Notice2022-15937
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Office of Naval Research's Arctic Research Activities in the Beaufort and Chukchi Seas (Year 5)
Primary source
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Published
July 26, 2022
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from Office of Naval Research (ONR) for authorization to take marine mammals incidental to Arctic Research Activities (ARA) in the Beaufort Sea and eastern Chukchi Sea. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an incidental harassment authorization (IHA) to incidentally take marine mammals during the specified activities. NMFS is also requesting comments on a possible one-time, one-year renewal that could be issued under certain circumstances and if all requirements are met, as described in Request for Public Comments at the end of this notice. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorization and agency responses will be summarized in the final notice of our decision. The ONR's activities are considered military readiness activities pursuant to the MMPA, as amended by the National Defense Authorization Act for Fiscal Year 2004 (2004 NDAA).
Full Text
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<title>Federal Register, Volume 87 Issue 142 (Tuesday, July 26, 2022)</title>
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[Federal Register Volume 87, Number 142 (Tuesday, July 26, 2022)]
[Notices]
[Pages 44339-44364]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-15937]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC070]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Office of Naval Research's
Arctic Research Activities in the Beaufort and Chukchi Seas (Year 5)
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
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SUMMARY: NMFS has received a request from Office of Naval Research
(ONR) for authorization to take marine mammals incidental to Arctic
Research Activities (ARA) in the Beaufort Sea and eastern Chukchi Sea.
Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting
comments on its proposal to issue an incidental harassment
authorization (IHA) to incidentally take marine mammals during the
specified
[[Page 44340]]
activities. NMFS is also requesting comments on a possible one-time,
one-year renewal that could be issued under certain circumstances and
if all requirements are met, as described in Request for Public
Comments at the end of this notice. NMFS will consider public comments
prior to making any final decision on the issuance of the requested
MMPA authorization and agency responses will be summarized in the final
notice of our decision. The ONR's activities are considered military
readiness activities pursuant to the MMPA, as amended by the National
Defense Authorization Act for Fiscal Year 2004 (2004 NDAA).
DATES: Comments and information must be received no later than August
25, 2022.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service and should be submitted via email to
<a href="/cdn-cgi/l/email-protection#a4edf0f48ad0c5ddc8cbd6e4cacbc5c58ac3cbd2"><span class="__cf_email__" data-cfemail="78312c28560c190114170a3816171919561f170e">[email protected]</span></a>.
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted online at
<a href="http://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a> without change. All personal identifying
information (e.g., name, address) voluntarily submitted by the
commenter may be publicly accessible. Do not submit confidential
business information or otherwise sensitive or protected information.
FOR FURTHER INFORMATION CONTACT: Jessica Taylor, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-military-readiness-activities</a>. In case of problems
accessing these documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed or, if the taking is limited to harassment, a notice of a
proposed 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 2004 NDAA (Pub. L. 108-136) removed the ``small numbers'' and
``specified geographical region'' limitations indicated above and
amended the definition of ``harassment'' as applied to a ``military
readiness activity.'' The activity for which incidental take of marine
mammals is being requested addressed here qualifies as a military
readiness activity. The definitions of all applicable MMPA statutory
terms cited above are included in the relevant sections below.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment.
In 2018, the U.S. Navy prepared an Overseas Environmental
Assessment (OEA; referred to as an EA in this document) analyzing the
project. Prior to issuing the IHA for the first year of this project,
NMFS reviewed the 2018 EA and the public comments received, determined
that a separate NEPA analysis was not necessary, and subsequently
adopted the document and issued a NMFS Finding of No Significant Impact
(FONSI) in support of the issuance of an IHA (83 FR 48799; September
27, 2018).
In 2019, the U.S. Navy prepared a supplemental EA. Prior to issuing
the IHA in 2019, NMFS reviewed the supplemental EA and the public
comments received, determined that a separate NEPA analysis was not
necessary, and subsequently adopted the document and issued a NMFS
FONSI in support of the issuance of an IHA (84 FR 50007; September 24,
2019).
In 2020, the U.S. Navy submitted a request for a renewal of the
2019 IHA. Prior to issuing the renewal IHA, NMFS reviewed ONR's
application and determined that the proposed action was identical to
that considered in the previous IHA. Because no significantly new
circumstances or information relevant to any environmental concerns had
been identified, NMFS determined that the preparation of a new or
supplemental NEPA document was not necessary and relied on the
supplement EA and FONSI from 2019 when issuing the renewal IHA in 2020
(85 FR 41560; July 10, 2020).
In 2021, the U.S. Navy submitted a request for an IHA for
incidental take of marine mammals during continuation of ARA. NMFS
reviewed the U.S. Navy's EA and determined it to be sufficient for
taking into consideration the direct, indirect, and cumulative effects
to the human environment resulting from continuation of the ARA. NMFS
subsequently adopted that EA and signed a Finding of No Significant
Impact (FONSI) (86 FR 54931, October 5, 2021).
Accordingly, NMFS preliminarily has determined to adopt the U.S.
Navy's OEA for Office of Naval Research Arctic Research Activities in
the Beaufort and Chukchi Seas 2022-2025, provided our independent
evaluation of the document finds that it includes adequate information
analyzing the effects on the human environment of issuing the IHA. NMFS
is a not cooperating agency on the U.S. Navy's OEA.
We will review all comments submitted in response to this notice
prior to concluding our NEPA process or making a final decision on the
IHA request.
Summary of Request
On March 21, 2022, NMFS received a request from ONR for an IHA to
take marine mammals incidental to ARA in the Beaufort and eastern
Chukchi Seas. The application was deemed adequate and complete on June
30, 2022. ONR's request is for take of beluga whales (Delphinapterus
leucas; two stocks) and ringed seals (Pusa hispida hispida) by Level B
harassment. Neither ONR nor NMFS expect serious injury or mortality
[[Page 44341]]
to result from this activity and, therefore, an IHA is appropriate.
This proposed IHA would cover the fifth year of a larger project
for which ONR obtained prior IHAs (83 FR 48799, September 27, 2018; 84
FR 50007, September 24, 2019; 85 FR 53333, August 28, 2020; 86 FR
54931, October 5, 2021) and may request take authorization for
subsequent facets of the overall project. This IHA would be valid for a
period of one year from the date of issuance (mid-September 2022 to
mid- September 2023). The larger project supports the development of an
under-ice navigation system under the ONR Arctic Mobile Observing
System (AMOS) project. ONR has complied with all the requirements
(e.g., mitigation, monitoring, and reporting) of the previous IHAs (83
FR 48799, September 27, 2018; 84 FR 50007, September 24, 2019; 85 FR
53333, August 28, 2020; 86 FR 54931, October 5, 2021).
Description of Proposed Activity
Overview
ONR's ARA include scientific experiments to be conducted in support
of the programs named above. Specifically, the project includes the
Arctic Mobile Observing System (AMOS) experiments in the Beaufort and
Chukchi Seas. Project activities involve acoustic testing and a multi-
frequency navigation system concept test using left-behind active
acoustic sources. More specifically, these experiments involve the
deployment of moored, drifting, and ice-tethered active acoustic
sources from the Research Vessel (R/V) Sikuliaq. Another vessel will be
used to retrieve the acoustic sources. Underwater sound from the
acoustic sources may result in Level B harassment of marine mammals.
Dates and Duration
This proposed action would occur from mid-September 2022 through
mid-September 2023. The 2022 cruise would leave from Nome, Alaska on
September 14, 2022 using the R/V Sikuliaq and involve 120 hours of
active source testing. During this first cruise, several acoustic
sources would be deployed from the ship. Some acoustic sources will be
left behind to provide year-round observation of the Arctic
environment. Gliders deployed during the September 2022 cruise may be
recovered before the research vessel departs the study area or during a
September 2023 cruise. Up to seven fixed acoustic navigation sources
transmitting at 900 Hertz (Hz) would remain in place for a year.
Drifting and moored oceanographic sensors would record environmental
parameters throughout the year. Autonomous weather stations and ice
mass balance buoys would also be deployed to record environmental
measurements throughout the year (Table 1). The research vessel is
planned to return to Nome, Alaska on October 28, 2022. ONR will apply
for a renewal or separate IHA, as appropriate, for activities conducted
during the planned September 2023 cruise.
During the scope of this proposed project, other activities may
occur at different intervals that would assist ONR in meeting the
scientific objectives of the various projects discussed above. However,
these activities are designated as de minimis sources in ONR's 2022-
2023 IHA application (consistent with analyses presented in support of
previous Navy ONR IHAs), or would not produce sounds detectable by
marine mammals (see discussion on de minimis sources below). These
include the deployment of a Woods Hole Oceanographic Institution (WHOI)
micromodem, acoustic Doppler current profilers (ADCP), and ice
profilers (Table 2).
Geographic Region
This proposed action would occur across the U.S. Exclusive Economic
Zone (EEZ) in both the Beaufort and Chukchi Seas, partially in the high
seas north of Alaska, the Global Commons, and within a part of the
Canadian EEZ (in which the appropriate permits would be obtained by the
Navy) (Figure 1). The proposed action would primarily occur in the
Beaufort Sea, but the analysis considers the drifting of active sources
on buoys into the eastern portion of the Chukchi Sea. The closest point
of the study area to the Alaska coast is 110 nm (204 km). The proposed
study area is approximately 639,267 km\2\.
BILLING CODE 3510-22-P
[[Page 44342]]
[GRAPHIC] [TIFF OMITTED] TN26JY22.156
BILLING CODE 3510-22-C
Detailed Description of Specific Activity
The ONR Arctic and Global Prediction Program supports two major
projects: Stratified Ocean Dynamics of the Arctic (SODA) and AMOS. The
SODA and AMOS projects have been previously discussed in association
with previously issued IHAs (83 FR 40234, August 14, 2018; 84 FR 37240,
July 31, 2019). However, only activities relating to the AMOS project
will occur during the period covered by this proposed action.
The AMOS project constitutes the development of a new system
involving very low (35 Hz)), low (900 Hz), and mid-frequency
transmissions (10 kilohertz (kHz)). The AMOS project would utilize
acoustic sources and receivers to provide a means of performing under-
ice navigation for
[[Page 44343]]
gliders and unmanned underwater vehicles (UUVs). This would allow for
the possibility of year-round scientific observations of the
environment in the Arctic. As an environment that is particularly
affected by climate change, year-round observations under a variety of
ice conditions are required to study the effects of this changing
environment for military readiness, as well as the implications of
environmental change to humans and animals. Very-low frequency
technology is important in extending the range of navigation systems.
The technology also has the potential to allow for development and use
of navigational systems that would not be heard by some marine mammal
species, and therefore would be less impactful overall.
Active acoustic sources would be lowered from the cruise vessel
while stationary, deployed on gliders and UUVs, or deployed on fixed
AMOS moorings. This project would use groups of drifting buoys with
sources and receivers communicating oceanographic information to a
satellite in near real time. These sources would employ low-frequency
transmissions only (900 Hz).
The proposed action would utilize non-impulsive acoustic sources,
although not all sources will cause take of marine mammals. Any marine
mammal takes would only arise from the operation of non-impulsive
active sources. Although not currently planned, ice breaking could
occur as part of this proposed action if a research vessel needs to
return to the study area before the end of the IHA period to ensure
scientific objectives are met. In this case, ice breaking could result
in potential Level B harassment takes.
Below are descriptions of the equipment and platforms that would be
deployed at different times during the proposed action.
Research Vessels
The R/V Sikuliaq would perform the research cruise in September
2022 and conduct testing of acoustic sources during the cruise, as well
as leave sources behind to operate as a year-round navigation system
observation. R/V Sikuliaq has a maximum speed of approximately 12 knots
(6.2 m/s) with a cruising speed of 11 knots (5.7 m/s) (University of
Alaska Fairbanks 2014). The R/V Sikuliaq is not an ice breaking ship,
but an ice strengthened ship. It would not be icebreaking and therefore
acoustic signatures of icebreaking for the R/V Sikuliaq are not
relevant.
The ship to be used in September 2023 to retrieve any acoustic
sources could potentially be the CGC Healy. CGC Healy travels at a
maximum speed of 17 knots (8.7 m/s) with a cruising speed of 12 knots
(6.2 m/s) (United States Coast Guard 2013), and a maximum speed of 3
knots (1.5 m/s) when traveling through 4.5 feet (1.07 m) of sea ice
(United States Coast Guard 2013). While no icebreaking cruise on the
CGC Healy is scheduled during the IHA period, need may arise.
Therefore, for the purposes of this IHA application, an icebreaking
cruise is considered.
The R/V Sikuliaq, CGC Healy, or any other vessel operating a
research cruise associated with the proposed action may perform the
following activities during their research cruises:
<bullet> Deployment of moored and/or ice-tethered passive sensors
(oceanographic measurement devices, acoustic receivers);
<bullet> Deployment of moored and/or ice-tethered active acoustic
sources to transmit acoustic signals;
<bullet> Deployment of UUVs;
<bullet> Deployment of drifting buoys, with or without acoustic
sources; or,
<bullet> Recovery of equipment.
Moored and Drifting Acoustic Sources
During the September 2022 cruise, active acoustic sources would be
lowered from the cruise vessel while stationary, deployed on gliders
and UUVs, or deployed on fixed AMOS moorings. This would be done for
intermittent testing of the system components. The total amount of
active source testing for ship-deployed sources used during the cruise
would be 120 hours. The testing would take place near the seven source
locations on Figure 1, with UUVs running tracks within the designated
box. During this testing, 35 Hz, 900 Hz, and 10 kHz acoustic signals,
as well as acoustic modems would be employed.
Up to seven fixed acoustic navigation sources transmitting at 900
Hz would remain in place for a year and continue transmitting during
this time. These moorings would be anchored on the seabed and held in
the water column with subsurface buoys. All sources would be deployed
by shipboard winches, which would lower sources and receivers in a
controlled manner. Anchors would be steel ``wagon wheels'' typically
used for this type of deployment. Two very low frequency (VLF) sources
transmitting at 35 Hz would be deployed in a similar manner. Two Ice
Gateway Buoys (IGB) would also be configured with active acoustic
sources. Autonomous vehicles would be able to navigate by receiving
acoustic signals from multiple locations and triangulating. This is
needed for vehicles that are under ice and cannot communicate with
satellites. Source transmits would be offset by 15 minutes from each
other (i.e., sources would not be transmitting at the same time). All
navigation sources would be recovered. The purpose of the navigation
sources is to orient UUVs and gliders in situations when they are under
ice and cannot communicate with satellites. For the purposes of this
proposed action, activities potentially resulting in take would not be
included in the fall 2023 cruise; a subsequent application would be
provided by ONR depending on the scientific plan associated with that
cruise.
Table 1--Characteristics for the Modeled Acoustic Sources for the Proposed Action
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Signal strength (dB
Platform Acoustic source Purpose/function Frequency re1uPa @1m) \1\ Band width
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REMUS 600 UUV (1)................. WHOI \2\/Micro-modem. Acoustic 900-950 Hz \3\......... NTE \3\ 180 dB by 50 Hz.
communication. sys design limits.
UUV/WHOI Micro-modem. Acoustic 8-14 kHz \3\........... NTE 185 dB by sys 5 kHz.
communication. design limits.
IGB \3\ (drifting) (2)............ WHOI Micro-modem..... Acoustic 900-950 Hz............. NTE 180 dB by sys 50 Hz.
communication. design limits.
WHOI Micro-modem..... Acoustic 8-14 kHz............... NTE 185 dB by sys 5 kHz.
communication. design limits.
Mooring (9)....................... WHOI Micro-modem (7). Acoustic navigation.. 900-950 Hz............. NTE 180 dB by sys 50 Hz.
design limits.
[[Page 44344]]
VLF \3\ (2).......... Acoustic navigation.. 35 Hz.................. NTE 190 dB.......... 6 Hz.
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\1\ dB re 1 [mu]Pa at 1 m = decibels referenced to 1 micropascal at 1 meter.
\2\ WHOI = Woods Hole Oceanographic Institution.
\3\ Hz = Hertz; IGB = Ice Gateway Buoy; kHz = 1 kilohertz; NTE = not to exceed; VLF = very low frequency
Activities Not Likely To Result in Take
The following in-water activities have been determined to be
unlikely to result in take of marine mammals. These activities are
described here but they are not discussed further in this document.
De minimis Sources--The Navy characterizes de minimis sources as
those with the following parameters: Low source levels, narrow beams,
downward directed transmission, short pulse lengths, frequencies
outside known marine mammal hearing ranges, or some combination of
these factors (Department of the Navy, 2013b). NMFS concurs with the
Navy's determination that the sources they have identified here as de
minimis are unlikely to result in take of marine mammals. The following
are some of the planned de minimis sources which would be used during
the proposed action: Woods Hole Oceanographic Institution (WHOI)
micromodem, ADCPs, ice profilers, and additional sources below 160 dB
re 1 [mu]Pa used during towing operations. ADCPs may be used on
moorings. Ice-profilers measure ice properties and roughness. The ADCPs
and ice-profilers would all be above 200 kHz and therefore out of
marine mammal hearing ranges, with the exception of the 75 kHz ADCP
which has the characteristics and de minimis justification listed in
Table 2. They may be employed on moorings or UUVs. Descriptions of some
de minimis sources are discussed below and in Table 2. More detailed
descriptions of these de minimis sources can be found in ONR's IHA
application under Section 1.1.1.2.
Table 2--Parameters for De Minimis Non-Impulsive Active Sources
----------------------------------------------------------------------------------------------------------------
Sound pressure
Frequency range level (dB re Pulse length Duty cycle De minimis
Source name (kHz) 1 [mu]Pa at 1 (s) (percent) justification
m)
----------------------------------------------------------------------------------------------------------------
ADCP......................... >200, 150, or 75 190 <0.001 <0.1 Very low pulse
length, narrow
beam, moderate
source level.
Nortek Signature 500 kHz 500............. 214 <0.1 <13 Very high
Doppler Velocity Log. frequency.
CTD \1\ Attached Echosounder. 5-20............ 160 0.004 2 Very low source
level.
----------------------------------------------------------------------------------------------------------------
\1\ Conductivity Temperature Depth.
Drifting Oceanographic Sensors
Observations of ocean-ice interactions require the use of sensors
that are moored and embedded in the ice. For the proposed action, it
will not be required to break ice to do this, as deployments can be
performed in areas of low ice-coverage or free floating ice. Sensors
are deployed within a few dozen meters of each other on the same ice
floe. Three types of sensors would be used: autonomous ocean flux
buoys, Integrated Autonomous Drifters, and ice-tethered profilers. The
autonomous ocean flux buoys measure oceanographic properties just below
the ocean-ice interface. The autonomous ocean flux buoys would have
ADCPs and temperature chains attached, to measure temperature,
salinity, and other ocean parameters in the top 20 ft (6 m) of the
water column. Integrated Autonomous Drifters would have a long
temperate string extending down to 656 ft (200 m) depth and would
incorporate meteorological sensors, and a temperature spring to
estimate ice thickness. The ice-tethered profilers would collect
information on ocean temperature, salinity and velocity down to 820 ft
(250 m) depth.
Up to 20 Argo-type autonomous profiling floats may be deployed in
the central Beaufort Sea. Argo floats drift at 4,921 ft (1,500 m)
depth, profiling from 6,562 ft (2,000 m) to the sea surface once every
10 days to collect profiles of temperature and salinity.
Moored Oceanographic Sensors
Moored sensors would capture a range of ice, ocean, and atmospheric
conditions on a year-round basis. These would be bottom anchored, sub-
surface moorings measuring velocity, temperature, and salinity in the
upper 1,640 ft (500 m) of the water column. The moorings also collect
high-resolution acoustic measurements of the ice using the ice
profilers described above. Ice velocity and surface waves would be
measured by 500 kHz multibeam sonars from Nortek Signatures. The moored
oceanographic sensors described above use only de minimis sources and
are therefore not anticipated to have the potential for impacts on
marine mammals or their habitat.
On-Ice Measurements
On-ice measurement systems would be used to collect weather data.
These would include an Autonomous Weather Station and an Ice Mass
Balance Buoy. The Autonomous Weather Station would be deployed on a
tripod; the tripod has insulated foot platforms that are frozen into
the ice. The system would consist of an anemometer, humidity sensor,
and pressure sensor. The Autonomous Weather Station also includes an
altimeter with a sound source that is de minimis due to its very high
frequency (200 kHz). The Ice Mass Balance Buoy is a 20 ft (6 m) sensor
string, which is deployed through a 2 inch (5 cm) hole drilled into the
ice. The string is weighted by a 2.2 lb (1 kg) lead weight, and is
supported by a tripod. The buoy contains a de minimis 200 kHz altimeter
and snow depth sensor. Autonomous Weather Stations and Ice Mass Balance
Buoys will be deployed,
[[Page 44345]]
and will drift with the ice, making measurements. The instruments are
destroyed as their host ice floes melt (likely in summer, roughly one
year after deployment). After the instruments are deployed they cannot
be recovered, and would sink to the seafloor as their host ice floes
melted.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, incorporated here by reference, instead of
reprinting the information. Additional information regarding population
trends and threats may be found in NMFS' Stock Assessment Reports
(SARs; <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">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 3 lists all species or stocks for which take is expected and
proposed to be authorized for this action, and summarizes information
related to the population or stock, including regulatory status under
the MMPA and Endangered Species Act (ESA) and potential biological
removal (PBR), where known. 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 and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. 2020 SARs (e.g., Muto et al. 2021), with the exception of
Beaufort Sea beluga whales. The 2020 SAR for the Beaufort Sea stock of
beluga whales has temporarily been withdrawn for further review,
therefore, the NMFS' U.S. 2021 draft SAR represents the most recent
stock assessment for this stock. All values presented in Table 3 are
the most recent available at the time of publication (including from
the draft 2021 SARs) online at: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 3--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Monodontidae:
Beluga Whale.................... Delphinapterus leucas.. Beaufort Sea........... -, -, N 39,258 (0.229, N/A, \4\ UND 104
1992).
Beluga Whale.................... Delphinapterus leucas.. Eastern Chukchi Sea.... -, -, N 13,305 (0.51, 8,875, 178 55
2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
Ringed Seal \5\................. Pusa hispida hispida... Arctic................. T, D, Y 171,418 (N/A, 158,507, 5,100 6,459
171,418.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <a href="http://www.nmfs.noaa.gov/pr/sars/">www.nmfs.noaa.gov/pr/sars/</a>. CV is the coefficient of variation; Nmin is the minimum estimate
of stock abundance. In some cases, CV is not applicable [explain if this is the case].
\3\ 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.
\4\ The 2016 guidelines for preparing SARs state that abundance estimates older than 8 years should not be used to calculate PBR due to a decline in the
reliability of an aged estimate. Therefore, the PBR for this stock is considered undetermined.
\5\ Abundance and associated values for ringed seals are for the U.S. population in the Bering Sea only.
As indicated above, the two species (with three managed stocks) in
Table 3 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. While bowhead whales
(Balaena mysticetus), gray whales (Eschrichtius robustus), bearded
seals (Erignathus barbatus), spotted seals (Phoca largha), ribbon seals
(Histiophoca fasciata), have been documented in the area, the temporal
and/or spatial occurrence of these species is such that take is not
expected to occur, and they are not discussed further beyond the
explanation provided below.
Due to the location of the study area (i.e., northern offshore,
deep water), there were no calculated exposures for the bowhead whale,
gray whale, spotted seal, bearded seal, and ribbon seal from
quantitative modeling of acoustic sources. Bowhead and gray whales are
closely associated with the shallow waters of the continental shelf in
the Beaufort Sea and are unlikely to be exposed to acoustic harassment
from this activity (Carretta et al., 2018; Muto et al., 2018).
Similarly, spotted seals tend to prefer pack ice areas with water
depths less than 200 m during the spring and move to coastal habitats
in the summer and fall, found as far north
[[Page 44346]]
as 69-72[deg] N (Muto et al., 2018). Although the study area includes
some waters south of 72[deg] N, the acoustic sources with the potential
to result in take of marine mammals are not found below that latitude
and spotted seals are not expected to be exposed. Ribbon seals are
found year-round in the Bering Sea but may seasonally range into the
Chukchi Sea (Muto et al., 2018). The proposed action occurs primarily
in the Beaufort Sea, outside of the core range of ribbon seals, thus
ribbon seals are not expected to be behaviorally harassed. Narwhals
(Monodon monoceros) are considered extralimital in the project area and
are not expected to be encountered. As no harassment is expected of the
bowhead whale, gray whale, spotted seal, bearded seal, narwhal, and
ribbon seal, these species will not be discussed further in this
proposed notice.
The Navy has utilized Conn et al., (2014) in their IHA application
as an abundance estimate for ringed seals, which is based upon aerial
abundance and distribution surveys conducted in the U.S. portion Bering
Sea in 2012 (171,418 ringed seals; Muto et al., 2021b). This value is
likely an underestimate due to the lack of accounting for availability
bias for seals that were in the water at the time of the surveys as
well as not including seals located within the shorefast ice zone (Muto
et al., 2021b). Muto et al., (2021b) notes that an accurate population
estimate is likely larger by a factor of two or more. However, no
accepted population estimate is present for Arctic ringed seals.
Therefore, in the interest in making conservative decisions, NMFS will
also adopt the Conn et al., (2014) abundance estimate (171,418) for
further analyses and discussions on this proposed action by ONR.
In addition, the polar bear (Ursus maritimus) and Pacific walrus
(Odobenus rosmarus) may be found both on sea ice and/or in the water
within the Beaufort Sea and Chukchi Sea. These species are managed by
the U.S. Fish and Wildlife Service (USFWS) and are not considered
further in this document.
Beluga Whale
Beluga whales are distributed throughout seasonally ice-covered
arctic and subarctic waters of the Northern Hemisphere (Gurevich,
1980), and are closely associated with open leads and polynyas in ice-
covered regions (Hazard, 1988). Belugas are both migratory and
residential (non-migratory), depending on the population. Seasonal
distribution is affected by ice cover, tidal conditions, access to
prey, temperature, and human interaction (Frost et al., 1985; Hauser et
al., 2014).
There are five beluga stocks recognized within U.S. waters: Cook
Inlet, Bristol Bay, eastern Bering Sea, eastern Chukchi Sea, and
Beaufort Sea. Two stocks, the Beaufort Sea and eastern Chukchi Sea
stocks, have the potential to occur in the location of this proposed
action.
A migratory Biologically Important Area (BIA) for belugas in the
Eastern Chukchi and Alaskan Beaufort Sea overlaps the southern and
western portion of the proposed project site. One migration corridor is
in use from April to May. The second corridor, located in the Alaskan
Beaufort Sea, is used by migrating belugas from September to October
(Calambokidis et al., 2015). During the winter, they can be found
foraging in offshore waters associated with pack ice. When the sea ice
melts in summer, they move to warmer river estuaries and coastal areas
for molting and calving (Muto et al., 2017). Annual migrations can span
over thousands of kilometers. The residential Beaufort Sea populations
participate in short distance movements within their range throughout
the year. Based on satellite tags (Suydam et al., 2001; Hauser et al.,
2014), there is some overlap in distribution with the eastern Chukchi
Sea beluga whale stock.
During the winter, eastern Chukchi Sea belugas occur in offshore
waters associated with pack ice. In the spring, they migrate to warmer
coastal estuaries, bays, and rivers where they may molt (Finley, 1982;
Suydam, 2009), give birth to, and care for their calves (Sergeant and
Brodie, 1969). Eastern Chukchi Sea belugas move into coastal areas,
including Kasegaluk Lagoon (outside of the proposed project site), in
late June and animals are sighted in the area until about mid-July
(Frost and Lowry, 1990; Frost et al., 1993). Satellite tags attached to
eastern Chukchi Sea belugas captured in Kasegaluk Lagoon during the
summer showed these whales traveled 593 nm (1,100 km) north of the
Alaska coastline, into the Canadian Beaufort Sea within three months
(Suydam et al., 2001). Satellite telemetry data from 23 whales tagged
during 1998-2007 suggest variation in movement patterns for different
age and/or sex classes during July-September (Suydam et al., 2005).
Adult males used deeper waters and remained there for the duration of
the summer; all belugas that moved into the Arctic Ocean (north of
75[deg] N) were males, and males traveled through 90 percent pack ice
cover to reach deeper waters in the Beaufort Sea and Arctic Ocean (79-
80[deg] N) by late July/early August. Adult and immature female belugas
remained at or near the shelf break in the south through the eastern
Bering Strait into the northern Bering Sea, remaining north of Saint
Lawrence Island over the winter.
Ringed Seals
Ringed seals are the most common pinniped in the proposed project
site and have wide distribution in seasonally and permanently ice-
covered waters of the Northern Hemisphere (North Atlantic Marine Mammal
Commission, 2004). Throughout their range, ringed seals have an
affinity for ice-covered waters and are well adapted to occupying both
shore-fast and pack ice (Kelly, 1988c). Ringed seals can be found
further offshore than other pinnipeds since they can maintain breathing
holes in ice thickness greater than 6.6 ft (2 m) (Smith and Stirling,
1975). The breathing holes are maintained by ringed seals using their
sharp teeth and claws found on their fore flippers. They remain in
contact with ice most of the year and use it as a platform for molting
in late spring to early summer, for pupping and nursing in late winter
to early spring, and for resting at other times of the year (Muto et
al., 2018).
Ringed seals have at least two distinct types of subnivean lairs:
Haulout lairs and birthing lairs (Smith and Stirling, 1975). Haul-out
lairs are typically single-chambered and offer protection from
predators and cold weather. Birthing lairs are larger, multi-chambered
areas that are used for pupping in addition to protection from
predators. Ringed seals pup on both land-fast ice as well as stable
pack ice. Lentfer (1972) found that ringed seals north of
Utqia[gdot]vik, Alaska (formally known as Barrow, Alaska) build their
subnivean lairs on the pack ice near pressure ridges. Since subnivean
lairs were found north of Utqia[gdot]vik, Alaska, in pack ice, they are
also assumed to be found within the sea ice in the proposed project
site. Ringed seals excavate subnivean lairs in drifts over their
breathing holes in the ice, in which they rest, give birth, and nurse
their pups for 5-9 weeks during late winter and spring (Chapskii, 1940;
McLaren, 1958; Smith and Stirling, 1975). Ringed seals are born
beginning in March, but the majority of births occur in early April.
About a month after parturition, mating begins in late April and early
May.
In Alaskan waters, during winter and early spring when sea ice is
at its maximum extent, ringed seals are abundant in the northern Bering
Sea, Norton and Kotzebue Sounds, and throughout the Chukchi and
Beaufort
[[Page 44347]]
seas (Frost, 1985; Kelly, 1988c). Passive acoustic monitoring of ringed
seals from a high frequency recording package deployed at a depth of
787 ft (240 m) in the Chukchi Sea 65 nautical miles (120 km) north-
northwest of Utqia[gdot]vik, Alaska detected ringed seals in the area
between mid-December and late May over the 4 year study (Jones et al.,
2014). In addition, ringed seals have been observed near and beyond the
outer boundary of the U.S. EEZ (Beland and Ireland, 2010). During the
spring and early summer, ringed seals may migrate north as the ice edge
recedes and spend their summers in the open water period of the
northern Beaufort and Chukchi Seas (Frost, 1985). Foraging-type
movements have been recorded over the continental shelf and north of
the continental shelf waters (Von Duyke et al., 2020). During this
time, sub-adult ringed seals may also occur in the Arctic Ocean Basin
(Hamilton et al., 2015; Hamilton et al., 2017).
With the onset of fall freeze, ringed seal movements become
increasingly restricted and seals will either move west and south with
the advancing ice pack with many seals dispersing throughout the
Chukchi and Bering Seas, or remaining in the Beaufort Sea (Crawford et
al., 2012; Frost and Lowry, 1984; Harwood et al., 2012). Kelly et al.,
(2010b) tracked home ranges for ringed seals in the subnivean period
(using shore-fast ice); the size of the home ranges varied from less
than 1 up to 279 km\2\ (median is 0.62 km\2\ for adult males and 0.65
km\2\ for adult females). Most (94 percent) of the home ranges were
less than 3 km\2\ during the subnivean period (Kelly et al., 2010b).
Near large polynyas, ringed seals maintain ranges, up to 7,000 km\2\
during winter and 2,100 km\2\ during spring (Born et al., 2004). Some
adult ringed seals return to the same small home ranges they occupied
during the previous winter (Kelly et al., 2010b). The size of winter
home ranges can vary by up to a factor of 10 depending on the amount of
fast ice; seal movements were more restricted during winters with
extensive fast ice, and were much less restricted where fast ice did
not form at high levels (Harwood et al., 2015).
Of the five recognized subspecies of ringed seals, the Arctic
ringed seal occurs in the Arctic Ocean and Bering Sea and is the only
stock that occurs in U.S. waters. NMFS listed the Arctic ringed seal
subspecies as threatened under the ESA on December 28, 2012 (77 FR
76706), primarily due to anticipated loss of sea ice through the end of
the 21st century. Climate change presents a major concern for the
conservation of ringed seals due to the potential for long-term habitat
loss and modification (Muto et al., 2021). Based upon an analysis of
various life history features and the rapid changes that may occur in
ringed seal habitat, ringed seals are expected to be highly sensitive
to climate change (Laidre et al., 2008; Kelly et al., 2010a).
Critical Habitat
On January 8, 2021, NMFS published a revised proposed rule for the
Designation of Critical Habitat for the Arctic Subspecies of the Ringed
Seal (86 FR 1452). This proposed rule revises NMFS' December 9, 2014,
proposed designation of critical habitat for the Arctic subspecies of
the ringed seal under the ESA. NMFS identified the physical and
biological features essential to the conservation of the species: (1)
Snow-covered sea ice habitat suitable for the formation and maintenance
of subnivean birth lairs used for sheltering pups during whelping and
nursing, which is defined as areas of seasonal landfast (shorefast) ice
and dense, stable pack ice, excluding any bottom-fast ice extending
seaward from the coastline (typically in waters less than 2 m deep),
that have undergone deformation and contain snowdrifts of sufficient
depth, typically at least 54 cm deep; (2) Sea ice habitat suitable as a
platform for basking and molting, which is defined as areas containing
sea ice of 15 percent or more concentration, excluding any bottom-fast
ice extending seaward from the coastline (typically in waters less than
2 m deep); and (3) Primary prey resources to support Arctic ringed
seals, which are defined to be Arctic cod, saffron cod, shrimps, and
amphipods. The revised proposed critical habitat designation comprises
a specific area of marine habitat in the Bering, Chukchi, and Beaufort
seas, extending from mean lower low water to an offshore limit within
the U.S. Exclusive Economic Zone, including a portion of the ONR ARA
Study Area (86 FR 1452; January 8, 2021). See the proposed ESA critical
habitat rule for additional detail and a map of the proposed area.
The majority of the proposed study area was excluded from the
proposed ringed seal critical habitat because the benefits of exclusion
due to national security impacts outweighed the benefits of inclusion
of this area (86 FR 1452; March 9, 2021). However, as stated in NMFS'
second revised proposed rule for the Designation of Critical Habitat
for the Arctic Subspecies of the Ringed Seal (86 FR 1452; March 9,
2021), the excluded area contains one or more of the essential features
of the Arctic ringed seal's critical habitat. However, the excluded
area contains features that are found throughout the specific area
designated as critical habitat (87 FR 19232, April 1, 2022), therefore
even though this area is excluded from critical habitat designation,
habitat with the physical and biological features essential for ringed
seal conservation is still available to the species. A small portion of
the study area overlaps with ringed seal critical habitat as shown in
Figure 2. As described later and in more detail in the Potential
Effects of Specified Activities on Marine Mammals and Their Habitat
section, we expect minimal impacts to marine mammal habitat as a result
of the ONR's activities, including impacts on prey availability.
[[Page 44348]]
[GRAPHIC] [TIFF OMITTED] TN26JY22.157
BILLING CODE 3510-22-C
Ice Seal Unusual Mortality Event
Since June 1, 2018, elevated strandings of ringed seals, bearded
seals, spotted seals, and several unidentified seals have occurred in
the Bering and Chukchi Seas. The National Oceanic and Atmospheric
Administration (NOAA), as of September 2019, have declared this event
an Unusual Mortality Event (UME). A UME is defined under the MMPA as a
stranding that is unexpected, involves a significant die-off of any
marine mammal population, and demands immediate response. From June 1,
2018 to January 7, 2022, there have been 368 dead seals reported, with
111 stranding in 2018, 164 in 2019, and 38 in 2020, and 55 in 2021,
which is much greater than the average number of strandings
[[Page 44349]]
of about 29 seals annually. All age classes of seals have been reported
stranded, and a subset of seals have been sampled for genetics and
harmful algal bloom/exposure, with a few having histopathology
collected. Results are pending and investigation into the cause of the
UME is ongoing, yet currently unknown. No ice seals have stranded in
2022, at the time of this publication, yet the UME is still considered
ongoing.
There was a previous UME involving ice seals from 2011 to 2016,
which was most active in 2011-2012. A minimum of 657 seals were
affected. The UME investigation determined that some of the clinical
signs were due to an abnormal molt, but a definitive cause of death for
the UME was never determined. The number of stranded ice seals involved
in this UME, and their physical characteristics, is not at all similar
to the 2011-2016 UME, as the seals in 2018-2020 have not been
exhibiting hair loss or skin lesions, which were a primary finding in
the 2011-2016 UME. More detailed information is available at: <a href="https://www.fisheries.noaa.gov/alaska/marine-life-distress/2018-2022-ice-seal-unusual-mortality-event-alaska">https://www.fisheries.noaa.gov/alaska/marine-life-distress/2018-2022-ice-seal-unusual-mortality-event-alaska</a>.
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 4.
Table 4--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans (dolphins, 150 Hz to 160 kHz.
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) (true 50 Hz to 86 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 39 kHz.
lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al., 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a discussion of the ways that components of
the specified activity may impact marine mammals and their habitat. The
Estimated Take section later in this document includes a quantitative
analysis of the number of individuals that are expected to be taken by
this activity. The Negligible Impact Analysis and Determination section
considers the content of this section, the Estimated Take section, and
the Proposed Mitigation section, to draw conclusions regarding the
likely impacts of these activities on the reproductive success or
survivorship of individuals and how those impacts on individuals may or
may not impact marine mammal species or stocks.
Description of Sound Sources
Here, we first provide background information on marine mammal
hearing before discussing the potential effects of the use of active
acoustic sources on marine mammals.
Sound travels in waves, the basic components of which are
frequency, wavelength, velocity, and amplitude. Frequency is the number
of pressure waves that pass by a reference point per unit of time and
is measured in Hz or cycles per second. Wavelength is the distance
between two peaks of a sound wave; lower frequency sounds have longer
wavelengths than higher frequency sounds and attenuate (decrease) more
rapidly in shallower water. Amplitude is the height of the sound
pressure wave or the `loudness' of a sound and is typically measured
using the dB scale. A dB is the ratio between a measured pressure (with
sound) and a reference pressure (sound at a constant pressure,
established by scientific standards). It is a logarithmic unit that
accounts for large variations in amplitude; therefore, relatively small
changes in dB ratings correspond to large changes in sound pressure.
When referring to sound pressure levels (SPLs; the sound force per unit
area), sound is referenced in the context of underwater sound pressure
to one micropascal (1 [mu]Pa). One pascal is the pressure resulting
from a force of one newton exerted over an area of one square meter.
The source level (SL) represents the sound level at a distance of 1 m
from the source (referenced to 1 [mu]Pa). The received level is the
sound level at the listener's position. Note that all underwater sound
levels in this document are referenced to a pressure of 1 [mu]Pa.
Root mean square (rms) is the quadratic mean sound pressure over
the duration of an impulse. RMS is calculated by squaring all of the
sound amplitudes, averaging the squares, and
[[Page 44350]]
then taking the square root of the average (Urick, 1983). RMS accounts
for both positive and negative values; squaring the pressures makes all
values positive so that they may be accounted for in the summation of
pressure levels (Hastings and Popper, 2005). This measurement is often
used in the context of discussing behavioral effects, in part because
behavioral effects, which often result from auditory cues, may be
better expressed through averaged units than by peak pressures.
When underwater objects vibrate or activity occurs, sound-pressure
waves are created. These waves alternately compress and decompress the
water as the sound wave travels. Underwater sound waves radiate in all
directions away from the source (similar to ripples on the surface of a
pond), except in cases where the source is directional. The
compressions and decompressions associated with sound waves are
detected as changes in pressure by aquatic life and man-made sound
receptors such as hydrophones.
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far (ANSI, 1995). The sound level of an area is
defined by the total acoustical energy being generated by known and
unknown sources. These sources may include physical (e.g., waves, wind,
precipitation, earthquakes, ice, atmospheric sound), biological (e.g.,
sounds produced by marine mammals, fish, and invertebrates), and
anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (as
determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate
through the environment. In turn, sound propagation is dependent on the
spatially and temporally varying properties of the water column and sea
floor, and is frequency-dependent. Because of the dependence on a large
number of varying factors, ambient sound levels can be expected to vary
widely over both coarse and fine spatial and temporal scales. Sound
levels at a given frequency and location can vary by 10-20 dB from day
to day (Richardson et al., 1995). The result is that, depending on the
source type and its intensity, sound from the specified activity may be
a negligible addition to the local environment or could form a
distinctive signal that may affect marine mammals.
Underwater sounds fall into one of two general sound types:
impulsive and non-impulsive (defined in the following paragraphs). The
distinction between these two sound types is important because they
have differing potential to cause physical effects, particularly with
regard to hearing (e.g., Ward, 1997 in Southall et al., 2007). Please
see Southall et al., (2007) for an in-depth discussion of these
concepts.
Impulsive sound sources (e.g., explosions, gunshots, sonic booms,
impact pile driving) produce signals that are brief (typically
considered to be less than one second), broadband, atonal transients
(ANSI, 1986; Harris, 1998; NIOSH, 1998; ISO, 2003; ANSI, 2005) and
occur either as isolated events or repeated in some succession.
Impulsive sounds are all characterized by a relatively rapid rise from
ambient pressure to a maximal pressure value followed by a rapid decay
period that may include a period of diminishing, oscillating maximal
and minimal pressures, and generally have an increased capacity to
induce physical injury as compared with sounds that lack these
features. However and as previously noted, no impulsive acoustic
sources will be used during ONR's proposed action.
Non-impulsive sounds can be tonal, narrowband, or broadband, brief
or prolonged, and may be either continuous or non-continuous (ANSI,
1995; NIOSH, 1998). Some of these non-impulsive sounds can be transient
signals of short duration but without the essential properties of
pulses (e.g., rapid rise time). Examples of non-impulsive sounds
include those produced by vessels, aircraft, machinery operations such
as drilling or dredging, vibratory pile driving, and active sonar
sources that intentionally direct a sound signal at a target that is
reflected back in order to discern physical details about the target.
These active sources are used in navigation, military training and
testing, and other research activities such as the activities planned
by ONR as part of the proposed action. The duration of such sounds, as
received at a distance, can be greatly extended in a highly reverberant
environment.
Acoustic Impacts
Please refer to the information given previously regarding sound,
characteristics of sound types, and metrics used in this document.
Anthropogenic sounds cover a broad range of frequencies and sound
levels and can have a range of highly variable impacts on marine life,
from none or minor to potentially severe responses, depending on
received levels, duration of exposure, behavioral context, and various
other factors. The potential effects of underwater sound from active
acoustic sources can potentially result in one or more of the
following: temporary or permanent hearing impairment, non-auditory
physical or physiological effects, behavioral disturbance, stress, and
masking (Richardson et al., 1995; Gordon et al., 2003; Nowacek et al.,
2007; Southall et al., 2007; Gotz et al., 2009). The degree of effect
is intrinsically related to the signal characteristics, received level,
distance from the source, and duration of the sound exposure. In
general, sudden, high level sounds can cause hearing loss, as can
longer exposures to lower level sounds. Temporary or permanent loss of
hearing will occur almost exclusively for noise within an animal's
hearing range. In this section, we first describe specific
manifestations of acoustic effects before providing discussion specific
to the proposed activities in the next section.
Permanent Threshold Shift--Marine mammals exposed to high-intensity
sound, or to lower-intensity sound for prolonged periods, can
experience hearing threshold shift (TS), which is the loss of hearing
sensitivity at certain frequency ranges (Finneran, 2015). TS can be
permanent (PTS), in which case the loss of hearing sensitivity is not
fully recoverable, or temporary (TTS), in which case the animal's
hearing threshold would recover over time (Southall et al., 2007).
Repeated sound exposure that leads to TTS could cause PTS. In severe
cases of PTS, there can be total or partial deafness, while in most
cases the animal has an impaired ability to hear sounds in specific
frequency ranges (Kryter, 1985).
Temporary Threshold Shift--TTS is the mildest form of hearing
impairment that can occur during exposure to sound (Kryter, 1985).
While experiencing TTS, the hearing threshold rises, and a sound must
be at a higher level in order to be heard. In terrestrial and marine
mammals, TTS can last from minutes or hours to days (in cases of strong
TTS). In many cases, hearing sensitivity recovers rapidly after
exposure to the sound ends.
When PTS occurs, there is physical damage to the sound receptors in
the ear (i.e., tissue damage), whereas TTS represents primarily tissue
fatigue and is reversible (Southall et al., 2007). In addition, other
investigators have suggested that TTS is within the normal bounds of
physiological variability and tolerance and does not represent
[[Page 44351]]
physical injury (e.g., Ward, 1997). Therefore, NMFS does not consider
TTS to constitute auditory injury.
Relationships between TTS and PTS thresholds have not been studied
in marine mammals--PTS data exists only for a single harbor seal
(Kastak et al., 2008)--but are assumed to be similar to those in humans
and other terrestrial mammals. PTS typically occurs at exposure levels
at least several decibels above (a 40-dB threshold shift approximates
PTS onset; e.g., Kryter et al., 1966; Miller, 1974) that inducing mild
TTS (a 6-dB threshold shift approximates TTS onset; e.g., Southall et
al., 2007). Based on data from terrestrial mammals, a precautionary
assumption is that the PTS thresholds for impulse sounds (such as
impact pile driving pulses as received close to the source) are at
least six dB higher than the TTS threshold on a peak-pressure basis and
PTS cumulative sound exposure level (SEL) thresholds are 15 to 20 dB
higher than TTS cumulative SEL thresholds (Southall et al., 2007).
Marine mammal hearing plays a critical role in communication with
conspecifics, and interpretation of environmental cues for purposes
such as predator avoidance and prey capture. Depending on the degree
(elevation of threshold in dB), duration (i.e., recovery time), and
frequency range of TTS, and the context in which it is experienced, TTS
can have effects on marine mammals ranging from discountable to
serious. For example, a marine mammal may be able to readily compensate
for a brief, relatively small amount of TTS in a non-critical frequency
range that occurs during a time where ambient noise is lower and there
are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during time when
communication is critical for successful mother/calf interactions could
have more serious impacts.
Many studies have examined noise-induced hearing loss in marine
mammals (see Finneran (2015) and Southall et al. (2019) for summaries).
For cetaceans, published data on the onset of TTS are limited to the
captive bottlenose dolphin, beluga, harbor porpoise, and Yangtze
finless porpoise, and for pinnipeds in water, measurements of TTS are
limited to harbor seals, elephant seals, and California sea lions.
These studies examine hearing thresholds measured in marine mammals
before and after exposure to intense sounds. The difference between the
pre-exposure and post-exposure thresholds can be used to determine the
amount of threshold shift at various post-exposure times. The amount
and onset of TTS depends on the exposure frequency. Sounds at low
frequencies, well below the region of best sensitivity, are less
hazardous than those at higher frequencies, near the region of best
sensitivity (Finneran and Schlundt, 2013). At low frequencies, onset-
TTS exposure levels are higher compared to those in the region of best
sensitivity (i.e., a low frequency noise would need to be louder to
cause TTS onset when TTS exposure level is higher), as shown for harbor
porpoises and harbor seals (Kastelein et al., 2019a, 2019b, 2020a,
2020b). In addition, TTS can accumulate across multiple exposures, but
the resulting TTS will be less than the TTS from a single, continuous
exposure with the same SEL (Finneran et al., 2010; Kastelein et al.,
2014; Kastelein et al., 2015a; Mooney et al., 2009). This means that
TTS predictions based on the total, cumulative SEL will overestimate
the amount of TTS from intermittent exposures such as sonars and
impulsive sources. Nachtigall et al. (2018) and Finneran (2018)
describe the measurements of hearing sensitivity of multiple odontocete
species (bottlenose dolphin, harbor porpoise, beluga, and false killer
whale) when a relatively loud sound was preceded by a warning sound.
These captive animals were shown to reduce hearing sensitivity when
warned of an impending intense sound. Based on these experimental
observations of captive animals, the authors suggest that wild animals
may dampen their hearing during prolonged exposures or if conditioned
to anticipate intense sounds. Another study showed that echolocating
animals (including odontocetes) might have anatomical specializations
that might allow for conditioned hearing reduction and filtering of
low-frequency ambient noise, including increased stiffness and control
of middle ear structures and placement of inner ear structures (Ketten
et al., 2021). Data available on noise-induced hearing loss for
mysticetes are currently lacking (NMFS, 2018).
Behavioral effects--Behavioral disturbance may include a variety of
effects, including subtle changes in behavior (e.g., minor or brief
avoidance of an area or changes in vocalizations), more conspicuous
changes in similar behavioral activities, and more sustained and/or
potentially severe reactions, such as displacement from or abandonment
of high-quality habitat. Behavioral responses to sound are highly
variable and context-specific and any reactions depend on numerous
intrinsic and extrinsic factors (e.g., species, state of maturity,
experience, current activity, reproductive state, auditory sensitivity,
time of day), as well as the interplay between factors (e.g.,
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007;
Weilgart, 2007; Archer et al., 2010; Southall et al., 2021). Behavioral
reactions can vary not only among individuals but also within an
individual, depending on previous experience with a sound source,
context, and numerous other factors (Ellison et al., 2012), and can
vary depending on characteristics associated with the sound source
(e.g., whether it is moving or stationary, number of sources, distance
from the source). A review of marine mammal responses to anthropogenic
sound was first conducted by Richardson (1995). More recent reviews
(Nowacek et al., 2007; Ellison et al., 2012; Gomez et al., 2016)
addressed studies conducted since 1995 and focused on observations
where the received sound level of the exposed marine mammal(s) was
known or could be estimated. Gomez et al. (2016) conducted a review of
the literature considering the contextual information of exposure in
addition to received level and found that higher received levels were
not always associated with more severe behavioral responses and vice
versa. Southall et al. (2016) states that results demonstrate that some
individuals of different species display clear yet varied responses,
some of which have negative implications, while others appear to
tolerate high levels, and that responses may not be fully predictable
with simple acoustic exposure metrics (e.g., received sound level).
Rather, the authors state that differences among species and
individuals along with contextual aspects of exposure (e.g., behavioral
state) appear to affect response probability.
The following subsections provide examples of behavioral responses
that provide an idea of the variability in behavioral responses that
would be expected given the differential sensitivities of marine mammal
species to sound and the wide range of potential acoustic sources to
which a marine mammal may be exposed. Behavioral responses that could
occur for a given sound exposure should be determined from the
literature that is available for each species, or extrapolated from
closely related species when no information exists, along with
contextual factors. Available studies show wide variation in response
to underwater sound; therefore, it is difficult to predict specifically
how any given sound in a particular instance
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might affect marine mammals perceiving the signal. If a marine mammal
does react briefly to an underwater sound by changing its behavior or
moving a small distance, the impacts of the change are unlikely to be
significant to the individual, the stock, or population. However, if a
sound source displaces marine mammals from an important feeding or
breeding area for a prolonged period, impacts on individuals and
populations could be significant (e.g., Lusseau and Bejder, 2007;
Weilgart, 2007; NRC, 2003). There are broad categories of potential
response, which we describe in greater detail here, that include
alteration of dive behavior, alteration of foraging behavior, effects
to breathing, interference with or alteration of vocalization,
avoidance, and flight.
Changes in dive behavior can vary widely, and may consist of
increased or decreased dive times and surface intervals as well as
changes in the rates of ascent and descent during a dive (e.g., Frankel
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et
al., 2004; Goldbogen et al., 2013). Seals exposed to non-impulsive
sources with a received sound pressure level within the range of
calculated exposures (142-193 dB re 1 [mu]Pa), have been shown to
change their behavior by modifying diving activity and avoidance of the
sound source (G[ouml]tz et al., 2010; Kvadsheim et al., 2010).
Variations in dive behavior may reflect interruptions in biologically
significant activities (e.g., foraging) or they may be of little
biological significance. The impact of an alteration to dive behavior
resulting from an acoustic exposure depends on what the animal is doing
at the time of the exposure and the type and magnitude of the response.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al., 2007;
Melc[oacute]n et al., 2012). In addition, behavioral state of the
animal plays a role in the type and severity of a behavioral response,
such as disruption to foraging (e.g., Silve et al., 2016; Wensveen et
al., 2017). A determination of whether foraging disruptions incur
fitness consequences would require information on or estimates of the
energetic requirements of the affected individuals and the relationship
between prey availability, foraging effort and success, and the life
history stage of the animal. Goldbogen et al. (2013) indicate that
disruption of feeding and displacement could impact individual fitness
and health. However, for this to be true, we would have to assume that
an individual could not compensate for this lost feeding opportunity by
either immediately feeding at another location, by feeding shortly
after cessation of acoustic exposure, or by feeding at a later time.
There is no indication this is the case, particularly since unconsumed
prey would likely still be available in the environment in most cases
following the cessation of acoustic exposure. Information on or
estimates of the energetic requirements of the individuals and the
relationship between prey availability, foraging effort and success,
and the life history stage of the animal will help better inform a
determination of whether foraging disruptions incur fitness
consequences.
Respiration naturally varies with different behaviors, and
variations in respiration rate as a function of acoustic exposure can
be expected to co-occur with other behavioral reactions, such as a
flight response or an alteration in diving. However, respiration rates
in and of themselves may be representative of annoyance or an acute
stress response. Studies with captive harbor porpoises showed increased
respiration rates upon introduction of acoustic alarms (Kastelein et
al., 2001; Kastelein et al., 2006) and emissions for underwater data
transmission (Kastelein et al., 2005). Various studies also have shown
that species and signal characteristics are important factors in
whether respiration rates are unaffected or change, again highlighting
the importance in understanding species differences in the tolerance of
underwater noise when determining the potential for impacts resulting
from anthropogenic sound exposure (e.g., Kastelein et al., 2005, 2006,
2018; Gailey et al., 2007; Isojunno et al., 2018).
Marine mammals vocalize for different purposes and across multiple
modes, such as whistling, echolocation click production, calling, and
singing. Changes in vocalization behavior in response to anthropogenic
noise can occur for any of these modes and may result from a need to
compete with an increase in background noise or may reflect increased
vigilance or a startle response. For example, in the presence of
potentially masking signals, humpback whales and killer whales have
been observed to increase the length of their songs (Miller et al.,
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales
have been observed to shift the frequency content of their calls upward
while reducing the rate of calling in areas of increased anthropogenic
noise (Parks et al., 2007; Rolland et al., 2012). Killer whales off the
northwestern coast of the United States have been observed to increase
the duration of primary calls once a threshold in observing vessel
density (e.g., whale watching) was reached, which has been suggested as
a response to increased masking noise produced by the vessels (Foote et
al., 2004; NOAA, 2014). In some cases, however, animals may cease or
alter sound production in response to underwater sound (e.g., Bowles et
al., 1994; Castellote et al., 2012; Cerchio et al., 2014). Studies also
demonstrate that even low levels of noise received far from the noise
source can induce changes in vocalization and/or behavioral responses
(Blackwell et al., 2013, 2015).
Avoidance is the displacement of an individual from an area or
migration path as a result of the presence of a sound or other
stressors, and is one of the most obvious manifestations of disturbance
in marine mammals (Richardson et al., 1995). Avoidance is qualitatively
different from the flight response, but also differs in the magnitude
of the response (i.e., directed movement, rate of travel, etc.).
Oftentimes avoidance is temporary, and animals return to the area once
the noise has ceased. Acute avoidance responses have been observed in
captive porpoises and pinnipeds exposed to a number of different sound
sources (Kastelein et al., 2001; Finneran et al., 2003; Kastelein et
al., 2006a; Kastelein et al., 2006b; Kastelein et al., 2015b; Kastelein
et al., 2015c; Kastelein et al., 2018). Short-term avoidance of seismic
surveys, low frequency emissions, and acoustic deterrents have also
been noted in wild populations of odontocetes (Bowles et al., 1994;
Goold, 1996; Goold and Fish, 1998; Stone et al., 2000; Morton and
Symonds, 2002; Hiley et al., 2021) and to some extent in mysticetes
(Malme et al., 1984; McCauley et al., 2000; Gailey et al., 2007).
Longer-term displacement is possible, however, which may lead to
changes in abundance or distribution patterns of the affected species
in the affected region if habituation to the presence of the sound does
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann
et al., 2006).
Forney et al. (2017) described the potential effects of noise on
marine mammal populations with high site
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fidelity, including displacement and auditory masking. In cases of
Western gray whales (Weller et al., 2006) and beaked whales,
anthropogenic effects in areas where they are resident or exhibit site
fidelity could cause severe biological consequences, in part because
displacement may adversely affect foraging rates, reproduction, or
health, while an overriding instinct to remain in the area could lead
to more severe acute effects. Avoidance of overlap between disturbing
noise and areas and/or times of particular importance for sensitive
species may be critical to avoiding population-level impacts because
(particularly for animals with high site fidelity) there may be a
strong motivation to remain in the area despite negative impacts.
A flight response is a dramatic change in normal movement to a
directed and rapid movement away from the perceived location of a sound
source. The flight response differs from other avoidance responses in
the intensity of the response (e.g., directed movement, rate of
travel). Relatively little information on flight responses of marine
mammals to anthropogenic signals exist, although observations of flight
responses to the presence of predators have occurred (Connor and
Heithaus, 1996). The result of a flight response could range from
brief, temporary exertion and displacement from the area where the
signal provokes flight to, in extreme cases, marine mammal strandings
(Evans and England, 2001). There are limited data on flight response
for marine mammals in water; however, there are examples of this
response in species on land. For instance, the probability of flight
responses in Dall's sheep Ovis dalli dalli (Frid, 2003), hauled-out
ringed seals Phoca hispida (Born et al., 1999), Pacific brant (Branta
bernicl nigricans), and Canada geese (B. canadensis) increased as a
helicopter or fixed-wing aircraft more directly approached groups of
these animals (Ward et al., 1999). However, it should be noted that
response to a perceived predator does not necessarily invoke flight
(Ford and Reeves, 2008), and whether individuals are solitary or in
groups may influence the response.
Habituation can occur when an animal's response to a stimulus wanes
with repeated exposure, usually in the absence of unpleasant associated
events (Wartzok et al., 2003). Animals are most likely to habituate to
sounds that are predictable and unvarying. It is important to note that
habituation is appropriately considered as a ``progressive reduction in
response to stimuli that are perceived as neither aversive nor
beneficial,'' rather than as, more generally, moderation in response to
human disturbance (Bejder et al., 2009). The opposite process is
sensitization, when an unpleasant experience leads to subsequent
responses, often in the form of avoidance, at a lower level of
exposure. As noted, behavioral state may affect the type of response.
For example, animals that are resting may show greater behavioral
change in response to disturbing sound levels than animals that are
highly motivated to remain in an area for feeding (Richardson et al.,
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with
captive marine mammals have showed pronounced behavioral reactions,
including avoidance of loud sound sources (Ridgway et al., 1997;
Finneran et al., 2003). Observed responses of wild marine mammals to
loud impulsive sound sources (typically seismic airguns or acoustic
harassment devices) have been varied but often consist of avoidance
behavior or other behavioral changes suggesting discomfort (Morton and
Symonds, 2002; see also Richardson et al., 1995; Nowacek et al., 2007).
Data on hooded seals (Cystophora cristata) indicate avoidance
responses to signals above 160-170 dB re 1 [mu]Pa (Kvadsheim et al.,
2010), and data on grey (Halichoerus grypus) and harbor seals indicate
avoidance response at received levels of 135-144 dB re 1 [mu]Pa
(G[ouml]tz et al., 2010). In each instance where food was available,
which provided the seals motivation to remain near the source,
habituation to the signals occurred rapidly. In the same study, it was
noted that habituation was not apparent in wild seals where no food
source was available (G[ouml]tz et al., 2010). This implies that the
motivation of the animal is necessary to consider in determining the
potential for a reaction. In one study to investigate the under-ice
movements and sensory cues associated with under-ice navigation of ice
seals, acoustic transmitters (60-69 kHz at 159 dB re 1 [mu]Pa at 1 m)
were attached to ringed seals (Wartzok et al., 1992a, Wartzok et al.,
1992b). An acoustic tracking system then was installed in the ice to
receive the acoustic signals and provide real-time tracking of ice seal
movements. Although the frequencies used in this study are at the upper
limit of ringed seal hearing, the ringed seals appeared unaffected by
the acoustic transmissions, as they were able to maintain normal
behaviors (e.g., finding breathing holes).
Behavioral disturbance can also impact marine mammals in more
subtle ways. Increased vigilance may result in costs related to
diversion of focus and attention (i.e., when a response consists of
increased vigilance, it may come at the cost of decreased attention to
other critical behaviors such as foraging or resting). These effects
have generally not been observed in marine mammals, but studies
involving fish and terrestrial animals have shown that increased
vigilance may substantially reduce feeding rates and efficiency (e.g.,
Beauchamp and Livoreil, 1997; Fritz et al., 2002; Purser and Radford,
2011). In addition, chronic disturbance can cause population declines
through reduction of fitness (e.g., decline in body condition) and
subsequent reduction in reproductive success, survival, or both (e.g.,
Harrington and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998).
Many animals perform vital functions, such as feeding, resting,
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption
of such functions resulting from reactions to stressors such as sound
exposure are more likely to be significant if they last more than one
diel cycle or recur on subsequent days (Southall et al., 2007).
Consequently, a behavioral response lasting less than one day and not
recurring on subsequent days is not considered particularly severe
unless it could directly affect reproduction or survival (Southall et
al., 2007). Note that there is a difference between multi-day
substantive behavioral reactions and multi-day anthropogenic
activities. For example, just because an activity lasts for multiple
days does not necessarily mean that individual animals are either
exposed to activity-related stressors for multiple days or, further,
exposed in a manner resulting in sustained multi-day substantive
behavioral responses.
Behavioral response studies have been conducted on odontocete
responses to sonar. Sperm whales were exposed to pulsed active sonar
(1-2 kHz) at moderate source levels and high source levels, as well as
continuously active sonar at moderate levels for which the summed
energy (SEL) equaled the summed energy of the high source level pulsed
sonar (Isojunno et al., 2020). Foraging behavior did not change during
exposures to moderate source level sonar, but non-foraging behavior
increased during exposures to high source level sonar and to the
continuous sonar, indicating that the energy of the sound (the SEL) was
a better predictor of response than SPL. Time of day of the exposure
was also an important covariate in determining the amount of non-
foraging behavior, as were order effects (e.g. the SEL of the previous
exposure); Isojunno et al. (2021) found that higher SELs reduced sperm
whale buzzing (i.e., foraging).
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Duration of continuous sonar activity also appears to impact sperm
whale displacement and foraging activity (Stanistreet et al., 2022).
During long bouts of sonar lasting up to 13 consecutive hours,
occurring repeatedly over an 8 day naval exercise (median and maximum
SPL = 120 dB and 164 dB), sperm whales substantially reduced how often
they produced clicks during sonar, indicating a decrease or cessation
in foraging behavior. Cur[eacute] et al. (2021) also found that sperm
whales exposed to continuous and pulsed active sonar were more likely
to produce low or medium severity responses with higher cumulative SEL.
Specifically, the probability of observing a low severity response
increased to 0.5 at approximately 173 dB SEL and observing a medium
severity response reached a probability of 0.35 at cumulative SELs
between 179 and 189 dB. These results again demonstrate that the
behavioral state and environment of the animal mediates the likelihood
of a behavioral response, as do the characteristics (e.g., frequency,
energy level) of the sound source itself.
Many of the contextual factors resulting from the behavioral
response studies (e.g., close approaches by multiple vessels or
tagging) would not occur during the proposed action. Odontocete
behavioral responses to acoustic transmissions from non-impulsive
sources used during the proposed action would likely be a result of the
animal's behavioral state and prior experience rather than external
variables such as ship proximity; thus, any behavioral responses are
expected to be minimal and short term.
To assess the strength of behavioral changes and responses to
external sounds and SPLs associated with changes in behavior, Southall
et al., (2007) developed and utilized a severity scale, which is a 10
point scale ranging from no effect (labeled 0), effects not likely to
influence vital rates (low; labeled from 1 to 3), effects that could
affect vital rates (moderate; labeled 4 to 6), to effects that were
thought likely to influence vital rates (high; labeled 7 to 9).
Southall et al., (2021) updated the severity scale by integrating
behavioral context (i.e., survival, reproduction, and foraging) into
severity assessment. For non-impulsive sounds (i.e., similar to the
sources used during the proposed action), data suggest that exposures
of pinnipeds to sources between 90 and 140 dB re 1 [mu]Pa do not elicit
strong behavioral responses; no data were available for exposures at
higher received levels for Southall et al., (2007) to include in the
severity scale analysis. Reactions of harbor seals were the only
available data for which the responses could be ranked on the severity
scale. For reactions that were recorded, the majority (17 of 18
individuals/groups) were ranked on the severity scale as a 4 (defined
as moderate change in movement, brief shift in group distribution, or
moderate change in vocal behavior) or lower; the remaining response was
ranked as a 6 (defined as minor or moderate avoidance of the sound
source).
Behavioral Responses to Ice Breaking Noise- Ringed seals on pack
ice showed various behaviors when approached by an icebreaking vessel.
A majority of seals dove underwater when the ship was within 0.5 nm
(0.93 km) while others remained on the ice. However, as icebreaking
vessels came closer to the seals, most dove underwater. Ringed seals
have also been observed foraging in the wake of an icebreaking vessel
(Richardson et al., 1995). In studies by Alliston (1980; 1981), there
was no observed change in the density of ringed seals in areas that had
been subject to icebreaking. Alternatively, ringed seals may have
preferentially established breathing holes in the ship tracks after the
icebreaker moved through the area. Previous observations and studies
using icebreaking ships provide a greater understanding in how seal
behavior may be affected by a vessel transiting through the area.
Adult ringed seals spend up to 20 percent of the time in subnivean
lairs during the winter season (Kelly et al., 2010b). Ringed seal pups
spend about 50 percent of their time in the lair during the nursing
period (Lydersen and Hammill, 1993). During the warm season ringed
seals haul out on the ice. In a study of ringed seal haul out activity
by Born et al., (2002), ringed seals spent 25-57 percent of their time
hauled out in June, which is during their molting season. Ringed seal
lairs are typically used by individual seals (haulout lairs) or by a
mother with a pup (birthing lairs); large lairs used by many seals for
hauling out are rare (Smith and Stirling, 1975). If the non-impulsive
acoustic transmissions are heard and are perceived as a threat, ringed
seals within subnivean lairs could react to the sound in a similar
fashion to their reaction to other threats, such as polar bears (their
primary predators), although the type of sound would be novel to them.
Responses of ringed seals to a variety of human-induced sounds (e.g.,
helicopter noise, snowmobiles, dogs, people, and seismic activity) have
been variable; some seals entered the water and some seals remained in
the lair. However, in all instances in which observed seals departed
lairs in response to noise disturbance, they subsequently reoccupied
the lair (Kelly et al., 1988d).
Ringed seal mothers have a strong bond with their pups and may
physically move their pups from the birth lair to an alternate lair to
avoid predation, sometimes risking their lives to defend their pups
from potential predators (Smith, 1987). If a ringed seal mother
perceives the proposed acoustic sources as a threat, the network of
multiple birth and haulout lairs allows the mother and pup to move to a
new lair (Smith and Hammill, 1981; Smith and Stirling, 1975). The
acoustic sources from this proposed action are not likely to impede a
ringed seal from finding a breathing hole or lair, as captive seals
have been found to primarily use vision to locate breathing holes and
no effect to ringed seal vision would occur from the acoustic
disturbance (Elsner et al., 1989; Wartzok et al., 1992a). It is
anticipated that a ringed seal would be able to relocate to a different
breathing hole relatively easily without impacting their normal
behavior patterns.
Stress responses-- An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle, 1950;
Moberg, 2000). In many cases, an animal's first and sometimes most
economical (in terms of energetic costs) response is behavioral
avoidance of the potential stressor. Autonomic nervous system responses
to stress typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha,
2000).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
[[Page 44355]]
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002b) and, more rarely, studied in wild populations
(e.g., Romano et al., 2002a). These and other studies lead to a
reasonable expectation that some marine mammals will experience
physiological stress responses upon exposure to acoustic stressors and
that it is possible that some of these would be classified as
``distress.'' In addition, any animal experiencing TTS would likely
also experience stress responses (NRC, 2003).
Auditory masking-- Sound can disrupt behavior through masking, or
interfering with, an animal's ability to detect, recognize, or
discriminate between acoustic signals of interest (e.g., those used for
intraspecific communication and social interactions, prey detection,
predator avoidance, navigation) (Richardson et al., 1995). Masking
occurs when the receipt of a sound is interfered with by another
coincident sound at similar frequencies and at similar or higher
intensity, and may occur whether the sound is natural (e.g., snapping
shrimp, wind, waves, precipitation) or anthropogenic (e.g., shipping,
sonar, seismic exploration) in origin. The ability of a noise source to
mask biologically important sounds depends on the characteristics of
both the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions.
Under certain circumstances, marine mammals experiencing
significant masking could also be impaired from maximizing their
performance fitness in survival and reproduction. Therefore, when the
coincident (masking) sound is anthropogenic, it may be considered
harassment when disrupting or significantly altering behavior patterns.
It is important to distinguish TTS and PTS, which persist after the
sound exposure, from masking, which occurs during the sound exposure.
Because masking (without resulting in TS) is not associated with
abnormal physiological function, it is not considered a physiological
effect, but rather a potential behavioral effect.
The frequency range of the potentially masking sound is important
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation
sounds produced by odontocetes but are more likely to affect detection
of mysticete communication calls and other potentially important
natural sounds such as those produced by surf and some prey species.
The masking of communication signals by anthropogenic noise may be
considered as a reduction in the communication space of animals (e.g.,
Clark et al., 2009) and may result in energetic or other costs as
animals change their vocalization behavior (e.g., Miller et al., 2000;
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt
et al., 2009). Masking can be reduced in situations where the signal
and noise come from different directions (Richardson et al., 1995),
through amplitude modulation of the signal, or through other
compensatory behaviors (Houser and Moore, 2014). Masking can be tested
directly in captive species (e.g., Erbe, 2008), but in wild populations
it must be either modeled or inferred from evidence of masking
compensation. There are few studies addressing real-world masking
sounds likely to be experienced by marine mammals in the wild (e.g.,
Branstetter et al., 2013).
Masking affects both senders and receivers of acoustic signals and
can potentially have long-term chronic effects on marine mammals at the
population level as well as at the individual level. Low-frequency
ambient sound levels have increased by as much as 20 dB (more than
three times in terms of SPL) in the world's ocean from pre-industrial
periods, with most of the increase from distant commercial shipping
(Hildebrand, 2009). All anthropogenic sound sources, but especially
chronic and lower-frequency signals (e.g., from vessel traffic),
contribute to elevated ambient sound levels, thus intensifying masking.
Due to the transient nature of marine mammals to move and avoid
disturbance, masking is not likely to have long-term impacts on marine
mammal species within the proposed study area.
Potential Effects on Prey-- The marine mammal species in the study
area feed on marine invertebrates and fish. Studies of sound energy
effects on invertebrates are few, and primarily identify behavioral
responses. It is expected that most marine invertebrates would not
sense the frequencies of the acoustic transmissions from the acoustic
sources associated with the proposed action. Although acoustic sources
used during the proposed action may briefly impact individuals,
intermittent exposures to non-impulsive acoustic sources are not
expected to impact survival, growth, recruitment, or reproduction of
widespread marine invertebrate populations.
The fish species residing in the study area include those that are
closely associated with the deep ocean habitat of the Beaufort Sea.
Nearly 250 marine fish species have been described in the Arctic,
excluding the larger parts of the sub-Arctic Bering, Barents, and
Norwegian Seas (Mecklenburg et al., 2011). However, only about 30 are
known to occur in the Arctic waters of the Beaufort Sea (Christiansen
and Reist, 2013). Although hearing capability data only exist for fewer
than 100 of the 32,000 named fish species, current data suggest that
most species of fish detect sounds from 50 to 100 Hz, with few fish
hearing sounds above 4 kHz (Popper, 2008). It is believed that most
fish have the best hearing sensitivity from 100 to 400 Hz (Popper,
2003). Fish species in the study area are expected to hear the low-
frequency sources associated with the proposed action, but most are not
expected to detect sound from the mid-frequency sources. Human
generated sound could alter the behavior of a fish in a manner than
would affect its way of living, such as where it tries to locate food
or how well it could find a mate. Behavioral responses to loud noise
could include a startle response, such as the fish swimming away from
the source, the fish ``freezing'' and staying in place, or scattering
(Popper, 2003). Misund (1997) found that fish ahead of a ship showed
avoidance reactions at ranges of 160 to 489 ft (49 to 149 m). Avoidance
behavior of vessels, vertically or horizontally in the water column,
has been reported for cod and herring, and was attributed to vessel
noise. While acoustic sources associated with the proposed action may
influence the behavior of some fish species, other fish species may be
equally unresponsive. Overall effects to fish from the proposed
[[Page 44356]]
action would be localized, temporary, and infrequent.
Effects to Physical and Foraging Habitat--Ringed seals haul out on
pack ice during the spring and summer to molt (Reeves et al., 2002;
Born et al., 2002). Additionally, some studies (Alliston, 1980; 1981)
suggested that ringed seals might preferentially establish breathing
holes in ship tracks after vessels move through the area. The amount of
ice habitat disturbed by activities is small relative to the amount of
overall habitat available and there will be no permanent or longer-term
loss or modification of physical ice habitat used by ringed seals.
Vessel movement would have minimal effect on physical beluga habitat as
beluga habitat is solely within the water column. Furthermore, the
deployed sources that would remain in use after the vessels have left
the survey area have low duty cycles and lower source levels, and any
impacts to the acoustic habitat of marine mammals would be minimal.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determinations.
Harassment is the only type of take expected to result from these
activities. For this military readiness activity, the MMPA defines
``harassment'' as (i) Any act that injures or has the significant
potential to injure a marine mammal or marine mammal stock in the wild
(Level A harassment); or (ii) Any act that disturbs or is likely to
disturb a marine mammal or marine mammal stock in the wild by causing
disruption of natural behavioral patterns, including, but not limited
to, migration, surfacing, nursing, breeding, feeding, or sheltering, to
a point where the behavioral patterns are abandoned or significantly
altered (Level B harassment).
Authorized takes would be by Level B harassment only, in the form
of disruption of behavioral patterns and/or TTS for individual marine
mammals resulting from exposure to ONR's acoustic sources. Based on the
nature of the activity, Level A harassment is neither anticipated nor
proposed to be authorized.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the proposed take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals 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). For the proposed IHA, ONR employed an advanced model known as
the Navy Acoustic Effects Model (NAEMO) for assessing the impacts of
underwater sound. Below, we describe the factors considered here in
more detail and present the proposed take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur PTS of some degree (equated to Level A
harassment).
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 (rms) for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources.
In this case, NMFS is proposing to adopt the Navy's approach to
estimating incidental take by Level B harassment from the active
acoustic sources for this action, which includes use of dose response
functions. The Navy's dose response functions were developed to
estimate take from sonar and similar transducers, but are not
applicable to ice breaking. Multi-year research efforts have conducted
sonar exposure studies for odontocetes and mysticetes (Miller et al.,
2012; Sivle et al., 2012). Several studies with captive animals have
provided data under controlled circumstances for odontocetes and
pinnipeds (Houser et al., 2013a; Houser et al., 2013b). Moretti et al.,
(2014) published a beaked whale dose-response curve based on passive
acoustic monitoring of beaked whales during U.S. Navy training activity
at Atlantic Underwater Test and Evaluation Center during actual Anti-
Submarine Warfare exercises. This information necessitated the update
of the behavioral response criteria for the U.S. Navy's environmental
analyses.
Southall et al., (2007), and more recently Southall et al., (2019),
synthesized data from many past behavioral studies and observations to
determine the likelihood of behavioral reactions at specific sound
levels. While in general, the louder the sound source the more intense
the behavioral response, it was clear that the proximity of a sound
source and the animal's experience, motivation, and conditioning were
also critical factors influencing the response (Southall et al., 2007;
Southall et al., 2019). After examining all of the available data, the
authors felt that the derivation of thresholds for behavioral response
based solely on exposure level was not supported because context of the
animal at the time of sound exposure was an important factor in
estimating response. Nonetheless, in some conditions, consistent
avoidance reactions were noted at higher sound levels depending on the
marine mammal species or group allowing conclusions to be drawn. Phocid
seals showed avoidance reactions at or below 190 dB re 1 [mu]Pa at 1m;
thus, seals may actually receive levels adequate to produce TTS before
avoiding the source.
Odontocete behavioral criteria for non-impulsive sources were
updated based on controlled exposure studies for dolphins and sea
mammals, sonar, and safety (3S) studies where odontocete behavioral
responses were reported after
[[Page 44357]]
exposure to sonar (Antunes et al., 2014; Houser et al., 2013b; Miller
et al., 2011; Miller et al., 2014; Miller et al., 2012). For the 3S
study, the sonar outputs included 1-2 kHz up- and down-sweeps and 6-7
kHz up-sweeps; source levels were ramped up from 152-158 dB re 1 [mu]Pa
to a maximum of 198-214 re 1 [mu]Pa at 1 m. Sonar signals were ramped
up over several pings while the vessel approached the mammals. The
study did include some control passes of ships with the sonar off to
discern the behavioral responses of the mammals to vessel presence
alone versus active sonar.
The controlled exposure studies included exposing the Navy's
trained bottlenose dolphins to mid-frequency sonar while they were in a
pen. Mid-frequency sonar was played at 6 different exposure levels from
125-185 dB re 1 [mu]Pa (rms). The behavioral response function for
odontocetes resulting from the studies described above has a 50 percent
probability of response at 157 dB re 1 [mu]Pa. Additionally, distance
cutoffs (20 km for MF cetaceans) were applied to exclude exposures
beyond which the potential of significant behavioral responses is
considered to be unlikely.
The pinniped behavioral threshold was updated based on controlled
exposure experiments on the following captive animals: hooded seal,
gray seal (Halichoerus grypus), and California sea lion (G[ouml]tz et
al., 2010; Houser et al., 2013a; Kvadsheim et al., 2010). Hooded seals
were exposed to increasing levels of sonar until an avoidance response
was observed, while the grey seals were exposed first to a single
received level multiple times, then an increasing received level. Each
individual California sea lion was exposed to the same received level
ten times. These exposure sessions were combined into a single response
value, with an overall response assumed if an animal responded in any
single session. The resulting behavioral response function for
pinnipeds has a 50 percent probability of response at 166 dB re 1
[mu]Pa. Additionally, distance cutoffs (10 km for pinnipeds) were
applied to exclude exposures beyond which the potential of significant
behavioral responses is considered unlikely. For additional information
regarding marine mammal thresholds for PTS and TTS onset, please see
NMFS (2018) and Table 6.
Empirical evidence has not shown responses to non-impulsive
acoustic sources that would constitute take beyond a few km from a non-
impulsive acoustic source, which is why NMFS and the Navy
conservatively set distance cutoffs for pinnipeds and mid-frequency
cetaceans (U.S. Department of the Navy, 2017a). The cutoff distances
for fixed sources are different from those for moving sources, as they
are treated as individual sources in Navy modeling given that the
distance between them is significantly greater than the range to which
environmental effects can occur. Fixed source cutoff distances used
were 2.7 nm (5 km) for pinnipeds and 5.4 nm (10 km) for beluga whales
(Table 5). As some of the on-site drifting sources could come closer
together, the drifting source cutoffs applied were 5.4 nm (10 km) for
pinnipeds and 10.8 nm (20 km) for beluga whales (Table 5). Regardless
of the received level at that distance, take is not estimated to occur
beyond these cutoff distances. Range to thresholds were calculated for
the noise associated with icebreaking in the study area. These all fall
within the same cutoff distances as non-impulsive acoustic sources;
range to behavioral threshold for both beluga whales and ringed seal
were under 2.7 nm (5 km), and range to TTS threshold for both under 15
m (Table 5).
Table 5--Thresholds\1\ and Cutoff Distances for Sources by Species
--------------------------------------------------------------------------------------------------------------------------------------------------------
Drifting
Fixed source source
Behavioral behavioral behavioral Behavioral Ice breaking
Species threshold for threshold threshold threshold for source cutoff TTS threshold PTS threshold
non-impulsive cutoff cutoff ice breaking distance \3\
acoustic sources distance \3\ distance \3\ sources (km)
(km) (km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ringed Seal.................. Pinniped Dose 5 10 120 dB re 1 <5 181 dB SEL 201 dB SEL
Response [mu]Pa step cumulative. cumulative.
Function \2\. function.
Beluga Whale................. Mid-Frequency 10 20 120 dB re 1 <15 178 dB SEL 198 dB SEL
BRF dose [mu]Pa step cumulative. cumulative.
Response function.
Function \2\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The threshold values provided are assumed for when the source is within the animal's best hearing sensitivity. The exact threshold varies based on
the overlap of the source and the frequency weighting.
\2\ See Figure 6-1 in application.
\3\ Take is not estimated to occur beyond these cutoff distances, regardless of the received level.
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). ONR's
proposed activity includes the use of non-impulsive acoustic sources;
however, Level A harassment is not expected as a result of the proposed
activities nor is it proposed to be authorized by NMFS.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 6--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: L0-pk,flat: 219 Cell 2: LE, LF,24h: 199 dB
dB; LE, LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: L0-pk,flat: 230 Cell 4: LE, MF,24h: 198 dB
dB; LE, MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: L0-pk,flat: 202 Cell 6: LE, HF,24h: 173 dB
dB; LE, HF,24h: 155 dB.
[[Page 44358]]
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: L0-pk,flat: 218 Cell 8: LE, PW,24h: 201 dB
dB; LE, PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: L0-pk,flat: 232 Cell 10: LE, OW,24h: 219 dB
dB; LE, OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS
onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,) has a reference value of 1[mu]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.
Quantitative Modeling
The Navy performed a quantitative analysis to estimate the number
of marine mammals likely to be exposed to underwater acoustic
transmissions above the previously described threshold criteria during
the proposed action. Inputs to the quantitative analysis included
marine mammal density estimates obtained from the Kaschner et al.
(2006) habitat suitability model and Ca[ntilde]adas et al. (2020),
marine mammal depth occurrence (U.S. Department of the Navy, 2017b),
oceanographic and mammal hearing data, and criteria and thresholds for
levels of potential effects. The quantitative analysis consists of
computer modeled estimates and a post-model analysis to determine the
number of potential animal exposures. The model calculates sound energy
propagation from the proposed non-impulsive acoustic sources, the sound
received by animat (virtual animal) dosimeters representing marine
mammals distributed in the area around the modeled activity, and
whether the sound received by animats exceeds the thresholds for
effects.
The Navy developed a set of software tools and compiled data for
estimating acoustic effects on marine mammals without consideration of
behavioral avoidance or mitigation. These tools and data sets serve as
integral components of the Navy Acoustic Effects Model (NAEMO). In
NAEMO, animats are distributed non-uniformly based on species-specific
density, depth distribution, and group size information and animats
record energy received at their location in the water column. A fully
three-dimensional environment is used for calculating sound propagation
and animat exposure in NAEMO. Site-specific bathymetry, sound speed
profiles, wind speed, and bottom properties are incorporated into the
propagation modeling process. NAEMO calculates the likely propagation
for various levels of energy (sound or pressure) resulting from each
source used during the training event.
NAEMO then records the energy received by each animat within the
energy footprint of the event and calculates the number of animats
having received levels of energy exposures that fall within defined
impact thresholds. Predicted effects on the animats within a scenario
are then tallied and the highest order effect (based on severity of
criteria; e.g., PTS over TTS) predicted for a given animat is assumed.
Each scenario, or each 24-hour period for scenarios lasting greater
than 24 hours is independent of all others, and therefore, the same
individual marine mammal (as represented by an animat in the model
environment) could be impacted during each independent scenario or 24-
hour period. In few instances, although the activities themselves all
occur within the proposed study location, sound may propagate beyond
the boundary of the study area. Any exposures occurring outside the
boundary of the study area are counted as if they occurred within the
study area boundary. NAEMO provides the initial estimated impacts on
marine species with a static horizontal distribution (i.e., animats in
the model environment do not move horizontally).
There are limitations to the data used in the acoustic effects
model, and the results must be interpreted within this context. While
the best available data and appropriate input assumptions have been
used in the modeling, when there is a lack of definitive data to
support an aspect of the modeling, conservative modeling assumptions
have been chosen (i.e., assumptions that may result in an overestimate
of acoustic exposures):
<bullet> Animats are modeled as being underwater, stationary, and
facing the source and therefore always predicted to receive the maximum
potential sound level at a given location (i.e., no porpoising or
pinnipeds' heads above water);
<bullet> Animats do not move horizontally (but change their
position vertically within the water column), which may overestimate
physiological effects such as hearing loss, especially for slow moving
or stationary sound sources in the model;
<bullet> Animats are stationary horizontally and therefore do not
avoid the sound source, unlike in the wild where animals would most
often avoid exposures at higher sound levels, especially those
exposures that may result in PTS;
<bullet> Multiple exposures within any 24-hour period are
considered one continuous exposure for the purposes of calculating
potential threshold shift, because there are not sufficient data to
estimate a hearing recovery function for the time between exposures;
and
<bullet> Mitigation measures were not considered in the model. In
reality, sound-producing activities would be reduced, stopped, or
delayed if marine mammals are detected by visual monitoring.
Due to these inherent model limitations and simplifications, model-
estimated results should be further analyzed, considering such factors
as the range to specific effects, avoidance, and the likelihood of
successfully implementing mitigation measures. This analysis uses a
number of factors in addition to the acoustic model results to predict
acoustic effects on marine mammals, as described below in the
[[Page 44359]]
Marine Mammal Occurrence and Take Estimation section.
The underwater radiated noise signature for icebreaking in the
central Arctic Ocean by CGC Healy during different types of ice-cover
was characterized in Roth et al. (2013). The radiated noise signatures
were characterized for various fractions of ice cover. For modeling,
the 8/10 and 3/10 ice cover were used. Each modeled day of icebreaking
consisted of 16 hours of 8/10 ice cover and 8 hours of 3/10 ice cover.
The sound signature of the 5/10 icebreaking activities, which would
correspond to half-power icebreaking, was not reported in (Roth et al.
2013); therefore, the full-power signature was used as a conservative
proxy for the half-power signature. Icebreaking was modeled for eight
days total. Since ice forecasting cannot be predicted more than a few
weeks in advance, it is unknown if icebreaking would be needed to
deploy or retrieve the sources after one year of transmitting.
Therefore, the potential for an icebreaking cruise on CGC Healy was
conservatively analyzed within this request for an IHA. As the R/V
Sikuliaq is not expected to be ice breaking, acoustic noise created by
ice breaking is only modeled for the CGC Healy. Figures 5a and 5b in
Roth et al. (2013) depict the source spectrum level versus frequency
for 8/10 and 3/10 ice cover, respectively. The sound signature of each
of the ice coverage levels was broken into 1-octave bins (Table 7). In
the model, each bin was included as a separate source on the modeled
vessel. When these independent sources go active concurrently, they
simulate the sound signature of CGC Healy. The modeled source level
summed across these bins was 196.2 dB for the 8/10 signature and 189.3
dB for the 3/10 ice signature. These source levels are a good
approximation of the icebreaker's observed source level (provided in
Figure 4b of (Roth et al., 2013)). Each frequency and source level was
modeled as an independent source, and applied simultaneously to all of
the animats within NAEMO. Each second was summed across frequency to
estimate sound pressure level (root mean square [SPL<INF>RMS</INF>]).
Any animat exposed to sound levels greater than 120 dB was considered a
take by Level B harassment. For PTS and TTS, determinations, sound
exposure levels were summed over the duration of the test and the
transit to the deep water deployment area. The method of quantitative
modeling for icebreaking is considered to be a conservative approach;
therefore, the number of takes estimated for icebreaking are likely an
overestimate and would not be expected to reach that level.
Table 7--Modeled Bins for 8/10 (Full Power) and 3/10 (Quarter Power) Ice
Coverage Ice Breaking on the CGC Healy
------------------------------------------------------------------------
Frequency (Hz) 8/10 source level (dB) 3/10 source level (dB)
------------------------------------------------------------------------
25 189 187
50 188 182
100 189 179
200 190 177
400 188 175
800 183 170
1600 177 166
3200 176 171
6400 172 168
12800 167 164
------------------------------------------------------------------------
For non-impulsive sources, NAEMO calculates the SPL and SEL for
each active emission during an event. This is done by taking the
following factors into account over the propagation paths: bathymetric
relief and bottom types, sound speed, and attenuation contributors such
as absorption, bottom loss, and surface loss. Platforms such as a ship
using one or more sound sources are modeled in accordance with relevant
vehicle dynamics and time durations by moving them across an area whose
size is representative of the testing event's operational area.
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information that
will inform the take calculations. We also describe how the marine
mammal occurrence information is synthesized to produce a quantitative
estimate of the take that is reasonably likely to occur and proposed
for authorization.
The beluga whale density numbers utilized for quantitative acoustic
modeling are from the Navy Marine Species Density Database (U.S.
Department of the Navy 2014). Where available (i.e., June through 15
October over the continental shelf primarily), density estimates used
were from Duke density modeling based upon line-transect surveys
(Ca[ntilde]adas et al., 2020). The remaining seasons and geographic
area were based on the habitat-based modeling by Kaschner et al. (2006)
and Kaschner (2004). Density for beluga whales was not distinguished by
stock and varied throughout the project area geographically and
monthly; the range of densities in the project area during September I
shown in Table 8. The density estimates for ringed seals are based on
the habitat suitability modeling by Kaschner et al., (2006) and
Kaschner (2004) and shown in Table 8 as well.
Table 8--Density Estimates of Impacted Species
------------------------------------------------------------------------
Density estimates
Common name (animals/km\2\)
------------------------------------------------------------------------
Beluga whale (Beaufort Sea) Stock.............. 0.000506 to 0.5176
Beluga whale (Eastern Chukchi Sea Stock).
Ringed seal (Arctic Stock)..................... 0.1108 to 0.3562
------------------------------------------------------------------------
[[Page 44360]]
Take of all species would occur by Level B harassment only. NAEMO
estimated for potential TTS exposure and predicted one exposure of
ringed seals may occur as a result of the proposed activities. Table 9
shows the total number of requested takes by Level B harassment that
NMFS proposes to authorize for both beluga whale stocks and the Arctic
ringed seal stock based upon NAEMO modeled results.
Density estimates for beluga whales are equal as estimates were not
distinguished by stock (Kaschner et al., 2006; Kaschner, 2004). The
ranges of the Beaufort Sea and Eastern Chukchi Sea beluga whales vary
within the study area throughout the year (Hauser et al., 2014). Based
upon the limited information available regarding the expected spatial
distributions of each stock within the study area, take has been
apportioned equally to each stock (Table 9). In addition, in NAEMO,
animats do not move horizontally or react in any way to avoid sound.
Therefore, the current model may overestimate non-impulsive acoustic
impacts.
Table 9--Requested Take by Level B harassment
----------------------------------------------------------------------------------------------------------------
Total proposed Percentage of
Non-impulsive Icebreaking Icebreaking authorized take stock
Species active acoustics (behavioral) (TTS) ------------------ requested for
(behavioral) Behavioral/TTS take \1\
----------------------------------------------------------------------------------------------------------------
Beluga whale--Beaufort Sea 134 11 0 145/0 0.369
Stock......................
Beluga whale--Eastern 134 11 0 145/0 1.09
Chukchi Sea Stock..........
Ringed seal................. 2,839 538 1 3,377/1 1.97
----------------------------------------------------------------------------------------------------------------
\1\ Percentage of stock taken calculated based on proportion of number of Level B takes per the stock population
estimate provided in Table 3-1 in the application.
Proposed Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses. 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)). The NDAA for FY 2004 amended the
MMPA as it relates to military readiness activities and the incidental
take authorization process such that ``least practicable impact'' shall
include consideration of personnel safety, practicality of
implementation, and impact on the effectiveness of the military
readiness activity.
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat, as
well as subsistence uses. This considers the nature of the potential
adverse impact being mitigated (likelihood, scope, range). It further
considers the likelihood that the measure will be effective if
implemented (probability of accomplishing the mitigating result if
implemented as planned), the likelihood of effective implementation
(probability implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
Mitigation for Marine Mammals and Their Habitat
The Navy would be required to abide by the mitigation measures
below. These measures are expected to: further minimize the likelihood
of ship strikes; reduce the likelihood that marine mammals are exposed
to sound levels during acoustic source deployment that would be
expected to result in TTS or more severe behavioral responses and also
to ensure that there are no other interactions between the deployed
gear and marine mammals, and; further ensure that there are no impacts
to subsistence uses.
Ships operated by or for the Navy have at least one personnel
assigned to stand watch at all times, day and night, when moving
through the water. Watch personnel must be trained through the U.S.
Navy Marine Species Awareness Training Program, which standardizes
watch protocols and trains personnel in marine species detection to
prevent adverse impacts to marine mammal species. While in transit,
ships must be alert at all times, use extreme caution and proceed at a
safe speed such that the ship can take proper and effective action to
avoid a collision with any marine mammals.
During mooring or UUV deployment, visual observation would start 15
minutes prior to and continue throughout the deployment within the
mitigation zone of 180 ft (55 m, roughly one ship length) around the
deployed mooring. Deployment will stop if a marine mammal is visually
detected within the exclusion zone. Deployment will re-commence if any
one of the following conditions are met: (1) The animal is observed
exiting the exclusion zone, (2) the animal is thought to have exited
the exclusion zone based on its course and speed, or (3) the exclusion
zone has been clear from any additional sightings for a period of 15
minutes for pinnipeds and 30 minutes for cetaceans.
Ships would avoid approaching marine mammals head-on and would
maneuver to maintain a mitigation zone of 500 yards (yd; 457 m) around
observed cetaceans, and 200 yd (183 m) around all other marine mammals,
provided it is safe to do so in ice-free waters. Ships captains and
subsistence whalers would also maintain at-sea communication to avoid
conflict of ship transit with hunting activity.
If a marine mammal species for which take is not authorized is
encountered or observed within the mitigation zone, or a species for
which authorization was granted but the authorized number of takes have
been met, activities must cease. Activities may not resume until
[[Page 44361]]
the animal is confirmed to have left the area.
These requirements do not apply if a vessel's safety is at risk,
such as when a change of course would create an imminent and serious
threat to safety, person, or vessel, and to the extent that vessels are
restricted in their ability to maneuver. No further action is necessary
if a marine mammal other than a cetacean continues to approach the
vessel after there has already been one maneuver and/or speed change to
avoid the animal. Avoidance measures should continue for any observed
cetacean in order to maintain a mitigation zone of 500 yd (457 m).
Based on our evaluation of the applicant's proposed measures, NMFS
has preliminarily determined that the proposed mitigation measures
provide the means of effecting the least practicable impact on the
affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of such species or stock for
subsistence uses.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and,
<bullet> Mitigation and monitoring effectiveness.
While underway, the ships (including non-Navy ships operating on
behalf of the Navy) utilizing active acoustics will have at least one
watch person during activities. Watch personnel must undertake
extensive training through the Navy's Marine Species Awareness
Training. Their duties may be performed in conjunction with other job
responsibilities, such as navigating the ship or supervising other
personnel. While on watch, personnel employ visual search techniques,
including the use of binoculars, using a scanning method in accordance
with the U.S. Navy Marine Species Awareness Training or civilian
equivalent. A primary duty of watch personnel is to detect and report
all objects and disturbances sighted in the water that may be
indicative of a threat to the ship and its crew, such as debris, or
surface disturbance. Per safety requirements, watch personnel also
report any marine mammals sighted that have the potential to be in the
direct path of the ship as a standard collision avoidance procedure.
While underway, the ships (including non-Navy ships operating on
behalf of the Navy) utilizing active acoustics and towed in-water
devices will have at least one watch person during activities. While
underway, watch personnel must be alert at all times and have access to
binoculars. Each day, the following information should be recorded:
<bullet> Vessel name;
<bullet> Watch personnel names and affiliations;
<bullet> Effort type (i.e., transit or deployment); and
<bullet> Environmental conditions (at the beginning of watch
personnel shift and whenever conditions changed significantly),
including Beaufort Sea State and any other relevant weather conditions
including cloud cover, fog, sun glare, and overall visibility to the
horizon.
Watch personnel must use standardized data collection forms,
whether electronic or hard copy, as well as distinguish between marine
mammal sightings that occur during ship transit or acoustic source
deployment. Upon visual observation of a marine mammal, the following
information would be recorded:
<bullet> Date/time of sighting;
<bullet> Identification of animal (e.g., genus/species, lowest
possible taxonomic level, or unidentified) and the composition of the
group if there is a mix of species;
<bullet> Location (latitude/longitude) of sighting;
<bullet> Estimated number of animals (high/low/best)
<bullet> Description (as many distinguishing features as possible
of each individual seen, including length, shape, color, pattern, scars
or markings, shape and size of dorsal fin, shape of head, and blow
characteristics);
<bullet> Detailed behavior observations (e.g., number of blows/
breaths, number of surfaces, breaching, spyhopping, diving, feeding,
traveling; as explicit and detailed as possible; length of time the
animal was observed within the harassment zone; note any observed
changes in behavior);
<bullet> Distance from ship to animal;
<bullet> Direction of animal's travel relative to the vessel
<bullet> Platform activity at time of sighting (i.e., transit,
deployment); and
<bullet> Weather conditions (i.e., Beaufort Sea State, cloud
cover).
The U.S. Navy has coordinated with NMFS to develop an overarching
program plan in which specific monitoring would occur. This plan is
called the Integrated Comprehensive Monitoring Program (ICMP)
(Department of the Navy, 2011). The ICMP has been developed in direct
response to Navy permitting requirements established through various
environmental compliance efforts. As a framework document, the ICMP
applies by regulation to those activities on ranges and operating areas
for which the Navy is seeking or has sought incidental take
authorizations. The ICMP is intended to coordinate monitoring efforts
across all regions and to allocate the most appropriate level and type
of effort based on a set of standardized research goals, and in
acknowledgement of regional scientific value and resource availability.
The ICMP is focused on Navy training and testing ranges where the
majority of Navy activities occur regularly as those areas have the
greatest potential for
[[Page 44362]]
being impacted. ONR's ARA in comparison is a less intensive test with
little human activity present in the Arctic. Human presence is limited
to the deployment of sources that would take place over several weeks.
Additionally, due to the location and nature of the testing, vessels
and personnel would not be within the study area for an extended period
of time. As such, more extensive monitoring requirements beyond the
basic information being collected would not be feasible as it would
require additional personnel and equipment to locate seals and a
presence in the Arctic during a period of time other then what is
planned for source deployment. However, ONR will record all
observations of marine mammals, including the marine mammal's species
identification, location (latitude and longitude), behavior, and
distance from project activities. ONR will also record date and time of
sighting. This information is valuable in an area with few recorded
observations.
If any injury or death of a marine mammal is observed during the
2022-2023 ARA, the Navy will immediately halt the activity and report
the incident to the Office of Protected Resources, NMFS, and the Alaska
Regional Stranding Coordinator, NMFS. The following information must be
provided:
<bullet> Time, date, and location of the discovery;
<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(s) was
discovered (e.g., deployment of moored or drifting sources or by
transiting vessel).
ONR will provide NMFS OPR and AKR with a draft monitoring report
within 90 days of the conclusion of each research cruise, or sixty days
prior to the issuance of any subsequent IHA for this project, whichever
comes first. The draft monitoring report will include data regarding
acoustic source use and any mammal sightings or detection documented.
The report will include the estimated number of marine mammals taken
during the activity. The report will also include information on the
number of shutdowns recorded. If no comments are received from NMFS
within 30 days of submission of the draft final report, the draft final
report will constitute the final report. If comments are received, a
final report must be submitted within 30 days after receipt of
comments.
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 discussion of our analysis applies to
beluga whales and ringed seals, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar. 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, they are
described independently in the analysis below.
Underwater acoustic transmissions associated with the proposed ARA,
as outlined previously, have the potential to result in Level B
harassment of beluga seals and ringed seals in the form of behavioral
disturbances. No serious injury, mortality, or Level A harassment are
anticipated to result from these described activities. Effects on
individual belugas or ringed seals taken by Level B harassment could
include alteration of dive behavior and/or foraging behavior, effects
to breathing rates, interference with or alteration of vocalization,
avoidance, and flight. More severe behavioral responses are not
anticipated due to the localized, intermittent use of active acoustic
sources. However, exposure duration is likely to be short-term and
individuals will, most likely, simply be temporarily displaced by
moving away from the acoustic source. Exposures are, therefore,
unlikely to result in any significant realized decrease in fitness for
affected individuals or adverse impacts to stocks as a whole.
Arctic ringed seals are listed as threatened under the ESA. The
primary concern for Arctic ringed seals is the ongoing and anticipated
loss of sea ice and snow cover resulting from climate change, which is
expected to pose a significant threat to ringed seals in the future
(Muto et al., 2021). In addition, Arctic ringed seals have also been
experiencing a UME since 2019 although the cause of the UME is
currently undetermined. As mentioned earlier, no mortality or serious
injury to ringed seals is anticipated nor proposed to be authorized.
Due to the short-term duration of expected exposures and required
mitigation measures to reduce adverse impacts, we do not expect the
proposed ARA to affect annual rates of ringed seal survival and
recruitment that may threaten population recovery or exacerbate the
ongoing UME.
A small portion of the proposed ARA study area overlaps with ringed
seal critical habitat. Although this habitat contains features
necessary for ringed seal formation and maintenance of subnivean birth
lairs, basking and molting, and foraging, these features are also
available throughout the rest of the designated critical habitat area.
Displacement of ringed seals from the proposed ARA study area would
likely not interfere with their ability to access necessary habitat
features. Therefore, we expect minimal impacts to any displaced ringed
seals as similar necessary habitat features would still be available
nearby.
The proposed ARA study area also overlaps with a beluga whale
migratory BIA. Due to the small amount of overlap between the BIA and
the proposed ARA study area as well as the low intensity and short-term
duration of acoustic sources and required mitigation measures, we
expect minimal impacts to migrating belugas. Shutdown zones will reduce
the potential for Level A harassment of belugas and ringed seals, as
well as the severity of any Level B
[[Page 44363]]
harassment. The requirements of trained dedicated watch personnel and
speed restrictions will also reduce the likelihood of any ship strikes
to migrating belugas.
In all, the proposed ARA are expected to have minimal adverse
effects on marine mammal habitat. While the activities may cause some
fish to leave the area of disturbance, temporarily impacting marine
mammals' foraging opportunities, this would encompass a relatively
small area of habitat leaving large areas of existing fish and marine
mammal foraging habitat unaffected. As such, the impacts to marine
mammal habitat are not expected to impact the health or fitness of any
marine mammals.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect any of the species
or stocks through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> Impacts would be limited to Level B harassment only;
<bullet> Only temporary behavioral modifications are expected to
result from these proposed activities;
<bullet> Impacts to marine mammal prey or habitat will be minimal
and short term.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
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.
Subsistence hunting is important for many Alaska Native
communities. A study of the North Slope villages of Nuiqsut, Kaktovik,
and Utqia[gdot]vik (formally Barrow) identified the primary resources
used for subsistence and the locations for harvest (Stephen R. Braund &
Associates, 2010), including terrestrial mammals (caribou, moose, wolf,
and wolverine), birds (geese and eider), fish (Arctic cisco, Arctic
char/Dolly Varden trout, and broad whitefish), and marine mammals
(bowhead whale, ringed seal, bearded seal, and walrus). Ringed seals
and beluga whales are likely located within the project area during
this proposed action, yet the proposed action would not remove
individuals from the population nor behaviorally disturb them in a
manner that would affect their behavior more than 100km farther inshore
where subsistence hunting occurs.. The permitted sources would be
placed far outside of the range for subsistence hunting. The closest
active acoustic source (fixed or drifting) within the proposed project
site that is likely to cause Level B take is approximately 110 nm (204
km) from land. This ensures a significant standoff distance from any
subsistence hunting area. The closest distance to subsistence hunting
(70 nm, or 130 km) is well the largest distance from the sound sources
in use at which behavioral harassment would be expected to occur (20
km) described above. Furthermore, there is no reason to believe that
any behavioral disturbance of beluga whales or ringed seals that occurs
far offshore (we do not anticipate any Level A harassment) would affect
their subsequent behavior in a manner that would interfere with
subsistence uses should those animals later interact with hunters.
In addition, ONR has been communicating with the Native communities
about the proposed action. The ONR chief scientist for AMOS gave a
virtual briefing on ONR research planned for 2022-2023 Alaska Eskimo
Whaling Commission (AEWC) meeting in February 2022. This briefing
communicated the lack of effect on subsistence hunting due to the
distance of the sources from hunting areas. ONR scientists also attend
Arctic Waterways Safety Committee (AWSC) and AEWC meetings regularly to
discuss past, present, and future ARA. While no take is anticipated to
result during transit, points of contact for at-sea communication will
also be established between ship captains and whalers to avoid any
conflict of ship transit with hunting activity.
Based on the description of the specified activity, distance of the
study area from subsistence hunting grounds, the measures described to
minimize adverse effects on the availability of marine mammals for
subsistence purposes, and the proposed mitigation and monitoring
measures, NMFS has preliminarily determined that there will not be an
unmitigable adverse impact on subsistence uses from ONR's proposed
activities.
Peer Review of the Monitoring Plan--The MMPA requires that
monitoring plans be independently peer reviewed where the proposed
activity may affect the availability of a species or stock for taking
for subsistence uses (16 U.S.C. 1371(a)(5)(D)(ii)(III)). Given the
factors discussed above, NMFS has also determined that the activity is
not likely to affect the availability of any marine mammal species or
stock for taking for subsistence uses, and therefore, peer review of
the monitoring plan is not warranted for this project.
Endangered Species Act
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally whenever we propose to authorize take for
endangered or threatened species, in this case with Alaska Regional
Office (AKR).
NMFS is proposing to authorize take of ringed seals, which are
listed under the ESA. The Permits and Conservation Division has
requested initiation of section 7 consultation with the AKR for the
issuance of this IHA. NMFS will conclude the ESA consultation prior to
reaching a determination regarding the proposed issuance of the
authorization.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to ONR for conducting their fifth year of ARA in the
Beaufort and eastern Chukchi Seas from September 2022--September 2023,
provided the previously mentioned mitigation, monitoring, and reporting
requirements are incorporated. A draft of the proposed IHA can be found
at: <a href="http://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a>.
[[Page 44364]]
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this notice of proposed IHA for the proposed ARA.
We also request comment on the potential renewal of this proposed IHA
as described in the paragraph below. Please include with your comments
any supporting data or literature citations to help inform decisions on
the request for this IHA or a subsequent renewal IHA.
On a case-by-case basis, NMFS may issue a one-time, one-year
renewal IHA following notice to the public providing an additional 15
days for public comments when (1) up to another year of identical or
nearly identical activities as described in the Description of Proposed
Activities section of this notice is planned or (2) the activities as
described in the Description of Proposed Activities section of this
notice would not be completed by the time the IHA expires and a renewal
would allow for completion of the activities beyond that described in
the Dates and Duration section of this notice, provided all of the
following conditions are met:
<bullet> A request for renewal is received no later than 60 days
prior to the needed renewal IHA effective date (recognizing that the
renewal IHA expiration date cannot extend beyond one year from
expiration of the initial IHA).
<bullet> The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
requested renewal IHA are identical to the activities analyzed under
the initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take).
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for renewal, the status of the affected
species or stocks, and any other pertinent information, NMFS determines
that there are no more than minor changes in the activities, the
mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: July 20, 2022.
Shannon Bettridge,
Chief, Marine Mammal and Sea Turtle Conservation Division,Office of
Protected Resources, National Marine Fisheries Service.
[FR Doc. 2022-15937 Filed 7-25-22; 8:45 am]
BILLING CODE 3510-22-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.