth of substrate to penetrate; pulse duration and mean, median, and 
maximum sound levels (dB re: 1 [micro]Pa): Root mean square sound 
pressure level (SPLrms); cumulative sound exposure level (SELcum), peak 
sound pressure level (SPLpeak), and single-strike sound exposure level 
(SELs-s);
    <bullet> For wire saw cutting (per pile): Duration of driving per 
pile; mean, median, and maximum sound levels (dB re: 1 [micro]Pa): Root 
mean square sound pressure level (SPLrms), cumulative sound exposure 
level (SELcum) (and timeframe over which the sound is averaged); and

[[Page 4864]]

    <bullet> One-third octave band spectrum and power spectral density 
plot.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder shall report 
the incident to the Office of Protected Resources (OPR) (301-427-8401), 
NMFS and to the West Coast Region Stranding Hotline (866-767-6114) as 
soon as feasible. If the death or injury was clearly caused by the 
specified activity, the IHA-holder must immediately cease the specified 
activities until NMFS is able to review the circumstances of the 
incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS.
    The report must include the following information:
    i. Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    ii. Species identification (if known) or description of the 
animal(s) involved;
    iii. Condition of the animal(s) (including carcass condition if the 
animal is dead);
    iv. Observed behaviors of the animal(s), if alive;
    v. If available, photographs or video footage of the animal(s); and
    vi. General circumstances under which the animal was discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, this introductory discussion of our analyses 
applies to all of the species listed in Table 14, given that many of 
the anticipated effects of this project on different marine mammal 
stocks are expected to be relatively similar in nature. Where there are 
meaningful differences between species or stocks in anticipated 
individual responses to activities, impact of expected take on the 
population due to differences in population status, or impacts on 
habitat, they are described independently in the analysis below, such 
as for the potential repeated and prolonged exposure of habituated 
harbor seals that feed on salmonids traversing through the lock system. 
The analysis below applies to both the Year 1 and Year 2 proposed IHAs, 
except where noted otherwise.
    Drilling, clipping, cutting, Pile driving and removal activities 
associated with the 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 A harassment and 
Level B harassment from underwater sounds generated by drilling, 
clipping, cutting, pile driving and removal. Potential takes could 
occur if marine mammals are present in zones ensonified above the 
thresholds for Level A or Level B harassment, identified above, while 
activities are underway.
    The nature of the drilling, clipping, cutting, pile driving project 
precludes the likelihood of serious injury or mortality. The mitigation 
is expected to ensure that no Level A harassment occurs to any species 
except harbor seal. The nature of the estimated takes anticipated to 
occur are similar among all species and similar in Year 1 and Year 2, 
other than the potential Level A harassment take of harbor seal in Year 
1, described further below and the likely comparatively higher number 
of repeated takes of some small number of harbor seals by Level B 
harassment during both Year 1 and Year 2
    For all species other than harbor seal, take would be limited to 
Level B harassment (behavioral disturbance and TTS) only. Effects on 
individuals that are taken by Level B harassment, on the basis of 
reports in the literature as well as monitoring from other similar 
activities, will likely include reactions such as increased swimming 
speeds, increased surfacing time, or decreased foraging (if such 
activity were occurring). Marine mammals present in the vicinity of the 
action area and taken by Level B harassment are most likely to move 
away from and avoid the area of elevated noise levels during in-water 
construction activities. The project site itself is located along a 
highly developed waterfront with high amounts of vessel traffic and, 
therefore, we expect that most animals disturbed by project sound would 
simply avoid the area and use more-preferred habitats. These short-term 
behavioral effects are not expected to affect marine mammals' fitness, 
survival, and reproduction due to the limited geographic area that 
would be affected in comparison to the much larger habitat for marine 
mammals in the Puget Sound. Harbor seals that are habituated to in-
water construction noise could be exposed for 5.4 hours per day for up 
to 10 consecutive days during impact driving activities in Year 1 only. 
These animals would likely remain in close proximity to the locks and 
may be exposed to enough accumulated energy to result in TTS or PTS 
(described below). Longer duration exposure could result in TTS in some 
cases if exposures occur within the Level B TTS zone. As discussed 
earlier in this document, TTS is a temporary loss of hearing 
sensitivity when exposed to loud sound, and the hearing threshold is 
expected to recover completely within minutes to hours. Any behavioral 
effects of repeated or long duration exposures are not expected to 
negatively impact survival or reproductive success of any individuals. 
Similarly, given that the exposure to these individuals is not expected 
to exceed 10 consecutive days for 5.4 or fewer hours at a time for any 
individual, any limited energetic impacts from the interruption of 
foraging or other important behaviors are not expected to affect the 
reproductive success of any individual harbor seals.
    In addition to the expected effects resulting from proposed Level B 
harassment, we anticipate that a limited number of habituated harbor 
seals (20) may sustain some Level A harassment in the form of auditory 
injury during 10 days of impact driving proposed for Year 1 only. 
However, any animals that experience PTS would likely only receive 
slight PTS, i.e. minor degradation of hearing capabilities

[[Page 4865]]

within regions of hearing that align most completely with the frequency 
range of the energy produced by pile driving (i.e., the low-frequency 
region below 2kHz), not severe hearing impairment or impairment in the 
reigns of greatest hearing sensitivity. If hearing impairment does 
occur, it is most likely that the affected animal would lose a few dBs 
in its hearing sensitivity, which in most cases, is not likely to 
meaningfully affect its ability to forage and communicate with 
conspecifics. These takes by Level A harassment (i.e., a small degree 
of PTS) of habituated harbor seals are not expected to accrue in a 
manner that would affect the reproductive success or survival of any 
individuals, much less result in adverse impacts on the species or 
stock. As described above, we expect that marine mammals would be 
likely to move away from a sound source that represents an aversive 
stimulus, especially at levels that would be expected to result in PTS, 
given sufficient notice through use of soft start.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
will not modify existing marine mammal habitat for a significant amount 
of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range; but, because 
of the short duration of the activities and the relatively small area 
of the habitat that may be affected, the impacts to marine mammal 
habitat are not expected to cause significant or long-term negative 
consequences.
    Portions of the southern resident killer whale range are within the 
proposed project area and the entire Puget Sound is designated as 
critical habitat for these whales under the ESA. However, BNSF would be 
required to shut down and suspend pile driving or pile removal 
activities when this stock is detected in the vicinity of the project 
area. We anticipate that take of southern resident killer whale would 
be avoided. There are no other known important areas for other marine 
mammals, such as feeding or pupping, areas.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
    <bullet> No mortality or serious injury is anticipated or 
authorized.
    <bullet> For all species except harbor seal and only during Year 1, 
no Level A harassment is anticipated or proposed for authorization.
    <bullet> The Level A harassment exposures to habituated harbor 
seals in Year 1 only are anticipated to result in slight PTS, within 
the lower frequencies associated with impact pile driving.
    <bullet> Though a small number of habituated harbor seals will 
accrue Level B harassment in the form of TTS from repeated days of 
exposure, hearing thresholds are expected to completely recover within 
minutes to hours.
    <bullet> Anticipated effects of Level B harassment in the form of 
behavioral modification would be temporary.
    <bullet> Although a small portion of the southern resident killer 
whale critical habitat is within the project area, strict mitigation 
measures such as implementing shutdown measures and suspending pile 
driving are expected to avoid take of this stock. No other important 
habitat for marine mammals exist in the vicinity of the project area.
    <bullet> We do not expect significant or long-term negative effects 
to marine mammal habitat.
    Year 1 IHA--Based on the analysis contained herein of the likely 
effects of the specified activity on marine mammals and their habitat, 
and taking into consideration the implementation of the proposed 
monitoring and mitigation measures, NMFS preliminarily finds that the 
total marine mammal take from BNSF's construction activities will have 
a negligible impact on all affected marine mammal species or stocks.
    Year 2 IHA--Based on the analysis contained herein of the likely 
effects of the specified activity on marine mammals and their habitat, 
and taking into consideration the implementation of the proposed 
monitoring and mitigation measures, NMFS preliminarily finds that the 
total marine mammal take from BNSF's construction activities will have 
a negligible impact on all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The amount of take NMFS proposes to authorize is below one third of 
the estimated stock abundance for all species during both Year 1 and 
Year 2. The proposed take of individuals during Year 1 is less than 
32.6 percent for harbor seals and less than 1 percent for all other 
authorized species. During year 2 the proposed take of individuals is 
less than 5.2 percent of the abundance of the affected species or stock 
as shown in Table 14. Note that harbor seal take during Year 1 likely 
includes multiple repeated takes of some small group of individuals. 
Similarly, for all other authorized species, the proposed take numbers 
probably represent conservative estimates because they assume all takes 
are of different individual animals, which is unlikely to be the case. 
Some individuals may return multiple times in a day, but PSOs would 
count them as separate takes if they cannot be individually identified.
    Year 1 IHA--Based on the analysis contained herein of the activity 
(including the mitigation and monitoring measures) and the anticipated 
take of marine mammals, NMFS preliminarily finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks in Year 1 of the project.
    Year 2 IHA--Based on the analysis contained herein of the activity 
(including the mitigation and monitoring measures) and the anticipated 
take of marine mammals, NMFS preliminarily finds that small numbers of 
marine mammals will be taken relative to the population size of the 
affected species or stocks in Year 2 of the project.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it

[[Page 4866]]

authorizes, funds, or carries out is not likely to jeopardize the 
continued existence of any endangered or threatened species or result 
in the destruction or adverse modification of designated critical 
habitat. To ensure ESA compliance for the issuance of IHAs, NMFS 
consults internally whenever we propose to authorize take for 
endangered or threatened species
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue two consecutive IHA's to BNSF for conducting maintenance of 
Bridge 6.3 in Kings County, WA from July 16, 2022 to July, 15, 2023 
(Year 1) and July 16, 2023 to July 15, 2024 (Year 2), provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. Drafts of the proposed IHAs can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this notification of proposed IHAs for the proposed 
action. We also request at this time comment on the potential Renewal 
of the proposed IHAs as described in the paragraph below. Please 
include with your comments any supporting data or literature citations 
to help inform decisions on the request for these IHAs or a subsequent 
Renewal IHA.
    On a case-by-case basis, NMFS may issue a one-time, one-year 
Renewal IHA following notice to the public providing an additional 15 
days for public comments when (1) up to another year of identical or 
nearly identical activities as described in the Description of Proposed 
Activities section of this notification is planned or (2) the 
activities as described in the Description of Proposed Activities 
section of this notification would not be completed by the time the IHA 
expires and a Renewal would allow for completion of the activities 
beyond that described in the Dates and Duration section of this 
notification, provided all of the following conditions are met:
    <bullet> A request for renewal is received no later than 60 days 
prior to the needed Renewal IHA effective date (recognizing that the 
Renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA);
    <bullet> The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal IHA are identical to the activities analyzed under 
the initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take); 
and
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
    Upon review of the request for Renewal, the status of the affected 
species or stocks, and any other pertinent information, NMFS determines 
that there are no more than minor changes in the activities, the 
mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: January 25, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2022-01833 Filed 1-28-22; 8:45 am]
BILLING CODE 3510-22-P


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