[Federal Register Volume 83, Number 31 (Wednesday, February 14, 2018)]
[Pages 6522-6532]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-03080]



National Oceanic and Atmospheric Administration

RIN 0648-XF470

Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to U.S. Navy 2018 Ice Exercise 
Activities in the Beaufort Sea and Arctic Ocean

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

ACTION: Notice; issuance of an incidental harassment authorization.


SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the United States Department of the Navy (Navy) to incidentally harass, 
by Level B harassment, marine mammals during Ice Exercise 2018 (ICEX18) 
activities within the Beaufort Sea and Arctic Ocean north of Prudhoe 
Bay, Alaska. The Navy's activities are considered a military readiness 
activity pursuant to the Marine Mammal Protection Act (MMPA), as 
amended by the National Defense Authorization Act for Fiscal Year 2004 

DATES: This authorization is applicable from February 1, 2018 through 
May 1, 2018.

FOR FURTHER INFORMATION CONTACT: Rob Pauline, Office of Protected 
Resources, NMFS, (301) 427-8408. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at www.nmfs.noaa.gov/pr/permits/incidental/military.htm. In case of problems accessing these documents, 
please call the contact listed above.



    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 
authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 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 
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 

[[Page 6523]]

    The MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, or sheltering 
(Level B harassment).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'' to read as follows (Section 3(18)(B) of 
the MMPA): (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).

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 the proposed action (i.e. the issuance of an 
incidental harassment authorization) with respect to environmental 
consequences on the human environment.
    The Navy has prepared an environmental assessment (EA) titled 
Environmental Assessment/Overseas Environmental Assessment for Ice 
Exercise. NMFS has adopted the Navy's EA/OEA, after an independent 
evaluation of the document found that it included adequate information 
analyzing the effects on the human environment of issuing incidental 
take authorizations. NMFS issued a Finding of No Significant Impact 
(FONSI), which is available for review at http://www.nmfs.noaa.gov/pr/permits/incidental/military.htm.

Summary of Request

    On April 12, 2017, NMFS received a request from the Navy for the 
taking of marine mammals incidental to submarine training and testing 
activities including establishment of a tracking range on an ice floe 
in the Beaufort Sea and Arctic Ocean north of Prudhoe Bay, Alaska. The 
Navy's request is for take of ringed seals (Pusa hispida hispida) by 
Level B harassment. Neither the Navy nor NMFS expects Level A 
harassment or mortality to result from this activity and, therefore, an 
IHA is appropriate.

Description of Specified Activity


    The Navy proposes to conduct submarine training and testing 
activities from an ice camp stationed on an ice floe in the Beaufort 
Sea and Arctic Ocean for six weeks between February and April 2018. 
Submarine activities associated with ICEX18 are classified, but 
generally entail safety maneuvers, active sonar use and exercise 
torpedo use. These maneuvers and sonar use are similar to submarine 
activities conducted in other undersea environments. They are being 
conducted in the Arctic to test their performance in a cold 
environment. A detailed description of the planned project is provided 
in the Federal Register notice for the proposed IHA (82 FR 48683; 
October 19, 2017). Since that time, no changes have been made to the 
planned activities. Therefore, a detailed description is not provided 
here. Please refer to that Federal Register notice for the description 
of the specific activity.

Comments and Responses

    A notice of NMFS's proposal to issue an IHA to the Navy was 
published in the Federal Register on October 19, 2017 (82 FR 48683). 
That notice describes the Navy's activity, the marine mammal species 
that may be affected by the activity, and the anticipated effects on 
marine mammals. During the 30-day public comment period, NMFS received 
comments from the Marine Mammal Commission (Commission) and the Office 
of the Mayor of North Slope Borough (NSB).
    Comment 1: The Commission noted that the Navy did not use Bayesian 
biphasic dose response functions (BRFs) to inform take estimates, but 
used cut-off distances instead. The Commission stated that the cut-off 
distances used by the Navy are unsubstantiated and the Navy arbitrarily 
set a cut-off distance of 10 kilometers (km) which could effectively 
eliminate a large portion of the estimated numbers of takes. The 
Commission, therefore, recommended that the Navy refrain from using 
cut-off distances in conjunction with the Bayesian BRFs.
    Response: The derivation of the behavioral response functions and 
associated cut-off distances is provided in the Phase III technical 
report (Navy, 2017a). The consideration of proximity (distance cutoff) 
was part of the criteria developed in consultation with NMFS and was 
applied within the Navy's acoustic effects model. Distance cutoffs 
beyond which the potential of significant behavioral responses were 
considered to be unlikely were used in conducting analysis for ringed 
seals for ICEX 18.
    As stated in the Criteria and Thresholds Technical Report (Navy, 
2017a), Southall et al. (2007) report that pinnipeds do not exhibit 
strong reactions to sound pressure levels (SPLs) up to 140 decibels 
(dB) re 1 micro Pascal ([mu]Pa) (which occurs at about 400m from the 
sources used here) from steady state (non-impulsive) sources. In some 
cases, pinnipeds tolerate impulsive exposures up to 180 dB re 1 [mu]Pa 
with limited avoidance noted (Southall et al., 2007), and no avoidance 
noted at distances as close as 42 m (Jacobs & Terhune, 2002). Though 
there are limited data on pinniped behavioral responses beyond about 3 
km in the water, there is evidence that there is a lack of strong 
reactions at shorter distances. The available data suggest that most 
pinnipeds likely do not exhibit significant behavioral reactions to 
sonar and other transducers beyond a few kilometers, independent of 
received levels of sound. Further, 160 dB rms, which is used as the 
behavioral harassment threshold for non-tactical intermittent sonar 
use, will not be received farther than a couple of hundred meters from 
the source (140 dB is received at 400m). Therefore, NMFS believes that 
the 10 km distance cutoff for pinnipeds is both conservative and 
adequate to evaluate the Level B harassment impacts for military 
readiness activities.
    Comment 2: Although the Office of Naval Research funded seal 
tagging studies indicate that most ice seals migrate southward at the 
onset of winter; NSB is aware of traditional ecological knowledge that 
provides evidence that there are resident ringed and bearded seal 
populations in the Beaufort Sea.
    Response: The Navy reached out to the Inupiat Community of the 
Arctic Slope (ICAS), Nuiqsut, and Kaktovic communities on September 28, 
2017, providing them a CD containing the draft Environmental 
Assessment/Overseas Environmental Assessment (EA/OEA) for ICEX 2018 and 
also sent emails to tribal representatives with an internet link to the 
document. The Navy was not provided with any information or data 
pertaining to resident and bearded seal populations in the Beaufort Sea 
that far offshore in late winter. There was also a public comment

[[Page 6524]]

period, which ran from September 29 to October 16, 2017. A complete 
discussion of potential impacts from ICEX 18 is contained in the ICEX 
2018 (EA/OEA) (http://www.aftteis.com/ICEX). The Navy used the best 
available science and data to assess potential impacts in the EA/OEA. 
NMFS also used best available science and data to make their 
determination regarding the issuance of the IHA. The Navy and NMFS are 
not aware of other data that would alter their findings.
    Furthermore, the Navy is funding Duke University to develop species 
density models for the Arctic region and would welcome any data the NSB 
and Arctic research community have available to incorporate into 
density models and impacts analysis.
    Comment 3: NSB expressed concern that potential creation of 
unseasonal leads due to submarine surfacing, possible destruction of 
winter lairs of ringed seals during encampment preparation, and use of 
motorized vehicles during the exercises may impact seals.
    Response: As part of the planned ICEX18 activities submarines will 
surface through the ice. In the area where the submarines will surface, 
ice leads are a frequent and natural occurrence, opening up and 
refreezing due to ocean currents and shifting ice. Submarine surfacing 
will occur in either open leads or first year ice as there is less 
potential to damage a submarine. While surfacing submarines may create 
small leads in some instances, each U.S. Navy submarine will surface no 
more than five times per ICEX. Therefore, potential impacts to seals 
would be minor and temporary. Furthermore, seal lairs are not expected 
to occur close to open leads or on first year ice. Additionally, 
mitigation and monitoring requirements listed in the IHA (e.g. no ice 
camp construction near ice ridges; avoidance of pressure ridges by 
snowmobiles and researchers) should prevent destruction of lairs and 
adverse impacts to seals. These issues were also evaluated in the EA/
OEA were not found to be not significant.
    Comment 4: NSB feels that the lack of available species-specific 
data (e.g. ice seal, arctic fish species, polar bears) precludes 
assessment of the consequences of sonar use on Arctic protected marine 
mammal species.
    Response: The Navy conducts numerous types of research to better 
understand how sound may affect marine mammals, and though not 
specifically Arctic species, the knowledge gained from those studies is 
transferable to Arctic species. This type of research has focused on 
the development of better tags and attachment mechanisms for 
monitoring, development and testing of new autonomous hardware 
platforms for detection of marine mammals, and ways to better 
understand and characterize the behavioral, physiological (hearing and 
stress response), and potentially population-level consequences of 
sound exposure on marine life.
    The Navy uses the best available science when analyzing the impacts 
of training and testing on the environment, including animals. To do 
this the Navy continually reviews published scientific literature, 
incorporates data from regulatory agencies such as National Oceanic and 
Atmospheric Administration and U.S. Fish and Wildlife Service, and 
funds or conducts research where data gaps exist. Furthermore, NMFS 
utilizes the best available science when making determinations 
regarding the issuance of IHAs and concluded that there was adequate 
information available to support the findings.
    Comment 5: NSB is concerned that the planned submarine exercises, 
which will employ sonar, have the potential to negatively impact marine 
mammals and affect the food chain. As a result, the Inupiaq subsistence 
life style may also be affected. Therefore, NSB recommends that the 
Navy initiate engagement with the North Slope leadership and the Arctic 
research community to develop studies that address the missing 
information needed for a better understanding of the effects of 
military sonar use on Arctic marine mammals and their prey.
    Response: The Navy's marine species monitoring website provides 
information on current and past monitoring projects and allows for the 
submittal of ideas or concepts for projects to be considered under the 
U.S Navy's Marine Species Monitoring Program at: https://www.navymarinespeciesmonitoring.us/project-submission-form/. The Navy's 
Living Marine Resources Program also solicits proposals for funding of 
research projects (http://greenfleet.dodlive.mil/environment/lmrproposals/), as well as the Office of Naval Research (https://www.onr.navy.mil/Science-Technology/Departments/Code-32/All-Programs/Atmosphere-Research-322/Marine-Mammals-Biology). These sites include a 
list of research projects the Navy is currently funding to improve the 
Navy's understanding of marine species and how Navy activities may 
affect those species. These websites offer NSB and the Arctic research 
community the opportunity to engage with the Navy through the 
submission of research proposals.

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 ringed seals (Pusa hispida hispida), 
which is the only potentially affected species. Total sea ice coverage 
is expected across the study area during the study period which 
precludes the presence of other arctic marine mammal species. Ringed 
seals temporally and spatially co-occur with the activity to the degree 
that take is reasonably likely to occur, and therefore we have 
authorized take after considering the anticipated amount and type of 
take and making the required findings. Additional information regarding 
population trends and threats may be found in NMFS's Stock Assessment 
Reports (Muto et al., 2016; www.nmfs.noaa.gov/pr/sars/) and more 
general information about this species (e.g., physical and behavioral 
descriptions) may be found on NMFS's website (www.nmfs.noaa.gov/pr/species/mammals/).

[[Page 6525]]

                                         Table 2--Marine Mammal Species Potentially Present in the Project Area
                                                                                                    Stock abundance (CV,
                                                                                 ESA/MMPA status;     Nmin, most recent                        Annual M/
           Common name                Scientific name            Stock         Strategic (Y/N) \1\    abundance survey)           PBR            SI \3\
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
                                                                    Family Balaenidai
Bowhead whale....................  Balaena mysticetus..  Western Arctic......  E/D;Y                16,982 (0.058,        161................         44
                                                                                                     16,091, 2011).
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
                                                                   Family Delphinidae
Beluga whale.....................  Delphinapterus        Beaufort Sea........  -/-;N                39,258 (0.229,        649................        166
                                    leucas.                                                          32,453, 1992).
                                                         Order Carnivora--Superfamily Pinnipedia
                                                             Family Phocidae (earless seals)
Ringed seal......................  Pusa hispida hispida  Alaska..............  -/-;N                170,000 (Bering Sea   5,100 (Bearing Sea-      1,054
                                                                                                     and Sea of Okhotsk    U.S. portion only).
Bearded seal.....................  Erignathus barbatus   Alaska..............  -/-;N                299,174 (-, 273,676,  8,210 (Bearing Sea-        1.4
                                    nauticus.                                                        2012) (Bearing Sea-   U.S. portion only).
                                                                                                     U.S. portion only).
\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: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable [explain if this is the case].
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
  associated with estimated mortality due to commercial fisheries is presented in some cases.
Note--Italicized species are not expected to be taken.

Potential Effects of the Specified Activity on Marine Mammals and Their 

    The effects of underwater noise from Navy's testing and training 
activities have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the action area. The Federal Register 
notice for the proposed IHA (82 FR 48683; October 19, 2017) included a 
discussion of the effects of anthropogenic noise on marine mammals and 
no new information has been received since publication of the proposed 
IHA, therefore that information is not repeated here; please refer to 
the Federal Register notice (82 FR 48683; October 19, 2017) for that 

Estimated Take

    This section provides an estimate of the number of incidental takes 
anticipated to occur and therefore authorized through this IHA, which 
will inform 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. Based on the 
nature of the activity, Level A harassment is neither anticipated nor 
authorized. In addition, no serious injury or mortality is anticipated 
or authorized for this activity. Source levels of acoustic transmission 
will not be at levels which would cause serious injury, or mortality. 
Deployment of the ice camp could potentially affect ringed seal habitat 
by physically damaging or crushing subnivean lairs, resulting in seal 
injury or mortality. However, seals usually choose to locate lairs near 
pressure ridges and the ice camp will be deployed in an area without 
pressure ridges in order to allow operation of an aircraft runway. 
Further, portable tents will be erected for lodging and operations 
purposes. Tents do not require building materials or typical 
construction methods. The tents are relatively easy to mobilize and 
will not be situated near areas featuring pressure ridges. Finally, the 
camp buildup will be gradual, with activity increasing over the first 
five days. This approach allows seals to move to different lair 
locations outside the ice camp area. Based on this information, we do 
not anticipate any damage to subnivean lairs that could result in 
ringed seal injury or mortality.
    Below we describe how the take is estimated.

[[Page 6526]]

    Described in the most basic way, 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. For the proposed IHA, 
the Navy employed a sophisticated model known as the Navy Acoustic 
Effects Model (NAEMO) for assessing the impacts of underwater sound.

Acoustic Thresholds

    Using the best available science, NMFS recommends acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to incur PTS 
of some degree (equated to Level A harassment), TTS, or behavioral 
harassment (Level B harassment). The thresholds used to predict 
occurrences of each type of take are described below.
    Behavioral harassment--In coordination with NMFS, the Navy 
developed behavioral harassment thresholds to support Phase III 
environmental analyses for the Navy's testing and training military 
readiness activities; these behavioral harassment thresholds are used 
here to evaluate the potential effects of this planned 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 Navy's behavioral response 
criteria for the Phase III environmental analyses.
    Southall et al. (2007) 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). After examining all of the available 
data, the authors felt that the derivation of thresholds for behavioral 
response based solely on exposure level was not supported because 
context of the animal at the time of sound exposure was an important 
factor in estimating response. Nonetheless, in some conditions, 
consistent avoidance reactions were noted at higher sound levels 
depending on the marine mammal species or group allowing conclusions to 
be drawn. Phocid seals showed avoidance reactions at or below 190 dB re 
1 [mu]Pa @1m; thus, seals may actually receive levels adequate to 
produce TTS before avoiding the source.
    The Navy's Phase III proposed pinniped behavioral threshold has 
been 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). 
Overall exposure levels were 110-170 dB re 1 [mu]Pa for hooded seals, 
140-180 dB re 1 [mu]Pa for gray seals and 125-185 dB re 1 [mu]Pa for 
California sea lions; responses occurred at received levels ranging 
from 125 to 185 dB re 1 [mu]Pa. However, the means of the response data 
were between 159 and 170 dB re 1 [mu]Pa. 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. Because these data represent a dose-response type relationship 
between received level and a response, and because the means were all 
tightly clustered, the Bayesian biphasic Behavioral Response Function 
for pinnipeds most closely resembles a traditional sigmoidal dose-
response function at the upper received levels and has a 50 percent 
probability of response at 166 dB re 1 [mu]Pa. Additional details 
regarding the Phase III criteria may be found in the technical report, 
Criteria and Thresholds for U.S. Navy Acoustic and Explosive Effects 
Analysis (2017a) which may be found at: http://aftteis.com/Portals/3/docs/newdocs/Criteria%20and%20Thresholds_TR_Submittal_05262017.pdf. 
This technical report was as part of the Navy's Atlantic Fleet Training 
and Testing Draft Environmental Impact Statement/Overseas Environmental 
Impact Statement (EIS/OEIS) (Navy 2017b) which is located at: http://www.aftteis.com/. NMFS is proposing the use of this dose response 
function to predict behavioral harassment of pinnipeds for this 
    Level A harassment and TTS--NMFS' Technical Guidance for Assessing 
the Effects of Anthropogenic Sound on Marine Mammal Hearing (Technical 
Guidance, 2016) 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).
    These thresholds were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers to inform the final product. The 
references, analysis, and methodology used in the development of the 
thresholds are described in NMFS 2016 Technical Guidance, which may be 
accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
    The PTS/TTS analyses begins with mathematical modeling to predict 
the sound transmission patterns from Navy sources, including sonar. 
These data are then coupled with marine species distribution and 
abundance data to determine the sound levels likely to be received by 
various marine species. These criteria and thresholds are applied to 
estimate specific effects that animals exposed to Navy-generated sound 
may experience. For weighting function derivation, the most critical 
data required are TTS onset exposure levels as a function of exposure 
frequency. These values can be estimated from published literature by 
examining TTS as a function of sound

[[Page 6527]]

exposure level (SEL) for various frequencies.
    To estimate TTS onset values, only TTS data from behavioral hearing 
tests were used. To determine TTS onset for each subject, the amount of 
TTS observed after exposures with different SPLs and durations were 
combined to create a single TTS growth curve as a function of SEL. The 
use of (cumulative) SEL is a simplifying assumption to accommodate 
sounds of various SPLs, durations, and duty cycles. This is referred to 
as an ``equal energy'' approach, since SEL is related to the energy of 
the sound and this approach assumes exposures with equal SEL result in 
equal effects, regardless of the duration or duty cycle of the sound. 
It is well known that the equal energy rule will over-estimate the 
effects of intermittent noise, since the quiet periods between noise 
exposures will allow some recovery of hearing compared to noise that is 
continuously present with the same total SEL (Ward 1997). For 
continuous exposures with the same SEL but different durations, the 
exposure with the longer duration will also tend to produce more TTS 
(Finneran et al., 2010; Kastak et al., 2007; Mooney et al., 2009a).
    As in previous acoustic effects analysis (Finneran and Jenkins 
2012; Southall et al., 2007), the shape of the PTS exposure function 
for each species group is assumed to be identical to the TTS exposure 
function for each group. A difference of 20 dB between TTS onset and 
PTS onset is used for all marine mammals including pinnipeds. This is 
based on estimates of exposure levels actually required for PTS (i.e. 
40 dB of TTS) from the marine mammal TTS growth curves, which show 
differences of 13 to 37 dB between TTS and PTS onset in marine mammals. 
Details regarding these criteria and thresholds can be found in NMFS' 
Technical Guidance (NMFS 2016).
    Table 3 below provides the weighted criteria and thresholds used in 
this analysis for estimating quantitative acoustic exposures of marine 
mammals from the planned action.

            Table 3--Injury (PTS) and Disturbance (TTS, Behavioral) Thresholds for Underwater Sounds
                                                                                  Physiological criteria
              Group                     Species           Behavioral     ---------------------------------------
                                                           criteria            Onset TTS           Onset PTS
Phocid (in water)...............  Ringed seal.......  Pinniped Dose       181 dB SEL          201 dB SEL
                                                       Response Function.  cumulative.         cumulative.

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 planned 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 density estimate used to estimate take is derived from habitat-
based modeling by Kaschner et al., (2006) and Kaschner (2004). The area 
of the Arctic where the action will occur (100-200 nm north of Prudhoe 
Bay, Alaska) has not been surveyed in a manner that supports 
quantifiable density estimation of marine mammals. In the absence of 
empirical survey data, information on known or inferred associations 
between marine habitat features and the likelihood of the presence of 
specific species have been used to predict densities using model-based 
approaches. These habitat suitability models include relative 
environmental suitability (RES) models. Habitat suitability models can 
be used to understand the possible extent and relative expected 
concentration of a marine species distribution. These models are 
derived from an assessment of the species occurrence in association 
with evaluated environmental explanatory variables that results in 
defining the RES suitability of a given environment. A fitted model 
that quantitatively describes the relationship of occurrence with the 
environmental variables can be used to estimate unknown occurrence in 
conjunction with known habitat suitability. Abundance can thus be 
estimated for each RES value based on the values of the environmental 
variables, providing a means to estimate density for areas that have 
not been surveyed. Use of the Kaschner's RES model resulted in a value 
of 0.3957 animals per km\2\ in the cold season (defined as December 
through May). The density numbers are assumed static throughout the ice 
camp action area for this species. The density data generated for this 
species was based on environmental variables known to exist within the 
planned ice camp action area during the late winter/early springtime 
    Note that while other surveys by Frost et al. (2004) and Bengston 
et al. (2005) provided ringed seal density estimates for areas near or 
within the Beaufort Sea, the Navy felt that those findings were not 
applicable to the planned action area. Frost et al. (2004) only 
surveyed ringed seals out to 40 km from shore in the Beaufort Sea. A 
small portion of the surveys from Bengston et al. (2005) were out to a 
maximum extent of 185 km (100 nm) from shore, but the surveys were 
located within the Chukchi Sea, not the Beaufort Sea. Frost et al. 
(2004) also stated the highest densities of ringed seals were in water 
depths from 5-25 m (1-1.33 seals per km\2\). Lower densities were seen 
in waters greater than 35 m in depth (0-0.77 seals per km\2\). The 
planned action area where acoustic transmissions would occur is 3,000 
to 4,000 m deep (International Bathymetric Chart of the Arctic Ocean 
2015), which makes the bathymetric nature of the areas different enough 
to be non-comparable. Furthermore, the ice camp is located on multi-
year ice and would not be located near the ice edge. Frost et al. 
(2004), and Bengston et al. (2005) both had a high percentage of fast 
or pack ice in their survey area which would not be present in the 
planned action area. Additionally, there were areas of cracked ice that 
were part of the surveys. As previously noted, the ice camp needs to be 
situated in an area without cracks in the ice. After reviewing both 
Frost et al. (2004) and Bengston et al. (2005) NMFS agrees with the 
Navy that the density data from the RES model provides the most 
appropriate density values to be assessed for acoustic transmissions 
during ICEX18.
    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 
planned active acoustic sources, the sound received by animat (virtual 
animal) dosimeters representing marine mammals distributed in the area 
around the

[[Page 6528]]

modeled activity, and whether the sound received by a marine mammal 
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 Navy's standard mitigations. These tools and 
data sets serve are 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 is independent of all others, and therefore, the same 
individual marine animal 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.
    There are limitations to the data used in the acoustic effects 
model, and the results must be interpreted within these context. While 
the most accurate data and input assumptions have been used in the 
modeling, when there is a lack of definitive data to support an aspect 
of the modeling, modeling assumptions believed to overestimate the 
number of exposures have been chosen:
     Animats are modeled as being underwater, stationary, and 
facing the source and therefore always predicted to receive the maximum 
sound level (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 the 
temporary or permanent hearing loss, because there are not sufficient 
data to estimate a hearing recovery function for the time between 
exposures; and
     Mitigation measures that are implemented were not 
considered in the model. In reality, sound-producing activities would 
be reduced, stopped, or delayed if marine mammals are detected by 
submarines via passive acoustic monitoring.
    Because of these inherent model limitations and simplifications, 
model-estimated results must 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.
    For non-impulsive sources, NAEMO calculates the sound pressure 
level (SPL) and SEL for each active emission over the entire duration 
of an event. These data are then processed using a bootstrapping 
routine to compute the number of animats exposed to SPL and SEL in 1 dB 
bins across all track iterations and population draws. (Bootstrapping 
is a type of resampling where large numbers of smaller samples of the 
same size are repeatedly drawn, with replacement, from a single 
original sample.) SEL is checked during this process to ensure that all 
animats are grouped in either an SPL or SEL category. A mean number of 
SPL and SEL exposures are computed for each 1 dB bin. The mean value is 
based on the number of animats exposed at that dB level from each track 
iteration and population draw. The behavioral risk function curve is 
applied to each 1 dB bin to compute the number of behaviorally exposed 
animats per bin. The number of behaviorally exposed animats per bin is 
summed to produce the total number of behavior exposures.
    Mean 1 dB bin SEL exposures are then summed to determine the number 
of PTS and TTS exposures. PTS exposures represent the cumulative number 
of animats exposed at or above the PTS threshold. The number of TTS 
exposures represents the cumulative number of animats exposed at or 
above the TTS threshold and below the PTS threshold. Animats exposed 
below the TTS threshold were grouped in the SPL category.
    Platforms such as a submarine 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 
training event's operational area. For analysis purposes, the Navy uses 
distance cutoffs, which is the maximum distance a Level B take would 
occur, beyond which the potential for significant behavioral responses 
is considered unlikely. For animals located beyond the range to 
effects, no significant behavioral responses are predicted. This is 
based on the Navy's Phase III environmental analysis (Navy 2017a). The 
Navy referenced Southall et al. (2007) who reported that pinnipeds do 
not exhibit strong reactions to SPLs up to 140 dB re 1 [mu]Pa from 
steady state (non-impulsive) sources. In some cases, pinnipeds tolerate 
impulsive exposures up to 180 dB re 1 [mu]Pa with limited avoidance 
noted (Southall et al., 2007), and no avoidance noted at distances as 
close as 42 m (Jacobs & Terhune 2002). While limited data exists on 
pinniped behavioral responses beyond 3 km in the water, the data that 
is available suggest that most pinnipeds likely do not exhibit 
significant behavioral reactions to sonar and other transducers beyond 
a few kilometers, independent of received levels of sound (Navy 2017a). 
Therefore, in the Navy's Phase III environmental analysis, the range to 
effects for pinnipeds is set at 5 km for moderate source level, single 
platform training and testing events and 10 km for all other events 
with multiple sonar platforms or sonar with source levels at or 
exceeding 215 dB re 1 [micro]Pa @1 m. Regardless of the source level, 
take beyond 10 km is not anticipated. These ranges are expected to 
reasonably contain the anticipated effects predicted by the behavioral 
response dose curve threshold reference above.
    For ICEX18 unclassified sources (i.e. Autonomous Reverberation 
Measurement System and MIT/Lincoln Labs continuous wave/chirp), the 
Navy models calculated a propagation loss measurement of 13.5 km from 

[[Page 6529]]

source to the 120 dB re 1 [mu]Pa SPL isopleth; 1.5 km from the source 
to the 130 dB re 1 [mu]Pa SPL isopleth; and 400 m from the source to 
the 140 dB dB re 1 [mu]Pa SPL isopleth. Propagation loss measurements 
cannot be provided for classified sources. However, the ranges in Table 
4 provide realistic maximum distances over which the specific effects 
from the use of all active acoustic sources during the planned action 
would be possible. Based on the information provided, NMFS is confident 
that the 10km zone safely encompasses the area in which Level B 
harassment can be expected from all active acoustic sources.

  Table 4--Range to Temporary Threshold Shift and Behavioral Effects in
                          the ICEX18 Study Area
                                          Maximum range to Level B takes
                                                  cold season (m)
             Source/exercise             -------------------------------
                                            Behavioral          TTS
Submarine Exercise......................          10,000             100
Autonomous Reverberation Measurement              10,000             <50
Massachusetts Institute of Technology/            10,000             <50
 Lincoln Labs Continuous Wave/chirp.....
Naval Research Laboratory Synthetic               10,000              90
 Aperture Sonar.........................

    As discussed above, within NAEMO animats do not move horizontally 
or react in any way to avoid sound. Furthermore, mitigation measures 
that are implemented during training or testing activities that reduce 
the likelihood of physiological impacts are not considered in 
quantitative analysis. Therefore, the current model overestimates 
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 (TTS or PTS). 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 planned action, the implementation of avoidance and mitigation 
factors were not included in this analysis.
    Utilizing the NAEMO model, the Navy projected that there will be 
1,665 behavioral Level B harassment takes and an additional 11 Level B 
takes due to TTS for a total of 1,676 takes of ringed seals. All takes 
would be underwater. Note that these quantitative results should be 
regarded as conservative estimates that are strongly influenced by 
limited marine mammal population data.


    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 
adverse 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, we carefully weigh two primary factors:
    (1) The manner in which, and the degree to which, implementation of 
the measure(s) is expected to reduce impacts to marine mammal species 
or stocks, their habitat, and their availability for subsistence uses 
(where relevant). This analysis will consider such things as the nature 
of the potential adverse impact (such as likelihood, scope, and range), 
the likelihood that the measure will be effective if implemented, and 
the likelihood of successful implementation; and
    (2) The practicability of the measures for applicant 
implementation. Practicability of implementation may consider such 
things as cost, impact on operations, and, in the case of a military 
readiness activity, specifically considers personnel safety, 
practicality of implementation, and impact on the effectiveness of the 
military readiness activity (16 U.S.C. 1371(a)(5)(A)(ii)).

Mitigation for Marine Mammals and Their Habitat

    The following general mitigation actions are planned for ICEX18 to 
avoid any take of ringed seals on the ice floe:
     Camp deployment would begin in mid-February and would be 
completed by March 15. Based on the best available science, Arctic 
ringed seal whelping is not expected to occur prior to mid-March. 
Construction of the ice camp would be completed prior to whelping in 
the area of ICEX18. As such, pups are not anticipated to be in the 
vicinity of the camp at commencement, and mothers would not need to 
move newborn pups due to construction of the camp. Additionally, if a 
seal had a lair in the area they would be able to relocate. Completing 
camp deployment before ringed seal pupping begins will allow ringed 
seals to avoid the camp area prior to pupping and mating seasons, 
reducing potential impacts;
     Camp location will not be in proximity to pressure ridges 
in order to allow camp deployment and operation of an aircraft runway. 
This will minimize physical impacts to subnivean lairs;
     Camp deployment will gradually increase over five days, 
allowing seals to relocate to lairs that are not in the immediate 
vicinity of the camp;

[[Page 6530]]

     Passengers on all on-ice vehicles would observe for marine 
and terrestrial animals; any marine or terrestrial animal observed on 
the ice would be avoided by 328 ft (100 m). On-ice vehicles would not 
be used to follow any animal, with the exception of actively deterring 
polar bears if the situation requires;
     Personnel operating on-ice vehicles would avoid areas of 
deep snowdrifts near pressure ridges, which are preferred areas for 
subnivean lair development; and
     All material (e.g., tents, unused food, excess fuel) and 
wastes (e.g., solid waste, hazardous waste) would be removed from the 
ice floe upon completion of ICEX18.
    The following mitigation actions are planned for ICEX18 activities 
involving acoustic transmissions:
    For activities involving active acoustic transmissions from 
submarines and torpedoes, passive acoustic sensors on the submarines 
will listen for vocalizing marine mammals for 15 minutes prior to the 
initiation of exercise activities. If a marine mammal is detected, the 
submarine will delay active transmissions, including the launching of 
torpedoes, and not restart until after 15 minutes have passed with no 
marine mammal detections. If there are no animal detections, it is 
assumed that the vocalizing animal is no longer in the immediate area 
and is unlikely to be subject to harassment. Ramp up procedures will 
not be required as they would result in an unacceptable impact on 
readiness and on the realism of training.
    Based on our evaluation of the applicant's planned measures, NMFS 
has determined that the planned mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, requirements pertaining to 
the monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
action area. Effective reporting is critical both to compliance as well 
as to ensuring that the most value is obtained from the required 
    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, 
     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.
    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) (U.S. 
Department of the Navy 2011). The ICMP has been created in direct 
response to Navy permitting requirements established in various MMPA 
Final Rules, ESA consultations, Biological Opinions, and applicable 
regulations. 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 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. ICEX18 in comparison is a short 
duration exercise that occurs approximately every other year. Due to 
the location and expeditionary nature of the ice camp, the number of 
personnel onsite is extremely limited and is constrained by the 
requirement to be able to evacuate all personnel in a single day with 
small planes. As such, a dedicated monitoring project would not be 
feasible as it would require additional personnel and equipment to 
locate, tag and monitor the seals.
    The Navy is committed to documenting and reporting relevant aspects 
of training and research activities to verify implementation of 
mitigation, comply with current permits, and improve future 
environmental assessments. All sonar usage will be collected via the 
Navy's Sonar Positional Reporting System database and reported. If any 
injury or death of a marine mammal is observed during the ICEX18 
activity, the Navy will immediately halt the activity and report the 
incident consistent with the stranding and reporting protocol in the 
Atlantic Fleet Training and Testing stranding response plan (Navy 
2013). This approach is also consistent with other Navy documents 
including the Atlantic Fleet Training and Testing Environmental Impact 
Statement/Overseas Environmental Impact Statement.
    The Navy will provide NMFS with a draft exercise monitoring report 
within 90 days of the conclusion of the planned activity. The draft 
exercise monitoring report will include data regarding sonar use and 
any mammal sightings or detection will be documented. The report will 
also include information on the number of sonar 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

[[Page 6531]]

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 
    Underwater acoustic transmissions associated with ICEX18, as 
outlined previously, have the potential to result in Level B harassment 
of ringed seals in the form of TTS and behavioral disturbance. No 
serious injury, mortality or Level A takes are anticipated to result 
from this activity. At close ranges and high sound levels approaching 
those that could cause PTS, avoidance of the area immediately around 
the sound source would be ringed seals' likely behavioral response. 
NMFS anticipates that there will be 11 Level B takes due to TTS and 
1,665 Level B behavioral harassment takes, for a total of 1,676 ringed 
seal takes.
    Note that there are only 11 Level B takes due to TTS since the TTS 
range to effects is small at only 100 meters or less while the 
behavioral effects range is significantly larger extending up to 10 km. 
TTS is a temporary impairment of hearing and TTS 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. 
Though TTS may occur in up to 11 animals out of a stock of 170,000 
animals, the overall fitness of these individuals is unlikely to be 
affected and negative impacts to the entire 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, 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 and mitigation by passive acoustic monitoring which will limit 
exposure to sound 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 [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 sound sources associated with the planned 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 Navy's planned activities are localized and of relatively short 
duration. While the total project area is large, the Navy expects that 
most activities will occur within the ice camp action area in 
relatively close proximity to the ice camp. The larger study area 
depicts the range where submarines may maneuver during the exercise. 
The ice camp will be in existence for up to six weeks with acoustic 
transmission occurring intermittently over four weeks. The Autonomous 
Reverberation Measurement System would be active for up to 30 days; the 
vertical line array would be active for up to four hours per day for no 
more than eight days, and; the unmanned underwater vehicle used for the 
deployment of a synthetic aperture source would transmit for 24 hours 
per day for up to eight days.
    The project is not expected to have significant adverse effects on 
marine mammal habitat. The project activities are limited in time and 
would not modify physical marine mammal habitat. While the activities 
may cause some fish to leave a specific area ensonified by acoustic 
transmissions, temporarily impacting marine mammals' foraging 
opportunities, these fish would likely return to the affected area.. As 
such, the impacts to marine mammal habitat are not expected to cause 
significant or long-term negative consequences.
    For on-ice activity, serious injury and mortality are not 
anticipated. Level B harassment could occur but is unlikely due to 
mitigation measures followed during the exercise. Foot and snowmobile 
movement on the ice will be designed to avoid pressure ridges, where 
ringed seals build their lairs; runways will be built in areas without 
pressure ridges; snowmobiles will follow established routes; and camp 
buildup is gradual, with activity increasing over the first five days 
providing seals the opportunity to move to a different lair outside the 
ice camp area. The Navy will also employ its standard 100-meter 
avoidance distance from any arctic animals. Implementation of these 
measures should ensure that ringed seal lairs are not crushed or 
damaged during ICEX18 activities and minimize the potential for seals 
and pups to abandon lairs and relocate.
    The ringed seal pupping season on the ice lasts for five to nine 
weeks during late winter and spring. Ice camp deployment would begin in 
mid-February and be completed by March 15, before the pupping season. 
This will allow ringed seals to avoid the ice camp area once the 
pupping season begins, thereby reducing potential impacts to nursing 
mothers and pups. Furthermore, ringed seal mothers are known to 
physically move pups from the birth lair to an alternate lair to avoid 
predation. If a ringed seal mother perceives the acoustic transmissions 
as a threat, the local network of multiple birth and haul-out lairs 
would allow the mother and pup to move to a new lair.
    The estimated population of the Alaska stock of ringed seals in the 
Bering Sea is 170,000 animals (Muto et al., 2016). The estimated 
population in the Alaska Chukchi and Beaufort Seas is at least 300,000 
ringed seals, which is likely an underestimate since the Beaufort Sea 
surveys were limited to within 40 km from shore (Kelly et al., 2010). 
Given these population estimates, only a limited percent of the stock 
affected would be taken (i.e. between 0.98 and 0.56 percent).
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
     No serious injury or mortality is anticipated or 
     Impacts will be limited to Level B harassment;
     A small percentage (<1 percent) of the Alaska stock of 
ringed seals would be subject to Level B harassment;

[[Page 6532]]

     TTS is expected to affect only a limited number of 
     There will be no loss or modification of ringed seal 
habitat and minimal, temporary impacts on prey;
     Physical impacts to ringed seal subnivean lairs will be 
avoided; and
     Mitigation requirements for ice camp activities would 
minimize impacts to animals during the pupping season.
    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 planned monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
the planned activity will have a negligible impact on all affected 
marine mammal species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    Impacts to subsistence uses of marine mammals resulting from the 
planned action are not anticipated. The planned action would occur 
outside of the primary subsistence use season (i.e. summer months), and 
the study area is 100-200 nmi seaward of known subsistence use areas. 
Harvest locations for ringed seals extend up to 80 nmi from shore 
during the summer months while winter harvest of ringed seals typically 
occurs closer to shore. Based on this information, NMFS has determined 
that there will not be an unmitigable adverse impact on subsistence 
uses from the Navy's planned activities.

Endangered Species Act (ESA)

    Section 7(a)(2) of the ESA 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 with our ESA Interagency Cooperation Division whenever we 
propose to authorize take for endangered or threatened species.
    No incidental take of ESA-listed species is authorized or expected 
to result from this activity. Therefore, NMFS has determined that 
consultation under section 7 of the ESA is not required for this 


    NMFS has issued an IHA to the Navy for the potential harassment of 
ringed seals incidental to the ICEX18 submarine test and training 
activities in the Beaufort Sea and Arctic Ocean, provided the 
previously described mitigation, monitoring and reporting requirements 
are incorporated.

    Dated: February 8, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
[FR Doc. 2018-03080 Filed 2-13-18; 8:45 am]