Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the O'Connell Bridge Lightering Float Pile Replacement Project in Sitka, Alaska, 7023-7041 [2019-03684]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 41 (Friday, March 1, 2019)]
[Notices]
[Pages 7023-7041]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-03684]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG644


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the O'Connell Bridge Lightering 
Float Pile Replacement Project in Sitka, Alaska

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from City and Borough of Sitka 
(CBS) for authorization to take marine mammals incidental to the 
O'Connell Bridge Lightering Float Pile Replacement Project in Sitka, 
Alaska. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is 
requesting comments on its proposal to issue an incidental harassment 
authorization (IHA) to incidentally take marine mammals during the 
specified activities. NMFS is also requesting comments on a possible 
one-year renewal 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 notice. NMFS will consider public comments 
prior to making any final decision on the issuance of the requested 
MMPA authorizations and agency responses will be summarized in the 
final notice of our decision.

DATES: Comments and information must be received no later than April 1, 
2019.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to ITP.Pauline@noaa.gov.
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. All personal identifying 
information (e.g., name, address) voluntarily submitted by the 
commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

FOR FURTHER INFORMATION CONTACT: Rob Pauline, Office of Protected 
Resources, NMFS, and (301) 427-8401. Electronic copies of the 
application and supporting documents, as well as a list of the 
references cited in this document, may be obtained online at: 
www.nmfs.noaa.gov/pr/permits/incidentalconstruction.htm. 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 issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be 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 such 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 such takings are set forth.
    The NDAA (Pub. L. 108-136) removed the ``small numbers'' and 
``specified geographical region'' limitations indicated above and 
amended the definition of ``harassment'' as it applies to a ``military 
readiness activity. The definitions of all applicable MMPA statutory 
terms cited above are included in the relevant sections below.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (incidental harassment authorizations 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 IHA qualifies to be categorically excluded 
from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On November 18, 2018, NMFS received a request from CBS for an IHA 
to take marine mammals incidental to pile driving and removal 
activities associated with the O'Connell Bridge Lightering Float Pile 
Replacement Project in Sitka, Alaska. The application was deemed 
adequate and complete on December 20, 2018. CBS's request is for take 
of small numbers of humpback whale (Megaptera novaeangliae), killer 
whale (Orcinus orca), harbor porpoise (Phocoena phocoena), harbor seal

[[Page 7024]]

(Phoca vitulina), and Steller sea lion (Eumetopias jubatus) by Level B 
harassment only. Neither CBS nor NMFS expects serious injury or 
mortality to result from this activity and, therefore, an IHA is 
appropriate.

Description of Proposed Activity

Overview

    CBS is repairing the O'Connell Bridge Lightering Float (float) 
located in Sitka Sound in Southeast Alaska. The applicant proposes to 
remove existing piles and replace them with piles that are more deeply 
socketed so that the float can accommodate larger vessels including 
yachts, fish processors, and research vessels. Existing piles are not 
socketed deep enough to provide proper stability to safely support 
these vessels. Additionally, the float was damaged during a storm in 
June of 2017, and the existing piles are now leaning. This project 
would replace the existing piles with new piles that are socketed 
deeper into the ocean floor. Once the piles are replaced, the float 
will safely accommodate these larger vessels. Vibratory pile removal, 
vibratory pile driving, impact pile driving, and drilling would 
introduce sound into nearby waters at levels that could result in 
behavioral harassment of marine mammals.

Dates and Duration

    Pile removal and installation is expected to occur for a total of 
approximately 13 hours over 3 days. The local Sitka Tribe requested 
that no pile driving occur between March 15 and May 31 to protect 
herring, as has been the case for past permitting in Sitka Sound. 
Therefore, and assuming weather conditions are favorable, CBS proposes 
to begin pile driving work on June 1, 2019. As a contingency, CBS 
requests an IHA for incidental take of marine mammals described within 
this application for one year, effective from June 1, 2019 through May 
31, 2020.

Specific Geographic Region

    The O'Connell Bridge Lightering Float is located near the prominent 
O'Connell Bridge within Crescent Bay and adjacent to Sitka Channel (see 
Figures 1, 2, and 3 of CBS's application). Crescent Bay is bounded by 
Sitka Channel to the northwest, Middle Channel to the southwest and 
Eastern Channel to the southeast, and a series of islands to the south. 
The bay is relatively shallow with a maximum depth of approximately 30 
meters. The north side of the bay has riprap protected developed areas, 
including a boat harbor, and undeveloped shorelines on small islands to 
the south and on the eastern side of the bay. Lower intertidal and 
shallow subtidal areas are primarily cobbles and boulders with varying 
amounts of silt. The sediment thickness varies from 3 to 30 inches (PND 
2017) until bedrock is reached. The float is located in an active 
marine commercial and industrial area.

Detailed Description of Specific Activity

    CBS plans to remove and replace the six piles that support the 
O'Connell Bridge Lightering Float. The existing float consists of two 
100-foot long by 5-foot wide aluminum gangways and a 180-foot long by 
10-foot wide concrete modular float system restrained by six 16-inch 
diameter steel pipe piles that are socketed 4 feet deep into bedrock. 
The existing piles would be removed and replaced with six new 16-inch 
diameter steel piles that would be socketed 12 feet deep into bedrock. 
Pile installation and removal is expected to occur over three days. 
Construction includes the following activities:
     Temporarily remove the existing concrete lightering float 
and associated aluminum gangways (Note: these components are removed 
each winter and reinstalled in the summer.);
     Remove six (6) 16-inch diameter steel pipe piles that 
support the float;
     Install six (6) 16-inch diameter galvanized steel pipe 
piles (0.5-inch wall); and
     Reinstall the floating dock and gangways.
    The following equipment would be used:
     Vibratory Hammer: ICE 44B/12,450 pounds static weight;
     Diesel Impact Hammer: Delmar D46/Max Energy 107,280 ft.-
pounds;
     Drilled shaft drill: Hole 100,000 ft-lb. top drive with 
down-the-hole (DTH) hammer and bit; and
     Socket drill: Whole 100,000 ft-lb. top drive with DTH 
hammer and under-reamer bit.
    The first step would be to remove the existing piles by direct pull 
using a crane. If the direct pull method is ineffective, the piles 
would be extracted with a vibratory hammer. In this case, the vibratory 
hammer would be clamped onto the pile and operated while using a crane 
to pull the pile upwards.
    Next, the new piles would be installed. First the piles would be 
vertically stabilized by being vibrated into the existing 4-foot deep 
sockets. Next the piles would be socketed into the underlying bedrock 
with a down-hole drill and under-reamer bit (the drill will be used 
first to drill a hole in the bedrock to a depth of approximately 12 
feet and then to socket the pile into the bedrock). After the pile is 
socketed, the contractor may choose to impact proof the piles. In this 
case, two to five blows of an impact hammer would be used per pile to 
confirm that piles are set into bedrock.
    Pile removal and installation are expected to occur on three days. 
On the first day the existing piles would be removed, and the new piles 
would be vibrated into position. Over the second and third day, the 
piles would be socketed into bedrock. At the end of the third day, the 
piles would be impact proofed, if necessary. Table 1 provides a 
conservative estimate of the amount of time required for pile 
installation and removal.

                                   Table 1--Pile Driving Construction Summary
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                                                                 Permanent  pile      Max  installation/ removal
                                     Existing pile  removal       installation                 per day
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Pile Diameter and Type.............  16-inch steel.........  16-inch steel.........
Number of Piles....................  6 piles...............  6 piles...............
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                                         Vibratory Pile Removal/Driving
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Max Number of Piles Vibrated Per     6 piles...............  6 piles...............  12 piles.
 Day.
Vibratory Time Per Pile............  5 minutes.............  5 minutes.............
Vibratory Time per day.............  30 minutes............  30 minutes............  60 minutes.
Vibratory Time Total...............  30 minutes............  30 minutes............
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[[Page 7025]]

 
                                         Socketing (down-hole drilling)
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Max Number of Piles Socketed per     0.....................  3 piles...............  3 piles.
 Day.
Socket Time Per Pile...............  0.....................  2 hours...............
Socket Time per Day................  0.....................  6 hours...............  6 hours.
Socket Time Total..................  0.....................  12 hours..............
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                                               Impact Pile Driving
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Max Number of Piles Impacted Per     0.....................  6 piles...............  6 piles.
 Day.
Number of Strikes Per Pile.........  0.....................  2-5 strikes...........  30 strikes.
Impact Time Per Pile...............  0.....................  30 seconds............
Impact Time per Day................  0.....................  3 minutes.............  3 minutes.
Impact Time Total..................  0.....................  3 minutes.............
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    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SAR; 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 with expected potential for occurrence in 
Crescent Bay and summarizes information related to the population or 
stock, including regulatory status under the MMPA and ESA and potential 
biological removal (PBR), where known. For taxonomy, we follow 
Committee on Taxonomy (2018). 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' 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' U.S. Alaska SARs (e.g., Muto et al. 2018). All values presented 
in Table 2 are the most recent available at the time of publication and 
are available in the 2017 SARs (Muto et al. 2018) and draft 2018 SARs 
(available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports)

                              Table 2--Marine Mammals Potentially Present Within Sitka Sound During the Specified Activity
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                                                                                         ESA/ MMPA status;   Stock abundance  (CV,
             Common name                  Scientific name               Stock            Strategic  (Y/N)      NMin, most recent       PBR     Annual  M/
                                                                                                \1\          abundance survey) \2\               SI \3\
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                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Balaenidae:
    Humpback whale..................  Megaptera novaeangliae.  Central North Pacific..  -, -, Y             10,103 (0.3, 7,891,            83         26
                                                                                                             2006).
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                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Alaska Resident........  -, -, N             2,347 (N/A, 2,347,             24          1
                                                                                                             2012) \4\.
                                                               Northern Resident......  -, -, N             261 (N/A, 261,               1.96          0
                                                                                                             2011)\4\.
                                                               Gulf of Alaska,          -, -, N             587 (N/A, 587, 2012)         5.87          1
                                                                Aleutian Islands,                            \4\.
                                                                Bering Sea Transient.
                                                               West Coast Transient...  -, -, N             243 (N/A, 243, 2009)          2.4          0
                                                                                                             \4\.
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  Southeast Alaska.......  -, -, Y             975 (0.12-0.14, 897,          8.9         34
                                                                                                             2012) \5\.
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[[Page 7026]]

 
                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Western U.S............  E, D, Y             54,267 (N/A, 54,267,          326        252
                                                                                                             2017).
                                                               Eastern U.S............  -, D, Y             41,638 (N/A, 41,638,         2498        108
                                                                                                             2015).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina           Sitka/.................  -, -, N             14,855 (N/A, 13,212,          555         77
                                       richardii.              Chatham Strait.........                       2011).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable (N/A).
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.
\4\ N is based on counts of individual animals identified from photo-identification catalogs.
\5\ In the SAR for harbor porpoise, NMFS identified population estimates and PBR for porpoises within inland southeast Alaska waters (these abundance
  estimates have not been corrected for g(0); therefore, they are likely conservative).

    Multiple additional marine mammal species may occasionally enter 
Sitka sound but would not be expected to occur in shallow nearshore 
waters of the action area. These include extralimital species, which 
are species that do not normally occur in a given area but for which 
there are one or more occurrence records that are considered beyond the 
normal range of the species. Gray whales are observed in and outside of 
Sitka Sound during their northward spring migration; however, they 
occur generally north and west of the project area in outer shelf 
waters of Sitka Sound during the summer. Similarly, minke whales in 
Alaska are migratory and would be found further north during the 
summer. Dall's porpoise are observed in mid- to outer-shelf coastal 
waters of Sitka Sound ranging to the Gulf of Alaska and are not 
expected to occur in the project area. Pacific white-sided dolphins 
occur in the outer-shelf slope in the Gulf of Alaska, which is outside 
of the project area. Sperm whales, fin whales and Cuvier's beaked 
whales generally occur in deeper offshore waters. During eight years of 
local surveys, only three gray whales and seven Pacific white sided 
dolphins were observed. The sperm whale, Cuvier's beaked whale, minke 
whale and Dall's porpoise were not observed (Straley et al. 2018). 
Therefore, no take is requested for these species and they are not 
considered further in this proposed IHA.

Cetaceans

Humpback Whale
    The humpback whale is distributed worldwide in all ocean basins. In 
winter, most humpback whales occur in the subtropical and tropical 
waters of the Northern and Southern Hemispheres, and migrate to high 
latitudes in the summer to feed. The historic summer feeding range of 
humpback whales in the North Pacific encompassed coastal and inland 
waters around the Pacific Rim from Point Conception, California, north 
to the Gulf of Alaska and the Bering Sea, and west along the Aleutian 
Islands to the Kamchatka Peninsula and into the Sea of Okhotsk and 
north of the Bering Strait.
    Under the MMPA, there are three stocks of humpback whales in the 
North Pacific: (1) The California/Oregon/Washington and Mexico stock, 
consisting of winter/spring populations in coastal Central America and 
coastal Mexico which migrate to the coast of California to southern 
British Columbia in summer/fall; (2) the central North Pacific stock, 
consisting of winter/spring populations of the Hawaiian Islands which 
migrate primarily to northern British Columbia/Southeast Alaska, the 
Gulf of Alaska, and the Bering Sea/Aleutian Islands; and (3) the 
western North Pacific stock, consisting of winter/spring populations 
off Asia which migrate primarily to Russia and the Bering Sea/Aleutian 
Islands. The central North Pacific stock is the only stock that is 
found near the project activities.
    On September 8, 2016, NMFS published a final rule dividing the 
globally listed endangered species into 14 Distinct Population Segments 
(DPS), removing the worldwide species-level listing, and in its place 
listing four DPSs as endangered and one DPS as threatened (81 FR 62259; 
effective October 11, 2016). Two DPSs (Hawaii and Mexico) are 
potentially present within the action area. The Hawaii DPS is not 
listed and the Mexico DPS is listed as threatened under the ESA. The 
Hawaii DPS is estimated to contain 11,398 animals where the Mexico DPS 
is estimated to contain 3,264 animals (Wade et al. 2016).
    Humpback whales are known to undertake seasonal migrations from 
their tropical calving and breeding grounds in winter to their high-
latitude feeding grounds in summer. However, they have been observed in 
Southeast Alaska in all months of the year. Humpback whales are most 
common in Sitka Sound's Eastern Channel in November, December, and 
January (Straley et al. 2018). In late fall and winter, herring 
sometimes overwinter in deep fjords in Silver Bay and Eastern Channel, 
and humpback whales aggregate in these areas to feed on them. At some 
point in the late winter, it is likely that whales migrate south across 
the North Pacific to their mating and calving grounds in Hawaii and 
Mexico; however, this likely occurs after herring have moved out of the 
fjords. In the summer when prey is dispersed throughout Sitka Sound, 
humpback whales also disperse throughout the

[[Page 7027]]

Sound and away from the project area (Straley 2017).
Killer Whale
    Killer whales have been observed in all oceans and seas of the 
world, but the highest densities occur in colder and more productive 
waters found at high latitudes. Killer whales are found throughout the 
North Pacific, and occur along the entire Alaska coast, in British 
Columbia and Washington inland waterways, and along the outer coasts of 
Washington, Oregon, and California (Muto et al. 2017).
    Based on data regarding association patterns, acoustics, movements, 
and genetic differences, eight killer whale stocks are now recognized: 
(1) The Alaska Resident stock; (2) the Northern Resident stock; (3) the 
Southern Resident stock; (4) the Gulf of Alaska, Aleutian Islands, and 
Bering Sea Transient stock; (5) the AT1 Transient stock; (6) the West 
Coast transient stock, occurring from California through southeastern 
Alaska; and (7) the Offshore stock, and (8) the Hawaiian stock. Only 
the Alaska resident; Northern resident; Gulf of Alaska, Aleutian 
Islands, and Bering Sea Transient (Gulf of Alaska transient); and the 
West coast transient stocks are considered in this application because 
other stocks occur outside the geographic area under consideration. Any 
of these four stocks could occur in the action area.
    Local observational data by Straley (2017) demonstrated that 
transient killer whales, primarily from the West Coast transient stock, 
occur most frequently in the project area. Less often, whales from the 
Eastern North Pacific Gulf of Alaska, Aleutian Islands, and Bering Sea 
transient stock occur in the project area. Because of their transient 
nature, it is difficult to predict when killer whales will be present 
in the area. Whales from the Alaska resident stock and the Northern 
resident stock primarily feed on fish and do occur in Southeast Alaska; 
however, they are rare in the project area (Straley 2017).
Harbor Porpoise
    The harbor porpoise inhabits temperate, subarctic, and arctic 
waters. In the eastern North Pacific, harbor porpoises range from Point 
Barrow, Alaska, to Point Conception, California. Harbor porpoise 
primarily frequent coastal waters and occur most frequently in waters 
less than 100 m deep (Hobbs and Waite 2010). They may occasionally be 
found in deeper offshore waters.
    In Alaska, harbor porpoises are currently divided into three 
stocks, based primarily on geography: (1) The Southeast Alaska stock--
occurring from the northern border of British Columbia to Cape 
Suckling, Alaska, (2) the Gulf of Alaska stock--occurring from Cape 
Suckling to Unimak Pass, and (3) the Bering Sea stock--occurring 
throughout the Aleutian Islands and all waters north of Unimak Pass. 
Only the Southeast Alaska stock is considered in this application 
because the other stocks are not found in the geographic area under 
consideration.
    Harbor porpoises commonly frequent nearshore waters, but are not 
common in the project vicinity. Monthly observation from Sitka's Whale 
Park show harbor porpoises occurring infrequently in or near the action 
area in March, April, and October between 1994 to 2002 (Straley et al. 
2018). Meanwhile, no harbor porpoises have been observed more recently 
during monitoring (Windward 2017 and Turnagain 2017, Turnagain 2018).

Pinnipeds

Steller Sea Lion
    The Steller sea lion is the largest of the eared seals, ranging 
along the North Pacific Rim from northern Japan to California, with 
centers of abundance and distribution in the Gulf of Alaska and 
Aleutian Islands. Steller sea lions were listed as threatened range-
wide under the ESA on November 26, 1990 (55 FR 49204). Subsequently, 
NMFS published a final rule designating critical habitat for the 
species as a 20 nautical mile buffer around all major haulouts and 
rookeries, as well as associated terrestrial, air and aquatic zones, 
and three large offshore foraging areas (58 FR 45269; August 27, 1993). 
In 1997, NMFS reclassified Steller sea lions into two DPSs based on 
genetic studies and other information (62 FR 24345; May 5, 1997). 
Steller sea lion populations that primarily occur west of 144[deg] W. 
(Cape Suckling, Alaska) comprise the western DPS (wDPS), while all 
others comprise the eastern DPS (eDPS); however, there is regular 
movement of both DPSs across this boundary (Jemison et al. 2013). Upon 
this reclassification, the wDPS became listed as endangered while the 
eDPS remained as threatened (62 FR 24345; May 5, 1997). In November 
2013, the eDPS was delisted (78 FR 66140). Based on recent observations 
of branded animals in Southeast Alaska, NMFS estimates that 98 percent 
of Steller sea lions occurring within the action area belong to the 
eDPS, leaving 2 percent to the wDPS (Suzie Teerlink, pers. comm, May 
19, 2017).
    Steller sea lions are common in the inside waters of southeastern 
Alaska and are common in the vicinity of the project and both Eastern 
DPS and Western DPS species are thought to be within Sitka Sound. 
Steller sea lions were seen during every month of monitoring (September 
to May) between 1994 and 2002 (Straley et al. 2018).
    Because the action area contains a herring processing plant, 
animals may linger in the area to feed opportunistically. Anecdotal 
evidence from staff at the fish processing plant indicate that multiple 
(up to 10) Steller sea lions may reside in the area for multiple days 
(Straley et al. 2018).
    The project action area does not overlap Steller sea lion critical 
habitat. The Biorka Island haulout is the closest designated critical 
habitat and is over 25 kilometers southwest of the project area. 
Steller sea lions also haul out on buoys and navigational markers in 
Sitka Sound and along the rocky shores of Sugarloaf south of the 
project site. However, these haulouts are far beyond the expected 
extent of in-water and in-air noise disturbance thresholds for hauled 
out pinnipeds.
Harbor Seal
    Harbor seals range from Baja California north along the coasts of 
Washington, Oregon, California, British Columbia, and Southeast Alaska; 
west through the Gulf of Alaska, Prince William Sound, and the Aleutian 
Islands; and north in the Bering Sea to Cape Newenham and the Pribilof 
Islands. They haul out on rocks, reefs, beaches, and drifting glacial 
ice, and feed in marine, estuarine, and occasionally fresh waters. 
Harbor seals are generally non-migratory, with local movements 
associated with such factors as tides, weather, season, food 
availability, and reproduction.
    Harbor seals in Alaska are partitioned into 12 separate stocks 
based largely on genetic structure: (1) The Aleutian Islands stock, (2) 
the Pribilof Islands stock, (3) the Bristol Bay stock, (4) the North 
Kodiak stock, (5) the South Kodiak stock, (6) the Prince William Sound 
stock, (7) the Cook Inlet/Shelikof stock, (8) the Glacier Bay/Icy 
Strait stock, (9) the Lynn Canal/Stephens Passage stock, (10) the 
Sitka/Chatham stock, (11) the Dixon/Cape Decision stock, and (12) the 
Clarence Strait stock. Only the Sitka/Chatham stock is considered in 
this proposed IHA. The range of this stock includes Cape Bingham south 
to Cape Ommaney and the adjacent coastal and inshore waters, including 
the project area.
    Harbor seals are common in the inside waters of southeastern 
Alaska, including

[[Page 7028]]

in the vicinity of the O'Connell Bridge Lightering Float. The species 
were seen during most months of monitoring (September through May) from 
observation from the Sitka Whale Park between 1994 and 2002, except in 
December and May (Straley et al. 2018). Harbor seals were also commonly 
observed at nearby locations according to recent monitoring reports 
(Turnagain 2017 and Windward 2017, Turnagain 2018). Similar to Steller 
sea lions, harbor seals may linger in the action area for multiple 
days; however, no designated haulouts are within close proximity.

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 dB 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Five marine mammal species (three cetacean and two pinniped (one 
otariid and one phocid) species) have the reasonable potential to co-
occur with the proposed survey activities. Of the cetacean species that 
may be present, one is classified as a low-frequency cetacean (i.e., 
humpback whale), one is classified as a mid-frequency cetacean (i.e., 
killer whale), and one is classified as a high-frequency cetacean 
(i.e., harbor porpoise).

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The Estimated Take by Incidental Harassment section 
later in this document includes a quantitative analysis of the number 
of individuals that are expected to be taken by this activity. The 
Negligible Impact Analysis and Determination section considers the 
content of this section, the Estimated Take by Incidental Harassment 
section, and the Proposed Mitigation section, to draw conclusions 
regarding the likely impacts of these activities on the reproductive 
success or survivorship of individuals and how those impacts on 
individuals are likely to impact marine mammal species or stocks.

Description of Sound Sources

    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 and removal, and 
drilling. 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 2018). Non-impulsive sounds (e.g. 
aircraft, machinery operations such as drilling or dredging, vibratory 
pile driving, 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

[[Page 7029]]

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 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).
    Drilling would be conducted using a down-the-hole drill inserted 
through the hollow steel piles. A down-the-hole drill is a drill bit 
that drills through the bedrock using an impact mechanism that 
functions at the bottom of the hole. This breaks up rock to allow 
removal of debris and insertion of the pile. The head extends so that 
the drilling takes place below the pile. The sounds produced by the 
down-the-hole drilling method are considered continuous as the noise 
from the drilling component is dominant. In addition, this method 
likely increases sound attenuation because the noise is primarily 
contained within the steel pile and below ground rather than impact 
hammer driving methods which occur at the top of the pile and introduce 
sound into the water column to a greater degree.
    The likely or possible impacts of CBS'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 and drilling.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal and down-the-hole drilling is 
the primary means by which marine mammals may be harassed from CBS'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 drilling 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 pile 
driving and drilling 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 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 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)--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.

[[Page 7030]]

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 (Tursiops truncatus), 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, vibratory pile driving, 
and down-the-hole drilling. For the project, these activities would not 
occur at the same time and there would likely be pauses in activities 
producing the sound during each day. Given these pauses and that many 
marine mammals are likely moving through the action area and not 
remaining for extended periods of time, the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
removal and drilling 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 and 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; Archer et al. 2010). Behavioral reactions can vary 
not only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al. 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). 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.
    In 2016, the Alaska Department of Transportation and Public 
Facilities (ADOT&PF) documented observations of marine mammals during 
construction activities (i.e., pile driving and down-hole drilling) at 
the Kodiak Ferry Dock (see 80 FR 60636 for Final IHA Federal Register 
notice). In the marine mammal monitoring report for that project (ABR 
2016), 1,281 Steller sea lions were observed within the Level B 
disturbance zone during pile driving or drilling (i.e., documented as 
Level B harassment take). Of these, 19 individuals demonstrated an 
alert behavior, 7 were fleeing, and 19 swam away from the project site. 
All other animals (98 percent) were engaged in activities such as 
milling, foraging, or fighting and did not change their behavior. In 
addition, two sea lions approached within 20 meters of active vibratory 
pile driving activities. Three harbor seals were observed within the 
disturbance zone during pile driving activities; none of them displayed 
disturbance behaviors. Fifteen killer whales and three harbor porpoise 
were also observed within the Level B harassment zone during pile 
driving. The killer whales were travelling or milling while all harbor 
porpoises were travelling. No signs of disturbance were noted for 
either of these species. Given the similarities in activities and 
habitat and the fact the same species are involved, we expect similar 
behavioral responses of marine mammals to the specified activity. That 
is, disturbance, if any, is likely to be temporary and localized (e.g., 
small area movements). Monitoring reports from other recent pile 
driving and down-the-hole drilling projects in Alaska have observed 
similar behaviors (for example, the Biorka Island Dock Replacement 
Project).
    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.,

[[Page 7031]]

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 pile driving 
and removal and down-the-hole drilling that have the potential to cause 
behavioral harassment, depending on their distance from pile driving 
activities. Cetaceans are not expected to be exposed to airborne sounds 
that would result in harassment as defined under the MMPA.
    Airborne noise would primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with 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. Thus, the behavioral harassment 
of these animals is already accounted for in these estimates of 
potential take. Therefore, we do not believe that authorization of 
incidental take resulting from airborne sound for pinnipeds is 
warranted, and airborne sound is not discussed further here.

Marine Mammal Habitat Effects

    CBS construction activities at the O'Connell Bridge lightering 
float could have localized, temporary impacts on marine mammal habitat 
and their prey by increasing in-water sound pressure levels and 
slightly decreasing water quality. 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 impact pile driving, elevated levels of underwater noise 
would ensonify a portion of Sitka Sound where both fish and mammals 
occur and could affect foraging success.
    Construction activities are of short duration and would likely have 
temporary impacts on marine mammal habitat through increases in 
underwater and airborne sound. These sounds would not be detectable at 
the nearest known Steller sea lion haulouts, and all known harbor seal 
haulouts are well beyond the maximum distance of predicted in-air 
acoustical disturbance.
    In-water pile driving, pile removal, and drilling activities would 
also cause short-term effects on water quality due to increased 
turbidity. Local strong currents are anticipated to disburse suspended 
sediments produced by project activities at moderate to rapid rates 
depending on tidal stage. CBS would employ standard construction best 
management practices, thereby reducing any impacts. Therefore, the 
impact from increased turbidity levels is expected to be discountable.

In-Water Construction Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in Crescent Bay and Sitka Sound and 
does not include any BIAs or ESA-designated critical habitat. Pile 
installation/removal and drilling may temporarily increase turbidity 
resulting from suspended sediments. Any increases would be temporary, 
localized, and minimal. CBS must comply with state water quality 
standards during these operations by limiting the extent of turbidity 
to the immediate project area. In general, turbidity associated with 
pile installation is localized to about a 25-foot radius around the 
pile (Everitt et al. 1980). Cetaceans are not expected to be close 
enough to the project pile driving areas to experience effects of 
turbidity, and any pinnipeds would be transiting the area and could 
avoid localized areas of turbidity. Therefore, the impact from 
increased turbidity levels is expected to be discountable to marine 
mammals. Furthermore, pile driving and removal at the project site 
would not obstruct movements or migration of marine mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity in Crescent Bay 
and Sitka Sound.
    The duration of the construction activities is relatively short. 
The construction window is for a maximum of 3 days during daylight 
hours only. Impacts to habitat and prey are expected to be minimal 
based on the short duration of activities.
    In-water Construction Effects on Potential Prey (Fish)--
Construction activities would produce continuous (i.e., vibratory pile 
driving and down-the-hole drilling) and intermittent (i.e. impact 
driving) sounds. Fish react to sounds that are especially strong and/or 
intermittent low-frequency sounds. Short duration, sharp sounds can 
cause overt or subtle changes in fish behavior and local distribution. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan 2001, 2002; Popper and Hastings 2009). 
Sound pulses at received levels of 160 dB may cause subtle changes in 
fish behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al. 1992; Skalski et al. 1992). SPLs of sufficient strength 
have been known to cause injury to fish and fish mortality.
    The most likely impact to fish from pile driving and drilling 
activities at the project area would be temporary behavioral avoidance 
of the area. The duration of fish avoidance of this area after pile 
driving stops is unknown, but a rapid return to normal recruitment, 
distribution and behavior is anticipated. In general, impacts to marine 
mammal prey species are expected to be minor and temporary due to the 
short timeframe for the project.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect forage fish and juvenile salmonid 
outmigratory routes

[[Page 7032]]

in the project area. Both herring and salmon form a significant prey 
base for Steller sea lions, herring is a primary prey species of 
humpback whales, and both herring and salmon are components of the diet 
of many other marine mammal species that occur in the project area. 
Increased turbidity is expected to occur in the immediate vicinity (on 
the order of 10 feet or less) of construction activities. However, 
suspended sediments and particulates are expected to dissipate quickly 
within a single tidal cycle. Given the limited area affected and high 
tidal dilution rates any effects on forage fish and salmon are expected 
to be minor or negligible. In addition, best management practices would 
be in effect, which would limit the extent of turbidity to the 
immediate project area.
    In summary, given the short daily duration of sound associated with 
individual pile driving and drilling events and the relatively small 
areas being affected, pile driving and drilling activities associated 
with the proposed action are not likely to have a permanent, adverse 
effect on any fish habitat, or populations of fish species. Thus, we 
conclude that impacts of the specified activity are not likely to have 
more than short-term adverse effects on any prey habitat or populations 
of prey species. Further, any impacts to marine mammal habitat are not 
expected to result in significant or long-term consequences for 
individual marine mammals, or to contribute to adverse impacts on their 
populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``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 B harassment only, in the form 
of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to impact and vibratory hammers and down-the-
hole drilling. Based on the nature of the activity and the anticipated 
effectiveness of the mitigation measures (i.e., shutdown--discussed in 
detail below in Proposed Mitigation section), Level A harassment is 
neither anticipated nor proposed to be authorized.
    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 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. 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

    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., 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. CBS's proposed activity includes the 
use of continuous (vibratory pile driving/removal and drilling) and 
impulsive (impact pile driving) sources, and therefore 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). CBS's proposed activity includes the use 
of impulsive (impact pile driving) and non-impulsive (vibratory pile 
driving/removal and drilling) 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 3--Thresholds identifying the onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                          PTS onset thresholds * (received level)
              Hearing group              -----------------------------------------------------------------------
                                                   Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans............  Lp,0-pk,flat: 219 dB; LE,p,  LE,p, LF,24h: 199 dB.
                                           LF,24h: 183 dB.

[[Page 7033]]

 
Mid-Frequency (MF) Cetaceans............  Lp,0-pk,flat: 230 dB; LE,p,  LE,p, MF,24h: 198 dB.
                                           MF,24h: 185 dB.
High-Frequency (HF) Cetaceans...........  Lp,0-pk,flat: 202 dB; LE,p,  LE,p, HF,24h: 173 dB.
                                           HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)......  Lp,0-pk.flat: 218 dB; LE,p,  LE,p, PW,24h: 201 dB.
                                           PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).....  Lp,0-pk,flat: 232 dB; LE,p,  LE,p, OW,24h: 219 dB.
                                           OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
  exposure level (LE,p) has a reference value of 1[micro]Pa\2\s. In this table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO 2017). The subscript ``flat''
  is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized
  hearing range of marine mammals (i.e., 7 Hz to 160 kHz). 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 weighted
  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 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 sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving, vibratory 
pile driving and removal and down-the-hole drilling). The maximum 
(underwater) ensonified area is truncated by land masses and largely 
confined to marine waters within Eastern Channel of Sitka Sound, 
extending approximately 7.7 kilometers through Crescent Bay, Middle 
Channel, and into Eastern Channel and encompassing approximately 7.26 
square kilometers (see Figure 5 in the application).
    The distances to the Level A and Level B harassment thresholds were 
calculated based on source levels from the Naval Base Kitsap at Bangor 
EHW-1 Pile Replacement Project, in Bangor, Washington (NAVFAC 2012) and 
the Kodiak Ferry Terminal Project in Kodiak, Alaska (Denes et. al. 
2016) for a given activity and pile type (e.g., vibratory removal/
installation, drilling, and impact pile driving of 24-inch diameter 
steel piles). The vibratory source level is proxy from 24-inch steel 
piles driven at the Naval Base Kitsap in Bangor, Washington (NAVFAC 
2012) and from acoustic modeling of nearshore marine pile driving at 
Navy installations in Puget Sound (United States Navy 2015). The 
socketing source level is proxy from mean measured sources levels from 
drilling of 24-inch diameter piles to construct the Kodiak Ferry 
Terminal (Denes et al. 2016). Sound pressure level root-mean-square 
(SPL rms) values were used to calculate distance to Level A and B 
harassment isopleths for impact pile driving. The source levels of 
168.2 SEL (for Level A harassment) and 181.3 SPL (for Level B 
harassment) are the mean measured levels from the Kodiak Ferry Terminal 
project (Denes et al. 2016).
    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log10 (R 1/R 2), where

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R 1= the distance of the modeled SPL from the driven 
pile, and
R 2= the distance from the driven pile of the initial 
measurement

    A practical spreading value of fifteen is often used under 
conditions, such as at the lightering dock location, where water 
increases with depth as the receiver moves away from the shoreline, 
resulting in an expected propagation environment that would lie between 
spherical and cylindrical spreading loss conditions. Practical 
spreading loss is assumed here.
    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 such as pile 
driving and drilling, NMFS User Spreadsheet predicts the closest 
distance at which, if a marine mammal remained at that distance the 
whole duration of the activity, it would not incur PTS. Inputs used in 
the User Spreadsheet, and the resulting isopleths are reported in 
Tables 4 and 5. Isopleths for Level B harassment associated with impact 
pile driving (160 dB) and vibratory pile driving/removal and drilling 
(120 dB) were also calculated and are can be found in Table 5.

[[Page 7034]]



              Table 4--User Spreadsheet Input Parameters Used for Calculating Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
                                       Vibratory driving         Drilling/socketing          Impact driving
                                  ------------------------------------------------------------------------------
                                   (A.1) Vibratory driving--                               (E.1): Impact pile
       Spreadsheet tab used         stationary source: non-    (A) Stationary source:      driving (stationary
                                     impulsive, continuous         non-impulsive,          source: impulsive,
                                                                     continuous               intermittent
----------------------------------------------------------------------------------------------------------------
Source Level (dB)................  161 RMS SPL                167.7 RMS SPL...........  168.2 SEL.
Weighting Factor Adjustment (kHz)  2.5......................  2.......................  2.
(a) Number of piles in 24-hr.....  12.......................  n/a.....................  6.
(b) Number of strikes/pile.......  n/a......................  n/a.....................  5.
(c) Duration of sound (hours)      n/a......................  6.......................  n/a.
 within 24-h period.
(d) Duration of drive single pile  5........................  n/a.....................  n/a.
 (minutes).
Propagation (xLogR)..............  15.......................  15......................  15.
Distance of source level           10.......................  10......................  10.
 measurement (meters).
----------------------------------------------------------------------------------------------------------------
* n/a: not applicable


         Table 5--Calculated Distances to Level A Harassment and Level B Harassment Isopleths During Pile Installation and Removal and Drilling
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Distance (m) to level A and level B thresholds
                                                         -----------------------------------------------------------------------------------------------
                                     Source level at 10                                       Level A
             Activity                    meters (dB)     --------------------------------------------------------------------------------
                                                           Low-frequency  Mid- frequency  High-frequency                                      Level B
                                                             cetaceans       cetaceans       cetaceans        Phocid          Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel removal and           161 SPL.............             6.8             0.6            10.1             4.2             0.3           5,412
 installation (12 piles) (~1 hour
 on 1 day).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Drilling/Socketing Pile Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6       167.7 SPL...........             6.3             0.4             5.6             3.4             0.2         *15,136
 piles) (6 hours per day on 2
 days).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6       168.2 SEL/181.3 SPL.             9.9             0.4            11.8             5.3             0.4             263
 piles) (~3 minutes per day on 1
 day).
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Ensonified are area would be truncated by land masses with a maximum extent of 7.7 km.

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 that will inform the take 
calculations and how this information is brought together to produce a 
quantitative take estimate.
    Density information is not available for marine mammals in the 
project area. Potential exposures for marine mammals were estimated 
from several sources. Between the months of September through May from 
1994 to 2002, weekly surveys were conducted at Sitka's Whale Park, 
located at the easternmost end of Eastern Channel as shown in Figure 5 
in the application. More recent data (from 2002 to present) were 
collected from small vessels or Allen Marine 100-foot catamarans during 
school field trips in and around Eastern Channel. Additionally, marine 
mammal observational data was collected in the Sitka Channel as part of 
the Gary Paxton Industrial Park (GPIP) Multipurpose Dock Project 
(Turnagain 2017). Monitors were present during twenty-two days of in 
water work as part of this project. This included ten days between 
October 9th and 20th, 2017 for wooden pile removal, where only one 
monitor was present each day and twelve days between October 22nd and 
November 9th, where two observers were monitoring during new pile 
installation. Additionally, data was collected in January and October/
November of 2017 in the Sitka Channel when Petro Marine Services 
removed and replaced a fuel float in the Sitka Channel and recorded 
marine mammal observations (Windward 2017). Finally, marine mammal 
observation reports covering the months of June through September, 2018 
were also reviewed (Turnagain 2018).

Level B Harassment Calculations

    The estimation of takes by Level B harassment uses the following 
calculation:
    Level B harassment estimate = N (number of animals in the 
ensonified area) * Number of days of noise generating activities.

Humpback Whale

    Humpback whales are the most commonly observed baleen whale in 
Southeast Alaska, particularly during spring and summer months. 
Humpback whales frequent the action area and could be encountered 
during any given

[[Page 7035]]

day of pile driving/removal activities. In the project vicinity, 
humpback whales typically occur in groups of 1 to 2 animals, with an 
estimated maximum group size of 4 animals. Most humpback whales 
observed in the area were solitary. When more than one whale was 
observed, available survey data reports a typical group size of 2-4 
whales (Straley et al. 2018). During work on GPIP Dock, groups of 5 and 
10 individuals were seen a few times, but most of the time, single 
whales were observed (Turnagain 2017). CBS conservatively estimates 
that a group of 5 humpback whales may occur within the Level B 
harassment zone every day of the 3-day construction window during 
active pile driving (5 animals in a group x 1 group each day x 3 days = 
15 animals). Therefore, CBS requests and NMFS proposes to authorize 15 
Level B harassment takes of humpback whales. Based on Wade et al. 
(2016), the probability is that 93.9 percent of the humpback whales 
taken would be from the Hawaii DPS (not listed under ESA) and 6.1 
percent of the humpback whales taken would be from the ESA-listed 
threatened Mexico DPS.

Killer Whale

    Killer whales pass through the action area and could be encountered 
during any given day of pile removal and installation. In the project 
vicinity, typical killer whale pod sizes vary from between 4-8 
individuals, with an estimated maximum group size of 8 animals (Straley 
et al. 2018). A pod of three killer whales were observed during 
monitoring for the Petro Marine Dock, and a pod of seven whales were 
observed on one day near Biorka Island (Windward 2017; Turnagain 2018). 
CBS estimates that a group of 8 killer whales may occur within the 
Level B harassment zone every day of during active pile driving (8 
animals in a group x 1 group each day x 3 days = 24 animals). 
Therefore, CBS requests and NMFS proposes to authorize 24 killer whales 
takes by Level B harassment.

Harbor Porpoise

    Harbor porpoises are seen infrequently in the action area, but they 
could be encountered during any given day of pile replacement 
activities. The mean group size of harbor porpoise in Southeast Alaska 
was estimated to be between 2 to 3 individuals (Dahlheim et al., 2009). 
In the project vicinity, harbor porpoises typically occur in groups of 
1-5 animals, with an estimated maximum group size of 8 animals (Straley 
et al. 2018). No harbor porpoises were seen during the Petro Marine 
Dock construction monitoring in January 2017 or during monitoring for 
the GPIP dock between October and November of 2017 (Windward 2017 and 
Turnagain 2017). CBS conservatively estimates that a group of 5 harbor 
porpoise may occur within the Level B harassment zone once each day 
during the 3-day construction window during active pile driving (5 
animals in a group x 1 group each day x 3 days = 15 animals). 
Therefore, CBS conservatively requests and NMFS proposes to authorize 
15 Level B harassment takes of harbor porpoises.

Harbor Seal

    Harbor seals are common in the action area and are expected to be 
encountered during pile replacement activities. In the action area 
harbor seals typically occur in groups of 1-3 animals. Observations 
near Sitka Channel recorded only individual seals, and observations for 
GPIP dock observed mostly individuals, however, a few groups with up to 
3 seals were observed. Near Biorka Island, recent sightings ranged from 
1 individual to a group of 9 (June and September 2018) groups up to 3 
(July 2018), and groups up to 8 (August 2018). Harbor seals could occur 
in the project area every day. CBS conservatively estimates that 2 
groups of 3 harbor seals may occur within the Level B harassment zone 
every day that pile driving occurs (3 animals in a group x 2 groups per 
day x 3 days = 18 animals). Therefore, CBS requests and NMFS proposes 
to authorize 18 harbor seal takes by Level B harassment.

Steller Sea Lion

    Steller sea lions are common in the action area and are expected to 
be encountered during pile removal and driving. In the project vicinity 
Steller sea lions typically occur in groups of 1-8 animals near the 
project area (Turnagain 2017 and Windward 2017), with an estimated 
maximum group size of 100 animals (Straley et al. 2018). Steller sea 
lions can occur in the action area every day during construction. CBS 
conservatively estimates that a group of 8 Steller sea lions may occur 
within the Level B harassment zone every day that pile driving occurs 
(8 animals in a group x 1 group x 3 days = 24 animals). Therefore, CBS 
requests and NMFS proposes to authorize 24 takes of sea lion by Level B 
harassment.
    CBS intends to avoid Level A harassment take by shutting down 
removal or installation activities at the approach of any marine mammal 
into their representative Level A harassment (PTS onset) zone.

            Table 6--Estimated Take by Level B Harassment, by Species and Stock and Percent of Stock
----------------------------------------------------------------------------------------------------------------
                                                                                                    Percent of
                    Species                                   Stock                   Level B          stock
----------------------------------------------------------------------------------------------------------------
Humpback Whale................................  Central North Pacific (10,103)..              15            0.01
Killer Whale..................................  Alaska Resident (2,347).........          \1\ 24            1.02
                                                Northern Resident (261)                                     9.20
                                                West Coast Transient (243)                                  9.88
                                                Gulf of Alaska, Aleutian                                     4.1
                                                 Islands, Bering Sea Transient
                                                 (587)
Harbor Porpoise...............................  Southeast Alaska (975)..........              15            1.54
Harbor Seal...................................  Sitka/Chatham Strait (14,855)...              18           <0.01
Steller Sea Lion..............................  Western DPS (54,267)............          \1\ 24            0.04
                                                Eastern DPS (41,638)                                        0.06
----------------------------------------------------------------------------------------------------------------
\1\ Assumes all takes come from each individual stock.

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for

[[Page 7036]]

incidental take authorizations to include information about the 
availability and feasibility (economic and technological) of equipment, 
methods, and manner of conducting such activity or other means of 
effecting the least practicable adverse impact upon the affected 
species or stocks and their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    In addition to the measures described later in this section, CBS 
will employ the following standard mitigation measures:
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity, and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For in-water heavy machinery work other than pile driving 
(e.g., standard barges, etc.), if a marine mammal comes within 10 m, 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions. This 
type of work could include the following activities: (1) Movement of 
the barge to the pile location; or (2) positioning of the pile on the 
substrate via a crane (i.e., stabbing the pile);
     Work may only occur during daylight hours, when visual 
monitoring of marine mammals can be conducted;
     For those marine mammals for which take by Level B 
harassment has not been requested, in-water pile installation/removal 
and drilling will shut down immediately if such species are observed 
within or on a path towards the monitoring zone (i.e., Level B 
harassment zone); and
     If take reaches the authorized limit for an authorized 
species, pile driving activities will be stopped as these species 
approach the Level B harassment zone to avoid additional take.
    The following measures would apply to CBS's mitigation 
requirements:
    Establishment of Shutdown Zone--For all pile driving/removal and 
drilling activities, CBS would establish a shutdown zone to avoid take 
by Level A harassment. The purpose of a shutdown zone is generally 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). The shutdown zone would be 10 m in all cases except 
for high-frequency cetaceans (harbor porpoises) during impact pile 
driving and vibratory pile driving/removal. In those situations the 
shutdown zone for high-frequency cetaceans would be 15 m (Table 7). 
These defined shutdown zones would be used to prevent incidental Level 
A harassment exposures and reduce the potential for such take for other 
species. The placement of Protected Species Observers (PSOs) during all 
pile driving and drilling activities (described in detail in the 
Monitoring and Reporting Section) will ensure shutdown zones are 
visible.

                                               Table 7--Proposed Shut Down Zone for Each Project Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Low-frequency      Mid-frequency      High-frequency
                       Noise source                            cetaceans      cetaceans (killer  cetaceans (harbor    Phocid (harbor      Otariid (sea
                                                            (humpback whale)        whale)           porpoise)            seal)              lion)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel removal and installation (12 piles) (~1                     10                 10                 15                 10                 10
 hour on 1 day)..........................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Drilling/Socketing Pile Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6 piles) (6 hours per day on                  10                 10                 10                 10                 10
 2 days).................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch steel installation (6 piles) (~3 minutes on 1                     10                 10                 15                 10                 10
 day)....................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Establishment of Monitoring Zones for Level B Harassment--CBS would 
establish monitoring zones to correlate with Level B harassment 
disturbance zones or zones of influence which are areas where SPLs are 
equal to or exceed the 160 dB rms threshold for impact driving and the 
120 dB rms threshold during vibratory driving and drilling. 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 cease of activity should the animal enter the shutdown 
zone. The proposed monitoring zones are described in Table 8. The 
monitoring zone for drilling activities extends 7,700 m from the noise 
source, corresponding to the maximum distance before landfall. It is 
likely that PSOs would not be able to effectively observe the entire 
monitoring zone. Therefore, Level B harassment exposures will be 
recorded and extrapolated based upon the number of observed takes and 
the

[[Page 7037]]

percentage of the Level B harassment zone that was not visible.

              Table 8--Level B Harassment Monitoring Zones
------------------------------------------------------------------------
                                                        Monitoring zones
                                                       for take by Level
              Pile driving noise source                   B harassment
                                                            (meters)
------------------------------------------------------------------------
                         Vibratory Pile Driving
------------------------------------------------------------------------
16-inch steel removal and installation (12 piles) (~1              5,500
 hour on 1 day)......................................
------------------------------------------------------------------------
                       Socketing Pile Installation
------------------------------------------------------------------------
16-inch steel installation (6 piles) (6 hours per day              7,700
 on 2 days)..........................................
------------------------------------------------------------------------
                           Impact Pile Driving
------------------------------------------------------------------------
16-inch steel installation (6 piles) (~3 minutes per                 265
 day on 1 day).......................................
------------------------------------------------------------------------

    Use of Pile Caps/Cushions--Pile driving softening material (i.e. 
pile caps/cushions) will be used to minimize noise during vibratory and 
impact pile driving. Much of the noise generated during pile 
installation comes from contact between the pile being driven and the 
steel template used to hold the pile in place. The contractor will use 
high-density polyethylene (HDPE) or ultra-high-molecular-weight 
polyethylene (UHMW) softening material on all templates to eliminate 
steel on steel noise generation.
    Direct Pull--To minimize construction noise levels as much as 
possible, the contractor will first attempt to direct pull old piles; 
if those efforts prove to be ineffective, they will proceed with a 
vibratory hammer.
    Reduced Energy-- To reduce noise production, the vibratory hammer 
will be operated at a reduced energy setting (30 to 50 percent of its 
rated energy).
    Soft Start--The use of 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 
would be required to provide an initial set of strikes from the hammer 
at reduced energy, with each strike followed by a 30-second waiting 
period. This procedure would be conducted a total of three times before 
impact pile driving begins. Soft start would be implemented at the 
start of each day's impact pile driving (if more than one day) and at 
any time following cessation of impact pile driving for a period of 
thirty minutes or longer. Soft start is not required during vibratory 
pile driving and removal activities.
    Pre-Activity Monitoring--Prior to the start of daily in-water 
construction activity, or whenever a break in pile driving/removal or 
drilling 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 cleared when a marine mammal has not been observed within the zone 
for the 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. If the Level B 
harassment zone has been observed for 30 minutes and non-permitted 
species are not present within the zone, soft start procedures can 
commence and work can continue even if visibility becomes impaired 
within the Level B harassment monitoring zone. When a marine mammal 
permitted for Level B take is present in the Level B harassment zone, 
activities may begin and Level B take will be recorded. As stated 
above, if the entire Level B harassment zone is not visible at the 
start of construction, piling driving or drilling activities can begin. 
If work ceases for more than 30 minutes, the pre-activity monitoring of 
both the Level B harassment and shutdown zone will commence.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

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

[[Page 7038]]

cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.
    Monitoring shall be conducted by NMFS-approved PSOs. Trained 
observers shall be placed from the best vantage point(s) practicable to 
monitor for marine mammals and implement shutdown or delay procedures 
when applicable through communication with the equipment operator. 
Observer training must be provided prior to project start, and shall 
include instruction on species identification (sufficient to 
distinguish the species in the project area), description and 
categorization of observed behaviors and interpretation of behaviors 
that may be construed as being reactions to the specified activity, 
proper completion of data forms, and other basic components of 
biological monitoring, including tracking of observed animals or groups 
of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal and drilling 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. Pile driving/removal and drilling 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.
    PSOs would scan the waters using binoculars, and/or spotting 
scopes, and would use a handheld GPS or range-finder device to verify 
the distance to each sighting from the project site. All PSOs would be 
trained in marine mammal identification and behaviors and are required 
to have no other project-related tasks while conducting monitoring. In 
addition, 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. CBS would adhere to 
the following observer qualifications:
    (i) Independent observers (i.e., not construction personnel) are 
required.
    (ii) At least one observer must have prior experience working as an 
observer.
    (iii) Other observers may substitute education (degree in 
biological science or related field) or training for experience.
    (iv) NMFS will require submission and approval of observer CVs.
    CBS must ensure that observers have the following additional 
qualifications:
    1. Ability to conduct field observations and collect data according 
to assigned protocols;
    2. Experience or training in the field identification of marine 
mammals, including the identification of behaviors;
    3. Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    4. 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
    5. 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.
    Two land-based PSOs would be used to monitor the area during all 
pile driving and removal activities. One PSO would monitor from the 
O'Connell Bridge which features a high vantage point with unobstructed 
views of, and close proximity to, the project site. A second monitor 
would be stationed east of the construction site, likely off Islander 
Drive. PSOs will work in shifts lasting no longer than 4 hours with at 
least a 1-hour break between shifts, and will not perform duties as a 
PSO for more than 12 hours in a 24-hr period to reduce PSO fatigue.
    A draft marine mammal monitoring report would be submitted to NMFS 
within 90 days after the completion of pile driving and removal and 
drilling activities. It will include an overall description of work 
completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
driven or removed and by what method (i.e., impact or vibratory);
     Weather parameters and water conditions during each 
monitoring period (e.g., wind speed, percent cover, visibility, sea 
state);
     The number of marine mammals observed, by species, 
relative to the pile location and if pile driving or removal was 
occurring at time of sighting;
     Age and sex class, if possible, of all marine mammals 
observed;
     PSO locations during marine mammal monitoring;
     Distances and bearings of each marine mammal observed to 
the pile being driven or removed for each sighting (if pile driving or 
removal was occurring at time of sighting);
     Description of any marine mammal behavior patterns during 
observation, including direction of travel;
     Number of individuals of each species (differentiated by 
month as appropriate) detected within the monitoring zone, and 
estimates of number of marine mammals taken, by species (a correction 
factor may be applied to total take numbers, as appropriate);
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any; and
     Description of attempts to distinguish between the number 
of individual animals taken and the number of incidences of take, such 
as ability to track groups or individuals.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury, serious injury or mortality, CBS would 
immediately cease the specified activities and report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the Alaska Regional Stranding Coordinator. The 
report would include the following information:
     Description of the incident;
     Environmental conditions (e.g., Beaufort sea state, 
visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;

[[Page 7039]]

     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with CBS to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. CBS would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that CBS discovers an injured or dead marine mammal, 
and the lead PSO determines that the cause of the injury or death is 
unknown and the death is relatively recent (e.g., in less than a 
moderate state of decomposition as described in the next paragraph), 
CBS would immediately report the incident to the Chief of the Permits 
and Conservation Division, Office of Protected Resources, NMFS, and the 
Alaska Regional Stranding Coordinator. The report would include the 
same information identified in the paragraph above. Activities would be 
able to continue while NMFS reviews the circumstances of the incident. 
NMFS would work with CBS to determine whether modifications in the 
activities are appropriate.
    In the event that CBS discovers an injured or dead marine mammal 
and the lead PSO determines that the injury or death is not associated 
with or related to the activities authorized in the IHA (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), CBS would report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the Alaska Regional Stranding Coordinator, within 
24 hours of the discovery. CBS would provide photographs, video footage 
(if available), or other documentation of the stranded animal sighting 
to NMFS and the Marine Mammal Stranding Network.

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).
    Pile driving, pile removal and drilling activities as outlined 
previously, have the potential to disturb or displace marine mammals. 
Specifically, the specified activities may result in take in the form 
of Level B harassment from underwater sounds generated from vibratory 
pile removal, vibratory pile driving, impact pile driving, and drilling 
over 3 days. Potential takes could occur if individuals of these 
species are present in the ensonified zone when these activities are 
underway. One day of work would be dedicated to removing 6 old and 
installing 6 new piles which would emit low levels of noise into the 
aquatic environment if removed via direct pull or vibratory hammer and 
installed via vibratory hammer as proposed. Vibratory removal and 
installation would take approximately one hour. Drilling would occur 
for only 6 hours per day over 2 days. Impact driving would be used to 
proof socketed piles and take place for a total of 3 minutes on a 
single day.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff 
2006; HDR, Inc. 2012; Lerma 2014; ABR 2016). Most likely, 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. The pile driving activities analyzed here are 
similar to, or less impactful than, numerous other construction 
activities conducted in southeast Alaska, which have taken place with 
no known long-term adverse consequences from behavioral harassment. 
Level B harassment will be reduced to the level of least practicable 
adverse impact through use of mitigation measures described herein and, 
if sound produced by project activities is sufficiently disturbing, 
animals are likely to simply avoid the area while the activity is 
occurring.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. 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 stock through 
effects on annual rates of recruitment or survival:
     No mortality is anticipated or authorized;
     No Level A take is authorized;
     Level B harassment may consist of, at worst, temporary 
modifications in behavior (e.g. temporary avoidance of habitat or 
changes in behavior);
     The specified activity is temporary and of short duration;
     The ensonified area is very small relative to the overall 
habitat ranges of all species and does not include habitat areas of 
special significance (BIAs or ESA-designated critical habitat); and
     The presumed efficacy of the proposed mitigation measures 
in reducing the effects of the specified activity to the level of least 
practicable adverse impact.
    In addition, although affected humpback whales and Steller sea 
lions may be from a DPS that is listed under the ESA, it is unlikely 
that minor noise effects in a small, localized area of habitat would 
have any effect on the stocks' ability to recover. In

[[Page 7040]]

combination, we believe that these factors, as well as the available 
body of evidence from other similar activities, demonstrate that the 
potential effects of the specified activities will have only minor, 
short-term effects on individuals. The specified activities are not 
expected to impact rates of recruitment or survival and will therefore 
not result in population-level impacts.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under 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. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    Table 6 presents the number of animals that could be exposed to 
received noise levels that may result in Level B take for the proposed 
work at O'Connell Bridge. Our analysis shows that less than 10 percent 
of the best available population estimate of each affected stock could 
be taken. Furthermore, these percentages conservatively assume that all 
takes of killer whale and Steller sea lion would be accrued to a single 
stock, when multiple stocks are known to occur in the project area. 
Therefore, the numbers of animals authorized to be taken for all 
species would be considered small relative to the relevant stocks or 
populations even if each estimated taking occurred to a new 
individual--an extremely unlikely scenario. For pinnipeds, especially 
harbor seals and Steller sea lions, occurring in the vicinity of the 
project site, there could be some overlap in individuals present day-
to-day, and these takes are likely to occur only within some small 
portion of the overall regional stock.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    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 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.
    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). The proposed project is in an area where subsistence hunting for 
harbor seals or sea lions could occur (Wolfe et al., 2013), but the 
area near the proposed project location is not preferred for hunting.
    During September 2018, CBS contacted the Alaska Harbor Seal 
Commission, the Alaska Sea Otter and Steller Sea Lion Commission, and 
the Sitka Tribe of Alaska. These organizations expressed no concerns 
about the impact of the proposed action on subsistence marine mammals 
or their harvest by hunters near the project area. The Sitka Tribe did 
request that no pile driving occur between March 15 and May 31 to 
protect herring, as has been the case for past permitting in Sitka 
Sound. In response to this request, CBS will not commence in-water 
construction operations prior to June 1, 2019 or between March 15, 2020 
and May 31, 2020.
    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 proposed mitigation and 
monitoring measures, NMFS has preliminarily determined that there will 
not be an unmitigable adverse impact on subsistence uses from CBS's 
proposed activities.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it 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 Alaska Regional Office, 
whenever we propose to authorize take for endangered or threatened 
species.
    NMFS is proposing to authorize take of the Steller sea lion western 
DPS and humpback whale Mexico DPS, which are listed under the ESA. The 
NMFS Office of Protected Resources has requested initiation of section 
7 consultation with the Alaska Regional Office for the issuance of this 
IHA. NMFS will conclude the ESA consultation prior to reaching a 
determination regarding the proposed issuance of the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to CBS for the O'Connell Bridge Lightering Float Pile 
Replacement project in Sitka, Alaska from June 1, 2019 through May 31, 
2020, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated. A draft of the IHA itself is 
available for review in conjunction with this notice at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed 
action. We also request comment on the potential for renewal of this 
proposed IHA as described in the paragraph below. Please include with 
your comments any supporting data or literature citations to help 
inform our final decision on the request for MMPA authorization.
    On a case-by-case basis, NMFS may issue a second one-year IHA 
without additional notice when (1) another year of identical or nearly 
identical activities as described in the Specified Activities section 
is planned or (2) the activities would not be completed by the time the

[[Page 7041]]

IHA expires and a second IHA would allow for completion of the 
activities beyond that described in the Dates and Duration section, 
provided all of the following conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA;
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted beyond the 
initial dates either are identical to the previously analyzed 
activities or include changes so minor (e.g., reduction in pile size) 
that the changes do not affect the previous analyses, take estimates, 
or mitigation and monitoring requirements; 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; and
     Upon review of the request for renewal, the status of the 
affected species or stocks, and any other pertinent information, NMFS 
determines that there are no more than minor changes in the activities, 
the mitigation and monitoring measures remain the same and appropriate, 
and the original findings remain valid.

    Dated: February 26, 2019.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2019-03684 Filed 2-28-19; 8:45 am]
BILLING CODE 3510-22-P