[Federal Register Volume 82, Number 209 (Tuesday, October 31, 2017)]
[Notices]
[Pages 50397-50411]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-23563]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF540


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Biorka Island Dock Replacement 
Project

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

ACTION: Notice; issuance of an incidental harassment authorization.

-----------------------------------------------------------------------

SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the Federal Aviation Administration (FAA) to incidentally harass, by 
Level A and Level B harassment, marine mammals during construction 
activities associated with the Biorka dock replacement project in 
Symonds Bay, AK.

DATES: This Authorization is applicable from May 1, 2018, through April 
30, 2019.

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected

[[Page 50398]]

Resources, NMFS, (301) 427-8401. Electronic copies of the applications 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce (as delegated to NMFS) to allow, upon 
request, the incidental, but not intentional, taking of small numbers 
of marine mammals by U.S. citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An Incidental Take Authorization (ITA) shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).

National Environmental Policy Act

    To comply with the National Environmental Policy Act (NEPA) of 1969 
(NEPA; 42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-
6A, NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to environmental 
consequences on the human environment. This action is consistent with 
categories of activities identified in CE B4 of the Companion Manual 
for NOAA Administrative Order 216-6A, which do not individually or 
cumulatively have the potential for significant impacts on the quality 
of the human environment and for which we have not identified any 
extraordinary circumstances that would preclude this categorical 
exclusion. Accordingly, NMFS has determined that the issuance of the 
IHA qualifies to be categorically excluded from further NEPA review and 
a Categorical Exclusion memo was signed in October 2017.

Summary of Request

    On March 31, 2017, NMFS received a request from the FAA for an IHA 
to take marine mammals incidental to pile driving and removal and down 
the hole (DTH) drilling in association with the Biorka Island Dock 
Replacement Project (Project) in Symonds Bay, Alaska. The FAA's request 
is for take of five species by Level A and Level B harassment. Neither 
the FAA nor NMFS expect mortality to result from this activity and, 
therefore, an IHA is appropriate.
    In-water work associated with the in-water construction is expected 
to be completed within 70 days starting May 1, 2018. We expect the in-
water construction work to occur between May 1, 2018 through September 
30, 2018; however, this IHA is valid for one year, from May 1, 2018, 
through April 30, 2019.

Description of the Specified Activity

Overview

    The FAA is constructing a replacement dock on Biorka Island in 
Symonds Bay near Sitka, Alaska. The purpose of the Project is to 
improve and maintain the sole point of access to Biorka Island and the 
navigational and weather facilities located on the island. The existing 
dock has deteriorated and reached the end of its useful life. Regular 
and repetitive heavy surging seas, along with constant use have 
destroyed the face of the existing floating marine dock, and have 
broken cleats making it difficult to tie a vessel to the existing dock. 
In its present condition, small vessels cannot use the dock to provide 
supplies to facilities on the island. The existing barge landing area 
is reinforced seasonally by adding fill to the landing at the 
shoreline, which is periodically washed away by storms and wave action. 
The Project would reconstruct the deteriorated existing dock and 
construct an improved barge landing area. A detailed description of the 
planned dock replacement project is provided in the Federal Register 
notice for the proposed IHA (82 FR 41229; August 30, 2017). Since that 
time, no changes have been made to the planned activities. Therefore, a 
detailed description is not provided here. Please refer to that Federal 
Register notice for the description of the specific activity.
    Table 1 provides a summary of the six methods of construction 
(``scenarios'') used in the modeling of the zone of influence (ZOI)s 
for the Biorka Project. The ZOIs effectively represent the mitigation 
zone that would be established around each pile to prevent Level A 
harassment to marine mammals, while providing estimates of the areas 
within which Level B harassment might occur.

                                             Table 1--Pile Driving Modeling Scenarios for the Biorka Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   Vibratory                DTH                 Impact
                                                                    Piles   ------------------------------------------------------------------
               Scenario                        Description        installed               Total                 Total                 Total      Shift
                                                                   per day    Hrs per   hours per  Hours per  hours per  Hours per   strikes      (hr)
                                                                                pile       day        pile       day        pile     per day
--------------------------------------------------------------------------------------------------------------------------------------------------------
S1....................................  Removal of existing              21       0.33       6.93          NA 2
                                         piles and installation/
                                         removal of temporary
                                         piles 1.
                                                        NA 2                      6.93
                                                                                                  --------------------------------------------

[[Page 50399]]

 
S2....................................  Installation of 18-inch           3  .........       0.99          2          6       0.17         15       7.49
                                         pipe piles (dock and
                                         dolphin).
                                                                                                  ----------------------
S3....................................  Installation of 18-inch           4  .........       1.32           NA                0.33       2720       2.65
                                         pipe piles (barge
                                         landing).
                                                                                                  ----------------------
S4....................................  Installation of 30-inch           2  .........       0.66          2          4       0.17         10       4.99
                                         pipe piles (dolphins).
                                                                                                  ----------------------
S5....................................  Installation of H piles           8  .........       2.64          NA 2               0.33       5440       5.31
                                         (dock wave barrier).
                                                                                                  ----------------------
S6....................................  Installation of sheet            12  .........       3.96          NA 2               0.25       6120       6.96
                                         piles (dock wave
                                         barrier and barge
                                         landing).
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1 Existing piles to be removed include 3 24-in concrete piles, 14 8-in steel piles, 8 10-in steel piles, 14 12.75-in steel piles, and 7 14- to 8-in
  timber piles.
2 NA indicates when a pile driving method was not required in a given scenario.

Comment and Responses

    A notice of NMFS's proposal to issue an IHA to the FAA was 
published in the Federal Register on August 30, 2017 (82 FR 41229). 
That notice described, in detail, the FAA's activity, the marine mammal 
species that may be affected by the activity, and the anticipated 
effects on marine mammals. During the 30-day public comment period, 
NMFS received comments from the Marine Mammal Commission (Commission).
    Comment 1: The Commission has concerns regarding the 
appropriateness of the manner in which NMFS has estimated Level A 
harassment zones. The Commission recommends that NMFS consult with both 
internal and external scientists and acousticians to determine the 
appropriate accumulation time that action proponents should use to 
determine the extent of the Level A harassment zones based on the 
associated permanent threshold shift (PTS) cumulative sound exposure 
level (SEL<INF>cum</INF>) thresholds for the various types of sound 
sources, including stationary sound sources, when simple area x density 
methods are employed. Estimated swimming speeds of various species and 
behavior patterns (including residency patterns) should be considered, 
and multiple scenarios should be evaluated using animat modeling.
    Response: NMFS will take the Commission's recommendation into 
consideration and will consult with internal scientists on this issue 
in the future; however it does not change our isopleths or the number 
of takes for this specific action. We also welcome the Commission and 
its Committee of Scientific Advisors on Marine Mammals to provide 
guidance on this issue.
    Comment 2: The Commission is unsure why NMFS is not implementing 
consistent measures for action proponents that plan to conduct similar 
activities (e.g. shutdowns for vibratory driving and DTH drilling). The 
Commission recommends that NMFS (1) determine whether action proponents 
would be required to implement delay or shut-down procedures during use 
of vibratory and down-the-hole hammers and (2) require, or refrain from 
requiring, those measures consistently for all authorizations involving 
those activities.
    Response: NMFS has confirmed that the FAA will be required to 
implement shutdown and delay procedures during the use of all 
construction equipment, including vibratory driving and removal and DTH 
drilling. In the future, NMFS will ensure consistency across all 
authorizations in our mitigation requirements.
    Comment 3: The Commission recommended that NMFS share the rounding 
criteria with the Commission such that the matter of when rounding 
should occur in the take calculation can be resolved in the near 
future.
    Response: NMFS will share the rounding criteria with the Commission 
soon and looks forward to working with them in the future to resolve 
this issue.

Description of Marine Mammals in the Area of the Specified Activity

    There are five marine mammal species that may transit through the 
waters nearby the Project area, and are likely to potentially be taken 
by the specified activity. These include the Steller sea lion 
(Eumetopias jubatus), harbor seal (Phoca vitulina), harbor porpoise 
(Phocoena phocoena), killer whale (Orcinus orca), and humpback whale 
(Megaptera noviaeangliae). Multiple additional marine mammal species 
may occasionally enter Sitka sound but are not expected to be present 
in the shallow nearshore waters of the action area.
    Sections 3 and 4 of the FAA's application summarize available 
information regarding status and trends, distribution and habitat 
preferences, and behavior and life history of the potentially affected 
species. Additional information regarding population trends and threats 
may be found in NMFS's Stock Assessment Reports (SAR; 
www.nmfs.noaa.gov/pr/sars/) and more general information about these 
species (e.g., physical and behavioral descriptions) may be found on 
NMFS's Web site (www.nmfs.noaa.gov/pr/species/mammals/).
    Table 2 lists all species with expected occurrence in Symonds Bay 
and Sitka Sound and summarizes information related to the population or 
stock, including potential biological removal (PBR), where known. For 
taxonomy, we follow Committee on Taxonomy (2016). 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

[[Page 50400]]

or authorized here, PBR and annual serious injury and mortality are 
included here as gross indicators of the status of the species and 
other threats.
    A detailed description of the of the species likely to be affected 
by the Project, including brief introductions to the species and 
relevant stocks as well as available information regarding population 
trends and threats, and information regarding local occurrence, were 
provided in the Federal Register notice for the proposed IHA (82 FR 
41229; August 30, 2017); since that time, we are not aware of any 
changes in the status of these species and stocks; therefore, detailed 
descriptions are not provided here. Please refer to that Federal 
Register notice for these descriptions. Please also refer to NMFS' Web 
site (www.nmfs.noaa.gov/pr/species/mammals/) for generalized species 
accounts.

                                      Table 2--Marine Mammals Potentially Present in the Vicinity of Biorka Island
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Stock abundance (CV,                         Relative occurrence in
                                                                ESA/MMPA status;       Nmin, most recent               Annual M/   Symonds Bay and Sitka
              Species                         Stock            strategic (Y/N) 1      abundance survey) 2     PBR 3       SI 4       Sound; season of
                                                                                                                                        occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise (Phocoena phocoena)  Southeast Alaska......  -; Y                   11,146 (0.242; n/a;        Undet.         34  Common.
                                                                                     1997).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Family Delphinidae (dolphins)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer whale (Orcinus orca)........  Eastern North Pacific   -; N                   587 (n/a; 587; 2012)..          0          0  Infrequent.
                                      Gulf of Alaska,
                                      Aleutian Island, and
                                      Bering Sea Transient.
                                     West Coast Transient..  -; N                   243 (n/a; 243; 2009)..        2.4          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Family Balaenopteridae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale 5 (Megaptera          Central North Pacific   -; Y                   10,103 (0.300; 7,890;          83         24  Likely.
 novaeangliae).                       stock.                                         2006).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion (Eumetopias         Western...............  E; Y                   49,497 (n/a; 49,497;          297        236  Common.
 jubatus).                                                                           2014).
                                     Eastern...............  -; N                   60,131 (n/a; 36,551;        1,645        108
                                                                                     2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal (Phoca vitulina).......  Sitka/Chatham.........  -; N                   14,855 (n/a; 13,212;          155         77  Common.
                                                                                     2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
1 Endangered Species Act (ESA) status: Yes (Y), No (N), Endangered (E), Threatened (T)/Marine Mammal Protection Act (MMPA) status: Depleted (D). A dash
  (-) indicates that the species is not listed under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for
  which the level of direct human-caused mortality exceeds PBR (see footnote 3) or which is determined to be declining and likely to be listed under the
  ESA within the foreseeable future. Any species or stock listed under the ESA is automatically designated under the MMPA as depleted and as a strategic
  stock.
2 CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For certain stocks, abundance
  estimates are actual counts of animals and there is no associated CV. The most recent abundance survey that is reflected in the abundance estimate is
  presented; there may be more recent surveys that have not yet been incorporated into the estimate.
3 Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
  marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP).
4 These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g, commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.
5 The humpback whales considered under the MMPA to be part of this stock could be from any of two different distinct population segment (DPS)s. In
  Alaska, it would be expected to primarily be whales from the Hawaii DPS but could also be whales from Mexico DPS.

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

    The effects of underwater noise from construction activities for 
the Project have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the action area. The Federal Register 
notice for the proposed IHA (82 FR 41229; August 30, 2017) included a 
discussion of the effects of anthropogenic noise on marine mammals, 
therefore that information is not repeated here; please refer to that

[[Page 50401]]

Federal Register notice for that information.

Estimated Take by Incidental Harassment

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which informed NMFS' consideration of both 
the ``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 be by Level A and Level B harassment, in the 
form of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to vibratory and impact pile driving and 
removal and DTH drilling, and potential PTS for animals that may 
transit through the Level A zones (described below) undetected (Table 
6). Based on the nature of the activity and the anticipated 
effectiveness of the mitigation measures (i.e., soft start, ramp-up, 
etc.--discussed in detail below in Mitigation Measures section), Level 
A harassment is not anticipated; however, a small number of takes by 
Level A harassment is authorized for most species as a precaution if 
animals go undetected before a shutdown is in place.
    As described previously, no mortality or serious injury is 
anticipated or authorized for this activity. Below we describe how the 
take is estimated.
    Described in the most basic way, we estimate take by considering: 
(1) Acoustic thresholds above which NMFS believes the best available 
science indicates marine mammals will be behaviorally harassed or incur 
some degree of permanent hearing impairment; (2) the area or volume of 
water that will be ensonified above these levels in a day; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and, (4) and the number of days of activities. Below, we describe these 
components in more detail and present the take estimate.
    The estimation of marine mammal takes typically uses the following 
calculation since site-specific density is unavailable:

Level B exposure estimate = N (number of animals) in the area * Number 
of days of noise generating activities.

Acoustic Thresholds

    Using the best available science, NMFS has developed 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., 2011). 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 decibels (dB) re 1 micropascal ([mu]Pa) root 
mean square (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.
    The FAA's Project activities include the use of continuous 
(vibratory pile driving and DTH drilling) and impulsive (impact pile 
driving) sources, and therefore the 120 and 160 dB re 1 [mu]Pa (rms) 
are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (NMFS 2016) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). The FAA's 
Project activity includes the use of impulsive (impact pile driving) 
and non-impulsive (vibratory pile driving and DTH drilling) sources.
    These thresholds were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers to inform the final product, and are 
provided in the table below. The references, analysis, and methodology 
used in the development of the thresholds are described in NMFS 2016 
Technical Guidance, which may be accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds * (received level)
             Hearing group             -------------------------------------------------------------------------
                                                Impulsive                          Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans...............  Cell 1: Lpk, flat: 219     Cell 2: LE, LF, 24h: 199 dB.
                                         dB; LE, LF, 24h: 183 dB.
Mid-frequency cetaceans...............  Cell 3: Lpk, flat: 230     Cell 4: LE, MF, 24h: 198 dB.
                                         dB; LE, MF, 24h: 185 dB.
High-frequency cetaceans..............  Cell 5: Lpk, flat: 202     Cell 6: LE, HF, 24h: 173 dB.
                                         dB; LE, HF, 24h: 155 dB.
Phocid Pinnipeds (underwaters)........  Cell 7: Lpk, flat: 218     Cell 8: LE, PW, 24h: 201 dB.
                                         dB; LE, PW, 24h: 185 dB.
Otariid Pinnipeds (underwater)........  Cell 9: Lpk, flat: 232     Cell 10: LE, OW, 24h: 219 dB.
                                         dB; LE, OW, 24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
1 NMFS 2016


[[Page 50402]]

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds.
    Pile driving and removal and DTH drilling generates underwater 
noise that can potentially result in disturbance to marine mammals in 
the Project area. Transmission loss (TL) is the decrease in acoustic 
intensity as an acoustic pressure wave propagates out from a source. TL 
parameters vary with frequency, temperature, sea conditions, current, 
source and receiver depth, water depth, water chemistry, and bottom 
composition and topography. The general formula for underwater TL is:

TL = B * log<INF>10</INF>(R<INF>1</INF>/R<INF>2</INF>),

Where:

R<INF>1</INF> = the distance of the modeled SPL from the driven 
pile, and
R<INF>2</INF> = the distance from the driven pile of the initial 
measurement.

This formula neglects loss due to scattering and absorption, which is 
assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log[range]). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log[range]).
    Underwater Sound--The intensity of pile driving and removal sounds 
is greatly influenced by factors such as the type of piles, hammers, 
and the physical environment in which the activity takes place. A 
number of studies, primarily on the west coast, have measured sound 
produced during underwater pile driving projects. These data are 
largely for impact driving of steel pipe piles and concrete piles as 
well as vibratory driving of steel pipe piles.
    JASCO Applied Sciences (JASCO) conducted acoustic modeling of pile 
installation and removal activities planned for the Project, which is 
included as Appendix A of the FAA's application. To assess potential 
underwater noise exposure of marine mammals during construction 
activities, Quijano and Austin (2017) determined source levels for six 
different construction scenarios (see Table 1). The source levels are 
frequency-dependent and suitable for modeling underwater acoustic 
propagation using JASCO's Marine Operations Noise Model (MONM). The 
modeling predicted the extent of ensonification and the acoustic 
footprint from construction activities, taking into account the effects 
of pile driving equipment, bathymetry, sound speed profile, and seabed 
geoacoustic parameters. Auditory weighting was applied to the modeled 
sound fields to estimate received levels relative to hearing 
sensitivities of five marine mammal hearing groups following NMFS 2016 
guidance.
    The results are based on currently adopted sound level thresholds 
for auditory injury (Level A) expressed as peak pressure level (PK) and 
24-hr SEL, and behavioral disturbance (Level B) expressed as sound 
pressure level (SPL). Using these guidelines, Quijano and Austin (2017) 
calculated the maximum extent (distance and ensonified areas) of the 
Level A and Level B exposure zones for each marine mammal functional 
hearing group. This was calculated for both impact and vibratory pile 
driving of 18- and 30-inch (in) piles for each of the following six 
Project scenarios.
    The model required, as input, source sound levels in \1/3\-octave 
bands between 10 hertz (Hz) and 25 kilohertz (kHz). Source levels for 
sheet pile and H pile installation were obtained from literature, but 
the available measurements did not cover the full frequency spectrum of 
interest; data for vibratory installation of sheet and H piles were 
available to maximum frequencies of 4 kHz and 10 kHz, respectively. 
Modeling of the six construction scenarios at the Project site on 
Biorka Island followed three steps:
    1. Piles driven into the sediment by impact, vibratory, or downhole 
drilling were characterized as sound-radiating sources. Source levels 
in \1/3\-octave-bands were obtained by modeling or by adjusting source 
levels found in the literature. The exact method to obtain the \1/3\-
octave-band levels depends on the pile geometry and pile driving 
equipment, and it is described on a case-by-case basis (see Appendix A 
of the FAA's application);
    2. Underwater sound propagation was applied to predict how sound 
propagates from the pile into the water column as a function of range, 
depth, and azimuthal direction. Propagation depends on several 
conditions including the frequency content of the sound, the 
bathymetry, the sound speed in the water column, and sediment 
geoacoustics; and
    3. The propagated sound field was used to compute received levels 
over a grid of simulated receivers, from which distances to criteria 
thresholds and maps of ensonified areas were generated.
    Modeled results are presented as tables of distances at which SPLs 
or SELs fell below thresholds defined by criteria. For marine mammal 
injury, the Level A thresholds considered here follow the NMFS 
guidelines (NMFS 2016). A detailed description of the modeling process 
is provided in Appendix A of the FAA's IHA application. A list of 
modeling parameters, including pile driving duration for computation of 
SEL, are provided in Table 1.

BILLING CODE 3510-22-P

[[Page 50403]]

[GRAPHIC] [TIFF OMITTED] TN31OC17.000

BILLING CODE 3510-22-C

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    At-sea densities for marine mammal species have not been determined 
for marine mammals in Sitka Sound; therefore, all estimates here are 
determined by using observational data from biologists, peer-reviewed 
literature, and information obtained from personal communication with 
researchers and state and Federal biologists, and from local charter 
boat operators.

Harbor Seals

    Harbor seals are expected to be in the Project area in low numbers 
(see Description of Marine Mammals in the Area of the Specified 
Activity Section). We estimate that up to five harbor seals per day may 
be present in the Project area on all days of construction. Therefore, 
we authorize 350 takes by Level B harassment. Because the largest Level 
A ZOI for harbor seals is nearly 1 kilometer (km) (Scenario 6), the FAA 
requests up to 13 harbor seal takes by Level A harassment. Level A 
harassment may occur if the animals enter the ZOI undetected on half of 
all days of construction in Scenario 6 and one time for each of the 
other five scenarios, and marine mammal observers (MMO) are not able to 
request a shutdown prior to the seals being exposed to potential Level 
A harassment.

Steller Sea Lion

    Steller sea lion abundance in the Project area is dependent on prey 
availability. Prey species are uncommon during the Project window; 
therefore, sea lion abundance is expected to be low. The FAA estimates 
that five sea lions may be in the Project area every day (70 days) of 
construction, therefore, we estimate that 350 sea lions may be taken by 
Level B harassment. We estimate that these takes would be split equally 
between the east distinct population segment (DPS) and west DPS (175 
each). The Level A zone is less than 10 m for all but Scenario 6, which 
is 80 m; however, to be conservative, the FAA is requesting a small 
group of Steller sea lions may be taken by Level A harassment. This 
would equate to six total animals if split equally by DPS (3 each).

[[Page 50404]]

Humpback Whale

    Humpback whales are found in Sitka Bay seasonally. During mid-
summer, tour boats generally see four to five whales per day, in the 
middle of Sitka Sound. Therefore, a count of 5 humpback whales per day 
(70 days) was used to estimate takes per day on every day of 
construction for a total of 350 takes by Level B harassment. All takes 
would be from the Central North Pacific stock under the MMPA. For ESA 
purposes, 93.9 percent would be from the Hawaii DPS (328 animals) and 
6.1 percent would be from the Mexico stock (22 animals) based on Wade 
et al., 2016. The maximum distance at which a humpback whale may be 
exposed to noise levels that exceed Level A thresholds is 1.4 km during 
Scenario 6. Even though the ensonified area extends outside of the 
entrance to Symonds Bay, a MMO stationed near the mouth of the bay at 
Hanus Point would be able to see a humpback whale outside Symonds Bay 
before it enters the Level A zone and could shut down the noise 
producing activity to avoid Level A take. In the unlikely event a whale 
would go undetected and enter the Level A zone, the FAA has requested 
three takes by Level A harassment for humpback whales. We estimate that 
all three humpback whales would be from the Hawaii DPS.

Killer Whale

    Generally, transient killer whales follow the movements of Steller 
sea lions and harbor seals on which they prey. Given the low numbers of 
Steller sea lions in Sitka Sound during summer, it is consistent that 
transient killer whales would also be rare or infrequent in the Project 
area (e.g., killer whales were only observed on five or six days by the 
whale watching industry). Small groups of 5 to 6 transient killer 
whales per day could be observed throughout the summer months; 
therefore, we estimate that a group of 6 animals could enter the 
Project area on 6 occasions during the construction window, for a total 
of 36 takes by Level B harassment. No Level A takes of killer whales is 
authorized for this species. The maximum linear distance to the Level A 
threshold for killer whales is less than 250 meters (m) from the source 
and a MMO would be able to observe animals at this distance and shut 
down activities in time to avoid Level A take.

Harbor Porpoise

    Harbor porpoise are expected to occur in the Project area in low 
numbers during the construction window. Sightings during this time 
period are infrequent; this species is not observed every day. The mean 
group size of harbor porpoise in Southeast Alaska was estimated to be 
between 2 to 3 individuals (Dahlheim et al., 2009); therefore, we 
conservatively estimate that a group of three harbor porpoise may be 
present every other day of construction for a total of 105 takes by 
Level B harassment. The distances to Level A thresholds for harbor 
porpoise (HFC) are largest during impulse driving under Scenarios 3, 5, 
and 6 (see Table 1), and extend beyond the entrance to Symonds Bay. The 
duration of Scenarios 3, 5, and 6 is expected to be 30 days (see Table 
1); therefore, we expect that a small group of three harbor porpoise 
may enter the Level A zone on half of the days of Scenarios 3, 5, and 6 
(15 days) for a total of 45 takes by Level A harassment.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    All estimates are conservative and include the following 
assumptions:
    <bullet> All pilings installed at each site would have an 
underwater noise disturbance equal to the piling that causes the 
greatest noise disturbance (i.e., the piling farthest from shore) 
installed with the method that has the ZOI. The largest underwater 
disturbance (Level B) ZOI would be produced by DTH drilling; therefore 
take estimates were calculated using the vibratory pile-driving ZOIs. 
The ZOIs for each threshold are not spherical and are truncated by land 
masses on either side of the Project area, which would dissipate sound 
pressure waves.
    <bullet> Exposures were based on an estimated total of 70 work 
days. Each activity ranges in number of days needed to be completed 
(Table 1).
    <bullet> All marine mammal individuals potentially available are 
assumed to be present within the relevant area, and thus incidentally 
taken;
    <bullet> An individual can only be taken once during a 24-hour 
period; and,
    <bullet> Exposures to sound levels at or above the relevant 
thresholds equate to take, as defined by the MMPA.
    Estimates of potential instances of take may be overestimates of 
the number of individuals taken. In the context of stationary 
activities such as pile driving and in areas where resident animals may 
be present, this number represents the number of total take that may 
accrue to a smaller number of individuals, with some number of animals 
being exposed more than once per individual. While pile driving and 
removal can occur any day throughout the in-water work window, and the 
analysis is conducted on a per day basis, only a fraction of that time 
(typically a matter of hours on any given day) is actually spent pile 
driving/removal. The potential effectiveness of mitigation measures in 
reducing the number of takes is typically not quantified in the take 
estimation process. For these reasons, these take estimates may be 
conservative.

          Table 5--Calculations for Incidental Take Estimation
------------------------------------------------------------------------
                                               Takes           Takes
                                           authorized by   authorized by
                 Species                      Level A         Level B
                                            harassment      harassment
------------------------------------------------------------------------
Steller sea lion: Eastern and Western                  6             350
 stock..................................
Harbor seal.............................              13             350
Humpback whale..........................               3             350
Killer whale: Eastern North Pacific Gulf               0              36
 of Alaska, Aleutian Island, and Bering
 Sea Transient stock and West Coast
 Transient stock........................
Harbor porpoise.........................              45             105
------------------------------------------------------------------------

Mitigation Measures

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds,

[[Page 50405]]

and areas of similar significance, and on the availability of such 
species or stock for taking for certain subsistence uses (latter not 
applicable for this action). NMFS regulations require applicants for 
incidental take authorizations to include information about the 
availability and feasibility (economic and technological) of equipment, 
methods, and manner of conducting such activity or other means of 
effecting the least practicable adverse impact upon the affected 
species or stocks and their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully balance 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--
which considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range), as well as the likelihood that 
the measure will be effective if implemented; and the likelihood of 
effective implementation, 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.
    The ZOIs were used to develop mitigation measures for pile driving 
and removal activities at the Project area. The ZOIs effectively 
represent the mitigation zone that would be established around each 
pile to prevent Level A harassment to marine mammals, while providing 
estimates of the areas within which Level B harassment might occur. In 
addition to the specific measures described later in this section, the 
FAA would conduct briefings between construction supervisors and crews, 
marine mammal monitoring team, and staff prior to the start of all pile 
driving activity, and when new personnel join the work, in order to 
explain responsibilities, communication procedures, marine mammal 
monitoring protocol, and operational procedures.

Monitoring and Shutdown for Construction Activities

    The following measures would apply to the FAA's mitigation through 
shutdown and disturbance zones:
    Shutdown Zone--For all pile driving activities, the FAA will 
establish a shutdown zone intended to contain the area in which SPLs 
equal or exceed the auditory injury criteria for cetaceans and 
pinnipeds. The purpose of a shutdown zone is to define an area within 
which shutdown of activity would occur upon sighting of a marine mammal 
(or in anticipation of an animal entering the defined area), thus 
preventing injury of marine mammals (as described previously under 
Potential Effects of the Specified Activity on Marine Mammals, serious 
injury or death are unlikely outcomes even in the absence of mitigation 
measures). Modeled radial distances for shutdown zones are shown in 
Table 6. However, a minimum shutdown zone of 10 m will be established 
during all pile driving activities, regardless of the estimated zone; 
and
    Disturbance Zone--Disturbance zones are the areas in which SPLs 
equal or exceed 160 and 120 dB rms (for impulse and continuous sound, 
respectively). Disturbance zones provide utility for monitoring 
conducted for mitigation purposes (i.e., shutdown zone monitoring) by 
establishing monitoring protocols for areas adjacent to the shutdown 
zones. Monitoring of disturbance zones enables observers to be aware of 
and communicate the presence of marine mammals in the Project area but 
outside the shutdown zone and thus prepare for potential shutdowns of 
activity. However, the primary purpose of disturbance zone monitoring 
is for documenting instances of Level B harassment; disturbance zone 
monitoring is discussed in greater detail later (see Monitoring and 
Reporting Measures). Nominal radial distances for disturbance zones are 
shown in Table 6.
    Given the size of the disturbance zone for vibratory pile driving 
and DTH drilling, it is impossible to guarantee that all animals would 
be observed or to make comprehensive observations of fine-scale 
behavioral reactions to sound, and only a portion of the zone (e.g., 
what may be reasonably observed by visual observers stationed between 
Symonds Bay and Sitka Sound) would be observed. In order to document 
observed instances of harassment, monitors record all marine mammal 
observations, regardless of location. The observer's location, as well 
as the location of the pile being driven, is known from a GPS. The 
location of the animal is estimated as a distance from the observer, 
which is then compared to the location from the pile. It may then be 
estimated whether the animal was exposed to sound levels constituting 
incidental harassment on the basis of predicted distances to relevant 
thresholds in post-processing of observational and acoustic data, and a 
precise accounting of observed incidences of harassment created. This 
information may then be used to extrapolate observed takes to reach an 
approximate understanding of actual total takes.
BILLING CODE 3510-22-P

[[Page 50406]]

[GRAPHIC] [TIFF OMITTED] TN31OC17.001

BILLING CODE 3510-22-C
    Monitoring Protocols--Monitoring would be conducted before, during, 
and after pile driving and vibratory removal activities. In addition, 
observers shall record all instances of marine mammal occurrence, 
regardless of distance from activity, and shall document any behavioral 
reactions in concert with distance from piles being driven. 
Observations made outside the shutdown zone will not result in 
shutdown; that pile segment would be completed without cessation, 
unless the animal approaches or enters the shutdown zone, at which 
point all pile driving activities would be halted. Monitoring will take 
place from 30 minutes prior to initiation through 30 minutes post-
completion of pile driving and removal activities. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes. Please see Section 11 of 
the FAA's application (www.nmfs.noaa.gov/pr/permits/incidental/construction.htm), for the FAA's monitoring protocols.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. A minimum of two 
observers will be required for all pile driving/removal

[[Page 50407]]

activities. MMO requirements for construction actions are as follows:
    (a) Independent observers (i.e., not construction personnel) are 
required;
    (b) At least one observer must have prior experience working as an 
observer;
    (c) Other observers (that do not have prior experience) may 
substitute education (undergraduate degree in biological science or 
related field) or training for experience;
    (d) Where a team of three or more observers are required, one 
observer should be designated as lead observer or monitoring 
coordinator. The lead observer must have prior experience working as an 
observer; and
    (e) NMFS will require submission and approval of observer resumes.
    (2) Qualified MMOs are trained biologists, and need the following 
additional minimum qualifications:
    (a) Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    (b) Ability to conduct field observations and collect data 
according to assigned protocols;
    (c) Experience or training in the field identification of marine 
mammals, including the identification of behaviors;
    (d) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    (e) Writing skills sufficient to prepare a report of observations 
including but not limited to the number and species of marine mammals 
observed; dates and times when in-water construction activities were 
conducted; dates and times when in-water construction activities were 
suspended to avoid potential incidental injury from construction sound 
of marine mammals observed within a defined shutdown zone; and marine 
mammal behavior; and
    (f) 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.
    (3) Prior to the start of pile driving activity, the shutdown zone 
will be monitored for 30 minutes to ensure that it is clear of marine 
mammals. Pile driving will only commence once observers have declared 
the shutdown zone clear of marine mammals; animals will be allowed to 
remain in the shutdown zone (i.e., must leave of their own volition) 
and their behavior will be monitored and documented. The shutdown zone 
may only be declared clear, and pile driving started, when the entire 
shutdown zone is visible (i.e., when not obscured by dark, rain, fog, 
etc.). In addition, if such conditions should arise during impact pile 
driving that is already underway, the activity would be halted.
    (4) If a marine mammal approaches or enters the shutdown zone 
during the course of pile driving operations, activity will be halted 
and delayed until either (A) the animal has voluntarily left and been 
visually confirmed beyond the shutdown zone, (B) 15 minutes have passed 
without re-detection of small cetaceans and pinnipeds, or (C) 30 
minutes have passed without re-detection of large cetaceans, whichever 
happens sooner. Monitoring will be conducted throughout the time 
required to drive a pile.
    (5) If a species for which authorization has not been granted, or a 
species for which authorization has been granted but the authorized 
takes are met, approaches or is observed within the Level B harassment 
zone, activities will shut down immediately using delay and shut-down 
procedures. Activities will not restart until the animals have been 
confirmed to have left the area.

Soft Start

    The use of a soft start procedure is believed to provide additional 
protection to marine mammals by warning or providing a chance to leave 
the area prior to the hammer operating at full capacity, and typically 
involves a requirement to initiate sound from the hammer at reduced 
energy followed by a waiting period. This procedure is repeated two 
additional times. It is difficult to specify the reduction in energy 
for any given hammer because of variation across drivers and, for 
impact hammers, the actual number of strikes at reduced energy will 
vary because operating the hammer at less than full power results in 
``bouncing'' of the hammer as it strikes the pile, resulting in 
multiple ``strikes.'' For impact driving, we require an initial set of 
three strikes from the impact hammer at reduced energy, followed by a 
30-second waiting period, then 2 subsequent 3 strike sets. Soft start 
will be required at the beginning of each day's impact pile driving 
work and at any time following a cessation of impact pile driving of 30 
minutes or longer.

Noise Attenuating Devices

    The FAA will use cushions during impact pile driving.

Timing Restrictions

    The FAA will only conduct construction activities during daytime 
hours. Construction will also be restricted to the months of May 
through September to avoid overlap with times when marine mammals have 
higher densities in the Project area.
    We have carefully evaluated the FAA's mitigation measures and 
considered their effectiveness in past implementation to determine 
whether they are likely to effect the least practicable impact on the 
affected marine mammal species and stocks and their habitat.
    Any mitigation measure(s) we prescribe should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    (1) Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal);
    (2) A reduction in the number (total number or number at 
biologically important time or location) of individual marine mammals 
exposed to stimuli expected to result in incidental take (this goal may 
contribute to 1, above, or to reducing takes by behavioral harassment 
only);
    (3) A reduction in the number (total number or number at 
biologically important time or location) of times any individual marine 
mammal would be exposed to stimuli expected to result in incidental 
take (this goal may contribute to 1, above, or to reducing takes by 
behavioral harassment only);
    (4) A reduction in the intensity of exposure to stimuli expected to 
result in incidental take (this goal may contribute to 1, above, or to 
reducing the severity of behavioral harassment only);
    (5) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying particular attention to the prey base, blockage or 
limitation of passage to or from biologically important areas, 
permanent destruction of habitat, or temporary disturbance of habitat 
during a biologically important time; and
    (6) For monitoring directly related to mitigation, an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of the FAA's measures, as well as any other 
potential measures considered by NMFS, NMFS has determined that the 
mitigation measures provide the means of effecting

[[Page 50408]]

the least practicable impact on marine mammal species or stocks and 
their habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance.

Monitoring and Reporting Measures

    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 
action area. Effective reporting is critical to both compliance and 
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 in action area (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) 
population, species, or stock;
    <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 Marine Mammal Observations

    The FAA will collect sighting data and behavioral responses to 
construction for marine mammal species observed in the region of 
activity during the period of activity. All MMOs will be trained in 
marine mammal identification and behaviors and are required to have no 
other construction-related tasks while conducting monitoring. A minimum 
of two MMOs will be required for all pile driving/removal activities. 
The FAA will monitor the shutdown zone and disturbance zone before, 
during, and after pile driving, with observers located at the best 
practicable vantage points. Based on our requirements, the FAA would 
implement the following procedures for pile driving and removal:
    <bullet> MMOs would be located at the best vantage point(s) in 
order to properly see the entire shutdown zone and as much of the 
disturbance zone as possible;
    <bullet> During all observation periods, observers will use 
binoculars and the naked eye to search continuously for marine mammals;
    <bullet> If the shutdown zones are obscured by fog or poor lighting 
conditions, pile driving at that location will not be initiated until 
that zone is visible. Should such conditions arise while driving, 
removal, or drilling is underway, the activity would be halted; and
    <bullet> The shutdown and disturbance zones around the pile will be 
monitored for the presence of marine mammals before, during, and after 
any pile driving or removal activity.

Data Collection

    We require that observers use approved data forms. Among other 
pieces of information, the FAA will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the FAA will attempt to 
distinguish between the number of individual animals taken and the 
number of incidences of take. We require that, at a minimum, the 
following information be collected on the sighting forms:
    <bullet> Date and time that monitored activity begins or ends;
    <bullet> Construction activities occurring during each observation 
period;
    <bullet> Weather parameters (e.g., percent cover, visibility);
    <bullet> Water conditions (e.g., sea state, tide state);
    <bullet> Species, numbers, and, if possible, sex and age class of 
marine mammals;
    <bullet> Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel, and if possible, 
the correlation to SPLs;
    <bullet> Distance from pile driving or removal activities to marine 
mammals and distance from the marine mammals to the observation point;
    <bullet> Description of implementation of mitigation measures 
(e.g., shutdown or delay);
    <bullet> Locations of all marine mammal observations; and
    <bullet> Other human activity in the area.

Sound Source Verification

    The SSV will establish source levels for impact pile driving, 
vibratory pile driving, and DTH drilling. The FAA will provide all 
monitoring data to NMFS. The reports would include the following 
information:

    1. Size and type of piles;
    2. A detailed description of the noise attenuation device, 
including design specifications;
    3. The impact hammer energy rating used to drive the piles, and the 
make and model of the hammer and the output energy;
    4. The physical characteristics of the bottom substrate into which 
the piles were driven;
    5. The depth of water into which the pile was driven;
    6. The depth into the substrate into which the pile was driven;
    7. A description of the sound monitoring equipment;
    8. The distance between hydrophones and pile;
    9. The depth of the hydrophones and depth of water at hydrophone 
locations;
    10. The distance from the pile to the water's edge;
    11. The total number of strikes to drive each pile and for all 
piles driven during a 24-hour period;
    12. The results of the hydroacoustic monitoring;
    13. Source levels for peak and RMS SPLs and single strike SEL at 10 
m from the pile, and RMS pulse duration that contains 90 percent of 
pulse energy.
    14. The distance at which peak, cumulative SEL, and RMS values 
exceed the respective threshold values;
    15. For vibratory pile driving, SEL based on 30 second averaging of 
sound intensity;

[[Page 50409]]

    16. The spectragraphs for each pile type; and
    17. A description of any observable marine mammal behavior in the 
immediate area and, if possible, correlation to underwater sound levels 
occurring at that time.
    A minimum of two piles of the 18-in and two piles of the 30-in 
piles for each construction type (i.e. impact and vibratory pile 
driving and DTH drilling) will be monitored. Piles chosen to be 
monitored will be representative of the different sizes and range of 
typical water depths at the project location where piles will be driven 
with an impact or vibratory hammer.
    One bottom-mounted hydrophone will be placed at the nearest 
distance, approximately 10 meters, from each pile being monitored. An 
additional hydrophone will be placed at mid-water depth at a distance 
of 100 to 200 m from the pile to provide two sound-level readings 
during ambient and pile driving conditions. A third hydrophone may be 
deployed at a greater distance (e.g., 1-2 km or further) for the 
purpose of better defining the long-distance sound propagation. 
Underwater sound levels will be continuously monitored during the 
entire duration of each pile being driven. Sound levels will be 
measured in dB re: 1 [mu]Pa.

Reporting

    A draft report will be submitted to NMFS within 90 days of the 
completion of marine mammal monitoring, or 60 days prior to the 
requested date of issuance of any future IHA for projects at the same 
location, whichever comes first. The report will include marine mammal 
observations pre-activity, during-activity, and post-activity during 
pile driving and removal days, and will also provide descriptions of 
any behavioral responses to construction activities by marine mammals 
and a complete description of all mitigation shutdowns and the results 
of those actions and an extrapolated total take estimate based on the 
number of marine mammals observed during the course of construction. A 
final report must be submitted within 30 days following resolution of 
comments on the draft report.

Negligible Impact Analysis and Determinations

    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, because the expected 
impacts to marine mammals of the affected species and stocks are 
similar (and we have no information to suggest otherwise), our 
discussion here applies to each of them.
    Pile driving and removal activities associated with the dock 
replacement 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 and Level B 
harassment (PTS and behavioral disturbance), from underwater sounds 
generated from pile driving and removal. Potential takes could occur if 
individuals of these species are present in the ensonified zone when 
pile driving and removal occurs. Most of the Level A takes are 
precautionary as marine mammals are not expected to enter and stay in 
the Level A ensonified area for the duration needed to incur PTS. 
However, if all authorized takes be Level A harassment were to occur, 
they would be of small numbers compared to the stock sizes and would 
not adversely affect the stock through effects on annual rates of 
recruitment or survival. Additionally, the FAA's mitigation measures, 
including a shutdown of construction activities if animals enter the 
Level A zone, further reduces the chance for PTS in marine mammals. 
Therefore, the effects to marine mammals are expected to be negligible.
    No temporary threshold shift (TTS), serious injury, or mortality is 
anticipated given the nature of the activities and measures designed to 
minimize the possibility of injury to marine mammals. The potential for 
these outcomes is minimized through the construction method and the 
implementation of the planned mitigation measures. Specifically, 
vibratory and impact hammers and drilling will be the primary methods 
of installation. Impact pile driving produces short, sharp pulses with 
higher peak levels and much sharper rise time to reach those peaks. If 
impact driving is necessary, implementation of soft start and shutdown 
zones significantly reduces any possibility of injury. Given sufficient 
``notice'' through use of soft start (for impact driving), marine 
mammals are expected to move away from a sound source that is annoying 
prior to it becoming potentially injurious, however, as noted 
previously a small number of potential takes by PTS are authorized and 
have been analyzed. The FAA will use a minimum of two MMOs stationed 
strategically to increase detectability of marine mammals, enabling a 
high rate of success in implementation of shutdowns to avoid injury.
    The FAA's Project activities are localized and of relatively short 
duration (a maximum of 70 days for pile driving and removal). The 
entire Project area is limited to Symonds Bay and into Sitka Sound for 
some scenarios. These localized and short-term noise exposures may 
cause short-term behavioral modifications in harbor seals, Steller sea 
lions, harbor porpoises, killer whales, and humpback whales. Moreover, 
the mitigation and monitoring measures are expected to reduce the 
likelihood of injury. Additionally, no important feeding and/or 
reproductive areas for marine mammals of any of these species/stocks 
are known to be within the ensonified area during the construction 
window.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff 
2006; Lerma 2014). Significant behavioral modifications that could 
potentially lead to effects on growth, survival, or reproduction are 
not expected to occur given the short duration and small scale of the 
project activities. Most likely,

[[Page 50410]]

individuals will simply move away from the sound source and be 
temporarily displaced from the areas of pile driving and drilling, 
although even this reaction has been observed primarily only in 
association with impact pile driving. Thus, even repeated Level B 
harassment of some small subset of the overall stock is unlikely to 
result in any significant realized decrease in fitness for the affected 
individuals, and thus would not result in any adverse impact to the 
stock as a whole. Non-auditory physiological effects and masking are 
not expected to occur from the FAA's Project activities.
    The Project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The Project activities 
would 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. However, 
because of the short duration of the activities and the relatively 
small area of the habitat that may be affected, and the decreased 
potential of prey species to be in the Project area during the 
construction work window, the impacts to marine mammal habitat are not 
expected to cause significant or long-term negative consequences.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stocks through 
effects on annual rates of recruitment or survival:
    <bullet> No mortality or serious injury is anticipated or 
authorized;
    <bullet> Level B harassment may consist of, at worst, temporary 
modifications in behavior (e.g. temporary avoidance of habitat or 
changes in behavior);
    <bullet> The lack of important feeding, pupping, or other areas in 
the action area during the construction window;
    <bullet> Mitigation is expected to minimize the likelihood and 
severity of the level of harassment; and
    <bullet> The small percentage of the species/stock that may be 
affected by Project activities (<15 percent for all species/stocks).
    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 monitoring and mitigation 
measures, NMFS finds that the total marine mammal take from the FAA's 
construction activities will have a negligible impact on the affected 
marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities.
    Table 7 details the number of instances that animals could be 
exposed to received noise levels that could cause Level A and Level B 
harassment for the planned work at the Project site relative to the 
total stock abundance. The numbers of animals authorized to be taken 
for each species or stock is considered small relative to the relevant 
species or stock size even if each estimated instance of take occurred 
to a new individual. The total percent of the population (if each 
instance was a separate individual) for which take is requested is less 
than 15 percent for each stock (Table 7). For pinnipeds, especially 
harbor seals occurring in the vicinity of the Project area, there will 
almost certainly be some overlap in individuals present day-to-day, and 
the number of individuals taken is expected to be notably lower.
    Based on the analysis contained herein of the Project activities 
(including the mitigation and monitoring measures) and the anticipated 
take of marine mammals, NMFS finds that small numbers of marine mammals 
will be taken relative to the population size of the affected species 
or stocks.

    Table 7--Estimated Numbers and Percentage of Stock That May Be Exposed to Level A and Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                                                                     Stock(s)      Percentage of
                     Species                        Authorized      Authorized       abundance      total stock
                                                   Level A takes   Level B takes   estimate \1\      (percent)
----------------------------------------------------------------------------------------------------------------
Harbor Seal (Phoca vitulina):
    Sitka/Chatham stock.........................              13             350          14,855            2.44
Steller sea lion (Eumatopias jubatus):
    Western U.S. Stock..........................               6             350          50,983           0.698
    Eastern U.S. Stock..........................  ..............  ..............          41,638           0.855
Killer whale (Orcinus orca):
    Eastern North Pacific, Gulf of AK, Aleutian                0              36             587            6.13
     Island, and Bering Sea Transient Stock.....
    West Coast Transient Stock..................  ..............  ..............             243            14.8
Humpback whale (Megaptera noviaengliae):
    Central North Pacific Stock.................               3             350          10,103            3.49
Harbor Porpoise (Phocoena phocoena):
    Southeast Alaska Stock......................              45             105          11,146            1.34
----------------------------------------------------------------------------------------------------------------
\1\ All stock abundance estimates presented here are from the 2016 Alaska Stock Assessment Report.

Unmitigable Adverse Impact Analysis and Determination

    In order to issue an IHA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as: an impact resulting from the specified activity: (1) 
That is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid

[[Page 50411]]

hunting areas; (ii) Directly displacing subsistence users; or (iii) 
Placing physical barriers between the marine mammals and the 
subsistence hunters; and (2) That cannot be sufficiently mitigated by 
other measures to increase the availability of marine mammals to allow 
subsistence needs to be met.
    Harbor seals and Steller sea lions are subsistence harvested in 
Alaska. During 2012, the estimated subsistence take of harbor seals in 
southeast Alaska was 595 seals with 49 of these taken near Sitka (Wolfe 
et al., 2013). This is the lowest number of seals taken since 1992 
(Wolfe et al., 2013) and is attributed to the decline in subsistence 
hunting pressure over the years as well as a decrease in efficiency per 
hunter (Wolf et al., 2013).
    The peak hunting season in southeast Alaska occurs during the month 
of November and again over the March to April time frame (Wolfe et al., 
2013). This corresponds to times when seals are aggregated in shoal 
areas as they prey on forage species such as herring, making them 
easier to find and hunt.
    The Project is in an area where subsistence hunting for harbor 
seals or sea lions could occur (Wolfe et al., 2013), but the location 
is not preferred for hunting. There is little to no hunting documented 
in the vicinity and there are no harvest quotas for non-listed marine 
mammals. For these reasons and the fact that Project activities would 
occur outside of the primary subsistence hunting seasons, there would 
be no impact on subsistence activities or on the availability of marine 
mammals for subsistence use.
    To satisfy requirements under Section 106 of the National Historic 
Preservation Act, R&M Consultants, Inc. reached out to the Sitka Tribe 
of Alaska, Central Council of the Tlingit and Haida, and Sealaska 
regarding cultural resources in 2016. No issues or concerns with the 
Project were raised during this effort.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the mitigation and monitoring 
measures, NMFS has determined that there will not be an unmitigable 
adverse impact on subsistence uses from the FAA's activities.

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 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, in this case with the Alaska Regional Office, 
whenever we propose to authorize take for endangered or threatened 
species.
    NMFS is authorizing take of two DPSs (i.e., western DPS of Steller 
sea lions and Mexico DPS of humpback whales), which are listed under 
the ESA. The Permit and Conservation Division requested initiation of 
Section 7 consultation with the Alaska Region for the issuance of this 
IHA. The NMFS Alaska Regional Office Protected Resources Division 
issued a Biological Opinion in October, 2017 under section 7 of the 
ESA, on the issuance of an IHA to the FAA under section 101(a)(5)(D) of 
the MMPA by the NMFS Permits and Conservation Division. The Biological 
Opinion concluded that the proposed action is not likely to jeopardize 
the continued existence of western DPS Steller sea lions or Mexico DPS 
of humpback whales, and is not likely to destroy or adversely modify 
western DPS Steller sea lion critical habitat.

Authorization

    NMFS has issued an IHA to the FAA for the potential harassment of 
small numbers of five marine mammal species incidental to the Biorka 
Island dock replacement project in Sitka, AK, provided the previously 
mentioned mitigation, monitoring and reporting requirements are 
incorporated.

    Dated: October 25, 2017.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2017-23563 Filed 10-30-17; 8:45 am]
 BILLING CODE 3510-22-P