Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Office of Naval Research Arctic Research Activities, 37240-37262 [2019-16318]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 147 (Wednesday, July 31, 2019)]
[Notices]
[Pages 37240-37262]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-16318]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XR023


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Office of Naval Research Arctic 
Research Activities

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 the U.S. Navy's Office of 
Naval Research (ONR) for authorization to take marine mammals 
incidental to Arctic Research Activities in the Beaufort and Chukchi 
Seas. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is 
requesting comments on its proposal to issue an incidental harassment 
authorization (IHA) to incidentally take marine mammals during the 
specified activities. NMFS is also requesting comments on a possible 
one-year renewal that could be issued under certain circumstances and 
if all requirements are met, as described in Request for Public 
Comments at the end of this notice. NMFS will consider public comments 
prior to making any final decision on the issuance of the requested 
MMPA authorizations and agency responses will be summarized in the 
final notice of our decision. ONR's activities are considered military 
readiness activities pursuant to the Marine Mammal Protection Act 
(MMPA), as amended by the National Defense Authorization Act for Fiscal 
Year 2004 (NDAA).

DATES: Comments and information must be received no later than August 
30, 2019.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act 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: Amy Fowler, 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: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.

[[Page 37241]]

    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of such species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth.
    The NDAA (Pub. L. 108-136) removed the ``small numbers'' and 
``specified geographical region'' limitations indicated above and 
amended the definition of ``harassment'' as it applies to a ``military 
readiness activity.'' The 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. The 
proposed action constitutes a military readiness activity because these 
proposed scientific research activities directly support the adequate 
and realistic testing of military equipment, vehicles, weapons, and 
sensors for proper operation and suitability for combat use by 
providing critical data on the changing natural and physical 
environment in which such materiel will be assessed and deployed. This 
proposed scientific research also directly supports fleet training and 
operations by providing up to date information and data on the natural 
and physical environment essential to training and operations.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    Accordingly, NMFS plans to adopt the Navy's Environmental 
Assessment/Overseas Environmental Assessment, provided our independent 
evaluation of the document finds that it includes adequate information 
analyzing the effects on the human environment of issuing the IHA. The 
Navy's OEA is available at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.
    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 April 25, 2019, NMFS received a request from ONR for an IHA to 
take marine mammals incidental to Arctic Research Activities in the 
Beaufort and Chukchi Seas. The application was deemed adequate and 
complete on July 16, 2019. ONR's request is for take of a small number 
of beluga whales (Delphinapterus leucas), bearded seals (Erignathus 
barbatus), and ringed seals (Pusa hispida hispida) by Level B 
harassment only. Neither ONR nor NMFS expects serious injury or 
mortality to result from this activity and, therefore, an IHA is 
appropriate.
    This proposed IHA would cover the second year of a larger project 
for which ONR obtained a prior IHA and intends to request take 
authorization for subsequent facets of the project. This IHA would be 
valid for a period of one year from the date of issuance. The larger 
three-year project involves several scientific objectives which support 
the Arctic and Global Prediction Program, as well as the Ocean 
Acoustics Program and the Naval Research Laboratory, for which ONR is 
the parent command. ONR complied with all the requirements (e.g., 
mitigation, monitoring, and reporting) of the previous IHA (83 FR 
48799; September 27, 2019).

Description of Proposed Activity

Overview

    ONR's Arctic Research Activities include scientific experiments to 
be conducted in support of the programs named above. Specifically, the 
project includes the Stratified Ocean Dynamics of the Arctic (SODA), 
Arctic Mobile Observing System (AMOS), Ocean Acoustics field work 
(including the Coordinated Arctic Active Tomography Experiment 
(CAATEX)), and Naval Research Laboratory experiments in the Beaufort 
and Chukchi Seas. These experiments involve deployment of moored and 
ice-tethered active acoustic sources, primarily from the U.S Coast 
Guard Cutter (CGC) HEALY. CGC HEALY may also be required to perform 
icebreaking to deploy the acoustic sources in deep water. Underwater 
sound from the acoustic sources and icebreaking may result in 
behavioral harassment of marine mammals.

Dates and Duration

    ONR's Arctic Research Activities began in August 2018 with 
deployment of autonomous gliders in the Beaufort and Chukchi Seas and 
subsequent deployment of moored acoustic sources in September 2018. The 
activities analyzed in this proposed IHA would begin in September 2019, 
with a tentative sail date of September 3, 2019. CGC HEALY would 
perform a research cruise for up to 60 days in September and October 
2019 to deploy acoustic sources. If required, a second, non-icebreaking 
ship would perform a cruise of up to 30 days to deploy any remaining 
sources in the fall of 2019. A total of eight days of icebreaking 
within the effective dates of this IHA are anticipated to be required 
to deploy and/or retrieve the northernmost acoustic sources. CGC HEALY, 
a similar icebreaking ship, or a non-icebreaking ship would be used for 
a subsequent research cruise for up to 60 days beginning in August 
2020. The initial stages of the August 2020 cruise (i.e., the spiral 
wave beacon, see Detailed Description of Specific Activity below) are 
included in the activities analyzed in this IHA. The latter stages of 
the 2020 cruise would be analyzed in a subsequent IHA

Specific Geographic Region

    The proposed actions would occur in either the U.S. Exclusive 
Economic Zone (EEZ) or the high seas north of Alaska (Figure 1). All 
activities, except for the transit of ships, would take place outside 
U.S. territorial waters. The total area of the study area is 835,860 
square kilometers (km\2\) (322,727 square miles (mi\2\)). The closest 
active acoustic source (aside from de minimis sources described below) 
within the study area is approximately 145 miles (mi; 233 kilometers 
(km)) from land.
BILLING CODE 3510-22-P

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[GRAPHIC] [TIFF OMITTED] TN31JY19.010

BILLING CODE 3510-22-C

Figure 1. Arctic Research Activities Study Area

Detailed Description of Specific Activity

    The ONR Arctic and Global Prediction Program is supporting two 
major projects (SODA and AMOS), which will both occur during time 
period covered by this IHA. The SODA project began field work in August 
2018, consisting of research cruises and the deployment of autonomous

[[Page 37243]]

measurement devices for year-round observation of water properties 
(temperature and salinity) and the associated stratification and 
circulation. These physical processes are related to the ice cover and 
as the properties of the ice cover change, the water properties will 
change as well. Warm water feeding into the Arctic Ocean also plays an 
important role changing the environment. Observations of these 
phenomena require geographical sampling of areas of varying ice cover 
and temperature profile, and year-round temporal sampling to understand 
what happens during different parts of the year. Unmanned gliders and 
autonomous platforms are needed for this type of year-round observation 
of a representative sample of arctic waters. The SODA project also 
involved the initial deployment of navigation sources for unmanned 
vehicles. Under the AMOS project, there will be new deployments of 
navigation sources in September 2019 (Figure 1). Geolocation of 
autonomous platforms requires the use of acoustic navigation signals, 
and therefore, year-long use of active acoustic signals.
    The ONR Ocean Acoustics Program also supports Arctic field work. 
The emphasis of the Ocean Acoustics Program field efforts is to 
understand how the changing environment affects acoustic propagation 
and the noise environment. The ONR Acoustic Program would be utilizing 
new technology for year-round observation of the large-scale (range and 
depth) temperature structure of the ocean at very low frequencies. The 
use of specialized waveforms and acoustic arrays allows signals to be 
received over 100 km from a source, while only requiring moderate 
source levels. The Ocean Acoustics program is planning to perform 
experiments in conjunction with the Arctic and Global Prediction 
Program by operating in the same general location and with the same 
research vessel.
    The Naval Research Laboratory would also conduct Arctic research in 
the same time frame, using drifting buoys with active acoustic sources 
that are deployed in the ice. The buoys are deployed for real-time 
environmental characterization to aid in mid-frequency sonar 
performance predictions. Real-time assimilation of acoustic data into 
an ocean model is also planned.
    Below are descriptions of the equipment and platforms that would be 
deployed at different times during the proposed action.

Research Vessels

    CGC HEALY would be the primary vessel performing the research 
cruise in September and October 2019. CGC HEALY travels at a maximum 
speed of 17 knots (kn) with a cruising speed of 12 kn (United States 
Coast Guard 2013), and a maximum speed of 3 kn when traveling through 
3.5 feet (ft; 1.07 meters (m)) of sea ice (Murphy 2010). CGC HEALY may 
be required to perform icebreaking to deploy the moored and ice 
tethered acoustic sources in deep water. Icebreaking would only occur 
during the warm season, presumably in the August through October 
timeframe. CGC HEALY has proven capable of breaking ice up to 8 ft (2.4 
m) thick while backing and ramming (Roth et al. 2013). A study in the 
western Arctic Ocean was conducted while CGC HEALY was mapping the 
seafloor north of the Chukchi Cap in August 2008. During this study, 
CGC HEALY icebreaker events generated signals with frequency bands 
centered near 10, 50, and 100 Hertz (Hz) with maximum source levels of 
190 to 200 decibel(s) (dB) referenced to 1 microPascal ([micro]Pa) at 1 
meter (dB re 1 [micro]Pa at 1 m; full octave band) (Roth et al. 2013). 
Icebreaking would likely only occur in the northernmost areas of the 
study area while deploying and/or retrieving sources.
    The CGC HEALY or other vessels may perform the following activities 
during the research cruises (some of these activities may result in 
take of marine mammals, while others may not, as described further 
below):
     Deployment of moored and/or ice-tethered passive sensors 
(e.g., oceanographic measurement devices, acoustic receivers);
     Deployment of moored and/or ice-tethered active acoustic 
sources to transmit acoustic signals for up to two years after 
deployment. Transmissions could be terminated during ice-free periods 
(August-October) each year, if needed;
     Deployment of unmanned surface, underwater, and air 
vehicles; and
     Recovery of equipment.
    Additional oceanographic measurements would be made using ship-
based systems, including the following:
     Modular Microstructure Profiler, a tethered profiler that 
would measure oceanographic parameters within the top 984 ft (300 m) of 
the water column;
     Shallow Water Integrated Mapping System, a winched towed 
body with a Conductivity Temperature Depth sensor, upward and downward 
looking Acoustic Doppler Current Profilers (ADCPs), and a temperature 
sensor within the top 328 ft (100 m) of the water column;
     Three-dimensional Sonic Anemometer, which would measure 
wind stress from the foremast of the ship;
     Surface Wave Instrument Float with Tracking (SWIFTs) buoys 
are freely drifting buoys measuring winds, waves, and other parameters 
with deployments spanning from hours to days; and
     A single mooring would be deployed to perform measurements 
of currents with an ADCP.

Moored and Drifting Acoustic Sources

    Up to 15 moored acoustic navigation sources would be deployed 
during the period September 2019 to September 2020 at the locations 
shown in Figure 1. Each navigation source transmits for 8 seconds every 
4 hours, with the sources transmitting with a five minute offset from 
each other. The purpose of the navigation sources is to allow 
autonomous vehicles and gliders to navigate by receiving acoustic 
signals from multiple locations and triangulating position. This is 
needed for vehicles that are under ice and cannot communicate with 
satellites.
    A single very low frequency (VLF) source would be deployed in the 
furthest north part of the study area, shown by the triangle symbols in 
Figure 1. The northernmost location is the preferred location, but the 
alternative location may be used. The VLF source provides capability 
for persistent (year-long) observation of Arctic oceanographic 
processes and measures oceanographic changes (e.g. regional increases 
in temperature) over long ranges.
    All 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.
    Up to six drifting sources would be deployed for the purpose of 
near-real time environmental characterization, which is accomplished by 
communicating information from the drifting buoys to a satellite. They 
would be deployed in the ice for purposes of buoy stability, but would 
eventually drift in open water. The sources would transmit signals to 
each other to measure oceanographic properties of the water between 
them. The sources would stop transmitting when this IHA expires in 
September 2020 or when they leave the Study Area, whichever comes 
first.

[[Page 37244]]

    On the fall 2020 cruise, a spiral wave beacon source would be 
tested for fine-scale navigation. The spiral wave beacon is a mid-
frequency source that transmits a 50 millisecond signal at 30 second 
intervals. The source would be deployed from a ship at a single 
location and transmit for up to 5 days. It will either be attached to 
the ship or moored near the ship. The ship will remain for the 5 days 
of the test, and the source will be recovered at the end of testing.

                                                  Table 1--Characteristics of Proposed Acoustic Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Sound pressure level
             Source name               Frequency   (dB re 1 [micro]Pa at 1   Pulse length    Duty cycle        Source type                 Usage
                                       range (Hz)             m)            (milliseconds)   (percent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Navigation Sources..................          900  185....................          8,000            <1  Moored.................  15 sources
                                                                                                                                   transmitting 8
                                                                                                                                   seconds every 4
                                                                                                                                   hours, up to 2 years.
Real-Time Sensing Sources...........  900 to 1000  184....................         60,000            <1  Drifting...............  6 sources transmitting
                                                                                                                                   1 minute every 4
                                                                                                                                   hours, up to 2 years.
Spiral Wave Beacon..................        2,500  183....................             50            <1  Moored.................  5 days.
Very Low Frequency (VLF source).....           34  185 (peak).............      1,800,000            <1  Moored.................  One source
                                                                                                                                   transmitting 30
                                                                                                                                   minutes every 6 days,
                                                                                                                                   up to 2 years.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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 their effects are not described further in this 
document.
    De minimis Sources--De minimis sources have 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). For further detail regarding the de minimis sources 
planned for use by the Navy, which are not quantitatively analyzed, 
please see the Navy's application. Descriptions of example sources are 
provided below and in Table 2.

                                                       Table 2--Parameters for De Minimis Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Sound
                                                                   pressure      Pulse
             Source name                 Frequency range (kHz)    level (dB      length     Duty cycle         Beamwidth                De minimis
                                                                 re 1 [mu]Pa    (milli-     (percent)                                 justification
                                                                   at 1 m)      seconds)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pressure Inverted Echosounders (PIES)  12......................      170-180            6        <0.01  45.....................  Extremely low duty
                                                                                                                                  cycle, low source
                                                                                                                                  level, very short
                                                                                                                                  pulse length.
ADCP.................................  >200, 150, or 75........          190           <1         <0.1  2.2....................  Very low pulse length,
                                                                                                                                  narrow beam, moderate
                                                                                                                                  source level.
Chirp sonar..........................  2-16....................          200           20           <1  narrow.................  Very short pulse
                                                                                                                                  length, low duty
                                                                                                                                  cycle, narrow beam
                                                                                                                                  width.
Expendable Mobile Anti-Submarine       700-1100 Hz and 1100-            <150          N/A       25-100  Omni...................  Very low source level.
 Warfare Training Targets (EMATTs).     4000 Hz.
Coring system........................  25-200..................      158-162           <1           16  Omni...................  Very low source
                                                                                                                                  level.\2\
CTD\1\ attached Echosounder..........  5-20....................          160            4            2  Omni...................  Very low source level.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ CTD = Conductivity Temperature Depth.
\2\ Within sediment, not within the water column.

    Drifting Oceanographic Sensors--Observations of ocean-ice 
interactions require the use of sensors which are moored and embedded 
in the 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 temperature string extending down to 656 ft 
(200 m) depth and would incorporate meteorological sensors, and a 
temperature string to estimate ice thickness. The Ice Tethered 
Profilers would collect information on ocean temperature, salinity, and 
velocity down to 820 ft (250 m) depth.
    Fifteen autonomous floats (Air-Launched Autonomous Micro Observers) 
would be deployed during the proposed action to measure seasonal 
evolution of the ocean temperature and salinity, as well as currents. 
They would be deployed on the eastern edge of the Chukchi Sea in water 
less than 3,280 ft (1,000 m) deep. Three autonomous floats would act as 
virtual moorings by originating on the seafloor, then moving up the 
water column to the surface and returning to the seafloor. The other 12 
autonomous floats would sit on the sea floor and at intervals begin to 
move toward the surface. At programmed intervals, a subset of the 
floats would release anchors and begin their profiling mission. Up to 
15 additional floats may be deployed by ships of opportunity in the 
Beaufort Gyre.
    The drifting 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.
    Moored Oceanographic Sensors--Moored sensors would capture a range 
of ice, ocean, and atmospheric conditions on a year-round basis. The 
location of the bottom-anchored sub-surface moorings are depicted by 
the purple stars in Figure 1-1 of the IHA application. 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

[[Page 37245]]

and surface waves would be measured by 500 kHz multibeam sonars.
    Additionally, Beaufort Gyre Exploration Project moorings BGOS-A and 
BGOS-B (depicted by the black plus signs in Figure 1-1 of the IHA 
application) would be augmented with McLane Moored Profilers. BGOS-A 
and BGOS-B would provide measurements near the Northwind Ridge, with 
considerable latitudinal distribution. Existing deployments of Nortek 
Acoustic Wave and Current Profilers on BGOS-A and BGOS-B would also be 
continued as part of the proposed action.
    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.
    Fixed and Towed Receiving Arrays--Horizontal and vertical arrays 
may be used to receive acoustic signals. Two receiving arrays will be 
deployed in September-October 2020 to receive signals from the CAATEX 
source. Other receiving arrays are the Single Hydrophone Recording 
Units and Autonomous Multichannel Acoustic Recorder. All these arrays 
would be moored to the seafloor and remain in place throughout the 
activity.
    These are passive acoustic sensors and therefore are not 
anticipated to have the potential for impacts on marine mammals or 
their habitat.
    Activities Involving Aircraft and Unmanned Air Vehicles--Naval 
Research Laboratory would be conducting flights to characterize the ice 
structure and character, ice edge and wave heights across the open 
water and marginal ice zone to the ice. Up to 4 flights, lasting 
approximately 3 hours in duration would be conducted over a 10 day 
period during February or March for ice structure and character 
measurements and during late summer/early fall for ice edge and wave 
height studies. Flights would be conducted with a Twin Otter aircraft 
over the seafloor mounted acoustic sources and receivers. Most flights 
would transit at 1,500 ft or 10,000 ft (457 or 3,048 m) above sea 
level. Twin Otters have a typical survey speed of 90 to 110 kn, 66 ft 
(20 m) wing span, and a total length of 26 ft (8 m) (U.S. Department of 
Commerce and NOAA 2015). At a distance of 2,152 ft (656 m) away, the 
received pressure levels of a Twin Otter range from 80 to 98.5 A-
weighted dB (expression of the relative loudness in the air as 
perceived by the human ear) and frequency levels ranging from 20 Hz to 
10 kHz, though they are more typically in the 500 Hz range (Metzger 
1995). The objective of the flights is to characterize thickness and 
physical properties of the ice mass overlying the experiment area.
    Rotary wing aircraft may also be used during the activity. 
Helicopter transit would be no longer than two hours to and from the 
ice location. A twin engine helicopter may be used to transit 
scientists from land to an offshore floating ice location. Once on the 
floating ice, the team would drill holes with up to a 10 inch (in; 25.4 
centimeter (cm)) diameter to deploy scientific equipment (e.g., source, 
hydrophone array, EMATT) into the water column. The science team would 
depart the area and return to land after three hours of data collection 
and leave the equipment and leave the equipment behind for a later 
recovery.
    The proposed action includes the use of an Unmanned Aerial System 
(UAS). The UAS would be deployed ahead of the ship to ensure a clear 
passage for the vessel and would have a maximum flight time of 20 
minutes. The UAS would not be used for marine mammal observations or 
hover close to the ice near marine mammals. The UAS that would be used 
during the proposed action is a small commercially available system 
that generates low sound levels and is smaller than military grade 
systems. The dimensions of the proposed UAS are, 11.4 in (29 cm) by 
11.4 in (29 cm) by 7.1 in (18 cm) and weighs 2.5 lb (1.13 kg). The UAS 
can operate up to 984 ft (300 m) away, which would keep the device in 
close proximity to the ship. The planned operation of the UAS is to fly 
it vertically above the ship to examine the ice conditions in the path 
of the ship and around the area (i.e., not flown at low altitudes 
around the vessel). Currently acoustic parameters are not available for 
the proposed models of UASs to be used. As stated previously, these 
systems are small and are similar to a remote control helicopter. It is 
likely marine mammals would not hear the device since the noise 
generated would likely not be audible from greater than 5 ft (1.5 m) 
away (Christiansen et al., 2016).
    All aircraft (manned and unmanned) would be required to maintain a 
minimum separation distance of 1,000 ft (305 m) from any pinnipeds 
hauled out on the ice. Therefore, no take of marine mammals is 
anticipated from these activities.
    On-Ice Measurement Systems--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 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 in (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, and will drift with the 
ice, making measurements, until their host ice floes melt, thus 
destroying the instruments (likely in summer, roughly one year after 
deployment). After the on-ice instruments are destroyed they cannot be 
recovered, and would sink to the seafloor as their host ice floes 
melted.
    All personnel conducting experiments on the ice would be required 
to maintain a minimum separation distance of 1,000 ft (305 m) from any 
pinnipeds hauled out on the ice. Therefore, no take of marine mammals 
is anticipated from these activities.
    Bottom Interaction Systems--Coring of bottom sediment could occur 
anywhere within the study area to obtain a more complete understanding 
of the Arctic environment. Coring equipment would take up to 50 samples 
of the ocean bottom in the study area annually. The samples would be 
roughly cylindrical, with a 3.1 in (8 cm) diameter cross-sectional 
area; the corings would be between 10 and 20 ft (3 and 6 m) long. 
Coring would only occur during research cruises, during the summer or 
early fall. The coring equipment moves slowly through the muddy bottom, 
at a speed of approximately 1 m per hour, and would not create any 
detectable acoustic signal within the water column, though very low 
levels of acoustic transmissions may be created in the mud (see 
parameters listed in Table 2).
    Weather Balloons--To support weather observations, up to 40 Kevlar 
or latex balloons would be launched per year for the duration of the 
proposed action. These balloons and associated radiosondes (a sensor 
package that is suspended below the balloon) are similar to those that 
have been deployed by the National Weather Service since the late 
1930s. When released, the balloon is approximately 5 to 6 ft (1.5-1.8 
m) in diameter and gradually expands as it rises due to the decrease in 
air pressure. When the balloon

[[Page 37246]]

reaches a diameter of 13-22 ft (4-7 m), it bursts and a parachute is 
deployed to slow the descent of the associated radiosonde. Weather 
balloons would not be recovered.
    The deployment of weather balloons does not include the use of 
active acoustics and is therefore not anticipated to have the potential 
for impacts on marine mammals or their habitat.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 3 lists all species with expected potential for occurrence in 
the study area and summarizes information related to the population or 
stock, including regulatory status under the MMPA and ESA and potential 
biological removal (PBR), where known. For taxonomy, we follow 
Committee on Taxonomy (2018). PBR is defined by the MMPA as the maximum 
number of animals, not including natural mortalities, that may be 
removed from a marine mammal stock while allowing that stock to reach 
or maintain its optimum sustainable population (as described in NMFS's 
SARs). While no mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species and 
other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's 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's U.S. 2018 SARs (e.g., Muto et al., 2019, Carretta et al., 2019). 
All values presented in Table 3 are the most recent available at the 
time of publication and are available in the 2018 SARs (Muto et al., 
2019; Carretta et al., 2019).

                                         Table 3--Marine Mammal Species Potentially Present in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         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 Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
    Gray whale......................  Eschrichtius robustus..  Eastern North Pacific..  -/- ; N             26960 (0.05, 25,849,          801        135
                                                                                                             2016).
Family Balaenidae:
    Bowhead whale...................  Balaena mysticetus.....  Western Arctic.........  E/D ; Y             16,820 (0.052, 16,100,        161         46
                                                                                                             2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Beluga whale....................  Delphinapterus leucas..  Beaufort Sea...........  -/- ; N             39,258 (0.229, N/A,     \4\ Undet        139
                                                                                                             1992).
    Beluga whale....................  Delphinapterus leucas..  Eastern Chukchi Sea....  -/- ; N             20,752 (0.70, 12.194,         244         67
                                                                                                             2012).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Phocidae (earless seals):
    Bearded seal \5\................  Erignathus barbatus....  Alaska.................  T/D ; Y             299,174...............      8,210        557
                                                                                                            (-, 273,676, 2013)....
    Ribbon seal.....................  Histriophoca fasciata..  Alaska.................  -/- ; N             184,697...............      9,785        3.9
                                                                                                            (-, 163,086, 2013)....
    Ringed seal \5\.................  Pusa hispida hispida...  Alaska.................  T/D ; Y             170,000...............      5,100      1,054
                                                                                                            (-, 170,000, 2013)....
    Spotted seal....................  Phoca largha...........  Alaska.................  -/- ; N             461,625...............     12,697        329
                                                                                                            (-, 423,237, 2013)....
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region/. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\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\ Abundances and associated values for bearded and ringed seals are for the U.S. population in the Bering Sea only.
Note: Italicized species are not expected to be taken or proposed for authorization.

    All species that could potentially occur in the proposed survey 
areas are included in Table 3. Activities conducted during the proposed 
action are expected to cause harassment, as defined by the MMPA as it 
applies to military readiness, to the beluga whale (of the Beaufort and 
Eastern Chukchi Sea stocks), bearded seal, and ringed seal. Due to the 
location of the study area (i.e., northern offshore, deep water), there 
were no calculated exposures for

[[Page 37247]]

the bowhead whale, gray whale, spotted seal, and ribbon seal from 
quantitative modeling of non-impulsive acoustic and icebreaking 
sources. Bowhead and gray whales remain closely associated with the 
shallow waters of the continental shelf in the Beaufort Sea and are 
unlikely to be exposed to acoustic harassment (Carretta et al., 2017; 
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 as 69-
72[deg] N (Muto et al., 2018). Although the study area includes 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 are considered 
extralimital in the project area and are not expected to be encountered 
or taken. As no harassment is expected of bowhead whales, gray whales, 
spotted seals, and ribbon seals, these species will not be discussed 
further in this IHA.

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).
    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 Study Area.
    There are two migration areas used by Beaufort Sea belugas that 
overlap the Study Area. One, located in the Eastern Chukchi and Alaskan 
Beaufort Sea, is a migration area in use from April to May. The second, 
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) 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) and 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 Study Area), 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 Kaseguluk 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. A whale tagged in the eastern Chukchi Sea in 2007 
overwintered in the waters north of Saint Lawrence Island during 2007/
2008 and moved to near King Island in April and May before moving north 
through the Bering Strait in late May and early June (Suydam 2009).

Bearded Seal

    Bearded seals are a boreoarctic species with circumpolar 
distribution (Burns 1967; Burns 1981; Burns and Frost 1979; Fedoseev 
1965; Johnson et al., 1966; Kelly 1988a; Smith 1981). Their normal 
range extends from the Arctic Ocean (85[deg] N) south to Sakhalin 
Island (45[deg] N) in the Pacific and south to Hudson Bay (55[deg] N) 
in the Atlantic (Allen 1880; King 1983; Ognev 1935). Bearded seals are 
widely distributed throughout the northern Bering, Chukchi, and 
Beaufort Seas and are most abundant north of the ice edge zone 
(MacIntyre et al., 2013). Bearded seals inhabit the seasonally ice-
covered seas of the Northern Hemisphere, where they whelp and rear 
their pups and molt their coats on the ice in the spring and early 
summer. The overall summer distribution is quite broad, with seals 
rarely hauled out on land, and some seals, mostly juveniles, may not 
follow the ice northward but remain near the coasts of Bering and 
Chukchi seas (Burns 1967; Burns 1981; Heptner et al., Nelson 1981). As 
the ice forms again in the fall and winter, most seals move south with 
the advancing ice edge through the Bering Strait into the Bering Sea 
where they spend the winter (Boveng and Cameron 2013; Burns and Frost 
1979; Cameron and Boveng 2007; Cameron and Boveng 2009; Frost et al., 
2005; Frost et al., 2008). This southward migration is less noticeable 
and predictable than the northward movements in late spring and early 
summer (Burns 1981; Burns and Frost 1979; Kelly 1988a). During winter, 
the central and northern parts of the Bering Sea shelf have the highest 
densities of bearded seals (Braham et al., 1981; Burns 1981; Burns and 
Frost 1979; Fay 1974; Heptner et al., 1976; Nelson et al., 1984). In 
late winter and early spring, bearded seals are widely but not 
uniformly distributed in the broken, drifting pack ice ranging from the 
Chukchi Sea south to the ice front in the Bering Sea. In these areas, 
they tend to avoid the coasts and areas of fast ice (Burns 1967; Burns 
and Frost 1979).
    Bearded seals along the Alaskan coast tend to prefer areas where 
sea ice covers 70 to 90 percent of the surface, and are most abundant 
20 to 100 nautical miles (nmi) (37 to 185 (km) offshore during the 
spring season (Bengston et al., 2000; Bengston et al., 2005; Simpkins 
et al., 2003). In spring, bearded seals may also concentrate in 
nearshore pack ice habitats, where females give birth on the most 
stable areas of ice (Reeves et al., 2003) and generally prefer to be 
near polynyas (areas of open water surrounded by sea ice) and other 
natural openings in the sea ice for breathing, hauling out, and prey 
access (Nelson et al., 1984; Stirling 1997). While molting between 
April and August, bearded seals spend substantially more time hauled 
out than at other times of the year (Reeves et al., 2002).
    In their explorations of the Canada Basin, Harwood et al. (2005) 
observed bearded seals in waters of less than 656 ft (200 m) during the 
months from August to September. These sightings were east of 140[deg] 
W. The Bureau of

[[Page 37248]]

Ocean Energy Management conducted an aerial survey from June through 
October that covered the shallow Beaufort and Chukchi Sea shelf waters, 
and observed bearded seals from Point Barrow to the border of Canada 
(Clarke et al., 2014). The farthest from shore that bearded seals were 
observed was the waters of the continental slope.
    On December 28, 2012, NMFS listed both the Okhotsk and the Beringia 
distinct population segments (DPSs) of bearded seals as threatened 
under the ESA (77 FR 76740). The Alaska stock of bearded seals consists 
of only Beringia DPS seals.

Ringed Seal

    Ringed seals are the most common pinniped in the Study Area 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). 
Breathing holes are maintained by ringed seals' sharp teeth and claws 
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., 2017).
    Ringed seals have at least two distinct types of subnivean lairs: 
Haulout lairs and birthing lairs (Smith and Stirling 1975). Haulout 
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 Barrow, 
Alaska build their subnivean lairs on the pack ice near pressure 
ridges. Since subnivean lairs were found north of Barrow, Alaska, in 
pack ice, they are also assumed to be found within the sea ice in the 
Study Area. 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). Snow depths of at least 20-26 
in (50-65 cm) are required for functional birth lairs (Kelly 1988b; 
Lydersen 1998; Lydersen and Gjertz 1986; Smith and Stirling 1975), and 
such depths typically are found only where 8-12 in (20-30 cm) or more 
of snow has accumulated on flat ice and then drifted along pressure 
ridges or ice hummocks (Hammill 2008; Lydersen et al., 1990; Lydersen 
and Ryg 1991; Smith and Lydersen 1991). 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 Alaska 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 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 nmi (120 km) north-
northwest of Barrow, Alaska detected ringed seals in the area between 
mid-December and late May over the 4 year study (Jones et al., 2014). 
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. 
(2010a) 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., 2010a). 
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., 2010a). The size of winter 
home ranges can, however, 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).
    Most taxonomists recognize five subspecies of ringed seals. The 
Arctic ringed seal subspecies occurs in the Arctic Ocean and Bering Sea 
and is the only stock that occurs in U.S. waters (referred to as the 
Alaska stock). 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.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 dB 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. 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 whales).........  7 Hz to 35 kHz.

[[Page 37249]]

 
Mid-frequency (MF) cetaceans (dolphins, toothed        150 Hz to 160 kHz.
 whales, beaked whales, bottlenose whales).
High-frequency (HF) cetaceans (true porpoises, Kogia,  275 Hz to 160 kHz.
 river dolphins, cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true seals)......  50 Hz to 86 kHz.
Otariid pinnipeds (OW) (underwater) (sea lions and     60 Hz to 39 kHz.
 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. 
Three marine mammal species (one cetacean and two pinniped (both 
phocid) species) have the reasonable potential to co-occur with the 
proposed survey activities. Please refer to Table 3. Beluga whales are 
classified as mid-frequency cetaceans.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

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

Description of Sound Sources

    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 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 [micro]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 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.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and the sound level 
of a region is defined by the total acoustical energy being generated 
by known and unknown sources. These sources may include physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). A number of 
sources contribute to ambient sound, including the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson, 1995). Under sea ice, noise generated by ice deformation 
and ice fracturing may be caused by thermal, wind, drift and current 
stresses (Roth et al., 2012);
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times. In the ice-covered study area, precipitation is unlikely to 
impact ambient sound;

[[Page 37250]]

     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz; and
     Anthropogenic: Sources of ambient noise related to human 
activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise 
typically dominates the total ambient noise for frequencies between 20 
and 300 Hz. In general, the frequencies of anthropogenic sounds are 
below 1 kHz and, if higher frequency sound levels are created, they 
attenuate rapidly (Richardson et al., 1995). Sound from identifiable 
anthropogenic sources other than the activity of interest (e.g., a 
passing vessel) is sometimes termed background sound, as opposed to 
ambient sound. Anthropogenic sources are unlikely to significantly 
contribute to ambient underwater noise during the late winter and early 
spring in the study area as most anthropogenic activities will not be 
active due to ice cover (e.g. seismic surveys, shipping) (Roth et al., 
2012).
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    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.
    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. Icebreaking is also considered a 
non-impulsive sound. 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., 2004; 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).
    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 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

[[Page 37251]]

to 20 dB higher than TTS cumulative SEL thresholds (Southall et al., 
2007).
    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.
    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.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale, harbor 
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis)) 
and three species of pinnipeds (northern elephant seal (Mirounga 
angustirostris), harbor seal, and California sea lion (Zalophus 
californianus)) exposed to a limited number of sound sources (i.e., 
mostly tones and octave-band noise) in laboratory settings (Finneran 
2015). TTS was not observed in trained spotted and ringed seals exposed 
to impulsive noise at levels matching previous predictions of TTS onset 
(Reichmuth et al., 2016). In general, harbor seals and harbor porpoises 
have a lower TTS onset than other measured pinniped or cetacean 
species. Additionally, the existing marine mammal TTS data come from a 
limited number of individuals within these species. There are no data 
available on noise-induced hearing loss for mysticetes. For summaries 
of data on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007), Finneran and Jenkins 
(2012), and Finneran (2015).
    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). 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). 
Please see Appendices B-C of Southall et al. (2007) for a review of 
studies involving marine mammal behavioral responses to sound.
    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).
    Available studies show wide variation in response to underwater 
sound; therefore, it is difficult to predict specifically how any given 
sound in a particular instance might affect marine mammals perceiving 
the signal. If a marine mammal does react briefly to an underwater 
sound by changing its behavior or moving a small distance, the impacts 
of the change are unlikely to be significant to the individual, let 
alone the stock or population. However, if a sound source displaces 
marine mammals from an important feeding or breeding area for a 
prolonged period, impacts on individuals and populations could be 
significant (e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 2003). 
However, 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). 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). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected

[[Page 37252]]

individuals and the relationship between prey availability, foraging 
effort and success, and the life history stage of the animal.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing 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. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, 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., 2001, 2005b, 2006; Gailey et 
al., 2007).
    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., 2007b). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    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). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from seismic surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
Morton and Symonds, 2002; 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).
    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). 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.
    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 demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (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). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    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.
    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). 
Additional 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 aimed 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

[[Page 37253]]

unaffected by the acoustic transmissions, as they were able to maintain 
normal behaviors (e.g., finding breathing holes).
    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). Although a minor change to a behavior may 
occur as a result of exposure to the sources in the proposed action, 
these changes would be within the normal range of behaviors for the 
animal (e.g., the use of a breathing hole further from the source, 
rather than one closer to the source, would be within the normal range 
of behavior) (Kelly et al. 1988).
    Some behavioral response studies have been conducted on odontocete 
responses to sonar. In studies that examined sperm whales (Physeter 
macrocephalus) and false killer whales (Pseudorca crassidens) (both in 
the mid-frequency cetacean hearing group), the marine mammals showed 
temporary cessation of calling and avoidance of sonar sources (Akamatsu 
et al., 1993; Watkins and Schevill 1975). Sperm whales resumed calling 
and communication approximately two minutes after the pings stopped 
(Watkins and Schevill 1975). False killer whales moved away from the 
sound source but returned to the area between 0 and 10 minutes after 
the end of transmissions (Akamatsu et al., 1993). 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, if significant behavioral responses occur they would likely be 
short term. In fact, no significant behavioral responses such as panic, 
stranding, or other severe reactions have been observed during 
monitoring of actual training exercises (Department of the Navy 2011, 
2014; Smultea and Mobley 2009; Watwood et al., 2012).
    Icebreaking noise has the potential to disturb marine mammals and 
elicit an alerting, avoidance, or other behavioral reaction (Huntington 
et al., 2015; Pirotta et al., 2015; Williams et al., 2014). Icebreaking 
in fast ice during the spring can cause behavioral reactions in beluga 
whales. However, icebreaking associated with the proposed action would 
only occur from August through October, which lessens the probability 
of a whale encountering the vessel (in comparison to other sources in 
the proposed action that would be active year-round).
    Ringed seals and bearded 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 nautical miles (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. Due to the time of year of the activity (August 
through October), ringed seals are not expected to be within the 
subnivean lairs nor pupping (Chapskii 1940; McLaren 1958; Smith and 
Stirling 1975).
    Adult ringed seals spend up to 20 percent of the time in subnivean 
lairs during the winter season (Kelly et al., 2010a). 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 both bearded 
seals and ringed seals haul out on the ice. In a study of ringed seal 
haulout 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. Bearded seals also spend a large amount of time hauled out 
during the molting season between April and August (Reeves et al., 
2002). 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., 1988).
    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 and icebreaking noise 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). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly

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replenished once the stress is alleviated. In such circumstances, the 
cost of the stress response would not pose serious fitness 
consequences. However, when an animal does not have sufficient energy 
reserves to satisfy the energetic costs of a stress response, energy 
resources must be diverted from other functions. This state of distress 
will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
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 altering critical behaviors. 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., 2007b; 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.
    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. Impacts to invertebrates 
from icebreaking noise is unknown, but it is likely that some species 
including crustaceans and cephalopods would be able to perceive the low 
frequency sounds generated from icebreaking. Icebreaking associated 
with the proposed action would be short-term and temporary as the 
vessel moves through an area, and it is not anticipated that this 
short-term noise would result in significant harm, nor is it expected 
to result in more than a temporary behavioral reaction of marine 
invertebrates in the vicinity of the icebreaking event.
    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).

[[Page 37255]]

Icebreaking noise has the potential to expose fish to both sound and 
general disturbance, which could result in short-term behavioral or 
physiological responses (e.g., avoidance, stress, increased heart 
rate). 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 and icebreaking 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 
action would be localized, temporary, and infrequent.
    Effects to Physical and Foraging Habitat--Icebreaking activities 
include the physical pushing or moving of ice to allow vessels to 
proceed through ice-covered waters. Breaking of pack ice that contains 
hauled out seals may result in the animals becoming startled and 
entering the water, but such effects would be brief. Bearded and ringed 
seals haul out on pack ice during the spring and summer to molt (Reeves 
et al. 2002; Born et al., 2002). Due to the time of year of the 
icebreaking activity (August through October), ringed seals are not 
expected to be within the subnivean lairs nor pupping (Chapskii 1940; 
McLaren 1958; Smith and Stirling 1975). Additionally, studies by 
Alliston (Alliston 1980; Alliston 1981) suggested that ringed seals may 
preferentially establish breathing holes in ship tracks after 
icebreakers move through the area. The amount of ice habitat disturbed 
by icebreaking activities is small relative to the amount of overall 
habitat available. There will be no permanent loss or modification of 
physical ice habitat used by bearded or ringed seals. Icebreaking would 
have no effect on physical beluga habitat as beluga habitat is solely 
within the water column.
    Testing of towed sources and icebreaking noise would be limited in 
duration and the deployed sources that would remain in use after the 
vessels have left the survey area have low duty cycles and lower source 
levels. There would not be any expected habitat-related effects from 
non-impulsive acoustic sources or icebreaking noise that could impact 
the in-water habitat of ringed seal, bearded seal, or beluga whale 
foraging habitat.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. 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 such 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 TTS for individual marine 
mammals resulting from exposure to acoustic transmissions and 
icebreaking noise. Based on the nature of the activity, Level A 
harassment is neither anticipated nor proposed to be authorized.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). For the proposed IHA, ONR 
employed a sophisticated 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 estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--In coordination with 
NMFS, the Navy developed behavioral thresholds to support environmental 
analyses for the Navy's testing and training military readiness 
activities utilizing active sonar sources; these behavioral harassment 
thresholds are used here to evaluate the potential effects of the 
active sonar components of the proposed action. The response of a 
marine mammal to an anthropogenic sound will depend on the frequency, 
duration, temporal pattern and amplitude of the sound as well as the 
animal's prior experience with the sound and the context in which the 
sound is encountered (i.e., what the animal is doing at the time of the 
exposure). The distance from the sound source and whether it is 
perceived as approaching or moving away can also affect the way an 
animal responds to a sound (Wartzok et al. 2003). For marine mammals, a 
review of responses to anthropogenic sound was first conducted by 
Richardson et al. (1995). Reviews by Nowacek et al. (2007) and Southall 
et al. (2007) address studies conducted since 1995 and focus on 
observations where the received sound level of the exposed marine 
mammal(s) was known or could be estimated.
    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 new 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

[[Page 37256]]

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 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 [micro]Pa to a maximum of 198-214 re 1 [micro]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 [micro]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 [micro]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, 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 to be unlikely.
    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 these dose response functions. 
The Navy's dose response functions were developed to estimate take from 
sonar and similar transducers and are not applicable to icebreaking. 
NMFS predicts that marine mammals are likely to be behaviorally 
harassed in a manner we consider Level B harassment when exposed to 
underwater anthropogenic noise above received levels of 120 dB re 1 
[mu]Pa (rms) for continuous (e.g., vibratory pile-driving, drilling, 
icebreaking) and above 160 dB re 1 [mu]Pa (rms) for non-explosive 
impulsive (e.g., seismic airguns) or intermittent (e.g., scientific 
sonar) sources. Thus, take of marine mammals by Level B harassment due 
to icebreaking has been calculated using the Navy's NAEMO model with a 
step-function at 120 dB re 1 [micro]Pa (rms) received level for 
behavioral response.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual 
criteria to assess auditory injury (Level A harassment) to five 
different marine mammal groups (based on hearing sensitivity) as a 
result of exposure to noise from two different types of sources 
(impulsive or non-impulsive). ONR's proposed activities involve only 
non-impulsive sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018 Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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


[[Page 37257]]

Quantitative Modeling

    The Navy performed a quantitative analysis to estimate the number 
of mammals that could be harassed by the underwater acoustic 
transmissions during the proposed action. Inputs to the quantitative 
analysis included marine mammal density estimates, marine mammal depth 
occurrence distributions (Navy 2017a), oceanographic and environmental 
data, marine 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 and 
icebreaking, 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 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 (which NMFS recommends in order to ensure more consistent 
quantification of take across actions), is independent of all others, 
and therefore, the same individual marine animal (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 study area, 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):
     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);
     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;
     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;
     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
     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.
    Because of 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.
    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 ice cover was used. Each modeled day of icebreaking consisted 
of 6 hours of 8/10 ice cover. Icebreaking was modeled for eight days 
for each of the 2019 and 2020 cruises. For each cruise, this includes 
four days of icebreaking for the deployment (or recovery) of the VLF 
source and four days of icebreaking for the deployment (or recovery) of 
the northernmost navigation sources. 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, icebreaking was conservatively analyzed within 
this IHA. Figure 5a and 5b in Roth et al. (2013) depicts the source 
spectrum level versus frequency for 8/10 ice cover. The sound signature 
of the ice coverage level was broken into 1-octave bins (Table 6). 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 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 (SPLRMS)). For PTS and TTS 
determinations, sound exposure levels were summed over the duration of 
the test and the transit to the 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 over-estimate and would not be expected.

 Table 6--Modeled Bins for Icebreaking in 8/10 Ice Coverage on CGC HEALY
------------------------------------------------------------------------
                                                                Source
                      Frequency  (Hz)                        level  (dB)
------------------------------------------------------------------------
25.........................................................          189

[[Page 37258]]

 
50.........................................................          188
100........................................................          189
200........................................................          190
400........................................................          188
800........................................................          183
1600.......................................................          177
3200.......................................................          176
6400.......................................................          172
12800......................................................          167
------------------------------------------------------------------------

    For the other 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. Table 7 provides range to effects for non-impulsive 
sources and icebreaking noise proposed for the Arctic research 
activities to mid-frequency cetacean and pinniped specific criteria. 
Marine mammals within these ranges would be predicted to receive the 
associated effect. Range to effects is important information in not 
only predicting non-impulsive acoustic impacts, but also in verifying 
the accuracy of model results against real-world situations and 
determining adequate mitigation ranges to avoid higher level effects, 
especially physiological effects in marine mammals. Therefore, the 
ranges in Table 7 provide realistic maximum distances over which the 
specific effects from the use of non-impulsive sources during the 
proposed action would be possible.

                                          Table 7--Range to PTS, TTS, and Behavioral Effects in the Study Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Range to behavioral effects      Range to TTS effects  (m)       Range to PTS effects  (m)
                                                                        (m)              ---------------------------------------------------------------
                         Source                          --------------------------------
                                                                              Piniped           MF            Piniped           MF            Piniped
                                                                MF           cetacean                        cetacean                        cetacean
--------------------------------------------------------------------------------------------------------------------------------------------------------
Navigation and real-time sensing sources................      20,000 \a\      10,000 \a\               0               6               0               0
Spiral Wave Beacon source...............................      20,000 \a\      10,000 \a\               0               0               0               0
Icebreaking noise.......................................           4,275           4,525               3              12               0               0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Cutoff distances applied.

    A behavioral response study conducted on and around the Navy range 
in Southern California (SOCAL BRS) observed reactions to sonar and 
similar sound sources by several marine mammal species, including 
Risso's dolphins (Grampus griseus), a mid-frequency cetacean (DeRuiter 
et al., 2013; Goldbogen et al., 2013; Southall et al., 2011; Southall 
et al., 2012; Southall et al., 2013; Southall et al., 2014). In 
preliminary analysis, none of the Risso's dolphins exposed to simulated 
or real mid-frequency sonar demonstrated any overt or obvious responses 
(Southall et al., 2012, Southall et al., 2013). In general, although 
the responses to the simulated sonar were varied across individuals and 
species, none of the animals exposed to real Navy sonar responded; 
these exposures occurred at distances beyond 10 km, and were up to 100 
km away (DeRuiter et al., 2013; B. Southall pers. comm.). These data 
suggest that most odontocetes (not including beaked whales and harbor 
porpoises) likely do not exhibit significant behavioral reactions to 
sonar and other transducers beyond approximately 10 km. Therefore, the 
Navy uses a cutoff distance for odontocetes of 10 km for moderate 
source level, single platform training and testing events, and 20 km 
for all other events, including the proposed Arctic Research Activities 
(Navy 2017a).
    Southall et al., (2007) report that pinnipeds do not exhibit strong 
reactions to SPLs up to 140 dB re 1 [micro]Pa from non-impulsive 
sources. While there are limited data on pinniped behavioral responses 
beyond about 3 km in the water, the Navy uses a distance cutoff of 5 km 
for moderate source level, single platform training and testing events, 
and 10 km for all other events, including the proposed Arctic Research 
Activities (Navy 2017a).
    NMFS and the Navy conservatively propose a distance cutoff of 10 km 
for pinnipeds, and 20 km for mid-frequency cetaceans (Navy 2017a). 
Regardless of the received level at that distance, take is not 
estimated to occur beyond 10 and 20 km from the source for pinnipeds 
and cetaceans, respectively. Sources that show a range of zero do not 
rise to the specified level of effects (i.e., there is no chance of PTS 
for either MF cetaceans or pinnipeds from any of the sources). No 
instances of PTS were modeled for any species or stock; as such, no 
take by Level A harassment is anticipated or proposed to be authorized.
    As discussed above, within NAEMO animats do not move horizontally 
or react in any way to avoid sound. Furthermore, mitigation measures 
that reduce the likelihood of physiological impacts are not considered 
in quantitative analysis. Therefore, the model may overestimate 
acoustic impacts, especially physiological impacts near the sound 
source. The behavioral criteria used as a part of this analysis 
acknowledges that a behavioral reaction is likely to occur at levels 
below those required to cause hearing loss. At close ranges and high 
sound levels approaching those that could cause PTS, avoidance of the 
area immediately around the sound source is the assumed behavioral 
response for most cases.
    In previous environmental analyses, the Navy has implemented 
analytical factors to account for avoidance behavior and the 
implementation of mitigation measures. The application of avoidance and 
mitigation factors has only been applied to model-estimated PTS 
exposures given the short distance over which PTS is estimated. Given 
that no PTS exposures were estimated during the modeling process for 
this proposed action, the quantitative consideration of avoidance and 
mitigation factors were not included in this analysis.
    The marine mammal density numbers utilized for quantitative 
modeling are from the Navy Marine Species Density Database (Navy 2014). 
Density estimates are based on habitat-based modeling by Kaschner et 
al., (2006) and Kaschner (2004). While density estimates for the two 
stocks of beluga whales are equal (Kaschner et al., 2006; Kaschner 
2004), take has been apportioned to each stock

[[Page 37259]]

proportional to the abundance of each stock. Table 8 shows the 
exposures expected for the beluga whale, bearded seal, and ringed seal 
based on NAEMO modeled results.

                                              Table 8--Quantitative Modeling Results of Potential Exposures
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Density
                                                             estimate         Level B         Level B
                                                           within study     harassment      harassment        Level A     Total proposed   Percentage of
                         Species                           area (animals   from deployed       from         harassment         take         stock taken
                                                          per square km)      sources       icebreaking
                                                                \a\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga Whale (Beaufort Sea Stock).......................          0.0087             331              32               0             363            0.92
Beluga Whale (Eastern Chukchi Sea stock)................          0.0087             178              18               0             196            0.94
Bearded Seal............................................          0.0332               0               0               0           \b\ 5           <0.01
Ringed Seal.............................................          0.3760           6,773           1,072               0           7,845            2.17
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Kaschner et al. (2006); Kaschner (2004)
\b\ Quantitative modeling yielded zero takes of bearded seals. However, in an abundance of caution, we are proposing to authorize five takes of bearded
  seals by Level B harassment.

Effects of Specified Activities on Subsistence Uses of Marine Mammals

    Subsistence hunting is important for many Alaska Native 
communities. A study of the North Slope villages of Nuiqsut, Kaktovik, 
and 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). Bearded seals, ringed seals, and 
beluga whales are located within the study area during the proposed 
action. The permitted sources would be placed outside of the range for 
subsistence hunting and the study plans have been communicated to the 
Native communities. The closest active acoustic source within the study 
area (aside from the de minimis sources), is approximately 145 mi (233 
km) from land. As stated above, the range to effects for non-impulsive 
acoustic sources in this experiment is much smaller than the distance 
from shore. In addition, the proposed action would not remove 
individuals from the population. Therefore, there would be no impacts 
caused by this action to the availability of bearded seal, ringed seal, 
or beluga whale for subsistence hunting. Therefore, subsistence uses of 
marine mammals are not expected to be impacted by the proposed action.

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses. NMFS regulations require applicants for incidental 
take authorizations to include information about the availability and 
feasibility (economic and technological) of equipment, methods, and 
manner of conducting such activity or other means of effecting the 
least practicable adverse impact upon the affected species or stocks 
and their habitat (50 CFR 216.104(a)(11)). 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, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat, 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

    Ships operated by or for the Navy have personnel assigned to stand 
watch at all times, day and night, when moving through the water. While 
in transit, ships must 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 mammal and can be stopped within a distance 
appropriate to the prevailing circumstances and conditions.
    During navigational source deployments, visual observation would 
start 30 minutes prior to and continue throughout the deployment within 
an exclusion zone of 55 m (180 ft, 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. Visual monitoring 
will continue through 30 minutes following the deployment of sources.

[[Page 37260]]

    Once deployed, the spiral wave beacon would transmit for five days. 
The ship will maintain position near the moored source and will monitor 
the surrounding area for marine mammals. Transmission will cease if a 
marine mammal enters a 55-m (180 ft) exclusion zone. Transmission 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 
and relative motion between the animal and the source, 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. The 
spiral wave beacon source will only transmit during daylight hours.
    Ships would avoid approaching marine mammals head on and would 
maneuver to maintain an exclusion zone of 1,500 ft (457 m) around 
observed mysticete whales, and 600 ft (183 m) around all other marine 
mammals, provided it is safe to do so in ice free waters.
    With the exception of the spiral wave beacon, moored/drifting 
sources are left in place and cannot be turned off until the following 
year during ice free months. Once they are programmed they will operate 
at the specified pulse lengths and duty cycles until they are either 
turned off the following year or there is failure of the battery and 
are not able to operate. Due to the ice covered nature of the Arctic is 
in not possible to recover the sources or interfere with their transmit 
operations in the middle of the deployment.
    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, vessel, or aircraft, and to the extent 
vessels are restricted in their ability to maneuver. No further action 
is necessary if a marine mammal other than a whale 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 whale in order to maintain an exclusion zone of 1,500 
ft (457 m).
    All personnel conducting on-ice experiments, as well as all 
aircraft operating in the study area, are required to maintain a 
separation distance of 1,000 ft (305 m) from any sighted marine mammal.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, 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 in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.
    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 undertake extensive 
training in accordance with the U.S. Navy Lookout Training Handbook or 
civilian equivalent, including on the job instruction and a formal 
Personal Qualification Standard program (or equivalent program for 
supporting contractors or civilians), to certify that they have 
demonstrated all necessary skills (such as detection and reporting of 
floating or partially submerged objects). Additionally, watch personnel 
have taken 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 
Lookout Training Handbook 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.
    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) (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 being impacted. ONR's Arctic Research Activities 
in comparison is a less intensive test with little human activity 
present in the Arctic. Human presence is limited to a minimal amount of 
days for source operations and source deployments, in contrast to the 
large majority (>95%) of time that the sources

[[Page 37261]]

will be left behind and operate autonomously. Therefore, a dedicated 
monitoring project is not warranted. However, ONR will record all 
observations of marine mammals, including the marine mammal's location 
(latitude and longitude), behavior, and distance from project 
activities, including icebreaking.
    The Navy is committed to documenting and reporting relevant aspects 
of research and testing activities to verify implementation of 
mitigation, comply with permits, and improve future environmental 
assessments. If any injury or death of a marine mammal is observed 
during the 2019-20 Arctic Research Activities, 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:
     Time, date, and location of the discovery;
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal(s) was 
discovered (e.g., during use of towed acoustic sources, deployment of 
moored or drifting sources, during on-ice experiments, or by transiting 
vessel).
    ONR will provide NMFS with a draft exercise monitoring report 
within 90 days of the conclusion of the proposed activity. The draft 
exercise monitoring report will include data regarding acoustic source 
use and any mammal sightings or detection will be 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 responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Underwater acoustic transmissions associated with the Arctic 
Research Activities, as outlined previously, have the potential to 
result in Level B harassment of beluga whales, ringed seals, and 
bearded seals in the form of TTS and behavioral disturbance. No serious 
injury, mortality, or Level A harassment are anticipated to result from 
this activity.
    Minimal takes of marine mammals by Level B harassment would be due 
to TTS since the range to TTS effects is small at only 12 m or less 
while the behavioral effects range is significantly larger extending up 
to 20 km (Table 7). TTS is a temporary impairment of hearing and can 
last from minutes or hours to days (in cases of strong TTS). In many 
cases, however, hearing sensitivity recovers rapidly after exposure to 
the sound ends. No takes from TTS were modeled, but if TTS did occur, 
the overall fitness of the individual is unlikely to be affected and 
negative impacts to the relevant stock are not anticipated.
    Effects on individuals that are taken by Level B harassment could 
include alteration of dive behavior, alteration of 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. Most likely, individuals will simply be temporarily 
displaced by moving away from the sound source. As described previously 
in the behavioral effects section, seals exposed to non-impulsive 
sources with a received sound pressure level within the range of 
calculated exposures (142-193 dB re 1 [micro]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). Although 
a minor change to a behavior may occur as a result of exposure to the 
sound sources associated with the proposed action, these changes would 
be within the normal range of behaviors for the animal (e.g., the use 
of a breathing hole further from the source, rather than one closer to 
the source, would be within the normal range of behavior). Thus, even 
repeated Level B harassment of some small subset of the overall stock 
is unlikely to result in any significant realized decrease in fitness 
for the affected individuals, and would not result in any adverse 
impact to the stock as a whole.
    The project is not expected to have significant 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. Icebreaking may temporarily affect the availability 
of pack ice for seals to haul out but the proportion of ice disturbed 
is small relative to the overall amount of available ice habitat. 
Icebreaking will not occur during the time of year when ringed seals 
are expected to be within subnivean lairs or pupping (Chapskii 1940; 
McLaren 1958; Smith and Stirling 1975). As such, the impacts to marine 
mammal habitat are not expected to cause significant or long-term 
negative consequences.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality is anticipated or authorized;
     Impacts will be limited to Level B harassment;
     Takes by Level B harassment will primarily be in the form 
of behavioral disturbance; and
     There will be no permanent or significant loss or 
modification of marine mammal prey or habitat.

[[Page 37262]]

    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

    Impacts to subsistence uses of marine mammals resulting from the 
proposed action are not anticipated. The closest active acoustic source 
within the study area is approximately 145 mi (233 km) from land, 
outside of known subsistence use areas. Based on this information, NMFS 
has preliminarily determined that there will be no unmitigable adverse 
impact on subsistence uses from ONR's proposed activities.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (16 U.S.C. 
1531 et seq.) requires that each Federal agency insure that any action 
it authorizes, funds, or carries out is not likely to jeopardize the 
continued existence of any endangered or threatened species or result 
in the destruction or adverse modification of designated critical 
habitat. To ensure ESA compliance for the issuance of IHAs, NMFS 
consults internally, in this case with the NMFS Alaska Regional Office 
(AKR), whenever we propose to authorize take for endangered or 
threatened species.
    NMFS is proposing to authorize take of ringed seals and bearded 
seals, which are listed under the ESA. The Permits and Conservation 
Division has requested initiation of section 7 consultation with the 
Protected Resources Division of 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 Arctic Research Activities in the 
Beaufort and Chukchi Seas, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated. A 
draft of the proposed IHA can be found at https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed 
action. We also request at this time 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.
    On a case-by-case basis, NMFS may issue a one-year IHA renewal with 
an additional 15 days for public comments when (1) another year of 
identical or nearly identical activities as described in the Specified 
Activities section of this notice is planned or (2) the activities as 
described in the Specified Activities section of this notice would not 
be completed by the time the IHA expires and a second IHA would allow 
for completion of the activities beyond that described in the Dates and 
Duration section of this notice, provided all of the following 
conditions are met:
     A request for renewal is received no later than 60 days 
prior to expiration of the current IHA;
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal 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 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal); and
    (2) A preliminary monitoring report showing the results of the 
required monitoring to date and an explanation showing that the 
monitoring results do not indicate impacts of a scale or nature not 
previously analyzed or authorized.
     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 26, 2019.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2019-16318 Filed 7-30-19; 8:45 am]
 BILLING CODE 3510-22-P