Notice2023-19903
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Ferry Berth Construction in Tongass Narrows in Ketchikan, Alaska
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
September 14, 2023
Effective
September 11, 2023
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to the Alaska Department of Transportation and Public Facilities (ADOT&PF) to incidentally harass marine mammals during construction activities associated with ferry berth construction in Tongass Narrows in Ketchikan, Alaska.
Full Text
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<title>Federal Register, Volume 88 Issue 177 (Thursday, September 14, 2023)</title>
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[Federal Register Volume 88, Number 177 (Thursday, September 14, 2023)]
[Notices]
[Pages 63067-63084]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-19903]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD199]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Ferry Berth Construction in Tongass
Narrows in Ketchikan, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; Issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the Alaska Department of Transportation and Public Facilities (ADOT&PF)
to incidentally harass marine mammals during construction activities
associated with ferry berth construction in Tongass Narrows in
Ketchikan, Alaska.
DATES: This authorization is effective from September 11, 2023 to
September 10, 2024.
ADDRESSES: 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>. In case of problems accessing these documents, please call
the contact listed below.
FOR FURTHER INFORMATION CONTACT: Kate Fleming, 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.
Summary of Request
On January 24, 2023, NMFS received a request from ADOT&PF for an
IHA to take marine mammals incidental to the construction of and
improvements to four (initially five--see explanation below) ferry
berths in Tongass Narrows in Ketchikan, Alaska. On February 23, 2023,
ADOT&PF submitted a memo proposing additional construction activities
at this project site, which was later retracted on March 21, 2023.
Following NMFS' review of the application and discussions between NMFS
and ADOT&PF, on May 2, 2023, ADOT&PF asked NMFS to halt processing of
the IHA until it submitted an acoustic monitoring report associated
with previous work at the project site. ADOT&PF submitted the report on
May 24, 2023. NMFS reviewed and accepted the results in the report, and
the application was deemed adequate and complete on June 27, 2023.
ADOT&PF's request is for take of 11 species of marine mammals, by Level
B harassment and, for Steller sea lion (Eumetopias jubatus), harbor
seal (Phoca vitulina), northern elephant seal (Mirounga
angustirostris), harbor porpoise (Phocoena phocoena), and Dall's
porpoise (Phocoenoides dalli), Level A harassment. Neither ADOT&PF nor
NMFS expect serious injury or mortality to result from this activity
and, therefore, an IHA is appropriate.
NMFS previously issued two consecutive IHAs to ADOT&PF for this
work (85 FR 673, January 7, 2020), which covered construction at the
following six sites: Revilla New Ferry Berth and Upland Improvements
(Revilla New Berth), New Gravina Island Shuttle Ferry Berth/Related
Terminal Improvements (Gravina New Berth), Gravina Airport Ferry Layup
Facility, Gravina Freight Facility, Revilla Refurbish Existing Ferry
Berth Facility, and Gravina Refurbish Existing Ferry Berth Facility
(Figure 1). Due to various project delays (and two minor changes to the
phase 1 IHA activities), the phase 1 IHA was renewed (86 FR 23938, May
05, 2021) and the phase 2 IHA was reissued (87 FR 12117, March 3,
2022). Upon the expiration of the phase 1 renewal, because a subset of
work had still not been completed, ADOT&PF requested, and NMFS issued,
a new IHA (87 FR 15387, March 18, 2022) which was renewed upon its
expiration (88 FR 13802, March 6, 2023). The reissued phase 2 IHA
expired on February 28, 2023. While the current renewal IHA (88 FR
13802, March 6, 2023) does not expire until March 5, 2024, ADOT&PF
proposed new project components that warrant a new IHA, and a subset of
activities covered under the reissued phase 2 IHA remain incomplete. As
such, ADOT&PF requested a new IHA to authorize take of marine mammals
associated with all remaining work at the Tongass Narrows sites. Work
at the Gravina Airport Ferry Layup Facility was completed prior to the
application for this new IHA. Since the submission of ADOT&PF's 2023
IHA
[[Page 63068]]
application, work has also been completed at the Gravina Freight
Facility. As such, remaining work planned is limited to four project
sites: Revilla New Berth, Gravina New Berth, Revilla Refurbish Existing
Ferry Berth Facility, and Gravina Refurbish Existing Ferry Berth
Facility. ADOT&PF has complied with all the requirements (e.g.,
mitigation, monitoring, and reporting) of the previous IHAs with the
exception of one incident in which ADOT&PF reported that a pile had
been removed without the presence of a Protected Species Observer (PSO)
on site. ADOT&PF reported the incident immediately and retrained the
Construction Contractor's Foreman and ADOT&PF's on-site representative.
ADOT&PF also notified NMFS on May 18, 2023 that 12 20'' piles that were
not included in the renewal, but were included in the initial IHA on
which the renewal was based, were driven after expiration of the
initial IHA (while the renewal was effective).
Monitoring results from the previous IHAs are discussed in the
Potential Effects of Specified Activities on Marine Mammals and their
Habitat and the Estimated Take of Marine Mammals section.
Description of Specified Activity
ADOT&PF is making improvements to two existing ferry berths and
constructing two new ferry berths on Gravina Island and Revillagigedo
(Revilla) Island in Tongass Narrows, near Ketchikan, in southeast
Alaska (see Figure 1 of the notice of proposed IHA (88 FR 46746; July
20, 2023). The existing ferry facilities improve access to developable
land on Gravina Island, improve access to the Ketchikan International
Airport, and facilitate economic development in the Ketchikan Gateway
Borough. The new ferry berths provide redundancy to the existing ferry
berths. The project's planned activities that have the potential to
take marine mammals, by Level A harassment and Level B harassment,
include down-the-hole (DTH) drilling of rock sockets and tension
anchors, vibratory installation and removal of temporary steel pipe
piles and/or H-piles, vibratory and impact installation of permanent
steel pipe piles, and vibratory removal of permanent piles (in cases
where work is being redone). The marine construction associated with
the planned activities is expected to occur over 131 non-consecutive
days over 1 year.
A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHA (88 FR
46746, July 20, 2023). Since that time, no changes have been made to
planned activities. Therefore, a detailed description is not provided
here. Please refer to that Federal Register notice for the description
of the specified activity.
Comments and Responses
A notice of NMFS' proposal to issue an IHA to ADOT&PF was published
in the Federal Register on July 20, 2023 (88 FR 46746). That notice
described, in detail, ADOT&PF's activities, the marine mammal species
that may be affected by the activities, and the anticipated effects on
marine mammals. In that notice, we requested public input on the
request for authorization described therein, our analyses, the proposed
authorization, and any other aspect of the notice of proposed IHA, and
requested that interested persons submit relevant information,
suggestions, and comments. During the 30-day public comment period,
NMFS did not receive any public comments.
Changes From the Proposed IHA to Final IHA
Since the Federal Register notice of the proposed IHA was published
(88 FR 46746, July 20, 2023), NMFS published the final 2022 Alaska and
Pacific Stock Assessment Reports (SARs), which describe revised stock
structures under the MMPA for humpback whales and southeast Alaska
harbor porpoise (Carretta et al., 2023; Young et al., 2023). In the
notice of proposed IHA, we explained that although we typically
consider updated peer-reviewed data provided in draft SARs to be the
best available science, and use the information accordingly, we make
exception for proposed revised stock structures. Upon finalization of
these revised stock structures, we have made appropriate updates,
including descriptions of the potentially affected stocks (see Table
1), attribution of take numbers to stock (see Estimated Take of Marine
Mammals), and by updating our analyses to ensure the necessary
determinations are made for the new stocks (see Negligible Impact
Analysis and Determination and Small Numbers).
Additionally, as requested by ADOT&PF, NMFS made two changes to the
PSO requirements since publication of the proposed IHA. First, NMFS
revised the requirement for PSOs to be independent of the activity
contractor (for example, employed by a subcontractor), to reflect that
PSOs must be independent (not be part of the construction crew) but not
necessarily employed by a subcontractor. This change is intended to
align this requirement with that in the active IHA to allow PSOs who
are currently working on the project to continue to do so. Second, NMFS
proposed to require ADOT&PF to employ three PSOs for DTH activities.
After publication of the proposed IHA, ADOT&PF requested for NMFS to
revise this measure to require two PSOs for DTH activities, given that
the zone sizes for DTH activities, like those of impact pile driving,
are small enough to be adequately monitored by two PSOs. NMFS
concurred, and therefore, the final IHA requires ADOT&PF to employ at
least two PSOs for DTH activities, rather than three.
Finally, NMFS corrected a typographical error in Table 8 of the
notice of the proposed IHA (88 FR 46746, July 20, 2023). The table
omitted the Level B harassment isopleth for DTH of tension anchors,
which should have been listed as 1,274 m. The corresponding table in
the proposed IHA at the time of publishing was correct.
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, incorporated here by reference, instead of
reprinting the information. Additional information regarding population
trends and threats may be found in NMFS' SARs (<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS'
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 1 lists all species or stocks for which take is expected and
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
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 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.
[[Page 63069]]
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Alaska and Pacific Ocean SARs All values presented in Table
1 are the most recent available at the time of publication (Caretta et
al., 2023, Young et al., 2023) and are available online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 1--Marine Mammal Species Likely Impacted by the Specified Activities \1\
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ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock Strategic (Y/N) Nmin, most recent PBR Annual M/SI
\2\ abundance survey) \3\ \4\
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Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
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Family Balaenopteridae (rorquals):
Minke Whale \5\................ Balaenoptera Alaska................ -,-,N N/A (N/A, N/A, N/A)... UND 0
acutorostrata.
Fin Whale \6\.................. Balaenoptera physalus. Northeast Pacific..... E, D, Y 3,168 (0.26, 2,554, UND 0.6
2013).
Humpback Whale \7\............. Megaptera novaeangliae Hawai[revaps]i........ -,-,N 11,278 (0.56, 7,265, 127 19.6
2020).
Mexico--North Pacific. T, D, Y N/A (N/A, N/A, 2006).. UND 0.56
Family Eschrichtiidae:
Gray whale..................... Eschrichtius robustus. Eastern North Pacific. -,-,N 26,960 (0.05, 25,849, 801 131
2016).
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Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Pacific White-sided Dolphin.... Lagenorhynchus N Pacific............. -,-,N 26,880 (N/A, N/A, UND 0
obliquidens. 1990).
Killer Whale................... Orcinus orca.......... Eastern North Pacific -,-,N 1,920, (N/A, 1,920, 19 1.3
Alaska Resident. 2019).
Eastern North Pacific -,-,N 302 (N/A, 302, 2018).. 2.2 0.2
Northern Resident.
West Coast Transient.. -,-,N 349 (N/A, 349, 2018).. 3.5 0.4
Family Phocoenidae (porpoises):
Harbor Porpoise \8\............ Phocoena phocoena..... Southern Southeast -,-,Y 890 (0.37, 610, 2019). 6.1 7.4
Alaska Inland Waters.
Dall's Porpoise \9\............ Phocoenoides dalli.... Alaska................ -,-,N 15,432 (0.097, 13,110, 131 37
2021).
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Steller Sea Lion............... Eumetopias jubatus.... Eastern............... -,-,N 43,201 (N/A, 43,201, 2,592 112
2017).
Family Phocidae (earless seals):
Northern Elephant Seal......... Mirounga CA Breeding........... -,-,N 187,386 (N/A, 85,369, 5,122 13.7
angustirostris. 2013).
Harbor Seal.................... Phoca vitulina........ Clarence Strait....... -,-,N 27,659 (N/A, 24,854, 746 40
2015).
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\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
(<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>; Committee on Taxonomy (2022)).
\2\ 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a> assessments. 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, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\5\ No population estimates have been made for the number of minke whales in the entire North Pacific. Some information is available on the numbers of
minke whales on some areas of Alaska, but in the 2009, 2013 and 2015 offshore surveys, so few minke whales were seen during the surveys that a
population estimate for the species in this area could not be determined (Rone et al., 2017). Therefore, this information is N/A (not available).
\6\ The best available abundance estimate for this stock is not considered representative of the entire stock as surveys were limited to a small portion
of the stock's range. Based upon this estimate and the Nmin, the PBR value is likely negatively biased for the entire stock.
\7\ Abundance estimates for the Mexico-North Pacific Stock of humpback whale are based upon data collected more than 8 years ago and therefore, current
estimates are considered unknown.
\8\ Abundance estimates assumed that detection probability on the trackline was perfect; work is underway on a corrected estimate. Additionally,
preliminary data results based on eDNA analysis show genetic differentiation between harbor porpoise in the northern and southern regions on the
inland waters of southeast Alaska. Geographic delineation is not yet known. Data to evaluate population structure for harbor porpoise in Southeast
Alaska have been collected and are currently being analyzed. Should the analysis identify different population structure than is currently reflected
in the Alaska SARs, NMFS will consider how to best revise stock designations in the future.
\9\ Previous abundance estimates covering the entire stock's range are no longer considered reliable and the current estimates presented in the SARs and
reported here only cover a portion of the stock's range. Therefore, the calculated Nmin and PBR is based on the 2015 survey of only a small portion of
the stock's range. PBR is considered to be biased low since it is based on the whole stock whereas the estimate of mortality and serious injury is for
the entire stock's range.
As indicated above, all 11 species (with 13 managed stocks) in
Table 1 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur.
A detailed description of the species likely to be affected by
ADOT&PF's project, including brief introductions to the species and
relevant stocks as well as available information regarding populations
trends and threats, and
[[Page 63070]]
information regarding local occurrence, were provided in the Federal
Register notice for the proposed IHA (88 FR 46746, July 20, 2023).The
2022 Alaska and Pacific SARs described a revised stock structure for
humpback whales which modifies the previous stocks designated under the
MMPA to align more closely with the ESA-designated DPSs (Caretta et
al., 2023; Young et al., 2023). Specifically, the three previous North
Pacific humpback whale stocks (Central and Western North Pacific stocks
and a CA/OR/WA stock) were replaced by five stocks, largely
corresponding with the ESA-designated DPSs. These include Western North
Pacific and Hawaii stocks and a Central America/Southern Mexico-CA/OR/
WA stock (which corresponds with the Central America DPS). The
remaining two stocks, corresponding with the Mexico DPS, are the
Mainland Mexico-CA/OR/WA and Mexico-North Pacific stocks (Caretta et
al., 2023; Young et al., 2023). The former stock is expected to occur
along the west coast from California to southern British Columbia,
while the latter stock may occur across the Pacific, from northern
British Columbia through the Gulf of Alaska and Aleutian Islands/Bering
Sea region to Russia.
In the proposed IHA, NMFS stated that the Central North Pacific
stock of humpback whale was likely to be impacted by ADOT&PF's
activities. Given the revised stock structure, NMFS has reanalyzed the
potential for take of each stock of humpback whale and determined that
the Hawaii stock and the Mexico- North Pacific stock are likely to be
impacted by ADOT&PF's activities.
The 2022 Alaska SARs described a revised stock structure for
southeast Alaska harbor porpoise, which were split from one stock into
three: the Northern Southeast Alaska Inland Waters, Southern Southeast
Alaska Inland Waters, and Yakutat/Southeast Alaska Offshore Waters
harbor porpoise stocks (Young et al., 2023). This update better aligns
harbor porpoise stock structure with genetics, trends in abundance, and
information regarding discontinuous distribution trends (Young et al.,
2023). Harbor porpoises found in the Tongass Narrows area are assumed
to be members of the Southern Southeast Alaska Inland Waters stock,
based on the geographical range of the stock. Please refer to the
notice of the proposed IHA (88 FR 46746, July 20, 2023) for species
descriptions. Please also refer to the NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) for generalized species accounts,
and to the SARs (<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) for more information about
the changes to humpback whale and harbor porpoise stock structures.
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 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 2.
Table 2--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
The effects of underwater noise from ADOT&PF's construction
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of the
proposed IHA (88 FR 46746, July 20, 2023) included a discussion of the
effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from ADOT&PF's construction activities on
marine mammals and their habitat. That information and analysis is
incorporated by reference into these final IHA determinations and is
not repeated here; please refer to the Federal Register notice of
proposed IHA (88 FR 46746, July 20, 2023).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
authorized through this IHA, which
[[Page 63071]]
informs 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 will primarily be by Level B harassment, as use of
the acoustic sources (i.e., impact and vibratory pile driving and
removal and DTH) 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 high frequency cetaceans, phocids, and otariids because predicted
auditory injury zones are larger than for other hearing groups.
Auditory injury is unlikely to occur for other groups. The 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 authorized for this activity. Below we describe how the
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 will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can 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 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).
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., impact pile driving) or intermittent (e.g.,
scientific sonar) sources. This take estimation includes disruption of
behavioral patterns resulting directly in response to noise exposure
(e.g., avoidance), as well as the resulting indirectly form the
associated impacts such as Temporary Threshold Shift (TTS) or masking.
ADOT&PF's planned activity includes the use of continuous (vibratory
pile driving/removal and DTH) and impulsive (impact pile driving and
DTH) sources, and therefore the RMS SPL thresholds of 120 and 160 dB re
1 [mu]Pa 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). ADOT&PF's
planned activity includes the use of impulsive (impact pile driving and
DTH) and non-impulsive (vibratory pile driving/removal and DTH)
sources.
These thresholds are provided in Table 3 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:
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds * (received level)
Hearing group -------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.......... Cell 1: Lp,0-pk,flat: 219 Cell 2: LE,p,LF,24h: 199 dB.
dB; LE,p,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans.......... Cell 3: Lp,0-pk,flat: 230 Cell 4: LE,p,MF,24h: 198 dB.
dB; LE,p,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans......... Cell 5: Lp,0-pk,flat: 202 Cell 6: LE,p,HF,24h: 173 dB.
dB; LE,p,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).... Cell 7: Lp,0-pk.flat: 218 Cell 8: LE,p,PW,24h: 201 dB.
dB; LE,p,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)... Cell 9: Lp,0-pk,flat: 232 Cell 10: LE,p,OW,24h: 219 dB.
dB; LE,p,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS
onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
associated with impulsive sounds, these thresholds are recommended for consideration.
[[Page 63072]]
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to be
more reflective of International Organization for Standardization standards (ISO 2017). The subscript ``flat''
is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized
hearing range of marine mammals (i.e., 7 Hz to 160 kHz). The subscript associated with cumulative sound
exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF, and HF
cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The weighted
cumulative sound exposure level thresholds could be exceeded in a multitude of ways (i.e., varying exposure
levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate the
conditions under which these thresholds will be exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that 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 planned 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).
The intensity of pile driving sounds is greatly influenced by
factors such as the type of piles (material and diameter), hammer type,
and the physical environment (e.g., sediment type) in which the
activity takes place. The ADOT&PF evaluated SPL measurements available
for certain pile types and sizes from similar activities elsewhere to
determine appropriate proxy levels for their planned activities. The
ADOT&PF also initially referred to preliminary results from a sound
source verification study to determine SPLs for DTH of 8-inch tension
anchors and Transmission Loss values (TLs) for all DTH activities. As
discussed in the Summary of Request section above, a Sound Source
Verification (SSV) report detailing sound source values and TL
coefficients collected at the project site was subsequently submitted.
To determine appropriate proxy SPLs for impact and vibratory pile
driving of all pile types, NMFS completed a comprehensive review of
source levels relevant to Southeast Alaska to generate regionally-
specific source levels. NMFS compiled all available data from Puget
Sound and Southeast Alaska and adjusted the data to standardize
distance from the measured pile to 10 meters (m). NMFS then calculated
average source levels for each project and for each pile type. NMFS
weighted impact pile driving project averages by the number of strikes
per pile following the methodology in Navy (2015). The source levels
for these various pile types, sizes and methods are listed in Table 4.
Additionally, ADOT&PF requested, and NMFS agreed, to use the 24-inch
sound source values for impact or vibratory pile driving of 14-inch H-
piles, because the source value of smaller piles of the same general
type (steel) are not expected to exceed a larger pile.
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. NMFS
(2022) recommended guidance on DTH systems (<a href="https://media.fisheries.noaa.gov/2022-11/PUBLIC%20DTH%20Basic%20Guidance_November%202022.pdf">https://media.fisheries.noaa.gov/2022-11/PUBLIC%20DTH%20Basic%20Guidance_November%202022.pdf</a>) outlines its
recommended source levels for DTH systems. NMFS has applied that
guidance in this analysis (see Table 4 for NMFS' source levels). Note
that the values in this table represent the SPL referenced to a
distance of 10 m (33 (feet) ft) from the source.
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
Absent site-specific acoustical monitoring with differing measured
transmission loss, a practical spreading value of 15 is used as the
transmission loss coefficient in the above formula. Site-specific
transmission loss data for the Tongass Narrows are not available for
vibratory pile installation and removal and impact pile driving;
therefore, the default coefficient of 15 is used to determine the
distances to the Level A harassment and Level B harassment thresholds
for these activities and associated pile types. In the case of DTH
activities, ADOT&PF conducted SSV at the project site for DTH of 24-
inch rock sockets and 8-inch tension anchors. NMFS reviewed the TL data
from this monitoring and has incorporated the most conservative
transmission loss values measured for each pile type at the project
site in its analysis herein (Table 4).
Table 4--Estimates of Mean Underwater Sound Levels Generated During Vibratory and Impact Pile Installation, DTH,
and Vibratory Pile Removal
----------------------------------------------------------------------------------------------------------------
Peak SPL (dB TL
RMS SPL (dB re SELss (dB re 1 re 1 References coefficient
1 [micro]Pa) [micro]Pa \2\ sec) [micro]Pa) levels (TL) \1\
----------------------------------------------------------------------------------------------------------------
Vibratory Hammer
----------------------------------------------------------------------------------------------------------------
30-inch steel piles.......... 166 NA NA NMFS Analysis-- 15
C. Hotchkin
April 24, 2023.
24-inch steel piles.......... 163 NA NA NMFS Analysis-- 15
C. Hotchkin
April 24, 2023.
Steel 14'' H-piles \2\....... 163 NA NA 24-inch as proxy 15
----------------------------------------------------------------------------------------------------------------
DTH of Rock Sockets and Tension Anchors--Continuous
----------------------------------------------------------------------------------------------------------------
24-inch (Rock Socket)........ 167 NA NA Heyvaert & Reyff 19.5
2021; (Reyff
and Ambaskar
2023).
[[Page 63073]]
8-inch DTH (Tension Anchor).. 156 NA NA Reyff & Heyvaert 17.1
2019; Reyff
2020; (Reyff
and Ambaskar
2023).
----------------------------------------------------------------------------------------------------------------
Impact Hammer
----------------------------------------------------------------------------------------------------------------
30-inch steel piles.......... 195 183 210 NMFS Analysis-- 15
C. Hotchkin
April 24, 2023.
24-inch steel piles.......... 190 177 203 Caltrans 2015, 15
Caltrans 2020.
Steel 14'' H-piles \2\....... 190 177 203 24-inch as proxy 15
----------------------------------------------------------------------------------------------------------------
DTH of rock sockets and tension anchors--Impulsive
----------------------------------------------------------------------------------------------------------------
24-inch (Rock Socket)........ NA 159 184 Heyvaert & Reyff 19.9
2021; (Reyff
and Ambaskar
2023).
8-inch (Tension anchor)...... NA 144 170 Reyff 2020; 17.1
(Reyff and
Ambaskar 2023).
----------------------------------------------------------------------------------------------------------------
\1\ NMFS recommends a default transmission loss of 15 * log10(R) when site-specific data are not available
(NMFS, 2020; NMFS, 2022).
\2\ For 14-inch H piles, NMFS uses sound source level data from 24-inch piles as a conservative proxy.
Note: all SPLs are unattenuated and represent the SPL referenced to a distance of 10 m from the source; NA = Not
applicable; dB re 1 [micro]Pa = decibels (dB) referenced to a pressure of 1 microPascal, measures underwater
SPL; dB re 1 [micro]Pa2-sec = dB referenced to a pressure of 1 microPascal squared per second, measures
underwater Sound Exposure Level (SEL).
All Level B harassment isopleths are reported in Table 5 below. Of
note, based on the geography of Tongass Narrows and the surrounding
islands, sound will not reach the full distance of the Level B
harassment isopleth in most directions. Generally, due to interaction
with land, only a thin slice of the possible area will be ensonified to
the full distance of the Level B harassment isopleth.
Table 5--Level B Harassment Isopleths by Activity and Pile Size
------------------------------------------------------------------------
Pile diameter Level B harassment
Activity (inch) isopleth (m)
------------------------------------------------------------------------
Vibratory Installation and 30 11,659
Removal........................ 24 7,365
14
DTH Rock Sockets................ 24 2,572
DTH Tension Anchor.............. 8 1,274
Impact Installation............. 30 2,154
24 1,000
14
------------------------------------------------------------------------
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 driving or removal or DTH using any of
the methods discussed above, 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 is expected to incur PTS.
Inputs used in the optional User Spreadsheet tool, and the resulting
estimated isopleths, are reported in Table 6 and Table 7.
Table 6--NMFS User Spreadsheet Inputs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile driving DTH Impact
-----------------------------------------------------------------------------------------------------------------------
30-inch steel 24-inch steel Rock socket (24 Tension anchor (8- 30-inch steel 24-inch steel
piles piles or steel H- inch) inch) piles piles or steel H-
-------------------- pile ------------------------------------------------------------ pile
-------------------- -------------------
Installation or Installation or Installation Installation Installation
removal removal Installation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used............ A.1) Vibratory A.1) Vibratory E.2) DTH Pile E.2) DTH Pile E.1) Impact Pile E.1) Impact Pile
Pile Driving. Pile Driving. Driving. Driving. Driving. Driving.
Source Level (SPL).............. 166 RMS........... 163 RMS........... 167 RMS, 159 SEL.. 156 RMS, 144 SEL.. 183 SEL........... 177 SEL.
[[Page 63074]]
Transmission Loss Coefficient... 15................ 15................ 19.5, 19.9........ 17.1, 17.1........ 15................ 15.
Weighting Factor Adjustment 2.5............... 2.5............... 2................. 2................. 2................. 2.
(kHz).
Activity Duration (hours) within 0.5-6 *........... 0.5-8 *........... 1-8............... 1-8...............
24 hours.
Strike rate strike per second... .................. .................. 10................ 19................
Number of strikes per pile...... .................. .................. .................. .................. 50 (temporary); 50 (temporary);
200 (permanent). 200 (permanent).
Number of piles per day......... 1-6............... 1-8............... 1................. 1................. 1-3............... 1-3.
Distance of sound pressure level 10................ 10................ 10................ 10................ 10................ 10.
measurement.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* A range of activity durations (vibratory and DTH), strikes per pile (impact), piles per day are listed because ADOT&PF anticipates that they can
install or remove piles of the same size at different rates at different sites. Duration estimates for DTH assume that multiple rock sockets and
tension anchors will be installed each day, with a maximum daily duration of 8 hours.
Level A harassment thresholds for impulsive sound sources (impact
pile driving and DTH) are defined for both cumulative sound exposure
level (SELcum) and Peak SPL with the threshold that results in the
largest modeled isopleth for each marine mammal hearing group used to
establish the Level A harassment isopleth. In this project, Level A
harassment isopleths based on SELcum were always larger than those
based on Peak SPL. It should be noted that there is a duration
component when calculating the Level A harassment isopleth based on
SELcum, and this duration depends on the number of piles that will be
driven in a day and strikes per pile. For some activities, ADOT&PF
plans to drive variable numbers of piles per day throughout the project
(See ``Average Piles per Day (Range)'' in Table 1 of the Federal
Register notice for the proposed IHA, (88 FR 46746, July 20, 2023)).
NMFS accounted for this variability in its analysis. For each activity,
ADOT&PF provided the minimum and maximum potential durations of the
activity. In some cases the difference in the Level A harassment zone
size between the minimum and maximum duration anticipated for an
activity for a given hearing group is quite large. ADOT&PF expressed
concerns about implementing the largest Level A harassment zones for an
activity on days where activity levels would be much lower,
particularly given that the shutdown zones for an activity (Table 9)
are based upon the Level A harassment zone sizes. Therefore, for low
frequency cetaceans and phocids, in order to provide flexibility while
ensuring the number of Level A harassment zones and associated shutdown
zones are manageable, NMFS has identified two Level A harassment
isopleths for a given activity in cases where the differences between
zone sizes associated with the minimum and maximum potential activity
duration spans >100 m. At the beginning of each pile driving day,
ADOT&PF will determine the maximum number or duration that piles will
be driven that day and implement the Level A harassment zone associated
with that amount of activity.
Table 7--Distances to Level A Harassment Isopleths, by Hearing Group, and Level B Harassment Zones, During Pile Installation and Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment Isopleths, by hearing group (m)
-----------------------------------------------------------------
LF MF HF PW OW
Max. daily ----------------------------------------------------------------- Level B
Pile duration/ Minke harassment
Activity diameter(s) number of whale, fin Pacific Harbor Harbor isopleth
(inches) piles * whale, white-sided porpoise, seal, Steller sea (m; hearing
humpback dolphin, Dall's northern lion groups)
whale, gray killer porpoise elephant
whale whale seal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation or Removal......... 30 <=360 48.6 4.3 71.8 29.5 2.1 11,659
24 or 14 <=480 37.1 3.3 54.9 22.6 1.6 7,356
DTH (Rock Socket)......................... 24 <=120 210.3 27.8 392.8 107.1 29.8 2,572
121-180 ........... ........... ........... 214.9 ........... ...........
181-480 344.3 ........... ........... ........... ........... ...........
DTH (Tension Anchor)...................... 8 <=480 118.7 6.4 138.4 68.6 6.9 1,274
Impact, 200 strikes....................... 30 1 542.1 25.3 846.2 182.8 27.7 2,154
2 ........... ........... ........... 380.2 ........... ...........
3 710.4 ........... ........... ........... ........... ...........
[[Page 63075]]
24 or 14 1 136.0 10.1 336.9 72.8 11.0 1,000
2 282.8 ........... ........... 151.4 ........... ...........
3 ........... ........... ........... ........... ........... ...........
Impact, 50 strikes........................ 24 or 14 1-3 112.2 4.0 133.7 60.1 4.4 1,000
--------------------------------------------------------------------------------------------------------------------------------------------------------
* For low frequency cetaceans and phocids, in cases where the Level A harassment zone spanned >=100 m between the minimum and maximum duration for the
same activity, NMFS analyzed a shorter activity duration to allow for flexibility.
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, including density, or group dynamics of marine mammals,
that will inform the take calculations. Additionally, we describe how
the occurrence information is synthesized to produce a quantitative
estimate of the take that is reasonably likely to occur and authorized.
Note that take estimates included in ADOT&PF's application reflect 152
construction days rather than 131 (see Summary of Request section, in
which it is described that one site has been completed since submission
of the application). A summary of take, including a percentage of
population for each of the species, is shown in Table 8.
Minke Whale
There are no known occurrences of minke whales within the project
area. No minke whales where reported during ADOT&PF's previous
construction activities at the project site (ADOT&PF 2021, 2023), nor
during other recent projects in the Tongass Narrows (e.g., City of
Ketchikan (COK) Rock Pinnacle Blasting Project, Sitkiewicz 2020, Ward
Cove Cruise Ship Dock in 2020, Power Systems and Supplies of Alaska,
2020). However, since their range extends into the project area, and
they have been observed in southeast Alaska, including in Clarence
Strait (Dahlheim et al., 2009), it is possible the species could occur
in the project area. Still, future observations of minke whale in the
project area are expected to be rare.
ADOT&PF conservatively requested take by Level B harassment of
three minke whales every 4 months across the 12 months that the IHA is
active. NMFS concurs with ADOT&PF's estimated group size and frequency,
but finds it more appropriate to estimate take according to the number
of actual months in which construction is planned. As such, NMFS
conservatively authorizes four takes by Level B harassment (3 minke
whales x 1.25 months = 4 takes by Level B harassment).
ADOT&PF is planning to implement shutdown zones for low-frequency
cetaceans that exceed the Level A harassment isopleth for all
activities. Therefore, especially in combination with the infrequent
occurrence of minke whales entering the project area, implementation of
the established shutdown zones is expected to eliminate the potential
for take by Level A harassment of minke whale. Therefore, ADOT&PF did
not request take by Level A harassment of minke whale, nor is NMFS
authorizing any.
Fin Whale
Fin whales typically inhabit deep, offshore waters and often travel
in open seas away from coasts, and are often observed in social groups
of two to seven. However, a single fin whale was recently observed in
Clarence Strait (Scheurer, personal communication). Since the
ensonified area extends to the mouth of Tongass Narrows, where it meets
Clarence Strait, there is a chance that fin whale could occur in the
project area during construction. As such, NMFS conservatively
authorizes two takes by Level B harassment of fin whale.
ADOT&PF is planning to implement shutdown zones for low-frequency
cetaceans that exceed the Level A harassment isopleth for all
activities. Therefore, especially given the rare occurrence of fin
whale in the surrounding area, implementation of the established
shutdown zones is expected to eliminate the potential for take by Level
A harassment of fin whale. Therefore, ADOT&PF did not request take by
Level A harassment of fin whale, nor is NMFS authorizing any.
Humpback Whale
While no systematic studies have documented humpback whale
abundance near Ketchikan, anecdotal information suggests that this
species is present in low numbers year-round in Tongass Narrows.
Additionally, during ADOT&PF's 215 days of monitoring associated with
previous construction, 80 humpback whales were observed, or 0.37
humpback whales per day (ADOT&PF 2021, 2023). According to ADOT&PF, the
average group size was 1.25 humpback whales, and the maximum group size
was 4.
ADOT&PF conservatively estimates, and NMFS concurs, that one
humpback whale may occur in the Level B harassment zone each day of
planned in-water work (1 humpback whale x 131 days = 131 takes by Level
B harassment).
ADOT&PF is planning to implement shutdown zones for low-frequency
cetaceans that exceed the Level A harassment isopleth for all
activities. Therefore, implementation of the established shutdown zones
is expected to eliminate the potential for take by Level A harassment
of humpback whale. Therefore, ADOT&PF did not request take by Level A
harassment of humpback whale, nor is NMFS authorizing any.
In the proposed IHA, NMFS anticipated that all takes of humpback
whale would be of the Central North Pacific stock. Given the revised
stock structure described in the Description of Marine Mammals in the
Area of Specified Activities section, NMFS has reanalyzed the potential
for take of each stock of humpback whale and anticipates that the
authorized takes would be of the new Hawaii stock and
[[Page 63076]]
new Mexico-North Pacific stock. To determine the number of estimated
takes of each stock, NMFS assumes that two percent of humpback whales
occurring in Southeast Alaska are from the Mexico-North Pacific stock
and the remaining humpback whales are from the Hawai'i stock (Wade et
al., 2021).
Gray Whale
Gray whales are rare in the project area and unlikely to occur in
Tongass Narrows. They were not observed during the Dahlheim et al.
(2009) surveys of Alaska's inland waters with surveys conducted in the
spring, summer and fall months. No gray whales where reported during
ADOT&PF's previous construction activities at the project site (ADOT&PF
2021, 2023), nor during other recent projects in the Tongass Narrows
(e.g., COK Rock Pinnacle Blasting Project, Sitkiewicz 2020; Ward Cove
Cruise Ship Dock in 2020, Power Systems and Supplies of Alaska, 2020).
However a gray whale could migrate through or near the project, during
November especially. Gray whales are generally solitary and travel
together, alone, or in small groups.
ADOT&PF requested 24 takes by Level B harassment of gray whales (1
group x 2 gray whales x 12 months that the IHA is active). NMFS concurs
with ADOT&PF's estimated group size and frequency, but finds it more
appropriate to base take estimates on planned duration of in-water
work. As such, NMFS authorizes 10 takes by Level B harassment (1 group
x 2 gray whales x 5 months = 10 takes by Level B harassment).
ADOT&PF is planning to implement shutdown zones for low-frequency
cetaceans that exceed the Level A harassment isopleth for all
activities. Therefore, especially in combination with the low
occurrence of gray whales in the project area, implementation of the
planned shutdown zones is expected to eliminate the potential for take
by Level A harassment of gray whale. Therefore, ADOT&PF did not request
take by Level A harassment of gray whale, nor is NMFS authorizing any.
Pacific White-Sided Dolphin
Pacific white-sided dolphins were not observed during the 215 days
of marine mammal monitoring associated with ADOT&PF's previous
construction activities at this site (ADOT&PF 2021, 2023). There were
also no sightings of Pacific white-sided dolphins during previous
monitoring conducted during other recent construction projects in the
Tongass Narrows (Sitkiewicz 2020, Power Systems and Supplies of Alaska,
2020).
While rare in the inside passageways of Southeast Alaska, a group
of 164 Pacific white-sided dolphins were observed in the Dixon entrance
to the south of Tongass Narrows during aerial surveys in 1997 (Muto et
al. 2018), and this species was also documented in Revillagigedo
Channel, Behm Canal, and Clarence Strait during surveys conducted from
April to May between 1991 and 1993 (Dahlheim and Towell 1994). Finally,
Dalheim et al. (2009) frequently encountered Pacific white-sided
dolphins in Clarence Strait. Observations were noted most typically in
open strait environments, near the open ocean. Mean group size was over
20, with no recorded winter observations nor observations made in the
Nichols Passage or Behm Canal, located on either side of the Tongass
Narrows. This observational data, combined with anecdotal information,
indicates that while Pacific white-sided dolphins are rare in the area,
they could occur in the project area during construction.
ADOT&PF requested Level B harassment take of one group of 50
Pacific white-sided dolphins. However, to remain consistent with mean
groups sizes detected near Tongass Narrows (Dalheim et al., 2009), NMFS
is authorizing three groups of 20 pacific white sided dolphins (60
takes by Level B harassment of Pacific white-sided dolphin).
ADOT&PF is planning to implement shutdown zones for mid-frequency
cetaceans that exceed the Level A harassment isopleth for all
activities. Additionally, the Level A harassment isopleths for mid-
frequency cetaceans are quite small, and therefore, shutdown zones
should be easily implemented. Therefore, especially in combination with
the low occurrence of Pacific white-sided dolphins in the project area,
implementation of the established shutdown zones is expected to
eliminate the potential for take by Level A harassment of Pacific
white-sided dolphin. Therefore, ADOT&PF did not request take by Level A
harassment of Pacific white-sided dolphin, nor is NMFS is authorizing
any.
Killer Whale
While no systematic studies of killer whales have been conducted in
or around Tongass Narrows, killer whales are observed in Tongass
Narrows year-round, and anecdotal reports suggest they are most common
during the summer Chinook salmon run (May-July) (84 FR 36891, July 30,
2019). Across the 215 days of monitoring during ADOT&PF's previous
Tongass Narrows construction activities, a total of 78 killer whales
were observed, for an observation rate of 0.36 per day (ADOT&PF 2021,
2023). According to ADOT&PF, the average group size observed was 4.6
killer whales and the maximum group size was 8.
While ADOT&PF requested 180 takes by Level B harassment ((1 group x
12 killer whales x 9 months) + (2 groups x 12 killer whales x 3 months)
= 180 takes by Level B harassment)), NMFS finds it more appropriate to
base take estimates off the maximum group size (8 killer whales)
observed during monitoring of previous construction activities and the
planned duration of in-water work (5 months). As such, NMFS authorizes
64 takes by Level B harassment ((2 pods x 8 killer whales x 3 months) +
(1 pod x 8 killer whales x 2 months) = 64 takes by Level B harassment).
ADOT&PF is planning to implement shutdown zones for mid-frequency
cetaceans that exceed the Level A harassment isopleth for all
activities. Additionally, the Level A harassment isopleths for mid-
frequency cetaceans are quite small and therefore shutdown zones should
be easily implemented. Therefore, implementation of the established
shutdown zones is expected to eliminate the potential for take by Level
A harassment of killer whale. Therefore, ADOT&PF did not request take
by Level A harassment of killer whale, nor is NMFS authorizing any.
Harbor Porpoise
Abundance data for harbor porpoise in Southeast Alaska were
collected during 18 seasonal surveys spanning 22 years, from 1991 to
2012 (Dahlheim et al. 2015). The project area falls within the Clarence
Strait to Ketchikan region, as identified by this study for the survey
effort. Harbor porpoise densities in this region in summer were low,
ranging from 0.01 to 0.02 harbor porpoises/kilometers\2\. During
ADOT&PF's 215 days of monitoring during previous construction
activities at this project site, the daily average observations of
harbor porpoise in the project area was 0.1 (ADOT&PF 2021, 2023).
According to ADOT&PF, the maximum group size observed during this
monitoring was five.
ADOT&PF estimates that two groups of five harbor porpoise may occur
in the Level B harassment zone across the 12 months that the IHA is
active. NMFS concurs with ADOT&PF's estimated group size but finds it
appropriate to increase the frequency of occurrence estimate in the
Level B harassment zone from two groups per month to three groups per
month of work. Additionally,
[[Page 63077]]
NMFS finds it more appropriate to estimate take by Level B harassment
according to the planned duration of in-water work (3 groups x 5 harbor
porpoises x 5 months = 75 takes by Level B harassment). Additionally,
ADOT&PF requested take by Level A harassment of one group of five
harbor porpoise every 4 months across 12 months that the IHA is active.
However, NMFS finds it more appropriate to estimate take by Level A
harassment according to the number of months in which the Level A
harassment zone may extend beyond the established shutdown zone (i.e.,
2.9 months, when DTH systems may be employed to install 24-inch piles,
or 24-inch and 30-inch piles may be installed with an impact pile
driver (200 strikes)). As such, NMFS authorizes 15 takes by Level A
harassment of harbor porpoise (1 group x 5 harbor porpoise x 2.9 months
= 15 takes by Level B harassment) and 60 takes by Level B harassment
((3 groups x 5 harbor porpoise x 5 months)-15 takes by Level A
harassment = 60 takes by Level B harassment).
In the proposed IHA, NMFS anticipated that all takes of harbor
porpoise would be of the Southern Southeast Alaska Inland Water stock.
Given the revised stock structure described in the Description of
Marine Mammals in the Area of Specified Activities section, NMFS has
reanalyzed the potential for take of each stock of harbor porpoise and
anticipates that the authorized takes would be of the new Southern
Southeast Alaska Inland Waters stock, as that is the only stock that
overlaps the project area.
Dall's Porpoise
Dall's porpoise have occasionally been observed during previous
construction projects completed in Tongass Narrows (Power Systems and
Supplies of Alaska, 2020), including during ADOT&PF's 215 days of
monitoring (ADOT&PF 2021, 2023). ADOT&PF reported that the average
group size observed was 5.6 and the maximum group size was 10. To
estimate take, ADOT&PF has assumed that Dall's porpoise may occur in
pods of 15 and across the 12 months that the IHA is active. NMFS finds
it more appropriate to base take estimates off the maximum group size
(10 Dall's porpoise) observed during monitoring of previous
construction activities and according to estimated duration of planned
pile driving and DTH activities.
As such, while ADOT&PF estimates that one pod of 15 Dall's porpoise
may occur within the Level B harassment zone across each of the 12
months that the IHA is active, NMFS finds it more appropriate to
conservatively estimate that 2 pods of 10 Dall's porpoise may occur in
the Level B harassment zone each month in which in-water work is
planned (2 pod x 10 Dall's porpoise x 5 months = 100).
Additionally, ADOT&PF has estimated that one pod of 15 Dall's
porpoise may occur within the Level A harassment zone across the 12
months that the IHA is active. However, NMFS finds it more appropriate
to estimate 10 takes by Level A harassment of Dall's porpoise across
the 2.9 months in which the Level A harassment zone may extend beyond
the shutdown zone for this species, which could occur when DTH systems
are employed to install 24-inch piles or an impact pile driver (200
strikes) is used to install 24-inch and 30-inch piles (1 group x 10
Dall's porpoise = 10 takes by Level A harassment). Therefore, NMFS is
authorizing 10 takes by Level A harassment of Dall's porpoise. Finally,
the authorized take by Level B harassment has been calculated as the
total calculated Dall's porpoise takes by Level B harassment minus the
authorized takes by Level A harassment (100 takes by Level B
harassment-10 takes by Level A harassment = 90 takes by Level B
harassment). Therefore, NMFS is authorizing 90 takes by Level B
harassment of Dall's porpoise.
Steller Sea Lion
Steller sea lions may be found in Tongass Narrows year-round, with
anecdotal reports suggesting an increase in abundance from March to
early May during the herring spawning season, and another increase in
late summer associated with salmon runs. During the 215 days of marine
mammal monitoring that took place during construction of previous
components of the Tongass Narrows Project, a total of 322 Steller sea
lions were observed (ADOT&PF 2021, 2023). According to ADOT&PF, the
average group size was 1.25 individuals and maximum group size observed
was five individuals. At least one Steller sea lion was observed during
each month that monitoring took place. Monitoring during construction
of the nearby Ward Cove Dock recorded 4.1 individuals per day (Power
Systems & Supplies of Alaska, 2020).
ADOT&PF estimates that one group of 10 Steller sea lions may be
taken by Level B harassment each day that in-water work is planned.
Based on ADOT&PF's 215 days of project-related monitoring, NMFS finds
it more appropriate to estimate that 1 group of 5 Steller sea lions may
be present in the Level B harassment zone each day (1 group x 5 Steller
sea lion x 131 construction days = 655 takes by Level B harassment).
ADOT&PF is required to implement a shutdown zone that exceeds the
Level A harassment zone for Steller sea lions during all project
activities. However, ADOT&PF expects that Steller sea lions could enter
the Level A harassment zone undetected on rare occasions. As such,
ADOT&PF requests take by Level A harassment of 5 percent of Steller sea
lions authorized for take by Level B harassment. NMFS concurs that,
given the various structures along the shoreline in the project area,
Steller sea lions could enter the Level A harassment zone and remain in
the zone undetected for a long enough duration to incur PTS before a
shutdown occurs. However, NMFS anticipates that 5 percent of the take
by Level B harassment would result in an overestimate of Level A
harassment. NMFS anticipates that 10 Steller sea lions could enter the
Level A harassment zone and remain in the zone undetected for a long
enough duration to incur PTS before a shutdown occurs across the 131
days of planned in-water work. As such, NMFS is authorizing 10 takes by
Level A harassment and 645 takes by Level B harassment ((1 group x 5
individuals x 131 construction days)-10 takes by Level A harassment =
645 takes by Level B harassment).
Northern Elephant Seal
Although northern elephant seals are known to visit the Gulf of
Alaska to feed on benthic prey, they rarely occur on the beaches of
Alaska. Despite the low probability of northern elephant seals entering
the project area, there have been recent reports of elephant seals
occurring in and near the Tongass Narrows, and two northern elephant
seals were observed during ADOT&PF's Tongass Narrows construction in
2022. As such, ADOT&PF requested take by Level B harassment of one
elephant seal per 6-day work week. NMFS concurs that one take by Level
B harassment per work week is appropriate. However, because ADOT&PF
plans 7-day work weeks, NMFS calculates the total number of work weeks
to occur within 131 construction days as 19 weeks rather than ADOT&PF's
planned 22 weeks (1 Northern elephant seal x 19 work weeks = 19 takes
by Level B harassment).
For most project activities, the established shutdown zone will
exceed the Level A harassment zone for Northern elephant seal. However,
the Level A harassment zone may extend beyond the established shutdown
zone for this species on 37 days (when DTH systems may be employed to
install 24-
[[Page 63078]]
inch piles or 30-inch piles may be installed with an impact pile driver
(200 strikes)). While unlikely given the already low occurrence of
Northern elephant seals, on those days, a Northern elephant seal could
occur in the Level A harassment zone and remain in the zone for a long
enough duration to incur PTS, and NMFS is conservatively authorizing
five takes by Level A harassment. As such, NMFS is authorizing 14 takes
by Level B harassment (1 Northern elephant seal x 19 work weeks-5 takes
by Level A harassment = 14 takes by Level B harassment).
Harbor Seal
During marine mammal monitoring associated with ADOT&PF's previous
Tongass Narrows construction activities, 550 harbor seals were observed
with an average of 1.2 harbor seals per day and a maximum group size of
5. The COK pinnacle rock blasting project recorded a total of 21 harbor
seal sightings of 24 individuals over 76.2 hours of pre- and post-blast
monitoring (Sitkiewicz 2020). Additionally, information from PSOs
associated with on-going construction indicates that a small number of
harbor seals are regularly sighted at about 820 ft (250 m) from the
project location (Wyatt, personal communication). Additionally, there
are two key harbor seal haulouts about 7.1 miles (11.5 kilometers) from
the project area on a mid-channel island to the southeast of the
project site. Each haulout was monitored in 2022 with 10 harbor seals
observed at one haulout and 50 harbor seals observed at the other
(Richland, personal communication).
ADOT&PF estimates, and NMFS concurs, that up to 2 groups of 3
harbor seals could enter the Level B harassment zone per day (2 groups
x 3 harbor seals x 131 days = 786). Further, NMFS also estimates that
half the harbor seals occurring at the haulout sites within the project
area could enter the Level B harassment zone on days when the
ensonified area (during 30'' vibratory pile driving) reaches these
haulout sites (30 harbor seals x 13 days = 390).
ADOT&PF also estimates that 1 harbor seal could be taken by Level A
harassment on each day of in-water work (1 harbor seal x 131 days = 131
takes by Level A harassment). For most project activities, the shutdown
zone exceeds the Level A harassment zone. However, when an impact pile
driver (200 strikes) is used to install 30-inch piles, the Level A
harassment zone exceeds the associated shutdown zone. This could occur
on 13 days. NMFS anticipates that three harbor seals could be taken by
Level A harassment on each day that the Level A harassment isopleth for
this species extends beyond the shutdown zone. Therefore, NMFS is
authorizing 39 takes by Level A harassment (3 harbor seal x 13 days =
39 takes by Level A harassment) and 1,137 takes by Level B harassment
(786 takes by Level B harassment + 390 takes by Level B harassment - 39
takes by Level A harassment = 1,137 takes by Level B harassment).
Table 8--Authorized Take by Stock and Harassment Type and as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
Authorized take Authorized take
-------------------------- as a percentage
Species Stock Level B Level A of stock
harassment harassment abundance
----------------------------------------------------------------------------------------------------------------
Minke whale............................ Alaska.................... 4 0 .................
Fin whale.............................. Northeast Pacific......... 2 0 0.1
Humpback whale......................... Hawai[revaps]i \1\........ 128 0 1.1
Mexico--North Pacific \1\. 3 0 .................
Gray whale............................. Eastern North Pacific..... 10 0 0.04
Pacific white-sided dolphin............ North Pacific............. 60 0 0.2
Killer whale........................... Eastern North Pacific 64 0 3.3
Alaska Resident.
Eastern North Pacific ........... ........... 21.2
Northern Resident.
West Coast Transient................... .......................... ........... ........... 16.3
Harbor porpoise........................ Southern Southeast Alaska 60 15 8.4
Inland \2\.
Dall's porpoise........................ Alaska.................... 90 10 0.8
Steller sea lion....................... Eastern U.S............... 645 10 1.5
Northern Elephant seal................. California Breeding....... 14 5 <0.1
Harbor seal............................ Clarence Strait........... 1,137 39 4.3
----------------------------------------------------------------------------------------------------------------
\1\ Given the revised stock structure for humpback whale, described in the Description of Marine Mammals in the
Area of Specified Activities section, NMFS assumes that two percent of humpback whales occurring in Southeast
Alaska are from the Mexico--North Pacific stock and the remaining humpback whales are from the Hawai[revaps]i
stock (Wade et al., 2021).
\2\ Given the revised stock structure described in the Description of Marine Mammals in the Area of Specified
Activities section, NMFS assumed all the authorized takes would be of the new Southern Southeast Alaska Inland
Waters stock, as that is the only stock that overlaps the project area.
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses. 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.
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
[[Page 63079]]
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.
ADOT&PF must ensure that construction supervisors and crews, the
monitoring team and relevant ADOT&PF staff are trained prior to the
start of all pile driving and DTH 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.
Protected Species Observers
ADOT&PF must employ PSOs and establish monitoring locations as
described in the NMFS-approved Marine Mammal Monitoring Plan and
Section 5 of the IHA. ADOT&PF 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 vibratory
pile driving and removal, ADOT&PF must employ at least three PSOs. For
all impact pile driving and DTH, ADOT&PF must employ at least two PSOs.
As noted in the Changes from the Proposed IHA to Final IHA section, in
the proposed IHA, NMFS proposed to require ADOT&PF to employ three PSOs
for DTH activities. After publication of the proposed IHA, ADOT&PF
requested for NMFS to revise this measure to require two PSOs for DTH
activities, given that the zone sizes for DTH activities were more
commensurate with that of impact pile driving. NMFS concurred, and
therefore, the final IHA requires ADOT&PF to employ at least two PSOs
for DTH activities, rather than three. The placement of the PSOs during
all pile driving and removal and DTH activities will ensure that the
entire shutdown zone is visible.
Pre- and Post-Activity Monitoring
Monitoring must take place from 30 minutes prior to initiation of
pile driving or DTH activity (i.e., pre-clearance monitoring) through
30 minutes post-completion of pile driving or DTH activity. 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 9 are clear of marine mammals. Pile driving may
commence following 30 minutes of observation when the determination is
made that the shutdown zones are clear of marine mammals. Further,
while not a requirement in the IHA, the 2023 Biological Opinion
requires that if a work stoppage occurs and PSOs do not monitor the
boundaries of the Level B harassment zone continuously during the work
stoppage, the entire Level B harassment zone must be surveyed again for
the presence of ESA-listed species before work may resume.
Additionally, the 2023 Biological Opinion requires that in-water
activities take place only between civil dawn and civil dusk when PSOs
can effectively monitor for the presence of marine mammals and when the
entire shutdown zone and adjacent waters are visible (e.g., monitoring
effectiveness is not reduced due to rain, fog, snow, etc.). The 2023
Biological Opinion allows for pile driving to continue for up to 30
minutes after sunset during evening civil twilight, as necessary to
secure a pile for safety prior to demobilization for the evening. PSOs
will continue to observe shutdown and monitoring zones during this
time. The length of the post-activity monitoring period may be reduced
if darkness precludes visibility of the shutdown and monitoring zones.
Soft Start
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. ADOT&PF
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.
Shutdown Zones
For all pile driving/removal and DTH activities, ADOT&PF will
establish shutdown zones (Table 9). The purpose of a shutdown zone is
generally to define an area within which shutdown of activity will
occur upon sighting of a marine mammal (or in anticipation of an animal
entering the defined area). Shutdown zones vary based on the activity
type and duration and marine mammal hearing group (Table 9). In most
cases, shutdown zones are based on the estimated Level A harassment
isopleth distances for each hearing group. However, in cases where
ADOT&PF asserted that it would be impracticable to shut down at the
Level A harassment isopleth due to excessive work stoppages, a smaller
shutdown zone has been established (e.g., for high-frequency cetaceans
and phocids during DTH rock socketing of 24-inch piles). Note that some
of the established shutdown zones differ from those proposed by the
ADOT&PF in their application (see Table 6-5 of ADOT&PF's application)
due to our incorporation of sound source levels and DTH TL coefficients
from ADOT&PF's SSV report.
ADOT&PF anticipates that the maximum amount of activity within a
given day may vary significantly (Table 6), with large differences in
maximum zones sizes possible (Table 7). Given this uncertainty and
concerns related to ESA-listed humpback whales and fin whales, and
practicability concerns with shutting down, ADOT&PF plans a tiered
system to identify and monitor the appropriate Level A harassment zones
and shutdown zones for large frequency cetaceans and phocids. This
tiered system is based on the maximum expected number of piles to be
installed (impact or vibratory pile driving) or the maximum expected
DTH duration in a given day. At the start of each work day, ADOT&PF
will determine the maximum scenario possible for that day (according to
the defined duration intervals in Tables 7 and 9), which will determine
the appropriate Level A harassment isopleth and associated shutdown
zone for that day. This Level A harassment zone (Table 7) and
associated shutdown zone (Table 9) must be implemented for the entire
work day.
The placement of PSOs during all pile installation and removal, and
DTH activities (described in detail in the Monitoring and Reporting
section) will ensure that the entire shutdown zones are visible during
pile driving. If a marine mammal is observed entering or within the
shutdown zones indicated in Table 9, pile driving 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 9) or 15 minutes (non-ESA-listed species) or 30
minutes (humpback whales and fin whales) have passed without re-
detection of the animal. Further, pile driving activity must be halted
upon observation of either a species for which incidental take is not
authorized or a species for which incidental take has been authorized
but the authorized number of takes has been met, entering or within the
harassment zone.
ADOT&PF must also avoid direct physical interaction with marine
[[Page 63080]]
mammals during construction activity. If a marine mammal comes within
10 m of such activity, operations must cease and vessels must reduce
speed to the minimum level required to maintain steerage and safe
working conditions.
Table 9--Shutdown Zones and Level B Harassment Zones
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Duration (min; Shutdown distances (m)
vibratory/DTH)/-------------------------------------------------------------------------------- Level B
Activity Pile diameter(s) (inches) # of piles harassment
(impact) LF MF HF PW OW isopleth (m)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation or Removal, temporary 30................................ <=360 50 10 80 30 10 11,659
and permanent. 24 or 14.......................... <=480 40 10 60 30 10 7,365
DTH (Rock Socket)........................... 24................................ <=120 220 30 300 110 30 2,572
121-180 .............. .............. .............. 220 .............. ..............
181-480 350 .............. .............. .............. .............. ..............
DTH (Tension Anchor)........................ 8................................. <=480 170 10 140 70 10 1,274
Impact permanent............................ 30................................ 1 550 30 300 190 30 2,154
2 .............. .............. .............. 300 .............. ..............
3 720 .............. .............. .............. .............. ..............
24 or 14.......................... 1 140 10 300 80 20 1,000
2 290 .............. .............. 160 .............. ..............
3 .............. .............. .............. .............. .............. ..............
Impact, temporary........................... 24 or 14.......................... 1-3 120 10 140 60 10 1,000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Based on our evaluation of the applicant's planned measures, as
well as other measures considered by NMFS, NMFS has determined that the
required mitigation measures provide the means effecting the least
practicable impact on the affected species or stocks and their habitat,
paying particular attention to rookeries, mating grounds, and areas of
similar significance.
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:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Monitoring must be conducted by qualified, NMFS-approved PSOs, who
will be present during all pile installation and removal activities,
including vibratory, impact, and DTH methods, in accordance with the
following:
<bullet> PSOs must be independent (i.e., not construction
personnel) and have no other assigned tasks during monitoring periods;
<bullet> At least one PSO must have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
IHA;
<bullet> Other PSOs may substitute other relevant experience,
education (degree in biological science or related field), or training
for prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued IHA;
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization; and
<bullet> PSOs must be approved by NMFS prior to beginning any
activity subject to this IHA.
PSOs should have the following additional qualifications:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number of species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
<bullet> Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
A minimum of one PSO (the lead PSO) must be assigned to the active
pile driving or DTH location to monitor the shutdown zones and as much
of the harassment zones as possible. The observation points of the
additional
[[Page 63081]]
PSOs may vary depending on the construction activity and location of
the piles. During impact pile driving or DTH activities, the second PSO
will select the best location to observe as much of the Level A
harassment and Level B harassment zones as possible. To select the best
observation locations during vibratory installation and removal, prior
to start of construction, the lead PSO will stand at the construction
site to monitor the shutdown zones while two or more PSOs travel in
opposite directions from the project site along Tongass Narrows until
they have reached the edge of the Level B harassment zone, where they
will identify suitable observation points from which to observe. If
visibility deteriorates so that the entire width of Tongass Narrows at
the harassment zone boundary is not visible, additional PSOs may be
positioned so that the entire width is visible, or work will be halted
until the entire width is visible to ensure that any humpback whales or
fin whales entering or within the harassment zone are detected by PSOs.
PSOs must record all observations of marine mammals, regardless of
distance from the pile being driven. PSOs shall document any behavioral
reactions in concert with distance from piles being driven or removed.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities, or 60 days prior to a requested date of issuance of 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:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> 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), the total
equipment duration for vibratory installation/removal or DTH for each
pile or hole and total number of strikes for each pile (impact
driving);
<bullet> PSO locations during marine mammal monitoring;
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance;
<bullet> Upon observation of a marine mammal, the following
information: Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting; Time of sighting; Identification of the
animal(s) (e.g., genus/species, lowest possible taxonomic level, or
unidentified), PSO confidence in identification, and the composition of
the group if there is a mix of species; Distance and bearing of each
marine mammal observed relative to the pile being driven for each
sighting (if pile driving was occurring at time of sighting); Estimated
number of animals (min/max/best estimate); Estimated number of animals
by cohort (adults, juveniles, neonates, group composition, sex class,
etc.); Animal's closest point of approach and estimated time spent
within the harassment zone; Description of any marine mammal behavioral
observations (e.g., observed behaviors such as feeding or traveling),
including an assessment of behavioral responses thought to have
resulted from the activity (e.g., no response or changes in behavioral
state such as ceasing feeding, changing direction, flushing, or
breaching);
<bullet> Number of marine mammals detected within the harassment
zones, by species;
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting changes in behavior of the
animal(s), if any.
ADOT&PF must also submit all PSO datasheets and/or raw sighting
data with the draft report, as specified in condition 6(b) of this IHA.
If no comments are received from NMFS within 30 days, the draft
report will constitute the final report. If comments are received, a
final report addressing NMFS comments must be submitted within 30 days
after receipt of comments.
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), NMFS and to the NMFS 24-hour
Stranding Hotline as soon as feasible. If the death or injury was
clearly caused by the specified activity, ADOT&PF 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:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> 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 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 majority of our analysis applies to all
the species listed in Table 1, given that many of the
[[Page 63082]]
anticipated effects of this project on different marine mammal stocks
are expected to be relatively similar in nature. Where there are
meaningful differences between species or stocks, or groups of species,
in anticipated individual responses to activities, impact of expected
take on the population due to differences in population status, or
impacts on habitat, NMFS has identified species-specific factors to
inform the analysis.
Pile driving and DTH 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 and DTH.
Potential takes could occur if marine mammals are present in zones
ensonified above the thresholds for Level B harassment or Level A
harassment, identified above, while activities are underway.
NMFS does not anticipate that serious injury or mortality will
occur as a result of ADOT&PF's planned activity given the nature of the
activity, even in the absence of required mitigation. Further, no take
by Level A harassment is anticipated for Pacific white-sided dolphin,
killer whale, humpback whale, gray whale, fin whale, or minke whale,
due to the likelihood of occurrence and/or required mitigation
measures. As stated in the mitigation section, ADOT&PF will implement
shutdown zones that equal or exceed many of the Level A harassment
isopleths shown in Table 9. Take by Level A harassment is authorized
for some species (Steller sea lion, harbor seal, northern elephant
seal, harbor porpoise, and Dall's porpoise) to account for the
potential that an animal could enter and remain within the area between
a Level A harassment zone and the shutdown zone for a duration long
enough to be taken by Level A harassment, and in some cases, to account
for the possibility that an animal could enter a shutdown zone without
detection given the various obstructions along the shoreline, and
remain in the Level A harassment zone for a duration long enough to be
taken by Level A harassment before being observed and a shutdown
occurring. Any take by Level A harassment is expected to arise from, at
most, a small degree of PTS because 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. Additionally, and
as noted previously, some subset of the individuals that are
behaviorally harassed could also simultaneously incur some small degree
of TTS for a short duration of time. Because of the small degree
anticipated, though, any PTS or TTS potentially incurred here is not
expected to adversely impact individual fitness, let alone annual rates
of recruitment or survival.
For all species and stocks, take is expected to occur within a
limited, confined area (adjacent to the project site) of the stock's
range. The intensity and duration of take by Level A harassment and
Level B harassment will be minimized through use of mitigation measures
described herein. Further the amount of take authorized is small when
compared to stock abundance.
Behavioral responses of marine mammals to pile driving, pile
removal, and DTH at the sites in Tongass Narrows 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 visually observable such
as changes in vocalization patterns. Given that pile driving, pile
removal, and DTH will occur for only a portion of the project's
duration and often on nonconsecutive days, any harassment would be
temporary. Additionally, many of the species present in Tongass Narrows
would only be present temporarily based on seasonal patterns or during
transit between other habitats. These species would be exposed to even
shorter periods of noise-generating activity, further decreasing the
impacts.
As previously described, a UME has been declared for gray whales.
However, we do not expect the takes authorized herein to exacerbate the
ongoing UME. No serious injury or mortality of gray whales is expected
or authorized, and take by Level B harassment is limited (10 takes over
the duration of the authorization). As such, the authorized take by
Level B harassment of gray whale is not expected to exacerbate or
compound upon the ongoing UME.
For all species except humpback whales, there are no known BIAs
near the project zone that will be impacted by ADOT&PF's planned
activities. For humpback whales, the inland waters of Southeast Alaska
is a seasonal feeding BIA from May through September (Wild et al.,
2023), however, the mouth of Tongass Narrows is a small passageway and
represents a very small portion of the total available habitat. Also,
while southeast Alaska is considered an important area for feeding
humpback whales during this time, it is not currently designated as
critical habitat for humpback whales (86 FR 21082, April 21, 2021).
More generally, there are no known calving or rookery grounds
within the project area, but anecdotal evidence from local experts
shows that marine mammals are more prevalent in Tongass Narrows and
Clarence Strait during spring and summer associated with feeding on
aggregations of fish, meaning the area may play a role in foraging.
Because ADOT&PF's activities could occur during any season, takes may
occur during important feeding times. However, the project area
represents a small portion of available foraging habitat and impacts on
marine mammal feeding for all species, including humpback whales,
should be minimal.
Any impacts on marine mammal prey that occur during ADOT&PF's
planned activity are expected to have, at most, short-term effects on
foraging of individual marine mammals, and likely no effect on the
populations of marine mammals as a whole. Indirect effects on marine
mammal prey during the construction are expected to be minor, and these
effects are unlikely to cause substantial effects on marine mammals at
the individual level, with no expected effect on annual rates of
recruitment or survival.
In addition, it is unlikely that minor noise effects in a small,
localized area of habitat will have any effect on the reproduction or
survival of any individuals, much less the stocks' annual rates of
recruitment or survival. 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 will have only minor, short-term effects on individuals. The
specified activities are not expected to impact rates of recruitment or
survival and will, therefore, not result in population-level impacts.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> Take by Level A harassment of Pacific white-sided dolphin,
killer whale, humpback whale, fin whale, gray whale, or minke whale is
not anticipated or authorized;
<bullet> ADOT&PF will implement mitigation measures including soft-
starts for impact pile driving and shutdown zones to minimize the
numbers of marine mammals exposed to
[[Page 63083]]
injurious levels of sound, and to ensure that any take by Level A
harassment is, at most, a small degree of PTS;
<bullet> The intensity of anticipated takes by Level B harassment
is relatively low for all stocks and will not be of a duration or
intensity expected to result in impacts on reproduction or survival;
<bullet> There are 10 known areas of specific biological
importance, covering a broad area of southeast Alaska, for humpback
whales. The project area overlaps a very small portion of one of these
BIAs. No other known areas of particular biological importance to any
of the affected species or stocks are impacted by the activity,
including ESA-designated critical habitat;
<bullet> The project area represents a very small portion of the
available foraging area for all potentially impacted marine mammal
species and stocks and anticipated habitat impacts are minor; and
<bullet> Monitoring reports from similar work in Tongass Narrows
have documented little to no effect on individuals of the same species
impacted by the specified activities.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the planned
activity will 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 authorized number of instances of take is below one-third of
the estimated stock abundance for all stocks (see Table 8). The number
of animals authorized to be taken from these stocks would be considered
small relative to the relevant stocks' abundances even if each
estimated taking occurred to a new individual, which is an unlikely
scenario. Some individuals may return multiple times in a day, but PSOs
will count them as separate takes if they cannot be individually
identified.
The Alaska stock of Dall's porpoise has no official NMFS abundance
estimate, as the most recent estimate is greater than 8 years old. The
most recent estimate was 13,110 animals for just a portion of the
stock's range. Therefore, the 100 authorized takes of this stock
clearly represent small numbers of this stock.
The Mexico--North Pacific stock of Humpback Whale has no official
NMFS abundance estimate, as the most recent estimate is greater than 8
years old. The most recent estimate was 571 animals for just a portion
of the stock's range (Revillagigedo Archipelago). Therefore, the three
takes of this stock authorized clearly represent small numbers of this
stock.
There is no current or historical estimate of the Alaska minke
whale stock, but there are known to be over 1,000 minke whales in the
Gulf of Alaska (Muto et al. 2018), so the 4 takes authorized is small
relative to estimated survey abundance, even if each take occurred to a
new individual. Additionally, the range of the Alaska stock of minke
whales is extensive, stretching from the Canadian Pacific coast to the
Chukchi Sea, and ADOT&PF's project area will impact a small portion of
this range.
The best available abundance estimate for fin whale is not
considered representative of the entire stock as surveys were limited
to a small portion of the stock's range, but there are known to be over
2,500 fin whales in the northeast Pacific stock (Muto et al. 2021). As
such, the two takes authorized is small relative to the estimated
survey abundance, even if each take occurred to a new individual.
Based on the analysis contained herein of the planned activity
(including the mitigation and monitoring measures) and the anticipated
take of marine mammals, NMFS finds that small numbers of marine mammals
are expected to 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.
Harbor seals are the marine mammal species most regularly harvested
for subsistence by households in Ketchikan and Saxman (a community a
few miles south of Ketchikan, on the Tongass Narrows). Eighty harbor
seals were harvested by Ketchikan residents in 2007, which ranked
fourth among all communities in Alaska that year for harvest of harbor
seals. Thirteen harbor seals were harvested by Saxman residents in
2007. In 2008, two Steller sea lions were harvested by Ketchikan-based
subsistence hunters, but this is the only record of sea lion harvest by
residents of either Ketchikan or Saxman. In 2012, the community of
Ketchikan had an estimated subsistence take of 22 harbor seals and 0
Steller sea lion (Wolf et al. 2013). NMFS is not aware of more recent
data. Hunting usually occurs in October and November (Alaska Department
of Fish and Game (ADF&G) 2009), but there are also records of
relatively high harvest in May (Wolfe et al. 2013). The ADF&G has not
recorded harvest of cetaceans from Ketchikan or Saxman (ADF&G 2023).
All project activities are planned to take place within the
industrial area of Tongass Narrows immediately adjacent to Ketchikan
where subsistence activities do not generally occur. Both harbor seals
and Steller sea lions may be temporarily displaced from the project
area. The project will also not have an adverse impact on the
availability of marine mammals for subsistence use at locations farther
away where these construction activities are not expected to take
place. Some minor, short-term harassment of the harbor seals could
occur, but given the information above, we do not expect such
harassment to have effects on subsistence hunting activities.
Based on the description of the specified activity, the measures
described to minimize adverse effects on the availability of marine
mammals for subsistence purposes, and the mitigation and monitoring
measures,
[[Page 63084]]
NMFS has determined that there will not be an unmitigable adverse
impact on subsistence uses from ADOT&PF's planned 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 plan to authorize take for
endangered or threatened species, in this case with NMFS' Alaska
Regional Office (AKRO).
NMFS is authorizing take of the Mexico--North Pacific stock of
humpback whale, and fin whale, which are listed as threatened or
endangered under the ESA. The NMFS AKRO issued a Biological Opinion
under section 7 of the ESA on the issuance of an IHA to ADOT&PF under
section 101(a)(5)(D) of the MMPA by NMFS OPR. The biological opinion
concluded that the action is not likely to jeopardize the continued
existence of the listed species.
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 proposed actions (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 determined that the
issuance of the IHA qualifies to be categorically excluded from further
NEPA review.
Authorization
NMFS has issued an IHA to ADOT&PF for the potential harassment of
small numbers of 11 marine mammal species incidental to ferry berth
construction in Tongass Narrows in Ketchikan, Alaska, that includes the
previously explained mitigation, monitoring, and reporting
requirements.
Dated: September 11, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2023-19903 Filed 9-13-23; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on September 14, 2023.
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