Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to City of Cordova Harbor Rebuild Project, Cordova, Alaska, 45149-45172 [2023-14686]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 134 (Friday, July 14, 2023)]
[Notices]
[Pages 45149-45172]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-14686]


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

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD031]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to City of Cordova Harbor Rebuild 
Project, Cordova, Alaska

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

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

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

SUMMARY: NMFS has received a request from the City of Cordova (Cordova) 
for authorization to take marine mammals incidental to the pile driving 
and removal activities over two years associated with the Cordova 
Harbor rebuild project in Cordova, Alaska. Pursuant to the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue two incidental harassment authorizations (IHAs) to 
incidentally take marine mammals during the specified activities. NMFS 
is also requesting comments on possible one-time, one-year renewals for 
each IHA that could be issued under certain circumstances and if all 
requirements are met, as described in Request for Public Comments at 
the end of this 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 August 
14, 2023.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service and should be submitted via email to 
[email protected]. 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.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems accessing these documents, please call 
the contact listed above.
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments, including all attachments, must 
not exceed a 25-megabyte file size. All comments received are a part of 
the public record and will generally be posted online at 
www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities without change. All 
personal identifying information (e.g., name, address) voluntarily 
submitted by the commenter may be publicly accessible. Do not submit 
confidential business information or otherwise sensitive or protected 
information.

FOR FURTHER INFORMATION CONTACT: Rachel Wachtendonk, Office of 
Protected Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth. 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 IHA) 
with respect to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has 
preliminarily determined that the issuance of the proposed 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

[[Page 45150]]

or making a final decision on the IHA request.

Summary of Request

    On February 16, 2023, NMFS received a request from the City of 
Cordova for two IHAs to take marine mammals incidental to pile driving 
and removal activities associated with the City of Cordova, Cordova 
Harbor Rebuild project, in Cordova, Alaska, over the course of two 
years. Following NMFS' review of the application, The City of Cordova 
(Cordova) submitted a revised version on April 19, 2023. The 
application was deemed adequate and complete on May 12, 2023. Cordova's 
request for the first IHA is for take of marine mammals by Level B 
harassment and, for a subset of these species, Level A harassment. For 
the second IHA, Cordova is requesting take of only Steller sea lion 
(Eumetopias jubatus) and harbor seal (Phocoena phocoena) by Level A and 
Level B harassment. Neither Cordova nor NMFS expect serious injury or 
mortality to result from this activity and, therefore, IHAs are 
appropriate.

Description of Proposed Activity

Overview

    Cordova proposes to replace existing structures in the Cordova 
Harbor in Cordova, Alaska. The purpose of this project is to remove old 
structures in the harbor and replace them with new structures which 
would improve the safety of the harbor and allow the harbor to better 
accommodate the commercial fishing industry. The City of Cordova is 
located in Orca Inlet within the Prince William Sound. Over the course 
of 2 years spanning September 2023-April 2024 and September 2024-April 
2025, Cordova would use a variety of methods, including vibratory, 
impact, and down-the-hole (DTH) pile driving to remove existing piles 
and to install new ones. These methods of pile driving would introduce 
underwater sounds that may result in take, by Level A and Level B 
harassment, of marine mammals.

Dates and Duration

    Cordova anticipates that the harbor rebuild project would occur 
over 2 years (phases). The in-water work window would last from 
September 2023 to April 2024 (Phase I) and September 2024 to April 2025 
(Phase II), although pile driving/removal activities are only 
anticipated to take 433 hours over 170 days in Phase I and 148 hours 
over 88 days in Phase II. All in-water pile driving would be completed 
during daylight hours. The Phase I IHA would be valid from August 31, 
2023 to August 30, 2024, and the Phase II IHA would be valid from 
August 31, 2024 to August 30, 2025.

Specific Geographic Region

    The City of Cordova harbor is located southeast of Spike Island and 
west of downtown Cordova within the Orca Inlet in Prince William Sound, 
approximately 241 kilometers (km) (150 miles (mi)) southeast of 
Anchorage, Alaska. With a capacity of 711 vessels, the harbor is one of 
Alaska's largest single basin harbors and houses one of the largest 
commercial fishing fleets in the country. The timing of this work is 
planned to not interfere with the commercial fishing season. The depth 
of the harbor ranges from ~2.5 to 7 meters (m) (8 to 22 feet (ft)) in 
depth.
    The harbor consists of two areas: the South Harbor and the North 
Harbor (see Figure 2 in the application for a detailed map). Phase I of 
this project would take place in the South Harbor while Phase II would 
take place in both North and South Harbor.

[[Page 45151]]

[GRAPHIC] [TIFF OMITTED] TN14JY23.000

Detailed Description of the Specified Activity

    The purpose of this project is to improve Cordova Harbor to offer 
safe vessel mooring and better accommodate the current and future 
commercial fishing industry and associated freight to support the local 
economy. Improvements would include replacing all the floats and 
gangways and adding a new drive-down floatplane and vessel service 
facility (drive-down dock) in the South Harbor. This project would not 
increase the number of slips in the harbor, but would provide safer 
access to the existing slips. An increase in vessel traffic is not 
expected as a direct result of the proposed project. This project would 
also include work that is not expected to result in take. During Phase 
I this would include the removal of walk floats, gangways, and a 
seaplane float. Additionally, new floats, gangways, access trestles, 
electrical service lighting, potable water service, fire suppression 
lines, and safety equipment would be installed in the South Harbor. 
During Phase II, the work not expected to result in take would be the 
installation of a bulkhead above the high tide line, a five-ton 
hydraulic crane, and a new boat launch ramp lane.
    Installation of bulkheads in the North (Phase II) and South (Phase 
I) Harbor would involve gravel fill to be placed behind the bulkheads. 
Gravel fill deposition would produce a continuous sound of a relatively 
short duration, does not require seafloor penetration, and would not 
affect habitat for marine mammals and their prey beyond that already 
affected by installation of H-piles and sheet piles, discussed below. 
Further, placement of gravel fill would occur in a dry area behind the 
sheet piles, and placement would occur in a controlled manner so as not 
to compromise the newly installed piles. Dredging in the South Harbor 
during Phase I would involve the removal of 7,646 cubic meters (10,000 
cubic yards) above the high tide line and therefore would not result in 
the take of marine mammals and it is not discussed further. During 
Phase II, approximately 16,820 cubic meters (22,000 cubic yards) of 
material would be removed below the high tide line by dredging in the 
North Harbor. A combination of the dredge soil and imported gravel 
would be used to fill in behind the bulkheads in both the North and 
South Harbor. While marine mammals may behaviorally respond in some 
small degree to the noise generated by dredging operations, given the 
slow, predictable movements of these vessels, and absent any other 
contextual features that would cause enhanced concern, NMFS does not 
expect Cordova's planned dredging to result in the take of marine 
mammals and it is not discussed further.
    Phase I would involve the removal of existing piles, the 
installation and removal of temporary piles, and the installation of 
permanent piles in the South Harbor. During Phase I 130 timber (12 inch 
(in) diameter; 0.3 meters (m)) and 61 old steel (12 in diameter; 0.3 m) 
piles would be removed. Once the existing piles are removed, 155 16-in 
(0.4 m), 70 18-in (0.5 m), and 30 30-in (0.8 m) permanent steel piles 
would be installed. The installation and removal of 61 temporary 24-in 
(0.6 m) steel pipe piles would be completed to support permanent pile 
installation. Vibratory hammers, impact hammers, and DTH drilling would 
be used for the installation and removal of all piles (Table 1). Piles 
would be removed by dead-pull or vibratory methods. The installation 
and removal of temporary piles would be conducted using vibratory 
hammers. All permanent piles

[[Page 45152]]

would be initially installed with a vibratory hammer. After vibratory 
driving, if needed, piles would be impacted into the bedrock with an 
impact hammer. For some piles, a DTH drill would be needed to drive 
piles the final few inches of embedment.
    Phase II would involve the removal of existing piles, the 
installation and removal of temporary piles, and the installation of 
permanent piles in the North and South Harbor. During Phase II 268 12-
in (0.3 m) timber piles would be removed. Then, 24 24-in (0.6 m) steel 
piles, 80 steel H-piles, and 80 steel sheet piles would be installed. 
The installation and removal of 31 temporary 24-in (0.6 m) steel pipe 
piles would be completed to support permanent pile installation. As in 
Phase I, vibratory hammers, impact hammers, and DTH drilling would be 
used for the installation and removal of all piles (Table 2). Piles 
would be removed by dead-pull or vibratory methods. The installation 
and removal of temporary piles would be conducted using vibratory 
hammers. All permanent piles would be initially installed with a 
vibratory hammer. After vibratory driving, if needed, piles would be 
impacted into the bedrock with an impact hammer. For some piles, a DTH 
drill would be needed to drive piles the final few inches of embedment.
BILLING CODE 3510-22-P

[[Page 45153]]

[GRAPHIC] [TIFF OMITTED] TN14JY23.001


[[Page 45154]]


[GRAPHIC] [TIFF OMITTED] TN14JY23.002

BILLING CODE 3510-22-C
    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. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; 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' website (https://www.fisheries.noaa.gov/find-species).
    Table 3 lists all species or stocks for which take is expected and 
proposed to be authorized for this activity, and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and Endangered Species Act (ESA) and potential biological 
removal (PBR), where known. PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a

[[Page 45155]]

marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population (as described in NMFS' SARs). While no 
serious injury or mortality is anticipated or proposed to be authorized 
here, PBR and annual serious injury and mortality from anthropogenic 
sources are included here as gross indicators of the status of the 
species or stocks 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. 2021 Alaska Marine Mammal SARs. All values presented in 
Table 3 are the most recent available at the time of publication 
(including from the draft 2022 SARs) and are available online at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                            Table 3--Species Likely Impacted by the Specified Activities \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/ MMPA status;   Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Killer whale....................  Orcinus orca...........  Alaska Resident........  -/-; N              1,920 (N/A, 1,920,             19        1.3
                                                                                                             2019).
                                                               Gulf of Alaska/Aleutian  -/-; N              587 (N/A, 587, 2012)..        5.9        0.8
                                                                Islands/Bering Sea
                                                                Transient.
                                                               AT1 Transient..........  -/D; N              7 (N/A, 7, 2019)......        0.1          0
Family Phocoenidae (porpoises):
    Dall's porpoise.................  Phocoenoides dalli.....  Alaska.................  -/-; N              UND (UND, UND, 2015)          UND         37
                                                                                                             \5\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Steller sea lion................  Eumetopias jubatus.....  Western DPS............  E/D; Y              52,932 (N/A, 52,932,          318        254
                                                                                                             2019).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  Prince William Sound...  -/-; N              44,756 (N/A, 41,776,         1253        413
                                                                                                             2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\2\ 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.
\3\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A
  CV associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ Population estimate of 13,110 based on surveys from western Prince William Sound, as abundance estimates for the Alaska stock are more than 8 years
  old and are no longer considered reliable (Muto et al., 2022). This population estimate will be used for small numbers calculations.

    As indicated above, all four species (with six managed stocks) in 
Table 3 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur. All species that could 
potentially occur in the proposed survey areas are included in Table 10 
of the IHA application. While northern fur seal, Pacific white-sided 
dolphin, harbor porpoise, humpback whale, fin whale, minke whale, and 
gray whale have been documented in Prince William Sound, the temporal 
and/or spatial occurrence of these species is such that take is not 
expected to occur, and they are not discussed further beyond the 
explanation provided here. These species are all considered to be rare 
(no sightings in recent years) or very rare (no local knowledge of 
sightings within the project vicinity) within Orca Bay according to the 
Prince William Sound Science Center in Cordova (Prince William Sound 
Science Center 2022; Schinella 2022). Given the shallow depths of the 
waters surrounding Cordova Harbor, it would also be unusual for many of 
these species to enter the project area. The take of these species has 
not been requested nor is proposed to be authorized and these species 
are not considered further in this document.

Killer Whale

    Killer whales have been observed in all the world's oceans, but the 
highest densities occur in colder and more productive waters found at 
high latitudes (NMFS 2016). They occur along the entire Alaska coast, 
in British Columbia and Washington inland waterways, and along the 
outer coasts of Washington, Oregon, and California (NMFS, 2016). The 
three stocks that are most likely to occur in Prince William Sound are 
the southern Alaska Resident stock, Gulf of Alaska/Aleutian Islands/
Bering Sea Transient stock, and the AT1 Transient stock (Muto et al., 
2022).
    There are three distinct ecotypes, or forms, of killer whales 
recognized: Resident, Transient, and Offshore. The three ecotypes 
differ morphologically, ecologically, behaviorally, and genetically. 
Both residents and transients are common in a variety of habitats and 
all major waterways, including protected bays and inlets. There does 
not appear to be strong seasonal variation in abundance or distribution 
of killer whales, but there was substantial variability between years 
(Dahlheim et al., 2009). Spatial distribution has been shown to vary 
among the different ecotypes, with resident and, to a lesser extent, 
transient killer whales more commonly observed along the continental 
shelf, and offshore killer whales more commonly observed in pelagic 
waters (Rice et al., 2017).
    In the Gulf of Alaska, the offshore killer whale ecotype is found 
in pelagic

[[Page 45156]]

waters off the Aleutian Islands to California and mainly prey on 
sharks; the resident ecotype (southern Alaska residents) ranges from 
Kodiak Island to Southeast Alaska and prefer to eat fish; and two 
different transient populations (Gulf of Alaska transients and AT1 
transients) prefer marine mammals are most often found near the 
Hinchinbrook Entrance and Montague Strait (Myers et al., 2021). A 
tagging study focused on resident killer whale movements in Prince 
William Sound found that killer whales' favored use areas were highly-
seasonal and pod specific, likely timed with seasonal salmon returns to 
spawning streams (Olsen et al., 2018).
    With the exception of the AT1 Transient stock, the populations that 
are known to occur in Prince William Sound are not strategic or 
depleted under the MMPA. Long-term studies of pods belonging to the 
southern Alaska resident stock in the Gulf of Alaska indicate these 
populations are increasing at an estimated growth rate of approximately 
3.4 percent (Matkin et al., 2014). However, both resident and transient 
killer whales were significantly impacted by the 1989 Exxon Valdez Oil 
spill. Prior to the spill, the resident AB pod consisted of 36 members 
and from 1989 to 1990, 14 whales disappeared from the pod. The AB pod 
is considered recovering; however, due to slow reproduction rates only 
28 individuals were observed in 2005 (Exxon Valdez Oil Spill Trustee 
Council 2021). The AT1 Transient stock also experienced high mortality 
following the oil spill, as 11 of the original 22 individuals 
disappeared between 1989 and 1992. The AT1 stock currently numbers only 
seven individuals (Muto et al., 2021).
    Results from the Olsen et al. (2018) satellite tagging surveys in 
Prince William Sound from 2006 to 2014 revealed several core use areas 
for resident killer whales based on pod and season. Most resident pods 
primarily concentrated at the southern end of Prince William Sound in 
Hinchinbrook Entrance during the summer and Montague Strait in the late 
summer and fall. The AD16 pod (estimated 9 animals) and AK pod 
(estimated 19 animals) were the most frequently observed in the 
northern glacial fjords of the sound (Muto et al., 2022; Olsen et al., 
2018).
    Additionally, a 27-year photo identification study in Prince 
William Sound and Kenai Fjords surveyed both populations of transient 
killer whales. The study found that the AT1 transients had higher site 
fidelity to the area, while the Gulf of Alaska transients had a higher 
exchange of individuals (Matkin et al., 2012). Throughout the study, 
survival estimates for both populations was generally high, but there 
was significant population reduction in the AT1 transient after the 
Exxon Valdez oil spill (Matkin et al., 2012). There was no detectable 
decline in the larger Gulf of Alaska transient population after the oil 
spill (Matkin et al., 2012).
    Communication with the Cordova Harbormaster and Prince William 
Sound Science Center scientists indicate that killer whales are 
occasionally observed in the deeper waters of Orca Inlet north of 
Cordova Harbor (Schinella 2022; Prince William Sound Science Center 
2022).

Steller Sea Lion

    Steller sea lions were listed as threatened range-wide under the 
ESA on November 26, 1990 (55 FR 49204). Steller sea lions were 
subsequently partitioned into the western and eastern Distinct 
Population Segments (DPSs; western and eastern stocks) in 1997 (62 FR 
24345, May 5, 1997). The eastern DPS remained classified as threatened 
until it was delisted in November 2013. The western DPS (those 
individuals west of the 144[deg] W longitude or Cape Suckling, Alaska) 
was upgraded to endangered status following separation of the DPSs, and 
it remains endangered today. There is regular movement of both DPSs 
across this 144[deg] W longitude boundary (Jemison et al., 2013) 
however, due to the distance from this DPS boundary, it is likely that 
only western DPS Steller sea lions are present in the project area. 
Therefore, animals potentially affected by the project are assumed to 
be part of the western DPS. Sea lions from the eastern DPS, are not 
likely to be affected by the proposed activity and are not discussed 
further.
    Steller sea lions do not follow traditional migration patterns, but 
will move from offshore rookeries in the summer to more protected 
haulouts closer to shore in the winter. They use rookeries and haulouts 
as resting spots as they follow prey movements and take foraging trips 
for days, usually within a few miles of their rookery or haulout. They 
are generalist marine predators and opportunistic feeders based on 
seasonal abundance and location of prey. Steller sea lions forage in 
nearshore as well as offshore areas, following prey resources. They are 
highly social and are often observed in large groups while hauled out 
but alone or in small groups when at sea (NMFS 2022).
    Steller sea lions are distributed throughout Prince William Sound, 
with patterns loosely correlated to aggregations of spawning and 
migrating prey species, particularly fish and cephalopod species 
(Womble 2005; Sinclair and Zeppelin 2002; Sinclair et al., 2013). 
Steller sea lions may be found in and around Orca Inlet throughout the 
year and are frequently observed inside Cordova Harbor (Schinella 2022; 
Prince William Sound Science Center 2022). They are drawn to fish 
processing plants and high forage value areas such as anadromous 
streams. The Cordova area has several anadromous streams that support 
salmon species (Alaska Department of Fish and Game [ADF&G] 2022) and 
six Alaska Department of Environmental Conservation permitted seafood 
processing plant outfalls that also attract Steller sea lions (ADEC 
2022). While the project action area is within designated Steller sea 
lion critical habitat, there are few essential physical and biological 
habitat features of critical habitat within in the action area. The 
nearest rookery to the proposed project is Seal Rocks (approximately 73 
km northeast of project) off the coast of Hinchinbrook Island and the 
nearest major haulouts are Hook Point (36 kilometers northeast of 
project) and Cape Hinchinbrook (59 km northwest of project; NMFS 2016). 
However, given the small footprint and shallow depth of water in the 
project's action area, prey resources and foraging habitats in the 
action area are expected to be minimal.

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. 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, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential techniques) or estimated hearing ranges (behavioral response 
data, anatomical modeling, etc.). Note that no direct measurements of 
hearing ability have been successfully completed for mysticetes (i.e., 
low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the

[[Page 45157]]

exception for lower limits for low-frequency cetaceans where the lower 
bound was deemed to be biologically implausible and the lower bound 
from Southall et al. (2007) retained. Marine mammal hearing groups and 
their associated hearing ranges are provided in Table 4.

                  Table 4--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section provides a discussion of the ways in which components 
of the specified activity may impact marine mammals and their habitat. 
The Estimated Take of Marine Mammals 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 of Marine Mammals 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 whether those impacts are reasonably expected to, or reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival.

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 vibratory pile removal, impact and vibratory pile installation, 
and Down-the-Hole (DTH) 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 (American National Standards Institute (ANSI) 
1986; National Institute for Occupational Safety and Health (NIOSH) 
1998; ANSI 2005; NMFS 2018a). 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 rise/decay time that 
impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018a). 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).
    Three types of hammers would be used on this project: impact, 
vibratory, and DTH. Impact hammers operate by repeatedly dropping a 
heavy piston onto a pile to drive the pile into the substrate. Sound 
generated by impact hammers is characterized by rapid rise times and 
high peak levels, a potentially injurious combination (Hastings and 
Popper, 2005). Vibratory hammers install piles by vibrating them and 
allowing the weight of the hammer to push them into the sediment. 
Vibratory hammers produce significantly less sound than impact hammers. 
Peak sound pressure levels (SPLs) may be 180 dB or greater, but are 
generally 10 to 20 dB lower than SPLs generated during impact pile 
driving of the same-sized pile (Oestman et al., 2009). Rise time is 
slower, reducing the probability and severity of injury, and sound 
energy is distributed over a greater amount of time (Nedwell and 
Edwards 2002; Carlson et al., 2005).
    A DTH hammer is essentially a drill bit that drills through the 
bedrock using a rotating function like a normal drill, in concert with 
a hammering mechanism operated by a pneumatic (or

[[Page 45158]]

sometimes hydraulic) component integrated into the DTH hammer to 
increase speed of progress through the substrate (i.e., it is similar 
to a ``hammer drill'' hand tool). The sounds produced by the DTH method 
contain both a continuous non-impulsive component from the drilling 
action and an impulsive component from the hammering effect. Therefore, 
we treat DTH systems as both impulsive and non-impulsive sound source 
types simultaneously.
    The likely or possible impacts of Cordova's proposed activity on 
marine mammals involve both non-acoustic and acoustic stressors. 
Potential non-acoustic stressors could result from the physical 
presence of equipment and personnel; however, any impacts to marine 
mammals are expected to be primarily acoustic in nature. Acoustic 
stressors include effects of heavy equipment operation during pile 
driving and drilling.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving or drilling is the primary means by which 
marine mammals may be harassed from the Cordova'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 or 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 or 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 decibels (dB). A TS can be 
permanent or temporary. As described in NMFS (2018), there are numerous 
factors to consider when examining the consequence of TS, including, 
but not limited to, the signal temporal pattern (e.g., impulsive or 
non-impulsive), likelihood an individual would be exposed for a long 
enough duration or to a high enough level to induce a TS, the magnitude 
of the TS, time to recovery (seconds to minutes or hours to days), the 
frequency range of the exposure (i.e., spectral content), the hearing 
and vocalization frequency range of the exposed species relative to the 
signal's frequency spectrum (i.e., how an animal uses sound within the 
frequency band of the signal; e.g., Kastelein et al., 2014), and the 
overlap between the animal and the source (e.g., spatial, temporal, and 
spectral).
    Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent, 
irreversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2018). Available data from 
humans and other terrestrial mammals indicate that a 40 dB threshold 
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward 1960; 
Kryter et al., 1966; Miller 1974; Ahroon et al., 1996; Henderson et 
al., 2008). PTS levels for marine mammals are estimates, as with the 
exception of a single study unintentionally inducing PTS in a harbor 
seal (Kastak et al., 2008), there are no empirical data measuring PTS 
in marine mammals largely due to the fact that, for various ethical 
reasons, experiments involving anthropogenic noise exposure at levels 
inducing PTS are not typically pursued or authorized (NMFS 2018).
    Temporary Threshold Shift (TTS)--TTS is a temporary, reversible 
increase in the threshold of audibility at a specified frequency or 
portion of an individual's hearing range above a previously established 
reference level (NMFS 2018). Based on data from cetacean TTS 
measurements (see Southall et al., 2007), a TTS of 6 dB is considered 
the minimum threshold shift clearly larger than any day-to-day or 
session-to-session variation in a subject's normal hearing ability 
(Schlundt et al., 2000; Finneran et al., 2000, 2002). As described in 
Finneran (2015), marine mammal studies have shown the amount of TTS 
increases with cumulative sound exposure level (SELcum) in an 
accelerating fashion: At low exposures with lower SELcum, the amount of 
TTS is typically small and the growth curves have shallow slopes. At 
exposures with higher SELcum, the growth curves become steeper and 
approach linear relationships with the noise SEL.
    Depending on the degree (elevation of threshold in dB), duration 
(i.e., recovery time), and frequency range of TTS, and the context in 
which it is experienced, TTS can have effects on marine mammals ranging 
from discountable to serious (similar to those discussed in auditory 
masking, below). For example, a marine mammal may be able to readily 
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal 
is traveling through the open ocean, where ambient noise is lower and 
there are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during a 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.
    Many studies have examined noise-induced hearing loss in marine 
mammals (see Finneran (2015) and Southall et al. (2019) for summaries). 
For cetaceans, published data on the onset of TTS are limited to the 
captive bottlenose dolphin (Tursiops truncatus), beluga whale 
(Delphinapterus leucas), harbor porpoise (Phocoena phocoena), and 
Yangtze finless porpoise (Neophocoena asiaeorientalis), and for 
pinnipeds in water, measurements of TTS are limited to harbor seals, 
elephant seals (Mirounga angustirostris), and California sea lions 
(Zalophus californianus). These studies examine hearing thresholds 
measured in marine mammals before and after exposure to intense sounds. 
The difference between the pre-exposure and post-exposure thresholds 
can be used to determine the amount of threshold shift at various post-
exposure times. The amount and onset of TTS depends on the exposure 
frequency. Sounds at low frequencies, well below the region of best 
sensitivity, are less hazardous than those at higher frequencies, near 
the region of best sensitivity (Finneran and Schlundt, 2013). At low 
frequencies, onset-TTS exposure levels are higher compared to

[[Page 45159]]

those in the region of best sensitivity (i.e., a low frequency noise 
would need to be louder to cause TTS onset when TTS exposure level is 
higher), as shown for harbor porpoises and harbor seals (Kastelein et 
al., 2019a, 2019b). In addition, TTS can accumulate across multiple 
exposures, but the resulting TTS will be less than the TTS from a 
single, continuous exposure with the same SEL (Finneran et al., 2010; 
Kastelein et al., 2014; Kastelein et al., 2015a; Mooney et al., 2009). 
This means that TTS predictions based on the total, cumulative SEL will 
overestimate the amount of TTS from intermittent exposures such as 
sonars and impulsive sources. Nachtigall et al. (2018) describe the 
measurements of hearing sensitivity of multiple odontocete species 
(bottlenose dolphin, harbor porpoise, beluga, and false killer whale 
(Pseudorca crassidens)) when a relatively loud sound was preceded by a 
warning sound. These captive animals were shown to reduce hearing 
sensitivity when warned of an impending intense sound. Based on these 
experimental observations of captive animals, the authors suggest that 
wild animals may dampen their hearing during prolonged exposures or if 
conditioned to anticipate intense sounds. Another study showed that 
echolocating animals (including odontocetes) might have anatomical 
specializations that might allow for conditioned hearing reduction and 
filtering of low-frequency ambient noise, including increased stiffness 
and control of middle ear structures and placement of inner ear 
structures (Ketten et al., 2021). Data available on noise-induced 
hearing loss for mysticetes are currently lacking (NMFS, 2018).
    Behavioral Harassment--Exposure to noise from pile driving and 
removal also has the potential to behaviorally disturb marine mammals. 
Available studies show wide variation in response to underwater sound; 
therefore, it is difficult to predict specifically how any given sound 
in a particular instance might affect marine mammals perceiving the 
signal. If a marine mammal does react briefly to an underwater sound by 
changing its behavior or moving a small distance, the impacts of the 
change are unlikely to be significant to the individual, let alone the 
stock or population. However, if a sound source displaces marine 
mammals from an important feeding or breeding area for a prolonged 
period, impacts on individuals and populations could be significant 
(e.g., Lusseau and Bejder 2007; Weilgart 2007).
    Disturbance may result in changing durations of surfacing and 
dives, number of blows per surfacing, or moving direction and/or speed; 
reduced/increased vocal activities; changing/cessation of certain 
behavioral activities (such as socializing or feeding); visible startle 
response or aggressive behavior (such as tail/fluke slapping or jaw 
clapping); avoidance of areas where sound sources are located. 
Pinnipeds may increase their haul out time, possibly to avoid in-water 
disturbance (Thorson and Reyff 2006). Behavioral responses to sound are 
highly variable and context-specific and any reactions depend on 
numerous intrinsic and extrinsic factors (e.g., species, state of 
maturity, experience, current activity, reproductive state, auditory 
sensitivity, time of day), as well as the interplay between factors 
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 
2007; Weilgart 2007). Behavioral reactions can vary not only among 
individuals but also within an individual, depending on previous 
experience with a sound source, context, and numerous other factors 
(Ellison et al., 2012), and can vary depending on characteristics 
associated with the sound source (e.g., whether it is moving or 
stationary, number of sources, distance from the source). In general, 
pinnipeds seem more tolerant of, or at least habituate more quickly to, 
potentially disturbing underwater sound than do cetaceans, and 
generally seem to be less responsive to exposure to industrial sound 
than most cetaceans. Please see Appendices B-C of Southall et al. 
(2007) for a review of studies involving marine mammal behavioral 
responses to sound.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg 
2000). In many cases, an animal's first and sometimes most economical 
(in terms of energetic costs) response is behavioral avoidance of the 
potential stressor. Autonomic nervous system responses to stress 
typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Lankford et al., 2005). Stress responses due to exposure to 
anthropogenic sounds or other stressors and their effects on marine 
mammals have also been reviewed (Fair and Becker 2000; Romano et al., 
2002b) and, more rarely, studied in wild

[[Page 45160]]

populations (e.g., Romano et al., 2002a). For example, Rolland et al. 
(2012) found that noise reduction from reduced ship traffic in the Bay 
of Fundy was associated with decreased stress in North Atlantic right 
whales. These and other studies lead to a reasonable expectation that 
some marine mammals will experience physiological stress responses upon 
exposure to acoustic stressors and that it is possible that some of 
these would be classified as ``distress.'' In addition, any animal 
experiencing TTS would likely also experience stress responses 
(National Research Council (NRC), 2003), however distress is an 
unlikely result of this project based on observations of marine mammals 
during previous, similar projects in the area.
    Masking--Sound can disrupt behavior through masking, or interfering 
with, an animal's ability to detect, recognize, or discriminate between 
acoustic signals of interest (e.g., those used for intraspecific 
communication and social interactions, prey detection, predator 
avoidance, navigation) (Richardson et al., 1995). Masking occurs when 
the receipt of a sound is interfered with by another coincident sound 
at similar frequencies and at similar or higher intensity, and may 
occur whether the sound is natural (e.g., snapping shrimp, wind, waves, 
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar, 
seismic exploration) in origin. The ability of a noise source to mask 
biologically important sounds depends on the characteristics of both 
the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions. Masking of natural sounds can result when human activities 
produce high levels of background sound at frequencies important to 
marine mammals. Conversely, if the background level of underwater sound 
is high (e.g., on a day with strong wind and high waves), an 
anthropogenic sound source would not be detectable as far away as would 
be possible under quieter conditions and would itself be masked.
    Airborne Acoustic Effects--Although pinnipeds are known to haul out 
regularly on man-made objects, we believe that incidents of take 
resulting solely from airborne sound are unlikely due to the sheltered 
proximity between the proposed project area and these haulout sites 
(outside of Orca Inlet). According to the Prince William Sound Science 
Center and the harbor master pinnipeds have not been observed to haul 
out on the breakwaters outside the harbor or on Spike Island facing the 
harbor. Therefore, take resulting solely from airborne sound is 
unlikely for the areas surrounding the harbor. There is a possibility 
that an animal could surface in-water, but with head out, within the 
area in which airborne sound exceeds relevant thresholds and thereby be 
exposed to levels of airborne sound that we associate with harassment. 
Any such occurrence on days with in-water pile driving activities would 
likely be accounted for in our estimation of incidental take from 
underwater sound. On days when pile driving is occurring on land 
immediately adjacent to the harbor, no take from underwater sound would 
occur. However, authorization of incidental take resulting from 
airborne sound for pinnipeds is warranted for days with only upland 
pile driving activities due to the potential for pinnipeds to be 
exposed while hauled out within the harbor or while swimming with their 
heads above the surface. Cetaceans are not expected to be exposed to 
airborne sounds that would result in harassment as defined under the 
MMPA.

Marine Mammal Habitat Effects

    Cordova's construction activities could have localized, temporary 
impacts on marine mammal habitat and their prey by increasing in-water 
sound pressure levels and slightly decreasing water quality. However, 
its proposed location is within the current harbor footprint and is 
located in an area that is currently used by numerous commercial 
fishing and personal vessels. Construction activities are of short 
duration and would likely have temporary impacts on marine mammal 
habitat through increases in underwater and airborne sound. Increased 
noise levels may affect acoustic habitat (see masking discussion above) 
and adversely affect marine mammal prey in the vicinity of the project 
area (see discussion below). During DTH drilling, impact, and vibratory 
pile driving, elevated levels of underwater noise would ensonify the 
project area where both fish and mammals occur and could affect 
foraging success. Additionally, marine mammals may avoid the area 
during construction; however, displacement due to noise is expected to 
be temporary and is not expected to result in long-term effects to the 
individuals or populations.
    Temporary and localized increase in turbidity near the seafloor 
would occur in the immediate area surrounding the area where piles are 
installed or removed. In general, turbidity associated with pile 
installation is localized to about a 25-ft (7.6 m) radius around the 
pile (Everitt et al., 1980). The sediments of the project site would 
settle out rapidly when disturbed. Cetaceans are not expected to be 
close enough to the pile driving areas to experience effects of 
turbidity, and any pinnipeds could avoid localized areas of turbidity. 
Therefore, we expect the impact from increased turbidity levels to be 
discountable to marine mammals and do not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals as the project would not 
expand mooring capacity in Cordova Harbor, and no increases in vessel 
traffic in the area are expected as a result of this project. The total 
seafloor area likely impacted by the project is relatively small 
compared to the available habitat in Southcentral Alaska. Orca Inlet is 
included in the designated critical habitat for western Steller sea 
lions and these sea lions could experience a temporary loss of suitable 
habitat in the action area for 1 to 5 hours per day over 170 days 
during Phase I and 1 to 8.5 hours per day over 88 days during Phase II 
of construction if elevated noise levels associated with in-water 
construction results in their displacement from the area. However, the 
project would only impact the essential physical and biological 
features that make the area critical habitat for western Steller sea 
lions, such as good water quality, prey availability, or open space for 
transiting and foraging when the ensonified area extends beyond Cordova 
Harbor. The area already has elevated noise levels because of busy 
vessel traffic transiting through the area, and critical habitat 
impacts would not be permanent nor would it result long-term effects to 
the local population. No known rookeries or major haulouts would be 
impacted. Additionally, the total seafloor area affected by pile 
installation and removal is a small area compared to the vast foraging 
area available to marine mammals in the area. At best, the impact area 
provides marginal foraging habitat for marine mammals and fishes. 
Furthermore, pile driving 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

[[Page 45161]]

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.

Effects on Potential Prey

    Sound may affect marine mammals through impacts on the abundance, 
behavior, or distribution of prey species (e.g., crustaceans, 
cephalopods, fish, zooplankton, etc.). Marine mammal prey varies by 
species, season, and location. Here, we describe studies regarding the 
effects of noise on known marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick and Mann, 1999; Fay, 
2009). Depending on their hearing anatomy and peripheral sensory 
structures, which vary among species, fishes hear sounds using pressure 
and particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to noise depends on the 
physiological state of the fish, past exposures, motivation (e.g., 
feeding, spawning, migration), and other environmental factors. 
Hastings and Popper (2005) identified several studies that suggest fish 
may relocate to avoid certain areas of sound energy. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 
2009). Several studies have demonstrated that impulse sounds might 
affect the distribution and behavior of some fishes, potentially 
impacting foraging opportunities or increasing energetic costs (e.g., 
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al., 
1992; Santulli et al., 1999; Paxton et al., 2017). However, some 
studies have shown no or slight reaction to impulse sounds (e.g., 
Wardle et al., 2001; Jorgenson and Gyselman, 2009).
    SPLs of sufficient strength have been known to cause injury to fish 
and fish mortality. However, in most fish species, hair cells in the 
ear continuously regenerate and loss of auditory function likely is 
restored when damaged cells are replaced with new cells. Halvorsen et 
al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours 
for one species. Impacts would be most severe when the individual fish 
is close to the source and when the duration of exposure is long. 
Injury caused by barotrauma can range from slight to severe and can 
cause death, and is most likely for fish with swim bladders. Barotrauma 
injuries have been documented during controlled exposure to impact pile 
driving (Halvorsen et al., 2012b; Casper et al., 2013).
    The most likely impact to fish from pile driving activities at the 
project areas would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of an area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect forage fish in the project area. 
Forage fish form a significant prey base for many marine mammal species 
that occur in the project area. Increased turbidity is expected to 
occur in the immediate vicinity (on the order of 10 ft (3 m) 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 are expected to be minor or negligible.
    In summary, given the short daily duration of sound associated with 
individual pile driving events and the relatively small areas being 
affected, pile driving activities associated with the proposed action 
are not likely to have a permanent adverse effect on any fish habitat, 
or populations of fish species. 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. 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 of Marine Mammals

    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 
determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the acoustic sources (i.e., vibratory or impact pile driving and DTH 
drilling) has the potential to result in disruption of behavioral 
patterns for individual marine mammals. There is also some potential 
for auditory injury (Level A harassment) to result, primarily for 
Dall's porpoise and harbor seals, due to the cryptic nature of these 
species in context of larger predicted auditory injury zones. Auditory 
injury is unlikely to occur for mid-frequency species and otariids, 
based on the likelihood of the species in the action area, the ability 
to monitor the entire smaller shutdown zone, and because of the 
expected ease of detection for the former groups. The proposed 
mitigation and monitoring measures are expected to minimize the 
severity of the taking to the extent practicable.
    As described previously, no serious injury or mortality is 
anticipated or proposed to be authorized for this activity. Below we 
describe how the proposed take numbers are estimated.
    For acoustic impacts, generally speaking, we estimate take by 
considering: (1) acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals would be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that would be ensonified above these levels in 
a day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these factors can

[[Page 45162]]

contribute to a basic calculation to provide an initial prediction of 
potential 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 estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment). Thresholds have also been developed identifying the 
received level of in-air sound above which exposed pinnipeds would 
likely be behaviorally harassed.
    Level B Harassment--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 or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile 
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources. For in-air sounds, NMFS predicts that harbor 
seals exposed above received levels of 90 dB re 20 [mu]Pa (rms) would 
be behaviorally harassed, and other pinnipeds would be harassed when 
exposed above 100 dB re 20 [mu]Pa (rms). Generally speaking, Level B 
harassment take estimates based on these behavioral harassment 
thresholds are expected to include any likely takes by TTS as, in most 
cases, the likelihood of TTS occurs at distances from the source less 
than those at which behavioral harassment is likely. TTS of a 
sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    Cordova's proposed activity includes the use of continuous 
(vibratory hammer and DTH drilling) and impulsive (DTH drilling and 
impact pile driving) sources, and therefore the 120 and 160 dB re 1 
[mu]Pa (rms) thresholds are applicable.
    Level A harassment--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). Cordova's 
proposed activity includes the use of impulsive (impact pile-driving 
and DTH drilling) and non-impulsive (vibratory hammer and DTH 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: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including 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 DTH).
    In order to calculate distances to the Level A harassment and Level 
B harassment thresholds for the methods and piles being used in this 
project, NMFS used acoustic monitoring data

[[Page 45163]]

from other locations to develop source levels for the various pile 
types, sizes and methods (Table 6). This analysis uses the practical 
spreading loss model, a standard assumption regarding sound propagation 
for similar environments, to estimate transmission of sound through 
water. For this analysis, the transmission loss factor of 15 (4.5 dB 
per doubling of distance) is used. A weighting adjustment factor of 2.5 
or 2, a standard default value for vibratory pile driving and removal 
or impact driving and DTH respectively, were used to calculate Level A 
harassment areas.
    NMFS recommends treating DTH systems as both impulsive and 
continuous, non-impulsive sound source types simultaneously. Thus, 
impulsive thresholds are used to evaluate Level A harassment, and 
continuous thresholds are used to evaluate Level B harassment. With 
regards to DTH mono-hammers, NMFS recommends proxy levels for Level A 
harassment based on available data regarding DTH systems of similar 
sized piles and holes (Denes et al., 2019; Guan and Miner, 2020; Reyff 
and Heyvaert, 2019; Reyff, 2020; Heyvaert and Reyff, 2021) (Table 1 and 
2 includes number of piles and duration for each phase; Table 6 
includes peak pressure, sound pressure, and sound exposure levels for 
each pile type).

               Table 6--Estimated Underwater Proxy Source Levels for Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
                                                      Proxy source levels (dB) at 10 m
             Pile type                   Phase    ---------------------------------------        Reference
                                                       Peak         RMS          SEL
----------------------------------------------------------------------------------------------------------------
                                             Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
12-24 in timber pile removal.......        I, II   ...........          162  ...........  Greenbusch et al.
                                                                                           (2018), CALTRANS
                                                                                           (2020).
12-24 in steel pile removal........            I   ...........          161  ...........  NAVFAC (2013; 2015).
24 in steel template pile install/         I, II
 removal.
16 in steel pile...................            I
18 in steel pile...................            I
24 in steel pile...................           II
30 in steel pile...................            I   ...........        161.9  ...........  Denes et al. (2016).
Steel H-pile.......................           II   ...........          165  ...........  CALTRANS (2015).
Steel sheet pile...................           II   ...........          162  ...........  Buehler et al. (2015).
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
16 in steel pile...................            I         192.8        181.1        168.3  Denes et al. (2016).
18 in steel pile...................            I
24 in steel pile...................           II
30 in steel pile...................            I           210          190          177  NMFS 2023 analysis *.
Steel H-pile.......................           II           200          177          170  CALTRANS (2015).
Steel sheet pile...................           II           205          190          180  CALTRANS (2015).
----------------------------------------------------------------------------------------------------------------
                                                  DTH Drilling
----------------------------------------------------------------------------------------------------------------
16 in steel pile...................            I   ...........          167          159  Heyvaert and Reyff
                                                                                           (2021).
18-24 in steel pile................         I,II
30 in steel pile...................            I   ...........          174          164  Denes et al. (2019),
                                                                                           Reyff and Heyvaert
                                                                                           (2019), Reyff (2020).
Steel H-pile.......................           II
----------------------------------------------------------------------------------------------------------------
Note: SEL= sound exposure level; RMS = root mean square.
* NMFS used the mean of regionally relevant measurements to determine suitable proxy source values for these
  pile types. Projects included in the analysis were Navy (2012, 2013) and Miner (2020), following the
  methodology of Navy (2015).


                 Table 7--Estimated In-Air Proxy Source Levels for Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
                                                     Proxy source levels  (dB) at 15 m
             Pile type                   Phase    ---------------------------------------        Reference
                                                       Peak         RMS          SEL
----------------------------------------------------------------------------------------------------------------
                                             Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
24 in steel template pile install/             I   ...........        103.2  ...........  Laughlin 2010.
 removal.
18 in steel pile...................
Steel H-pile.......................
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
18 in steel pile...................            I   ...........          101  ...........  Ghebreghzabiher et al.
Steel H-pile.......................                                                        (2017).
----------------------------------------------------------------------------------------------------------------

[[Page 45164]]

 
                                                DTH Drilling \1\
----------------------------------------------------------------------------------------------------------------
18 in steel pile...................            I   ...........          101  ...........  Ghebreghzabiher et al.
Steel H-pile.......................                                                        (2017).
----------------------------------------------------------------------------------------------------------------
Note: SEL = sound exposure level; RMS = root mean square.
\1\ We conservatively assume that the proxy value for DTH driving is the same as for impact driving.

Level B Harassment Zones
    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * log10 (R1/R2),

Where:

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement.

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for Cordova's proposed underwater activities. The Level B 
harassment zones and approximate amount of area ensonified for the 
proposed underwater activities are shown in Table 8. The Level B 
harassment zones for the proposed upland pile driving activities that 
may generate airborne noise are shown in Table 7.

Level A Harassment Zones

    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources, such as pile installation or removal, the optional 
User Spreadsheet tool predicts the distance at which, if a marine 
mammal remained at that distance for the duration of the activity, it 
would be expected to incur PTS. The isopleths generated by the User 
Spreadsheet used the same TL coefficient as the Level B harassment zone 
calculations (i.e., the practical spreading value of 15). Inputs used 
in the User Spreadsheet (e.g., number of piles per day, duration and/or 
strikes per pile) are presented in Tables 1 and 2. The maximum RMS SPL, 
SEL, and resulting isopleths are reported in Tables 6, 7, and 8.

                                      Table 8--Level A and Level B Harassment Isopleths for Pile Driving Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Distances to Level A and Level B thresholds (m)
                                                     ------------------------------------------------------------------------
                Pile type                    Phase                      Level A                                               Ensonified area\1\ \2\ for
                                                     --------------------------------------------           Level B                 Level B (km\2\)
                                                          MF         HF       Phocid    Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Vibratory Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-24 in timber pile removal............      I, II         1.8       30.5       12.5        0.9  6,309.6...................  125.
12-24 in steel pile removal.............          I         1.6       26.1       10.7        0.8  5,411.7...................  92.
24 in steel template pile install/            I, II         0.9       14.2        5.8        0.4
 removal.
16 in steel pile........................          I         1.1       18.6        7.6        0.5
18 in steel pile........................          I         1.4       22.5        9.3        0.7
24 in steel pile........................         II
30 in steel pile........................          I         1.4       24.1        9.9        0.7  6,213.5...................  121.2.
steel H-pile............................         II         1.1       18.7        7.7        0.5  10,000....................  314.
steel sheet pile........................         II         0.7       11.8        4.8        0.3  6,310.....................  125.
In-air pile installation/removal........          I   .........  .........  .........  .........  68.6 (Phocid)/22.8          0.01 (Phocid)/0.002
                                                                                                   (Otariid).                  (Otariid).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
16 in steel pile........................          I         4.7      158.8       71.4        5.2  255.......................  0.2.
18 in steel pile........................          I
24 in steel pile........................         II
30 in steel pile........................          I        23.6      791.3      355.5       25.9  1,000.....................  3.14.
steel H-pile............................         II        12.1      405.3      182.1       13.3  341.5.....................  0.37.
steel sheet pile........................         II        56.2    1,881.2      845.2       61.5  1,000.....................  3.14.
In-air pile installation/removal........          I   .........  .........  .........  .........  53.2 (Phocid)/16.8          0.009 (Phocid)/0.0009
                                                                                                   (Otariid).                  (Otariid).
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 45165]]

 
                                                                      DTH Drilling
--------------------------------------------------------------------------------------------------------------------------------------------------------
16 in steel pile........................          I        32.1    1,075.7      483.3       35.2  13,593.6..................  580.2.
18-24 in steel pile.....................       I,II
30 in steel pile........................          I        61.3   2,052.20        922       67.1  39,810.7..................  4976.6.
steel H-pile............................         II
In-air pile installation/removal........          I   .........  .........  .........  .........  53.2 (Phocid)/16.8          0.009 (Phocid)/0.0009
                                                                                                   (Otariid).                  (Otariid).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Areas were calculated based on areas of a circle with the specified radius from Table 6 and 7 and realized ensonified areas will be smaller due to
  truncation by land masses.
\2\ The ensonified area within Cordova harbor will be no more than 0.19 km.\2\

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including presence, density, local knowledge, or other 
relevant information which will inform the take calculations.
    Daily occurrence probability of each marine mammal species in the 
action area is based on consultation with local researchers and marine 
professionals. Occurrence probability estimates are based on 
conservative density approximations for each species and factor in 
historic data of occurrence, seasonality, and group size in Orca Bay, 
Orca Inlet, and/or Prince William Sound. A summary of proposed take is 
shown in Table 9. To accurately describe species occurrence near the 
action area, marine mammals were described as either common (multiple 
sightings every month, could occur each day), frequent (multiple 
sightings every year, could occur each month), or infrequent (few 
sightings every year, could occur each month).

                       Table 9--Estimated Occurrence of Group Sightings of Marine Mammals
----------------------------------------------------------------------------------------------------------------
           Species                    Frequency               Seasonality           Occurrence    Group size \a\
----------------------------------------------------------------------------------------------------------------
Steller sea lion:
    (within harbor)..........  Common.................  Year-round.............  1 group per day         \b\ 4.1
    (outside harbor).........  Common.................  Year-round.............  2 groups per            \b\ 4.1
                                                                                  day.
Harbor seal:
    (within harbor)..........  Frequent...............  Year-round.............  1 group per day         \c\ 3.5
    (outside harbor).........  Common.................  Year-round.............  2 groups per            \c\ 3.5
                                                                                  day.
Killer whale.................  Infrequent.............  Year-round.............  1 group every            \d\ 14
                                                                                  10 days.
Dall's porpoise..............  Infrequent.............  Year-round.............  1 group every           \e\ 4.3
                                                                                  10 days.
----------------------------------------------------------------------------------------------------------------
\a\ Group size was averaged from seasonal data (Steller sea lions and harbor seals), pod size (killer whales),
  and observational data (Dall's porpoise) for more information see application.
\b\ Leonard and Wisdom (2020); Sigler et al. (2017).
\c\ ADF&G (2022a).
\d\ Muto et al. (2022).
\e\ Moran et al. (2018).

Take Estimation

    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and proposed for authorization.
    For total underwater take estimate, the daily occurrence 
probability for a species was multiplied by the estimated group size 
and by the number of days of each type of pile driving activity. Group 
size is based on the best available published research for these 
species and their presence in this area.

Estimated take = Group size x Groups per day x Days of pile driving 
activity

    Take of pinnipeds by Level B harassment due to airborne noise was 
calculated based on the proportion of area within the harbor likely to 
be ensonified above the thresholds for harbor seals and other 
pinnipeds, respectively. The percent of the harbor ensonified was then 
multiplied by the number of days of pile driving, the group size, and 
groups per day, as done for underwater take estimates. The total 
numbers of takes by Level B harassment due to airborne noise proposed 
for authorization for harbor seal and Steller sea lion are 7 and 0, 
respectively.
    Take by Level A harassment is requested for Steller sea lions and 
harbor seals given that these species are known to spend extended 
periods of time within Cordova Harbor and most Level A isopleths are 
contained within Cordova Harbor. The take by Level A harassment 
calculations are based on lower daily occurrence estimates for each 
species than take by Level B harassment calculations based on input 
from marine professionals in the community about their presence in 
within the smaller ensonified zone of the harbor (Table 9; Greenwood 
2022). Take by Level A harassment is also requested for Dall's porpoise 
for impact driving of sheet piles and DTH drilling of 30 in and H-piles 
as it is not practicable to observe and shut down for porpoises 
throughout the entire Level A zone (1,885 m for impact driving and 
2,050 m for DTH drilling). Additionally, Level A harassment isopleths 
for most hearing groups and pile types were less than 10 m (Table 8) 
which is the minimum shutdown zone for this project (see Proposed 
Mitigation). Because the Level A isopleths for those piles are within 
the minimum 10 m shutdown zone, no takes by Level A harassment are 
expected to occur from those activities, and therefore the predicted 
take by Level A harassment were removed from the total take 
calculations (Table 10).
    During Phase II, killer whale and Dall's porpoise are not expected 
to occur within any harassment zones due

[[Page 45166]]

to the relatively shallow water that would be ensonified (south of 
Spike Island into tidal mud flats) and therefore no take was requested 
for these species.

 Table 10--Proposed Take of Marine Mammals by Level A and Level B Harassment and Percent of Stock Proposed To Be
                                                 Taken by Phase
----------------------------------------------------------------------------------------------------------------
                                                        Proposed authorized take
           Species                 Stock/DPS    ---------------------------------------  Stock size   % of stock
                                                   Level A      Level B     Total take      \1\
----------------------------------------------------------------------------------------------------------------
                                                     Phase I
----------------------------------------------------------------------------------------------------------------
Steller sea lion.............  Western DPS.....          107          788          895       52,932         1.69
Harbor seal..................  Prince William            154          681          835       44,756         1.87
                                Sound.
Killer whale \2\.............  Alaska Resident.  ...........           83           83        1,920         4.35
                               Gulf of Alaska/   ...........           26           26          587         4.35
                                Aleutian
                                Islands/Bering
                                Sea Transient.
Dall's porpoise..............  Alaska..........           10           32           42       13,110         0.32
----------------------------------------------------------------------------------------------------------------
                                                    Phase II
----------------------------------------------------------------------------------------------------------------
Steller sea lion.............  Western DPS.....           98          730          828       52,932         1.56
Harbor seal..................  Prince William            133          623          756       44,756         1.69
                                Sound.
----------------------------------------------------------------------------------------------------------------
\1\ Stock size comes from the most recent SARs except for Dall's porpoise whose stock estimate is based on
  surveys from western Prince William Sound only, as abundance estimates for the Alaska stock are more than
  eight years old and no longer considered reliable (Muto et al., 2022).
\2\ AT1 transient stock take calculation resulted in 0.3 takes, therefore no takes were requested or are
  proposed for authorization.

Proposed Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence. NMFS regulations require applicants for incidental take 
authorizations to include information about the availability and 
feasibility (economic and technological) of equipment, methods, and 
manner of conducting the activity or other means of effecting the least 
practicable adverse impact upon the affected species or stocks, and 
their habitat (50 CFR 216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers 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, as 
well as subsistence uses. 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, and impact on 
operations.
    The following mitigation measures are included in the proposed 
IHAs:

Mitigation Measures

    Cordova must follow mitigation measures as specified below:
     Ensure that construction supervisors and crews, the 
monitoring team, and relevant Cordova staff are trained prior to the 
start of all pile driving and DTH drilling activity, so that 
responsibilities, communication procedures, monitoring protocols, and 
operational procedures are clearly understood. New personnel joining 
during the project must be trained prior to commencing work;
    [cir] Employ Protected Species Observers (PSOs) and establish 
monitoring locations as described in the application and the IHA. The 
Holder must monitor the project area to the maximum extent possible 
based on the required number of PSOs, required monitoring locations, 
and environmental conditions. For all pile driving and removal at least 
one PSO must be used. The PSO will be stationed as close to the 
activity as possible;
     The placement of the PSOs during all pile driving and 
removal and DTH drilling activities will ensure that the entire 
shutdown zone is visible during pile installation;
     Monitoring must take place from 30 minutes prior to 
initiation of pile driving or DTH drilling activity (i.e., pre-
clearance monitoring) through 30 minutes post-completion of pile 
driving or DTH drilling activity;
    [cir] Pre-start clearance monitoring must be conducted during 
periods of visibility sufficient for the lead PSO to determine that the 
shutdown zones indicated in Table 11 are clear of marine mammals. Pile 
driving and DTH drilling may commence following 30 minutes of 
observation when the determination is made that the shutdown zones are 
clear of marine mammals;
    [cir] Cordova must use soft start techniques when impact pile 
driving. Soft start requires contractors to provide an initial set of 
three strikes at reduced energy, followed by a 30-second waiting 
period, then two subsequent reduced-energy strike sets. A soft start 
must be implemented at the start of each day's impact pile driving and 
at any time following cessation of impact pile driving for a period of 
30 minutes or longer; and
    [cir] If a marine mammal is observed entering or within the 
shutdown zones indicated in Table 11, pile driving and DTH drilling 
must be delayed or halted. If pile driving is delayed or halted due to 
the presence of a marine mammal, the activity may not commence or 
resume until either the animal has voluntarily exited and been visually 
confirmed beyond the shutdown zone (Table 11) or 15 minutes have passed 
without re-detection of the animal;
     As proposed by the applicant, in water activities will 
take place only

[[Page 45167]]

between civil dawn and civil dusk when PSOs can effectively monitor for 
the presence of marine mammals; during conditions with a Beaufort sea 
state of 4 or less. Pile driving and DTH drilling may continue for up 
to 30 minutes after sunset during evening civil twilight, as necessary 
to secure a pile for safety prior to demobilization during this time. 
The length of the post-activity monitoring period may be reduced if 
darkness precludes visibility of the shutdown and monitoring zones.

Shutdown Zones

    Cordova will establish shutdown zones for all pile driving and DTH 
drilling activities. The purpose of a shutdown zone is generally to 
define an area within which shutdown of the activity would occur upon 
sighting of a marine mammal (or in anticipation of an animal entering 
the defined area). Shutdown zones would be based upon the Level A 
harassment isopleth for each pile size/type and driving method where 
applicable, as shown in Table 11.
    For in-water heavy machinery activities other than pile driving, if 
a marine mammal comes within 10 m, work will stop and vessels will 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions. A 10 m shutdown zone serves to protect marine 
mammals from physical interactions with project vessels during pile 
driving and other construction activities, such as barge positioning or 
drilling. If an activity is delayed or halted due to the presence of a 
marine mammal, the activity may not commence or resume until either the 
animal has voluntarily exited and been visually confirmed beyond the 
shutdown zone indicated in Table 11 or 15 minutes have passed without 
re-detection of the animal. Construction activities must be halted upon 
observation of a species for which incidental take is not authorized or 
a species for which incidental take has been authorized but the 
authorized number of takes has been met entering or within the 
harassment zone.
    All marine mammals will be monitored in the Level B harassment 
zones and throughout the area as far as visual monitoring can take 
place. If a marine mammal enters the Level B harassment zone, 
construction activities including in-water work will continue and the 
animal's presence within the estimated harassment zone will be 
documented.
    Cordova would also establish shutdown zones for all marine mammals 
for which take has not been authorized or for which incidental take has 
been authorized but the authorized number of takes has been met. These 
zones are equivalent to the Level B harassment zones for each activity. 
If a marine mammal species not covered under this IHA enters the 
shutdown zone, all in-water activities will cease until the animal 
leaves the zone or has not been observed for at least 15 minutes, and 
NMFS will be notified about species and precautions taken. Pile driving 
will proceed if the non-IHA species is observed to leave the Level B 
harassment zone or if 15 minutes have passed since the last 
observation.
    If shutdown and/or clearance procedures would result in an imminent 
safety concern, as determined by Cordova or its designated officials, 
the in-water activity will be allowed to continue until the safety 
concern has been addressed, and the animal will be continuously 
monitored.

                                Table 11--Proposed Shutdown and Monitoring Zones
----------------------------------------------------------------------------------------------------------------
                                                         Minimum shutdown zone (m)
             Pile type                 Phase   --------------------------------------------  Monitoring zone (m)
                                                    MF         HF       Phocid    Otariid
----------------------------------------------------------------------------------------------------------------
Barge movements, pile positioning,      I, II          10         10         10         10  10.
 etc..
----------------------------------------------------------------------------------------------------------------
                                             Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
12-24 in timber pile removal......      I, II          10         35         25         10  6,310.
12-24 in steel pile removal.......          I          10         35         20         10  5,425.
24 in steel template pile install/      I, II          10         25         10         10  5,425.
 removal 16-24 in steel pile.
30 in steel pile..................          I          10         25         10         10  6,225.
Steel H-pile......................         II          10         35         25         10  10,000.
Steel sheet pile..................         II          10         25         10         10  6,310.
In air pile install/removal.......          I   .........  .........  .........  .........  70 (phocids)/25
                                                                                             (otariids).
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
16-24 in steel pile...............          I          10        185         75         10  255.
30 in steel pile..................          I          25        800        360         25  1,000.
Steel H-pile......................         II          25        410        185         25  350.
Steel sheet pile..................         II          75      1,000        500         75  1,000.
In air pile install...............          I   .........  .........  .........  .........  55 (phocids)/20
                                                                                             (otariids).
----------------------------------------------------------------------------------------------------------------
                                                  DTH Drilling
----------------------------------------------------------------------------------------------------------------
16-24 in pile.....................      I, II          35      1,000        500         40  13,594.
30 in pile........................          I          75      1,000        500         75  39,811.
Steel H-pile......................         II          75      1,000        500         75  39,811.
In air pile install...............          I   .........  .........  .........  .........  55 (phocids)/20
                                                                                             (otariids).
----------------------------------------------------------------------------------------------------------------

Protected Species Observers

    The placement of PSOs during all construction activities (described 
in the Proposed Monitoring and Reporting section) would ensure that the 
entire shutdown zone is visible. Should environmental conditions 
deteriorate such that the entire shutdown zone would not be visible 
(e.g., fog, heavy rain), pile driving would be delayed until the PSO is 
confident marine mammals within the shutdown zone could be detected.
    PSOs would monitor the full shutdown zones and the remaining

[[Page 45168]]

Level A harassment and the Level B harassment zones to the extent 
practicable. 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 areas outside the 
shutdown zones and thus prepare for a potential cessation of activity 
should the animal enter the shutdown zone.

Pre-Activity Monitoring

    Prior to the start of daily in-water construction activity, or 
whenever a break in pile driving or DTH drilling of 30 minutes or 
longer occurs, PSOs would observe the shutdown and monitoring zones for 
a period of 30 minutes. The shutdown zone would be considered cleared 
when a marine mammal has not been observed within the zone for that 30-
minute period. If a marine mammal is observed within the shutdown zones 
listed in Table 11, pile driving activity would be delayed or halted. 
If work ceases for more than 30 minutes, the pre-activity monitoring of 
the shutdown zones would commence. A determination that the shutdown 
zone is clear must be made during a period of good visibility (i.e., 
the entire shutdown zone and surrounding waters must be visible to the 
naked eye).

Soft-Start Procedures

    Soft-start procedures 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 three strikes from the hammer at reduced energy, 
followed by a 30-second waiting period, then two subsequent reduced-
energy strike sets. Soft-start would be implemented at the start of 
each day's impact pile driving and at any time following cessation of 
impact pile driving for a period of 30 minutes or longer.
    Based on our evaluation of the applicant's proposed measures NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means of 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 while 
conducting the activities. 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 activity; 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 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.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
conditions in this section and the IHA. Marine mammal monitoring during 
pile driving activities would be conducted by PSOs meeting NMFS' 
following requirements:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods would be used;
    [cir] At least one PSO would have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
    [cir] Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
    [cir] Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator would be designated. The lead 
observer would be required to have prior experience working as a marine 
mammal observer during construction.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
     Cordova must employ up to five PSOs depending on the size 
of the monitoring and shutdown zones. A minimum of two PSOs (including 
the lead PSO) must be assigned to the active pile driving location to 
monitor the shutdown zones and as much of the Level B harassment zones 
as possible.
     Cordova must establish monitoring locations with the best 
views of monitoring zones as described in the IHA and Application.
     Up to five monitors will be used at a time depending on 
the size of the monitoring area. PSOs would be deployed in strategic 
locations around the area of potential effects at all times during in-
water pile driving and removal. PSOs will be positioned at locations 
that provide full views of the impact hammering monitoring zone and the 
Level A harassment Shutdown Zones. All PSOs would have access to

[[Page 45169]]

high-quality binoculars, range finders to monitor distances, and a 
compass to record bearing to animals as well as radios or cells phones 
for maintaining contact with work crews.
    [cir] During work in the South Harbor, up to three PSOs will be 
stationed at the following locations: along the South Harbor parking 
area, on the Breakwater Trail, and at a viewpoint along New England 
Cannery Road.
    [cir] During work in the North Harbor, up to five PSOs will be 
stationed at the following locations: along the North Harbor parking 
area, on the Breakwater Trail, at the viewpoint along the shore near 
Saddle Point, at a viewpoint along Whitshed Road, and on a vessel in 
Orca Inlet.
    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after all in water construction activities. In addition, PSOs 
would record all incidents of marine mammal occurrence, regardless of 
distance from activity, and would document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes.
    Cordova shall conduct briefings between construction supervisors 
and crews, PSOs, Cordova staff prior to the start of all pile driving 
activities and when new personnel join the work. These briefings would 
explain responsibilities, communication procedures, marine mammal 
monitoring protocol, and operational procedures.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities for each IHA, or 60 days prior to a requested date of 
issuance from any future IHAs for projects at the same location, 
whichever comes first. The report will include an overall description 
of work completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including the number and type of piles driven or 
removed and by what method (i.e., impact, vibratory, or DTH drilling) 
and the total equipment duration for vibratory removal for each pile or 
total number of strikes for each pile (impact driving);
     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and end of PSO shift and whenever conditions change 
significantly), including Beaufort sea state and any other relevant 
weather conditions including cloud cover, fog, sun glare, and overall 
visibility to the horizon, and estimated observable distance;
     Upon observation of a marine mammal, the following 
information:
    [cir] Name of PSO who sighted the animal(s) and PSO location and 
activity at the time of sighting;
    [cir] Time of sighting;
    [cir] Identification of the animal(s) (e.g., genus/species, lowest 
possible taxonomic level, or unidentifiable), PSO confidence in 
identification, and the composition of the group if there is a mix of 
species;
    [cir] Distance and bearing of each marine mammal observed relative 
to the pile being driven for each sightings (if pile driving was 
occurring at time of sighting);
    [cir] Estimated number of animals (min/max/best estimate);
    [cir] Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, sex class, etc.);
    [cir] Animal's closest point of approach and estimated time spent 
within the harassment zone;
    [cir] Description of any marine mammal behavioral observations 
(e.g., observed behaviors such as feeding or traveling), including an 
assessment of behavioral responses thought to have resulted from the 
activity (e.g., no response or changes in behavioral state such as 
ceasing feeding, changing direction, flushing, or breaching);
    [cir] Number of marine mammals detected within the harassment zones 
and shutdown zones; by species; and
    [cir] Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensured, and resulting changes in behavior of the 
animal(s), if any.
    If no comments are received from NMFS within 30 days, the draft 
reports will constitute the final reports. If comments are received, a 
final report addressing NMFS comments must be submitted within 30 days 
after receipt of comments.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the IHA-holder must 
immediately cease the specified activities and report the incident to 
the Office of Protected Resources (OPR) 
([email protected]), NMFS and to the Alaska Regional 
Stranding Coordinator as soon as feasible. If the death or injury was 
clearly caused by the specified activity, Cordova must immediately 
cease the specified activities until NMFS is able to review the 
circumstances of the incident and determine what, if any, additional 
measures are appropriate to ensure compliance with the terms of the 
IHA. The IHA-holder must not resume their activities until notified by 
NMFS. The report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), 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' implementing regulations (54 FR 40338, 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are

[[Page 45170]]

incorporated into this analysis via their impacts on the baseline 
(e.g., as reflected in the regulatory status of the species, population 
size and growth rate where known, ongoing sources of human-caused 
mortality, or ambient noise levels).
    To avoid repetition, the discussion of our analysis applies to all 
the species listed in Table 3, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be similar. There is little information about the nature or severity of 
the impacts, or the size, status, or structure of any of these species 
or stocks that would lead to a different analysis for this activity. 
Also, because both the number and nature of the estimated takes 
anticipated to occur are identical in Phase I and Phase II, the 
analysis below applies to each of the IHAs.
    Pile driving and DTH drilling activities associated with the 
project, as outlined previously, have the potential to disturb or 
displace marine mammals. Specifically, the specified activities may 
result in take, in the form of Level B harassment and, for some 
species, Level A harassment from underwater sounds generated by pile 
driving. Potential takes could occur if individuals are present in the 
ensonified zone when these activities are underway.
    No serious injury or mortality would be expected, even in the 
absence of required mitigation measures, given the nature of the 
activities. Further, no take by Level A harassment is anticipated for 
killer whales due to the application of planned mitigation measures, 
such as shutdown zones that encompass the Level A harassment zones for 
the species, the rarity of the species near the action area, and the 
shallow depths of the harbor. The potential for harassment would be 
minimized through the construction method and the implementation of the 
planned mitigation measures (see Proposed Mitigation section).
    Take by Level A harassment is proposed for three species (Steller 
sea lion, harbor seal, and Dall's porpoise) as the Level A harassment 
isopleths exceed the size of the shutdown zones for specific 
construction scenarios. Additionally, the two pinniped species are 
common in and around the action area. Therefore, there is the 
possibility that an animal could enter a Level A harassment zone and 
remain within that zone for a duration long enough to incur PTS. Level 
A harassment of these species is therefore proposed for authorization. 
Any take by Level A harassment is expected to arise from, at most, a 
small degree of PTS (i.e., minor degradation of hearing capabilities 
within regions of hearing that align most completely with the energy 
produced by impact pile driving such as the low-frequency region below 
2 kHz), not severe hearing impairment or impairment within the ranges 
of greatest hearing sensitivity. Animals would need to be exposed to 
higher levels and/or longer duration than are expected to occur here in 
order to incur any more than a small degree of PTS.
    Further, the amount of take proposed for authorization by Level A 
harassment is very low for the marine mammal stocks and species. If 
hearing impairment occurs, it is most likely that the affected animal 
would lose only a few decibels in its hearing sensitivity. Due to the 
small degree anticipated, any PTS potential incurred would not be 
expected to affect the reproductive success or survival of any 
individuals, much less result in adverse impacts on the species or 
stock.
    The Level A harassment zones identified in Tables 7 and 8 are based 
upon an animal exposed to pile driving or DTH drilling of several piles 
per day (up to 25 piles per day for vibratory removal, 10 piles per day 
of vibratory installation, 6 piles per day of impact driving, and 4 
piles per day of DTH drilling). Given the short duration to impact 
drive or vibratory install or extract, or use DTH drilling, each pile 
and break between pile installations (to reset equipment and move piles 
into place), an animal would have to remain within the area estimated 
to be ensonified above the Level A harassment threshold for multiple 
hours. This is highly unlikely given marine mammal movement patterns in 
the area. If an animal was exposed to accumulated sound energy, the 
resulting PTS would likely be small (e.g., PTS onset) at lower 
frequencies where pile driving energy is concentrated, and unlikely to 
result in impacts to individual fitness, reproduction, or survival.
    Additionally, some subset of the individuals that are behaviorally 
harassed could also simultaneously incur some small degree of TTS for a 
short duration of time. However, since the hearing sensitivity of 
individuals that incur TTS is expected to recover completely within 
minutes to hours, it is unlikely that the brief hearing impairment 
would affect the individual's long-term ability to forage and 
communicate with conspecifics, and would therefore not likely impact 
reproduction or survival of any individual marine mammal, let alone 
adversely affect rates of recruitment or survival of the species or 
stock.
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. For all species and stocks, take would 
occur within a limited, confined area (adjacent to the project site) of 
the stock's range. Take by Level A and Level B harassment would be 
reduced to the level of least practicable adverse impact through use of 
mitigation measures described herein. Further, the amount of take 
proposed to be authorized is extremely small when compared to stock 
abundance.
    Behavioral responses of marine mammals to pile driving, pile 
removals, and DTH drilling in Cordova Harbor and the surrounding Orca 
Inlet are expected to be mild, short term, and temporary. Marine 
mammals within the Level B harassment zones may not show any visual 
cues they are disturbed by activities or they could become alert, avoid 
the area, leave the area, or display other mild responses that are not 
observable such as changes in vocalization patterns. Given that pile 
driving, pile removal, and DTH drilling are temporary activities and 
effects would cease when equipment is not operating, any harassment 
occurring would be temporary. Additionally, many of the species present 
in region would only be present temporarily based on seasonal patterns 
or during transit between other habitats. These species would be 
exposed to even smaller periods of noise-generating activity, further 
decreasing the impacts.
    Nearly all inland waters of southeast Alaska, including Orca Inlet, 
are included in the southeast Alaska humpback whale feeding 
Biologically Important Area (BIA) (Ferguson et al., 2015), though 
humpback whale distribution in southeast Alaska varies by season and 
waterway (Dahlheim et al., 2009). Humpback whales are present within 
Orca Inlet intermittently and in low numbers, however due to the 
shallow waters around Cordova Harbor, the BIA is not expected to be 
affected. Therefore, the proposed project is not expected to have 
significant adverse effects on the foraging of Alaska humpback whale. 
The same regions are also a part of the Western DPS Steller sea lion 
ESA critical habitat. While Steller sea lions are common in the project 
area, there are no essential physical and biological habitat features, 
such as haulouts or rookeries, within the proposed project area. The 
nearest haulout and rookery are over 30 km away from the proposed 
project area. Therefore, the proposed project is not expected to have 
significant adverse effects on the critical habitat of Wester DPS 
Steller sea lions. No areas of specific biological importance (e.g., 
ESA

[[Page 45171]]

critical habitat, other BIAs, or other areas) for any other species are 
known to co-occur with the project area.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on each stock's ability 
to recover. In combination, we believe that these factors, as well as 
the available body of evidence from other similar activities, 
demonstrate that the potential effects of the specified activities 
would have only minor, short-term effects on individuals. The specified 
activities are not expected to impact rates of recruitment or survival 
and would therefore not result in population-level impacts.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect any of the species 
or stocks through effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
authorized;
     Level A harassment would be very small amounts and of low 
degree;
     Level A harassment takes of only Steller sea lions and 
harbor seals;
     For all species, the Orca Inlet and the Cordova Harbor is 
a very small and peripheral part of their range;
     Anticipated takes by Level B harassment are relatively low 
for all stocks. Level B harassment would be primarily in the form of 
behavioral disturbance, resulting in avoidance of the project areas 
around where impact or vibratory pile driving is occurring, with some 
low-level TTS that may limit the detection of acoustic cues for 
relatively brief amounts of time in relatively confined footprints of 
the activities;
     Effects on species that serve as prey for marine mammals 
from the activities are expected to be short-term and, therefore, any 
associated impacts on marine mammal feeding are not expected to result 
in significant or long-term consequences for individuals, or to accrue 
to adverse impacts on their populations;
     The ensonified areas are very small relative to the 
overall habitat ranges of all species and stocks, and would not 
adversely affect ESA-designated critical habitat for any species or any 
areas of known biological importance;
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat; and
     Cordova would implement mitigation measures including 
soft-starts and shutdown zones to minimize the numbers of marine 
mammals exposed to injurious levels of sound, and to ensure that take 
by Level A harassment is, at most, a small degree of PTS.
    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, specific to each of the two consecutive years of proposed 
activity, would have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The amount of take NMFS proposes to authorize, specific to each of 
the two consecutive years of proposed activity, is below one third of 
the estimated stock abundance for all species (in fact, take of 
individuals is less than five percent of the abundance of the affected 
stocks, see Table 10). This is likely a conservative estimate because 
we assume all takes are of different individual animals, which is 
likely not the case. Some individuals may return multiple times in a 
day, but PSOs would count them as separate takes if they cannot be 
individually identified.
    The most recent estimate for the Alaska stock of Dall's porpoise 
was 13,110 animals however this number just accounts for a portion of 
the stock's range. Therefore, the 42 takes of this stock proposed for 
authorization is believed to be an even smaller portion of the overall 
stock abundance.
    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 would 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 Alutiiq and Eyak people of Prince William Sound traditionally 
harvested marine mammals, however the last recorded subsistence harvest 
in Cordova was in 2014 as part of a regional effort to update the 
status of subsistence uses in Exxon Valdez Oil Spill communities, 
during which no marine mammals were harvested in Cordova (Fall and 
Zimpelman 2016).
    In the decades since the Exxon Valdez Oil Spill, there have been 
declines in the number of households hunting and harvesting larger 
marine mammals in Prince William Sound. Surveys gathering subsistence 
data found that 10 percent or fewer households harvest or use harbor 
seals or sea lions (Poe et al., 2010). Subsistence hunters in Prince 
William Sound report having to travel farther from their home 
communities to be successful when harvesting marine mammals (Keating et 
al., 2020).
    The proposed project is not likely to adversely impact the 
availability of any marine mammal species or stocks that are commonly 
used for subsistence purposes or to impact subsistence harvest of 
marine mammals in the region because:
     There is no recent recorded subsistence harvest of marine 
mammals in the area;
     Construction activities are localized and temporary;
     Mitigation measures will be implemented to minimize 
disturbance of marine mammals in the action area; and,
     The project will not result in significant changes to 
availability of subsistence resources.

[[Page 45172]]

    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 Cordova's 
proposed activities.

Endangered Species Act

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species, in this case with the Alaska Regional 
Office.
    NMFS is proposing to authorize take of the Western DPS of Steller 
Sea Lions, which are listed under the ESA. The Permits and Conservation 
Division has requested initiation of Section 7 consultation with the 
Alaska Region 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 Authorizations

    As a result of these preliminary determinations, NMFS proposes to 
issue two sequential IHAs, each lasting one year, to the City of 
Cordova for conducting the Cordova Harbor Rebuild Project in Cordova, 
Alaska, starting in August 2023 for Phase I and August 2024 for Part 
II, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated. A draft of the proposed IHAs 
can be found 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 authorizations, 
and any other aspect of this notice of proposed IHAs for the proposed 
construction project. We also request comment on the potential renewals 
of these proposed IHAs as described in the paragraph below. Please 
include with your comments any supporting data or literature citations 
to help inform decisions on the request for these IHAs or subsequent 
renewal IHAs.
    On a case-by-case basis, NMFS may issue a one-time, one-year 
renewal for each of the two IHAs following notice to the public 
providing an additional 15 days for public comments when (1) up to 
another year of identical or nearly identical activities as described 
in the Description of Proposed Activity section of this notice is 
planned or (2) the activities as described in the Description of 
Proposed Activity section of this notice would not be completed by the 
time the IHA expires and a renewal would allow for completion of the 
activities beyond that described in the Dates and Duration section of 
this notice, provided all of the following conditions are met:
     A request for renewal is received no later than 60 days 
prior to the needed renewal IHA effective date (recognizing that the 
renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA).
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested renewal IHA are identical to the activities analyzed under 
the initial IHA, are a subset of the activities, or include changes so 
minor (e.g., reduction in pile size) that the changes do not affect the 
previous analyses, mitigation and monitoring requirements, or take 
estimates (with the exception of reducing the type or amount of take).
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
    Upon review of the request for renewal, the status of the affected 
species or stocks, and any other pertinent information, NMFS determines 
that there are no more than minor changes in the activities, the 
mitigation and monitoring measures will remain the same and 
appropriate, and the findings in the initial IHA remain valid.

    Dated: July 5, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-14686 Filed 7-13-23; 8:45 am]
BILLING CODE 3510-22-P