[Federal Register Volume 83, Number 148 (Wednesday, August 1, 2018)]
[Proposed Rules]
[Pages 37638-37699]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-16114]



[[Page 37637]]

Vol. 83

Wednesday,

No. 148

August 1, 2018

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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50 CFR Part 219





Taking and Importing Marine Mammals; Taking Marine Mammals Incidental 
to Alaska Fisheries Science Center Fisheries Research; Proposed Rule

Federal Register / Vol. 83 , No. 148 / Wednesday, August 1, 2018 / 
Proposed Rules

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 219

[Docket No. 170127128-8546-01]
RIN 0648-BG64


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Alaska Fisheries Science Center Fisheries Research

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

ACTION: Proposed rule; request for comments.

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SUMMARY: NMFS's Office of Protected Resources (OPR) has received a 
request from NMFS's Alaska Fisheries Science Center (AFSC) for 
authorization to take marine mammals incidental to fisheries research 
conducted in multiple specified geographical regions, over the course 
of five years from the date of issuance. As required by the Marine 
Mammal Protection Act (MMPA), NMFS is proposing regulations to govern 
that take, and requests comments on the proposed regulations. NMFS will 
consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorization and agency responses will 
be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than August 
31, 2018.

ADDRESSES: You may submit comments on this document, identified by 
NOAA-NMFS-2018-0070, by any of the following methods:
    <bullet> Electronic submission: Submit all electronic public 
comments via the federal e-Rulemaking Portal. Go to 
www.regulations.gov/#!docketDetail;D=NOAA-NMFS-2018-0070, click the 
``Comment Now!'' icon, complete the required fields, and enter or 
attach your comments.
    <bullet> Mail: Submit written comments to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service, 1315 East-West Highway, Silver 
Spring, MD 20910.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. All comments received are a part of the 
public record and will generally be posted for public viewing on 
www.regulations.gov without change. All personal identifying 
information (e.g., name, address), confidential business information, 
or otherwise sensitive information submitted voluntarily by the sender 
will be publicly accessible. NMFS will accept anonymous comments (enter 
``N/A'' in the required fields if you wish to remain anonymous). 
Attachments to electronic comments will be accepted in Microsoft Word, 
Excel, or Adobe PDF file formats only.

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

SUPPLEMENTARY INFORMATION: 

Availability

    A copy of AFSC's application and any 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/research.htm. In 
case of problems accessing these documents, please call the contact 
listed above (see FOR FURTHER INFORMATION CONTACT).

Purpose and Need for Regulatory Action

    This proposed rule would establish a framework under the authority 
of the MMPA (16 U.S.C. 1361 et seq.) to allow for the authorization of 
take of marine mammals incidental to the AFSC's fisheries research 
activities in the Gulf of Alaska, Bering Sea, and Arctic Ocean. AFSC's 
request also includes fisheries research activities of the 
International Pacific Halibut Commission (IPHC), which occur in the 
Bering Sea, Gulf of Alaska, and off of the U.S. west coast.
    We received an application from the AFSC requesting five-year 
regulations and authorization to take multiple species of marine 
mammals. Take would occur by Level B harassment incidental to the use 
of active acoustic devices, as well as by visual disturbance of 
pinnipeds, and by Level A harassment, serious injury, or mortality 
incidental to the use of fisheries research gear. Please see 
``Background'' below for definitions of harassment.

Legal Authority for the Proposed Action

    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs 
the Secretary of Commerce 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 for up to five years 
if, after notice and public comment, the agency makes certain findings 
and issues regulations that set forth permissible methods of taking 
pursuant to that activity and other means of effecting the ``least 
practicable adverse impact'' on the affected species or stocks and 
their habitat (see the discussion below in the ``Proposed Mitigation'' 
section), as well as monitoring and reporting requirements. Section 
101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR 
part 216, subpart I provide the legal basis for issuing this proposed 
rule containing five-year regulations, and for any subsequent LOAs. As 
directed by this legal authority, this proposed rule contains 
mitigation, monitoring, and reporting requirements.

Summary of Major Provisions Within the Proposed Rule

    Following is a summary of the major provisions of this proposed 
rule regarding AFSC fisheries research activities. These measures 
include:
    <bullet> Required monitoring of the sampling areas to detect the 
presence of marine mammals before deployment of certain research gear.
    <bullet> Required implementation of the mitigation strategy known 
as the ``move-on rule mitigation protocol'' which incorporates best 
professional judgment, when necessary during certain research fishing 
operations.

Background

    Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1361 et seq.) directs 
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, regulations are issued, and notice is 
provided to the public.
    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 
survival.
    NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 
as

[[Page 37639]]

an impact resulting from the specified activity:
    (1) That is likely to reduce the availability of the species to a 
level insufficient for a harvest to meet subsistence needs by: (i) 
Causing the marine mammals to abandon or avoid hunting areas; (ii) 
directly displacing subsistence users; or (iii) placing physical 
barriers between the marine mammals and the subsistence hunters; and
    (2) That cannot be sufficiently mitigated by other measures to 
increase the availability of marine mammals to allow subsistence needs 
to be met.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).

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 evaluate our proposed action (i.e., the promulgation of 
regulations and subsequent issuance of incidental take authorization) 
and alternatives with respect to potential impacts on the human 
environment.
    Accordingly, NMFS has prepared a draft Environmental Assessment 
(EA; Draft Programmatic Environmental Assessment for Fisheries and 
Ecosystem Research Conducted and Funded by the Alaska Fisheries Science 
Center) to consider the environmental impacts associated with the 
AFSC's proposed activities as well as the issuance of the regulations 
and subsequent incidental take authorization. The EA is posted online 
at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm. Information 
in the EA, AFSC's application, and this notice collectively provide the 
environmental information related to proposed issuance of these 
regulations and subsequent incidental take authorization for public 
review and comment. We will review all comments submitted in response 
to this notice prior to concluding our NEPA process or making a final 
decision on the request for incidental take authorization.

Summary of Request

    On June 28, 2016, we received an adequate and complete request from 
AFSC for authorization to take marine mammals incidental to fisheries 
research activities. On October 18, 2016 (81 FR 71709), we published a 
notice of receipt of AFSC's application in the Federal Register, 
requesting comments and information related to the AFSC request for 
thirty days. We received comments jointly from The Humane Society of 
the United States and Whale and Dolphin Conservation (HSUS/WDC). 
Subsequently, AFSC presented substantive revisions to the application, 
including revisions to the take authorization request as well as 
incorporation of the IPHC fisheries research activities. We received 
this revised application, which was determined to be adequate and 
complete, on September 6, 2017. We then published a notice of its 
receipt in the Federal Register, requesting comments and information 
for thirty days, on September 14, 2017 (82 FR 43223). We received no 
comments in response to this second review period. The original 
comments received from HSUS/WDC were considered in development of this 
proposed rule and are available online at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm.
    AFSC proposes to conduct fisheries research using trawl gear used 
at various levels in the water column, hook-and-line gear (including 
longlines with multiple hooks), gillnets, and other gear. If a marine 
mammal interacts with gear deployed by AFSC, the outcome could 
potentially be Level A harassment, serious injury (i.e., any injury 
that will likely result in mortality), or mortality. Although any given 
gear interaction could result in an outcome less severe than mortality 
or serious injury, we do not have sufficient information to allow 
parsing these potential outcomes. Therefore, AFSC presents a pooled 
estimate of the number of potential incidents of gear interaction and, 
for analytical purposes we assume that gear interactions would result 
in serious injury or mortality. AFSC also uses various active acoustic 
devices in the conduct of fisheries research, and use of these devices 
has the potential to result in Level B harassment of marine mammals. 
Level B harassment of pinnipeds hauled out may also occur, as a result 
of visual disturbance from vessels conducting AFSC research.
    AFSC requests authorization to take individuals of 19 species by 
Level A harassment, serious injury, or mortality (hereafter referred to 
as M/SI) and of 25 species by Level B harassment. The proposed 
regulations would be valid for five years from the date of issuance.

Description of the Specified Activity

Overview

    The AFSC collects a wide array of information necessary to evaluate 
the status of exploited fishery resources and the marine environment. 
AFSC scientists conduct fishery-independent research onboard NOAA-owned 
and operated vessels or on chartered vessels. Such research may also be 
conducted by cooperating scientists on non-NOAA vessels when the AFSC 
helps fund the research. The AFSC proposes to administer and conduct 
approximately 58 survey programs over the five-year period, within 
three separate research areas (some survey programs are conducted 
across more than one research area). The gear types used fall into 
several categories: Towed nets fished at various levels in the water 
column, longline gear, gillnets and seine nets, traps, and other gear. 
Only use of trawl nets, longlines, and gillnets are likely to result in 
interaction with marine mammals. Many of these surveys also use active 
acoustic devices.
    The Federal government has a responsibility to conserve and protect 
living marine resources in U.S. waters and has also entered into a 
number of international agreements and treaties related to the 
management of living marine resources in international waters outside 
the United States. NOAA has the primary responsibility for managing 
marine finfish and shellfish species and their habitats, with that 
responsibility delegated within NOAA to NMFS.
    In order to direct and coordinate the collection of scientific 
information needed to make informed fishery management decisions, 
Congress created six regional fisheries science centers, each a 
distinct organizational entity and the scientific focal point within 
NMFS for region-based Federal fisheries-related research. This research 
is aimed at monitoring fish stock recruitment, abundance, survival and 
biological rates, geographic distribution of species and stocks, 
ecosystem process changes, and marine ecological research. The AFSC is 
the research arm of NMFS in the Alaska region of the United States. The 
AFSC conducts research and provides scientific advice to manage 
fisheries and conserve protected species in the geographic research 
area described below and provides scientific information to support the 
North Pacific Fishery

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Management Council and other domestic and international fisheries 
management organizations.
    The IPHC, established by a convention between the governments of 
Canada and the United States, is an international fisheries 
organization mandated to conduct research on and management of the 
stocks of Pacific halibut (Hippoglossus stenolepis) within the 
Convention waters of both nations. The Northern Pacific Halibut Act of 
1982 (16 U.S.C. 773), which amended the earlier Northern Pacific 
Halibut Act of 1937, is the enabling legislation that gives effect to 
the Convention in the United States. Although operating in U.S. waters 
(and, therefore, subject to the MMPA prohibition on ``take'' of marine 
mammals), the IPHC is not appropriately considered to be a U.S. citizen 
(as defined by the MMPA) and cannot be issued an incidental take 
authorization. For purposes of MMPA compliance, the AFSC sponsors the 
IPHC research activities occurring in U.S. waters, with applicable 
mitigation, monitoring, and reporting requirements conveyed to the IPHC 
via Letters of Acknowledgement issued by the AFSC pursuant to the 
Magnuson-Stevens Fishery Conservation and Management Act (MSA).
    Fishery-independent data necessary to the management of halibut 
stocks is collected using longline gear aboard chartered commercial 
vessels within multiple IPHC regulatory areas, including within U.S. 
waters of the Bering Sea, Gulf of Alaska, and off the U.S. west coast. 
The IPHC proposes to conduct two survey programs over the five-year 
period. IPHC activity and requested take authorization is described in 
Appendix C of AFSC's application.

Dates and Duration

    The specified activity may occur at any time during the five-year 
period of validity of the proposed regulations. Dates and duration of 
individual surveys are inherently uncertain, based on congressional 
funding levels for the AFSC, weather conditions, or ship contingencies. 
In addition, cooperative research is designed to provide flexibility on 
a yearly basis in order to address issues as they arise. Some 
cooperative research projects last multiple years or may continue with 
modifications. Other projects only last one year and are not continued. 
Most cooperative research projects go through an annual competitive 
selection process to determine which projects should be funded based on 
proposals developed by many independent researchers and fishing 
industry participants.

Specified Geographical Region

    The AFSC conducts research in Alaska within three research areas 
considered to be distinct specified geographical regions: the Gulf of 
Alaska Research Area (GOARA), the Bering Sea/Aleutian Islands Research 
Area (BSAIRA), and the Chukchi Sea and Beaufort Sea Research Area 
(CSBSRA). Please see Figures 2-1 through 2-3 in the AFSC application 
for maps of the three research areas. We note here that, while the 
specified geographical regions within which the AFSC operates may 
extend outside of the U.S. Exclusive Economic Zone (EEZ), i.e., into 
the Canadian EEZ (but not including Canadian territorial waters), the 
MMPA's authority does not extend into foreign territorial waters. For 
further information about the specified geographical regions, please 
see the descriptions found in Sherman and Hempel (2009) and Wilkinson 
et al. (2009). As referred to here, productivity refers to fixated 
carbon (i.e., g C/m\2\/yr) and can be related to the carrying capacity 
of an ecosystem.
    The GOARA includes marine waters offshore from Canada north to 
Alaska and west to longitude 170[deg] W, including marine waters in the 
archipelagos of southeast Alaska, Prince William Sound, Cook Inlet, 
Kodiak, and the Alaska Peninsula. The region encompasses fjord-
dominated regions out to the Alaska Panhandle as well as the North 
Pacific slope and basin and is characterized by numerous islands, deep 
fjords, and sheltered straits, as well as significant freshwater runoff 
from numerous rivers. The major oceanographic influence on the region 
is the Alaska Current, and sea ice is generally absent from the region. 
Average sea surface temperatures (SST) are 1-9 [deg]C (winter) and 10-
16 [deg]C (summer), and the region is considered to be of moderately 
high productivity.
    The BSAIRA includes marine waters west of longitude 170[deg] W 
along the Aleutian Islands chain and north to the Bering Strait, 
primarily east of the international date line but also including an 
area west of the date line south of the Gulf of Anadyr. The Bering Sea, 
noted for its high productivity, is the world's third-largest semi-
enclosed water body. This region includes the extremely wide, gradually 
sloping shelf of the Eastern Bering Sea, the narrow shelf and deep 
passes along the Aleutian chain, the deep Aleutian Basin, Kamchatka 
Basin and Bowers Ridge. The continental slope is incised with many 
canyons before dropping to a generally flat abyssal plain. The annual 
formation and retreat of sea ice through the Bering Strait and out over 
the northeast shelf is a major determinant of species distribution. 
Annual SST in the Bering Sea ranges from less than 2 [deg]C (winter) to 
6-14 [deg]C (summer); in the Aleutian Islands annual SST ranges from 1-
10 [deg]C. Areas of note within the region include the Pribilof Islands 
and Bristol Bay.
    The Aleutian Islands archipelago includes approximately 150 islands 
extending about 2,260 km westward from the Alaska Peninsula to the 
Kamchatka Peninsula that create a partial geographic barrier to the 
exchange of northern Pacific marine waters with Eastern Bering Sea 
waters; net circulation flow is from the Bering Sea to the Chukchi Sea 
through the Bering Strait. The Aleutian Islands continental shelf is 
narrow, ranging in width on the north and south sides of the islands 
from about 4 to 46 km, compared with the Eastern Bering Sea shelf, 
which ranges from 600-800 km from the shore to the shelf edge. The 
archipelago is adjacent to the Aleutian Trench, a subduction zone 
characterized by volcanic activity and earthquake zones. Numerous 
straits and passes connect the temperate North Pacific to the subpolar 
Bering Sea; the unique combination of rish nutrients and underwater 
volcanoes has created diverse and abundant coral habitat.
    The CSBSRA includes waters of the Chukchi Sea east of the 
International Date Line and the Beaufort Sea west of the U.S.-Canada 
border within the U.S. EEZ. The region is a relatively shallow marginal 
sea with an extensive continental shelf and is characterized by the 
annual formation and deformation of sea ice. The Chukchi Sea portion is 
shallow (water depths to approximately 100 m), while the Beaufort Sea 
portion consists of narrow, shallow shelf descending to the Arctic 
Ocean slope and plains of the deep Canada Basin. SST is less than 12 
[deg]C in summer and averages 8 [deg]C in the southwest and along the 
Beaufort coast. The area is considered to be of moderately high 
productivity in the summer during ice melt; however, the region is 
considered to be heterogeneous, with the Chukchi more productive than 
the Beaufort. The ice-free zone of the summer is generally about 150-
200 km wide. However, the Arctic climate is changing significantly, and 
one result of the change is a reduction in the sea ice extent in at 
least some regions of the Arctic (e.g., Doney et al., 2012; Melillo et 
al., 2014). Kotzebue Sound is a major coastal region here.
    IPHC research activities are carried out within the BSAIRA and 
GOARA but also within a fourth specified

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geographical region, i.e., off the U.S. west coast (see Figure C-3 of 
the AFSC application). The IPHC operates from 36[deg]40' N 
(approximately Monterey Bay, California) at the southernmost extension 
northward to the Canadian border, including U.S. waters within Puget 
Sound. The California Current Large Marine Ecosystem (off the U.S. west 
coast) is considered to be of moderately high productivity. SST is 
fairly consistent, ranging from 9-14 [deg]C in winter and 13-15 [deg]C 
in summer. Cape Mendocino represents a major biogeographic break, and 
the region includes major estuaries such Puget Sound. The shelf is 
generally narrow in the region, and shelf-break topography (e.g., 
underwater canyons) creates localized upwelling conditions that 
concentrate nutrients into areas of high topographic relief. The 
California Current determines the general hydrography off the coast of 
California. The current moves south along the western coast of North 
America, with extensive seasonal upwelling of colder, nutrient-rich 
subsurface waters predominant in the area south of Cape Mendocino. 
Significant interannual variation in productivity results from the 
effects of this coastal upwelling as well as from the El Ni[ntilde]o-
Southern Oscillation and the Pacific Decadal Oscillation. Both 
oscillations involve transitions from cooler, more productive 
conditions to warmer, less productive conditions but over different 
timescales.
    IPHC conducts research within Puget Sound, which is affected by 
high amounts of runoff from the Fraser River. The river plume 
stimulates primary productivity, carrying nutrients northwards past 
Vancouver Island year-round. Puget Sound is one of the largest 
estuaries in the United States and is a place of great physical and 
ecological complexity and productivity. The average surface water 
temperature is 12.8 [deg]C in summer and 7.2 [deg]C in winter (Staubitz 
et al., 1997), but surface waters frequently exceed 20 [deg]C in the 
summer and fall. With nearly six million people (doubled since the 
1960s), Puget Sound is also heavily influenced by human activity.

Detailed Description of Activities

    The Federal government has a trust responsibility to protect living 
marine resources in waters of the United States. These waters extend to 
200 nm from the shoreline and include the EEZ. The U.S. government has 
also entered into a number of international agreements and treaties 
related to the management of living marine resources in international 
waters outside of the EEZ (i.e., the high seas). To carry out its 
responsibilities over U.S. and international waters, Congress has 
enacted several statutes authorizing certain Federal agencies to 
administer programs to manage and protect living marine resources. 
Among these Federal agencies, NOAA has the primary responsibility for 
protecting marine finfish and shellfish species and their habitats. 
Within NOAA, NMFS has been delegated primary responsibility for the 
science-based management, conservation, and protection of living marine 
resources under statutes including the MSA, MMPA, and the Endangered 
Species Act (ESA). As noted above, the IPHC conducts research in 
support of halibut management under the terms of a convention between 
the United States and Canada, originally ratified in 1924 and amended 
most recently in 1979.
    Within NMFS, six regional fisheries science centers direct and 
coordinate the collection of scientific information needed to inform 
fisheries management decisions. Each science center is a distinct 
entity and is the scientific focal point for a particular region. AFSC 
conducts research and provides scientific advice to manage fisheries 
and conserve protected species in Alaska. AFSC provides scientific 
information to support the North Pacific Fishery Management Council and 
other domestic and international fisheries management organizations.
    The AFSC collects a wide array of information necessary to evaluate 
the status of exploited fishery resources and the marine environment. 
AFSC scientists conduct fishery-independent research onboard NOAA-owned 
and operated vessels or on chartered vessels, and some AFSC-funded 
research is conducted by cooperative scientists. The AFSC proposes to 
administer and conduct approximately 58 survey programs over the five-
year period, with an additional two survey programs conducted by the 
IPHC.
    The gear types used fall into several categories: Towed nets fished 
at various levels in the water column, longline gear, gillnets and 
seine nets, traps, and other gear. Only use of trawl nets, longlines, 
and gillnets are likely to result in interaction with marine mammals. 
Many of these surveys also use active acoustic devices. These surveys 
may be conducted aboard NOAA-operated research vessels (R/V), including 
the Oscar Dyson and Fairweather, the Alaska Department of Fish and 
Game-operated Resolution, and assorted other small vessels owned by 
AFSC, aboard vessels owned and operated by cooperating agencies and 
institutions, or aboard charter vessels.
    In the following discussion, we summarily describe various gear 
types used by AFSC, with reference to specific fisheries and ecosystem 
research activities conducted by the AFSC. This is not an exhaustive 
list of gear and/or devices that may be utilized by AFSC but is 
representative of gear categories and is complete with regard to all 
gears with potential for interaction with marine mammals. Additionally, 
relevant active acoustic devices, which are commonly used in AFSC 
survey activities, are described separately in a subsequent section. 
Please see Appendix A of AFSC's application for further description, 
pictures, and diagrams of research gear and vessels. Full details 
regarding planned research activities are provided in Tables 1-1 and C-
1 of AFSC's application, with specific gear used in association with 
each research project and full detail regarding gear characteristics 
and usage provided. Full detail is not repeated here.
    Trawl nets--A trawl is a funnel-shaped net towed behind a boat to 
capture fish. The codend (or bag) is the fine-meshed portion of the net 
most distant from the towing vessel where fish and other organisms 
larger than the mesh size are retained. In contrast to commercial 
fishery operations, which generally use larger mesh to capture 
marketable fish, research trawls often use smaller mesh to enable 
estimates of the size and age distributions of fish in a particular 
area. The body of a trawl net is generally constructed of relatively 
coarse mesh that functions to gather schooling fish so that they can be 
collected in the codend. The opening of the net, called the mouth, is 
extended horizontally by large panels of wide mesh called wings. The 
mouth of the net is held open by hydrodynamic force exerted on the 
trawl doors attached to the wings of the net. As the net is towed 
through the water, the force of the water spreads the trawl doors 
horizontally apart. The top of a net is called the headrope, and the 
bottom is called the footrope. Bottom trawls may use bobbins or roller 
gear to protect the footrope as the net is dragged along the seabed.
    The trawl net is usually deployed over the stern of the vessel and 
attached with two cables (or warps) to winches on the deck of the 
vessel. The cables are played out until the net reaches the fishing 
depth. Trawl vessels typically travel at speeds of 2-5 kn while towing 
the net for time periods up to several hours. The duration of the tow 
depends on the purpose of the trawl, the catch rate, and the target 
species. At the end of the tow the net is retrieved and the

[[Page 37642]]

contents of the codend are emptied onto the deck. For research 
purposes, the speed and duration of the tow and the characteristics of 
the net are typically standardized to allow meaningful comparisons of 
data collected at different times and locations. Active acoustic 
devices (described later) incorporated into the research vessel and the 
trawl gear monitor the position and status of the net, speed of the 
tow, and other variables important to the research design.
    AFSC research trawling activities utilize pelagic (or midwater) and 
surface trawls, which are designed to operate at various depths within 
the water column but not to contact the seafloor, as well as bottom 
trawls. Some research efforts use various commercial trawl nets 
(commercial midwater trawls may be 75-136 m in width with opening 
height of 10-20 m, while commercial bottom trawls may be 18-24 m in 
width with 4-8 m opening height), while others use specific trawls. 
Examples of the latter include the Poly Nor'eastern bottom trawl, which 
has a 27.2-m headrope, 24.9-m footrope, and 5.8-m vertical opening; 
otter bottom trawl with 6-m headrope; the 83-112 Eastern bottom trawl, 
with 25-m headrope and 34-m footrope; Kodiak bottom trawl (3 m x 4 m x 
8 m); the 20 m x 20 m Nordic 264 midwater trawl; 12 m x 12 m midwater 
anchovy trawl (midwater); Cantrawl surface trawl, with 55-m width and 
25-m depth; and Aleutian wing pelagic trawl, with 82.3-m footrope/
headrope and a 27.4-m vertical opening. Tow durations are typically 10-
30 min (though some experimental trawls may be conducted for much 
longer, i.e., a period of hours), with tow depths dependent on the 
purpose of the survey.
    AFSC also uses beam trawls, a type of bottom trawl in which the 
horizontal opening of the net is provided by a heavy beam mounted at 
each end on guides or skids that travel along the seabed. AFSC beam 
trawls are 1 m x 1m. On sandy or muddy bottoms, a series of ``tickler'' 
chains are strung between the skids ahead of the net to stir up the 
fish from the seabed and chase them into the net. On rocky grounds, 
these ticklers may be replaced with chain matting. Several trawls may 
be towed, one on each side of the vessel. The trawls are towed along 
the seafloor at speeds of 1 to 2 kn. In some shallow, nearshore 
locations, push trawls may be used, i.e., vessels push nets.
    Longline--Longline vessels fish with baited hooks attached to a 
mainline (or groundline). The length of the longline and the number of 
hooks depend on the species targeted, the size of the vessel, and the 
purpose of the fishing activity. Hooks are attached to the mainline by 
another thinner line called a gangion. The length of the gangion and 
the distance between gangions depends on the purpose of the fishing 
activity. Depending on the fishery, longline gear can be deployed on 
the seafloor (bottom longline), in which case weights are attached to 
the mainline, or near the surface of the water (pelagic longline), in 
which case buoys are attached to the mainline to provide flotation and 
keep the baited hooks suspended in the water. Radar reflectors, radio 
transmitters, and light sources are often used to help fishers 
determine the location of the longline gear prior to retrieval. 
Segments of bottom longline gear, which are connected to form a single 
continuous mainline, are often referred to as skates.
    A commercial longline can be miles long and have thousands of hooks 
attached, although longlines used for research surveys are often 
shorter. However, the longline gear used for AFSC research surveys is 
typically similar in scale to commercial gear, with 16-km mainlines and 
7,200 hooks. IPHC gear consists of 1,800-ft (549-m) skates, with 100 
hooks per skate. Three to ten skates may be fished at each sampling 
station. There are no internationally-recognized standard measurements 
for hook size, and a given size may be inconsistent between 
manufacturers. Larger hooks, as are used in longlining, are referenced 
by increasing whole numbers followed by a slash and a zero as size 
increases (e.g., 1/0 up to 20/0). The numbers represent relative sizes, 
normally associated with the gap (the distance from the point tip to 
the shank).
    The time period between deployment and retrieval of the longline 
gear is the soak time. Soak time is an important parameter for 
calculating fishing effort. For commercial fisheries the goal is to 
optimize the soak time in order to maximize catch of the target species 
while minimizing the bycatch rate and minimizing damage to target 
species that may result from predation by sharks or other predators. 
AFSC soak times range from 2-3 hours, while IPHC soak times are 
typically 5 hours. AFSC also uses hook-and-line, i.e., rod-and-reel, 
for some survey efforts, totaling approximately 240 rod-hrs per year 
over 5 days.
    Other nets--AFSC surveys utilize various small, fine-mesh, towed 
nets designed to sample small fish and pelagic invertebrates. These 
nets can be broadly categorized as small trawls (which are separated 
from large trawl nets due to small trawls' discountable potential for 
interaction with marine mammals; see ``Potential Effects of the 
Specified Activity on Marine Mammals and their Habitat'') and plankton 
nets.
    1. The Tucker trawl is a medium-sized single-warp net used to study 
pelagic fish and zooplankton. The Tucker trawl consists of a series of 
nets that can be opened and closed sequentially via stepping motor 
without retrieving the net from the fishing depth. It is designed for 
deep oblique tows where up to three replicate nets can be sequentially 
operated by a double release mechanism and is typically equipped with a 
full suite of instruments, including inside and outside flow meters; 
conductivity, temperature, and depth profilers (CTD); and pitch sensor.
    2. The Multiple Opening/Closing Net and Environmental Sensing 
System (MOCNESS) uses a stepping motor to sequentially control the 
opening and closing of the net. The MOCNESS uses underwater and 
shipboard electronics to control the device. The electronics system 
continuously monitors the functioning of the nets, frame angle, 
horizontal velocity, vertical velocity, volume filtered, and selected 
environmental parameters, such as salinity and temperature. The MOCNESS 
is used for specialized zooplankton surveys.
    3. AFSC also uses various neuston nets, which are frame trawls 
towed horizontally at the top of the water column in order to capture 
neuston (i.e., organisms that inhabit the water's surface).
    4. An epibenthic tow sled is an instrument designed to collect 
organisms that live on bottom sediments. It consists of a fine mesh 
net, typically 1 m x 1 m opening, attached to a rigid frame with 
runners to help it move along the substrate.
    The remainder of nets described here are plankton nets, which 
usually consist of fine mesh attached to a weighted frame which spreads 
the mouth of the net to cover a known surface area in order to sample 
plankton and fish eggs from various parts of the water column.
    5. Ring nets are used to capture plankton with vertical tows. These 
nets consist of a circular frame and a cone-shaped net with a 
collection jar at the codend. The net, attached to a labeled dropline, 
is lowered into the water while maintaining the net's vertical 
position. When the desired depth is reached, the net is pulled straight 
up through the water column to collect the sample.
    6. Bongo nets are towed through the water at an oblique angle to 
sample plankton over a range of depths. Similar to ring nets, these 
nets typically have a

[[Page 37643]]

cylindrical section coupled to a conical portion that tapers to a 
detachable codend constructed of nylon mesh. During each plankton tow, 
the bongo nets are deployed to depth and are then retrieved at a 
controlled rate so that the volume of water sampled is uniform across 
the range of depths. A collecting bucket, attached to the codend of the 
net, is used to contain the plankton sample. Some bongo nets can be 
opened and closed using remote control to enable the collection of 
samples from particular depth ranges. A group of depth-specific bongo 
net samples can be used to establish the vertical distribution of 
zooplankton species in the water column at a site. Bongo nets are 
generally used to collect zooplankton for research purposes and are not 
used for commercial harvest.
    Gillnets--Gillnets consist of vertical netting held in place by 
floats and weights to selectively target fish of uniform size depending 
on the netting size. Typical gillnets consist of monofilament, multi-
monofilament, or multifilament nylon constructed of single, double, or 
triple netting/paneling of varying mesh sizes, depending on their use 
and target species. A specific mesh size will catch a target species of 
a limited size range, allowing this gear type to be very selective. 
Some AFSC survey activities use small gillnets (10 m x 2 m) with 30-
minute set durations; however, gillnet survey activities at Little Port 
Walter Marine Station in southeast Alaska use larger nets (150 ft x 15 
ft (46 m x 5 m)) with longer soak times (2-4 hours).
    Seine nets--Seine nets typically hang vertically in the water with 
the bottom edge held down by weights and the top edge buoyed by floats. 
Seine nets can be deployed from the shore as a beach seine or from a 
boat and are actively fished, in comparison with gillnets which may be 
similar but fish passively. AFSC uses beach seines, which are deployed 
from shore to surround all fish in the nearshore area, and typically 
have one end fastened to the shore while the other end is set out in a 
wide arc and brought back to the beach. This may be done by hand or 
with a small boat. AFSC research uses some larger beach seines (61 m x 
5 m) as well as smaller nets (5 m x 2.5 m). A pole seine is a type of 
beach seine deployed by hand. The net is pulled along the bottom by 
hand as two or more people hold the poles and walk through the water. 
Fish and other organisms are captured by walking the net towards shore 
or tilting the poles backwards and lifting the net out of the water.
    Traps and pots--Traps and pots are submerged, three-dimensional 
devices, often baited, that permit organisms to enter the enclosure but 
make escape extremely difficult or impossible. Most traps are attached 
by a rope to a buoy on the surface of the water and may be deployed in 
series. The trap entrance can be regulated to control the maximum size 
of animal that can enter, and the size of the mesh in the body of the 
trap can regulate the minimum size that is retained. In general, the 
species caught depends on the type and characteristics of the pot or 
trap used. AFSC uses fyke traps and crab pots of various sizes.
    Fyke traps are bag-shaped nets held open by frames or hoops, often 
outfitted with wings and/or leaders to guide fish towards the entrance 
of the actual trap. Fyke trap wings can be set up to form a barrier 
across a channel, trapping fish that attempt to proceed through the 
channel. As the tide ebbs, fish eventually seek to leave the wetland 
channel and are then trapped. AFSC sets fyke traps that are 
approximately 40 m wide; however, these are only used in freshwater. 
AFSC also uses net pens, hoop nets, and weirs for some research.
    Dredge--A typical dredge consists of a mouth frame with an attached 
collection bag. Fishers drag a dredge across the sea floor, either 
scraping or penetrating the bottom. Scraping dredges collect target 
species (e.g., oysters, scallops, clams, and mussels) in the top layer 
of seafloor sediment with rakes or teeth that scoop up the substrate. 
AFSC uses a six foot wide Virginia crab style dredge, which consists of 
a heavy metal rectangular form bearing a toothed drag bar and a mesh 
bag to collect specimens.
    Conductivity, temperature, and depth profilers--A CTD profiler is 
the primary research tool for determining chemical and physical 
properties of seawater. A shipboard CTD is made up of a set of small 
probes attached to a large (1-2 m diameter) metal rosette wheel. The 
rosette is lowered through the water column on a cable, and CTD data 
are observed in real time via a conducting cable connecting the CTD to 
a computer on the ship. The rosette also holds a series of sampling 
bottles that can be triggered to close at different depths in order to 
collect a suite of water samples that can be used to determine 
additional properties of the water over the depth of the CTD cast. A 
standard CTD cast, depending on water depth, requires two to five hours 
to complete. The data from a suite of samples collected at different 
depths are often called a depth profile. Depth profiles for different 
variables can be compared in order to glean information about physical, 
chemical, and biological processes occurring in the water column. 
Salinity, temperature, and depth data measured by the CTD instrument 
are essential for characterization of seawater properties.
    Tables 1-1 and C-1 of the AFSC's application provide detailed 
information of all surveys planned by AFSC and IPHC; full detail is not 
repeated here. We note here that IPHC survey activities do not use 
active acoustic systems for data acquisition purposes. Therefore, we do 
not consider the potential for Level B harassment that may result from 
use of such systems other than for AFSC research programs in the GOARA, 
BSAIRA, and CSBSRA. Many of these surveys also use small trawls, 
plankton nets, and/or other gear; however, only gear with likely 
potential for marine mammal interaction is described. Here we provide a 
summary of projected annual survey effort in the different research 
areas for those gears that we believe present the potential for marine 
mammal interaction (Table 1). This summary is intended only to provide 
a sense of the level of effort, and actual level of effort may vary 
from year to year. Gear specifications vary; please see Tables 1-1 and 
C-1 of AFSC's application.

                   Table 1--Projected Annual AFSC Survey Effort by Research Area and Gear Type
----------------------------------------------------------------------------------------------------------------
          Survey type                  Gear type               Tows/sets              Duration per tow/set
----------------------------------------------------------------------------------------------------------------
                                                      GOARA
----------------------------------------------------------------------------------------------------------------
Bottom trawl..................  Poly Nor-Eastern (PNE)  59....................  10 min.
Bottom trawl..................  Eastern otter.........  380...................  10-25 min.
Bottom trawl..................  Various (commercial)..  20-40.................  45 min to 6.5 hr.
Bottom trawl..................  To be determined......  50....................  20 min.
Bottom trawl..................  PNE...................  820...................  15 min.
Bottom trawl..................  PNE...................  70....................  15-30 min.

[[Page 37644]]

 
Bottom trawl..................  PNE...................  20....................  10-20 min.
Bottom trawl..................  PNE...................  20....................  variable.
Bottom trawl..................  Various (commercial)..  4-8...................  5-10 min.
Bottom trawl..................  Various (commercial)..  6-8...................  5-45 min.
Midwater trawl................  Various (commercial)..  20-40.................  45 min to 3 hr.
Midwater trawl................  Anchovy...............  50-75.................  Up to 1 hr.
Midwater trawl................  Otter.................  20....................  20 min.
Midwater trawl................  Nordic 264............  96....................  20 min.
Midwater trawl................  Cantrawl..............  80....................  30 min.
Midwater trawl................  Aleutian wing (AWT)...  140...................  10 min to 1 hr.
Gillnet.......................  10 m x 2 m............  10....................  30 min.
Gillnet.......................  46 m x 5 m............  50....................  2-4 hr.
Bottom longline...............  7,200 hooks (13/0)....  95....................  3 hr.
Bottom longline...............  < 300 hooks (13/0)....  7.....................  2 hr.
----------------------------------------------------------------------------------------------------------------
                                                     BSAIRA
----------------------------------------------------------------------------------------------------------------
Bottom trawl..................  PNE...................  420...................  15 min.
Bottom trawl..................  PNE...................  70....................  15-30 min.
Bottom trawl..................  Bering Sea Combo 101/   Variable (average 88).  10-90 min.
                                 130.
Bottom trawl..................  83-112 Eastern otter..  536...................  30 min.
Bottom trawl..................  83-112 Eastern otter..  15....................  variable.
Bottom trawl..................  Various (commercial)..  40-90.................  45 min to 6.5 hr
Bottom trawl..................  PNE...................  10....................  variable.
Bottom trawl..................  PNE...................  200...................  30 min.
Bottom trawl..................  To be determined......  50....................  20 min.
Midwater trawl................  Marinovich............  35....................  15-60 min.
Midwater trawl................  Cantrawl..............  185...................  30 min.
Midwater trawl................  Various (commercial)..  40-90.................  45 min to 3 hr.
Midwater trawl................  Anchovy...............  100-125...............  variable.
Midwater trawl................  AWT...................  110...................  10 min to 1 hr.
Bottom longline...............  7,200 hooks (13/0)....  75....................  3 hr.
----------------------------------------------------------------------------------------------------------------
                                                     CSBSRA
----------------------------------------------------------------------------------------------------------------
Bottom trawl..................  83-112 Eastern otter..  143...................  15 min.
Midwater trawl................  Cantrawl..............  70....................  30 min.
----------------------------------------------------------------------------------------------------------------

    Please note that Table 1 does not include projected survey effort 
by IPHC. IPHC uses bottom longline gear to sample between an estimated 
1,100 and 1,300 survey stations in U.S. waters per year. Although the 
number of survey stations is estimated, IPHC states that the maximum 
number of stations would not exceed 1,500. At each station, IPHC fishes 
3-10 skates of longline gear, each with 100 hooks (16/0), for a soak 
time of 5 hours at each station. Hooks are spaced at 18-ft (5.5-m) 
intervals on 24- to 48-in (0.6- to 1.2-m) gangions. Survey stations are 
located in water depths from 18-732 m in shelf waters. Please see 
Figures C-3 through C-5 for depictions of IPHC's survey station 
distribution.
    IPHC also conducts survey effort in order to collect specimens of 
halibut gonads on a monthly basis. Gear is not standardized for these 
surveys and would be that which is typically used by the commercial 
halibut and sablefish fleet. Gear differences are not expected to 
differentially affect marine mammals, which interact similarly with all 
of these commercial gears. IPHC requires collection of 50 male and 50 
female specimens per month and estimates that this requires 
approximately 50 total annual days at sea.
    Description of Active Acoustic Sound Sources--This section contains 
a brief technical background on sound, the characteristics of certain 
sound types, and on metrics used in this proposal inasmuch as the 
information is relevant to AFSC's specified activity and to a 
discussion of the potential effects of the specified activity on marine 
mammals found later in this document. We also describe the active 
acoustic devices used by AFSC. As noted previously, IPHC does not use 
active acoustic devices for data acquisition purposes. For general 
information on sound and its interaction with the marine environment, 
please see, e.g., Au and Hastings (2008); Richardson et al. (1995); 
Urick (1983).
    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 or corresponding points of a sound wave (length of 
one cycle). Higher frequency sounds have shorter wavelengths than lower 
frequency sounds, and typically attenuate (decrease) more rapidly, 
except in certain cases in shallower water. Amplitude is the height of 
the sound pressure wave or the ``loudness'' of a sound and is typically 
described using the relative unit of the dB. A sound pressure level 
(SPL) in dB is described as the ratio between a measured pressure and a 
reference pressure (for underwater sound, this is 1 microPascal 
([mu]Pa)) and is a logarithmic unit that accounts for large variations 
in amplitude; therefore, a relatively small change in dB corresponds to 
large changes in sound pressure. The source level (SL) represents the 
SPL referenced at a distance of 1 m from the source (referenced to 1 
[mu]Pa), while the received level is the SPL at the listener's position 
(referenced to 1 [mu]Pa).
    Root mean square (rms) is the quadratic mean sound pressure over 
the

[[Page 37645]]

duration of an impulse. Root mean square is calculated by squaring all 
of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square 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.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy in a stated frequency band over a stated 
time interval or event, and considers both intensity and duration of 
exposure. The per-pulse SEL is calculated over the time window 
containing the entire pulse (i.e., 100 percent of the acoustic energy). 
SEL is a cumulative metric; it can be accumulated over a single pulse, 
or calculated over periods containing multiple pulses. Cumulative SEL 
represents the total energy accumulated by a receiver over a defined 
time window or during an event.
    Peak sound pressure (also referred to as zero-to-peak sound 
pressure or 0-pk) is the maximum instantaneous sound pressure 
measurable in the water at a specified distance from the source and is 
represented in the same units as the rms sound pressure. Another common 
metric is peak-to-peak sound pressure (pk-pk), which is the algebraic 
difference between the peak positive and peak negative sound pressures. 
Peak-to-peak pressure is typically approximately 6 dB higher than peak 
pressure (Southall et al., 2007).
    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 a 
manner similar to ripples on the surface of a pond and may be either 
directed in a beam or beams (as for the sources considered here) or may 
radiate in all directions (omnidirectional sources). 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, which is 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). 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., wind and 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
(e.g., vessels, dredging, construction) sound. A number of sources 
contribute to ambient sound, including wind and waves, which are a main 
source of naturally occurring ambient sound for frequencies between 200 
hertz (Hz) and 50 kilohertz (kHz) (Mitson, 1995). In general, ambient 
sound levels tend to increase with increasing wind speed and wave 
height. Precipitation can become an important component of total sound 
at frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times. Marine mammals can contribute significantly to ambient sound 
levels, as can some fish and snapping shrimp. The frequency band for 
biological contributions is from approximately 12 Hz to over 100 kHz. 
Sources of ambient sound related to human activity include 
transportation (surface vessels), dredging and construction, oil and 
gas drilling and production, geophysical surveys, sonar, and 
explosions. Vessel noise typically dominates the total ambient sound 
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.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human 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 decibels (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. Details of source types are described in the following 
text.
    Sounds are often considered to fall into one of two general types: 
pulsed and non-pulsed (defined in the following). 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. 
The distinction between these two sound types is not always obvious, as 
certain signals share properties of both pulsed and non-pulsed sounds. 
A signal near a source could be categorized as a pulse; but, due to 
propagation effects as it moves farther from the source, the signal 
duration becomes longer (e.g., Greene and Richardson, 1988).
    Pulsed sound sources (e.g., airguns, 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, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed 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-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems. The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.
    We use generic sound exposure thresholds of 160 dB rms SPL and 120 
dB rms SPL to determine when an activity that produces impulsive or 
continuous sound, respectively, might result in impacts to a marine 
mammal such that a take by Level B harassment might occur. These 
thresholds should be considered guidelines for estimating when 
harassment may occur (i.e., when an animal is exposed to levels equal 
to or exceeding the relevant criterion) in specific contexts; however, 
useful contextual information that may inform our assessment of effects 
is typically

[[Page 37646]]

lacking and we consider these thresholds as step functions.
    As noted above, continuous sounds are those whose sound pressure 
level remains above that of the ambient sound, with negligibly small 
fluctuations in level, while intermittent sounds are defined as sounds 
with interrupted levels of low or no sound. Thus, echosounder signals 
are not continuous sounds but rather intermittent sounds. Intermittent 
sounds can further be defined as either impulsive or non-impulsive. 
Similar to impulsive sounds, echosounder signals have durations that 
are typically very brief (< 1 sec) and have temporal characteristics 
that more closely resemble those of impulsive sounds than non-impulsive 
sounds, which typically have more gradual rise times and longer decays. 
With regard to behavioral thresholds, we consider the temporal and 
spectral characteristics of echosounder signals to more closely 
resemble those of an impulse sound than a continuous sound. Therefore, 
NMFS has determined that the 160-dB threshold for impulsive sources is 
most appropriate for use in considering the potential effects of the 
AFSC's activities.
    A wide range of active acoustic devices are used in AFSC fisheries 
surveys for remotely sensing bathymetric, oceanographic, and biological 
features of the environment. Most of these sources involve relatively 
high frequency, directional, and brief repeated signals tuned to 
provide sufficient focus and resolution on specific objects. AFSC also 
uses passive listening sensors (i.e., remotely and passively detecting 
sound rather than producing it), which do not have the potential to 
impact marine mammals. AFSC active acoustic sources include various 
echosounders (e.g., multibeam systems), scientific sonar systems, 
positional sonars (e.g., net sounders for determining trawl position), 
and environmental sensors (e.g., current profilers).
    Mid- and high-frequency underwater acoustic sources typically used 
for scientific purposes operate by creating an oscillatory overpressure 
through rapid vibration of a surface, using either electromagnetic 
forces or the piezoelectric effect of some materials. A vibratory 
source based on the piezoelectric effect is commonly referred to as a 
transducer. Transducers are usually designed to excite an acoustic wave 
of a specific frequency, often in a highly directive beam, with the 
directional capability increasing with operating frequency. The main 
parameter characterizing directivity is the beam width, defined as the 
angle subtended by diametrically opposite ``half power'' (-3 dB) points 
of the main lobe. For different transducers at a single operating 
frequency the beam width can vary from 180[deg] (almost 
omnidirectional) to only a few degrees. Transducers are usually 
produced with either circular or rectangular active surfaces. For 
circular transducers, the beam width in the horizontal plane (assuming 
a downward pointing main beam) is equal in all directions, whereas 
rectangular transducers produce more complex beam patterns with 
variable beam width in the horizontal plane. Please see Zykov and Carr 
(2014) for further discussion of electromechanical sound sources.
    The types of active sources employed in fisheries acoustic research 
and monitoring may be considered in two broad categories here (Category 
1 and Category 2), based largely on their respective operating 
frequency (e.g., within or outside the known audible range of marine 
species) and other output characteristics (e.g., signal duration, 
directivity). As described below, these operating characteristics 
result in differing potential for acoustic impacts on marine mammals.
    Category 1 active fisheries acoustic sources include those with 
high output frequencies (>180 kHz) that are outside the known 
functional hearing capability of any marine mammal. Sounds that are 
above the functional hearing range of marine animals may be audible if 
sufficiently loud (e.g., M[oslash]hl, 1968). However, the relative 
output levels of these sources mean that they would potentially be 
detectable to marine mammals at maximum distances of only a few meters, 
and are highly unlikely to be of sufficient intensity to result in 
behavioral harassment. These sources also generally have short duration 
signals and highly directional beam patterns, meaning that any 
individual marine mammal would be unlikely to even receive a signal 
that would almost certainly be inaudible.
    We are aware of two studies (Deng et al., 2014; Hastie et al., 
2014) demonstrating some behavioral reaction by marine mammals to 
acoustic systems operating at user-selected frequencies above 200 kHz. 
These studies generally indicate only that sub-harmonics could be 
detectable by certain species at distances up to several hundred 
meters. However, this detectability is in reference to ambient noise, 
not to NMFS's established 160-dB threshold for assessing the potential 
for incidental take for these sources. Source levels of the secondary 
peaks considered in these studies--those within the hearing range of 
some marine mammals--range from 135-166 dB, meaning that these sub-
harmonics would either be below levels likely to result in Level B 
harassment or would attenuate to such a level within a few meters. 
Beyond these important study details, these high-frequency (i.e., 
Category 1) sources and any energy they may produce below the primary 
frequency that could be audible to marine mammals would be dominated by 
a few primary sources that are operated near-continuously, and the 
potential range above threshold would be so small as to essentially 
discount them. Therefore, Category 1 sources are not expected to have 
any effect on marine mammals. Further, recent sound source verification 
testing of these and other similar systems did not observe any sub-
harmonics in any of the systems tested under controlled conditions 
(Crocker and Fratantonio, 2016). While this can occur during actual 
operations, the phenomenon may be the result of issues with the system 
or its installation on a vessel rather than an issue that is inherent 
to the output of the system. Category 1 sources are not considered 
further in this document.
    Category 2 acoustic sources, which are present on most AFSC fishery 
research vessels, include a variety of single, dual, and multi-beam 
echosounders (many with a variety of modes), sources used to determine 
the orientation of trawl nets, and several current profilers with lower 
output frequencies than Category 1 sources. Category 2 active acoustic 
sources have moderate to high output frequencies (10 to 180 kHz) that 
are generally within the functional hearing range of marine mammals and 
therefore have the potential to cause behavioral harassment. However, 
while likely potentially audible to certain species, these sources have 
generally short ping durations and are typically focused (highly 
directional) to serve their intended purpose of mapping specific 
objects, depths, or environmental features. These characteristics 
reduce the likelihood of an animal receiving or perceiving the signal. 
A number of these sources, particularly those with relatively lower 
output frequencies coupled with higher output levels can be operated in 
different output modes (e.g., energy can be distributed among multiple 
output beams) that may lessen the likelihood of perception by and 
potential impact on marine mammals.
    We now describe specific acoustic sources used by AFSC. The 
acoustic system used during a particular survey is optimized for 
surveying under specific environmental conditions (e.g., depth and 
bottom type). Lower frequencies of sound travel further in

[[Page 37647]]

the water (i.e., good range) but provide lower resolution (i.e., are 
less precise). Pulse width and power may also be adjusted in the field 
to accommodate a variety of environmental conditions. Signals with a 
relatively long pulse width travel further and are received more 
clearly by the transducer (i.e., good signal-to-noise ratio) but have a 
lower range resolution. Shorter pulses provide higher range resolution 
and can detect smaller and more closely spaced objects in the water. 
Similarly, higher power settings may decrease the utility of collected 
data. Power level is also adjusted according to bottom type, as some 
bottom types have a stronger return and require less power to produce 
data of sufficient quality. Power is typically set to the lowest level 
possible in order to receive a clear return with the best data. Survey 
vessels may be equipped with multiple acoustic systems; each system has 
different advantages that may be utilized depending on the specific 
survey area or purpose. In addition, many systems may be operated at 
one of two frequencies or at a range of frequencies. Primary source 
categories are described below, and characteristics of representative 
predominant sources are summarized in Table 2. Predominant sources are 
those that, when operated, would be louder than and/or have a larger 
acoustic footprint than other concurrently operated sources, at 
relevant frequencies.
    (1) Multi-Frequency Narrow Beam Scientific Echosounders--
Echosounders and sonars work by transmitting acoustic pulses into the 
water that travel through the water column, reflect off the seafloor, 
and return to the receiver. Water depth is measured by multiplying the 
time elapsed by the speed of sound in water (assuming accurate sound 
speed measurement for the entire signal path), while the returning 
signal itself carries information allowing ``visualization'' of the 
seafloor. Multi-frequency split-beam sensors are deployed from AFSC 
survey vessels to acoustically map the distributions and estimate the 
abundances and biomasses of many types of fish; characterize their 
biotic and abiotic environments; investigate ecological linkages; and 
gather information about their schooling behavior, migration patterns, 
and avoidance reactions to the survey vessel. The use of multiple 
frequencies allows coverage of a broad range of marine acoustic survey 
activity, ranging from studies of small plankton to large fish schools 
in a variety of environments from shallow coastal waters to deep ocean 
basins. Simultaneous use of several discrete echosounder frequencies 
facilitates accurate estimates of the size of individual fish, and can 
also be used for species identification based on differences in 
frequency-dependent acoustic backscattering between species.
    (2) Multibeam Echosounder and Sonar--Multibeam echosounders and 
sonars operate similarly to the devices described above. However, the 
use of multiple acoustic ``beams'' allows coverage of a greater area 
compared to single beam sonar. The sensor arrays for multibeam 
echosounders and sonars are usually mounted on the keel of the vessel 
and have the ability to look horizontally in the water column as well 
as straight down. Multibeam echosounders and sonars are used for 
mapping seafloor bathymetry, estimating fish biomass, characterizing 
fish schools, and studying fish behavior.
    (3) Single-Frequency Omnidirectional Sonar--These sources provide 
omnidirectional imaging around the source with different vertical 
beamwidths available, which results in differential transmitting beam 
patterns. The cylindrical multi-element transducer allows the 
omnidirectional sonar beam to be electronically tilted down to -
90[deg], allowing automatic tracking of schools of fish within the 
entire water volume around the vessel.
    (4) Acoustic Doppler Current Profiler (ADCP)--An ADCP is a type of 
sonar used for measuring water current velocities simultaneously at a 
range of depths. Whereas current depth profile measurements in the past 
required the use of long strings of current meters, the ADCP enables 
measurements of current velocities across an entire water column. The 
ADCP measures water currents with sound, using the Doppler effect. A 
sound wave has a higher frequency when it moves towards the sensor 
(blue shift) than when it moves away (red shift). The ADCP works by 
transmitting ``pings'' of sound at a constant frequency into the water. 
As the sound waves travel, they ricochet off particles suspended in the 
moving water, and reflect back to the instrument. Due to the Doppler 
effect, sound waves bounced back from a particle moving away from the 
profiler have a slightly lowered frequency when they return. Particles 
moving toward the instrument send back higher frequency waves. The 
difference in frequency between the waves the profiler sends out and 
the waves it receives is called the Doppler shift. The instrument uses 
this shift to calculate how fast the particle and the water around it 
are moving. Sound waves that hit particles far from the profiler take 
longer to come back than waves that strike close by. By measuring the 
time it takes for the waves to return to the sensor, and the Doppler 
shift, the profiler can measure current speed at many different depths 
with each series of pings.
    An ADCP anchored to the seafloor can measure current speed not just 
at the bottom, but at equal intervals to the surface. An ADCP 
instrument may be anchored to the seafloor or can be mounted to a 
mooring or to the bottom of a boat. ADCPs that are moored need an 
anchor to keep them on the bottom, batteries, and a data logger. 
Vessel-mounted instruments need a vessel with power, a shipboard 
computer to receive the data, and a GPS navigation system so the ship's 
movements can be subtracted from the current velocity data. ADCPs 
operate at frequencies between 75 and 300 kHz.
    (5) Net Monitoring Systems--During trawling operations, a range of 
sensors may be used to assist with controlling and monitoring gear. Net 
sounders give information about the concentration of fish around the 
opening to the trawl, as well as the clearances around the opening and 
the bottom of the trawl; catch sensors give information about the rate 
at which the codend is filling; symmetry sensors give information about 
the optimal geometry of the trawls; and tension sensors give 
information about how much tension is in the warps and sweeps.

                              Table 2--Operating Characteristics of Representative Predominant AFSC Active Acoustic Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Single ping duration
      Active acoustic system           Operating frequencies       Maximum source    (ms) and repetition rate         Orientation/            Nominal
                                                                       level                   (Hz)                  directionality          beamwidth
--------------------------------------------------------------------------------------------------------------------------------------------------------
Simrad EK60 narrow beam             18, 38, 70, 120, 200 kHz..  226.7 dB...........  1 ms at 1 Hz............  Downward looking.........         11[deg]
 echosounder.

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Simrad ME70 narrow beam             70 kHz....................  226.7 dB...........  1 ms at 1 Hz............  Downward looking.........         11[deg]
 echosounder.
Simrad ES60 multibeam echosounder.  38 and 120 kHz............  226.6 dB...........  1 ms at 1 Hz............  Downward looking.........          7[deg]
Reson 7111 multibeam echosounder..  38, 50, 100, 180, 300 kHz.  230 dB.............  not provided............  Downward looking.........        150[deg]
--------------------------------------------------------------------------------------------------------------------------------------------------------

Description of Marine Mammals in the Area of the Specified Activity

    We have reviewed AFSC's species descriptions--which summarize 
available information regarding status and trends, distribution and 
habitat preferences, behavior and life history, and auditory 
capabilities of the potentially affected species--for accuracy and 
completeness and refer the reader to Sections 3 and 4 of AFSC's 
application (and Sections 3 and 4 of Appendix C, which specifically 
addresses the IPHC activities), instead of reprinting the information 
here. Additional information regarding population trends and threats 
may be found in NMFS's Stock Assessment Reports (SAR; 
www.nmfs.noaa.gov/pr/sars/) and more general information about these 
species (e.g., physical and behavioral descriptions) may be found on 
NMFS's website (www.nmfs.noaa.gov/pr/species/mammals/).
    Table 3 lists all species with expected potential for occurrence in 
the specified geographical regions where AFSC and IPHC propose to 
conduct the specified activities 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 (2017). PBR, 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, is discussed in 
greater detail later in this document (see ``Negligible Impact 
Analysis'').
    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 the specified geographical 
regions are assessed in either NMFS's U.S. Alaska SARs or U.S. Pacific 
SARs. All values presented in Table 3 are the most recent available at 
the time of writing and are available in the 2016 SARs (Carretta et 
al., 2017; Muto et al., 2017) or draft 2017 SARs (available online at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).
    Forty species (with 88 managed stocks) are considered to have the 
potential to co-occur with AFSC and IPHC activities. Species that could 
potentially occur in the proposed research areas but are not expected 
to have the potential for interaction with AFSC research gear or that 
are not likely to be harassed by AFSC's use of active acoustic devices 
are described briefly but omitted from further analysis. These include 
extralimital species, which are species that do not normally occur in a 
given area but for which there are one or more occurrence records that 
are considered beyond the normal range of the species. The only species 
considered to be extralimital here are the narwhal (Monodon monoceros; 
CSBSRA only) and the Bryde's whale (Balaenoptera edeni brydei; IPHC 
U.S. west coast research area only). In addition, the sea otter is 
found in coastal waters--with the northern (or eastern) sea otter 
(Enhydra lutris kenyoni) found in Alaska--and the Pacific walrus 
(Odobenus rosmarus divergens) and polar bear (Ursus maritimus) may also 
occur in AFSC research areas. However, these species are managed by the 
U.S. Fish and Wildlife Service and are not considered further in this 
document.
    Two populations of gray whales are recognized, eastern and western 
North Pacific (ENP and WNP). WNP whales are known to feed in the 
Okhotsk Sea and off of Kamchatka before migrating south to poorly known 
wintering grounds, possibly in the South China Sea. The two populations 
have historically been considered geographically isolated from each 
other; however, data from satellite-tracked whales indicate that there 
is some overlap between the stocks. Two WNP whales were tracked from 
Russian foraging areas along the Pacific rim to Baja California (Mate 
et al., 2011), and, in one case where the satellite tag remained 
attached to the whale for a longer period, a WNP whale was tracked from 
Russia to Mexico and back again (IWC, 2012). Between 22-24 WNP whales 
are known to have occurred in the eastern Pacific through comparisons 
of ENP and WNP photo-identification catalogs (IWC, 2012; Weller et al., 
2011; Burdin et al., 2011). Urban et al. (2013) compared catalogs of 
photo-identified individuals from Mexico with photographs of whales off 
Russia and reported a total of 21 matches. Therefore, a portion of the 
WNP population is assumed to migrate, at least in some years, to the 
eastern Pacific during the winter breeding season.
    However, the AFSC does not believe that any gray whale (WNP or ENP) 
would be likely to interact with its research gear, as it is extremely 
unlikely that a gray whale in close proximity to AFSC research activity 
would be one of the few WNP whales that have been documented in the 
eastern Pacific. The likelihood that a WNP whale would interact with 
AFSC research gear is insignificant and discountable, and WNP gray 
whales are omitted from further analysis.
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    Prior to 2016, humpback whales were listed under the ESA as an 
endangered species worldwide. Following a 2015 global status review 
(Bettridge et al.,

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2015), NMFS established 14 distinct population segments (DPS) with 
different listing statuses (81 FR 62259; September 8, 2016) pursuant to 
the ESA. The DPSs that occur in U.S. waters do not necessarily equate 
to the existing stocks designated under the MMPA and shown in Table 3. 
Because MMPA stocks cannot be portioned, i.e., parts managed as ESA-
listed while other parts managed as not ESA-listed, until such time as 
the MMPA stock delineations are reviewed in light of the DPS 
designations, NMFS considers the existing humpback whale stocks under 
the MMPA to be endangered and depleted for MMPA management purposes 
(e.g., selection of a recovery factor, stock status).
    Within Alaska and U.S. west coast waters, four current DPSs may 
occur: The Western North Pacific (WNP) DPS (endangered), Hawaii DPS 
(not listed), Mexico DPS (threatened), and Central America DPS 
(endangered). According to Wade et al. (2016), in the Aleutian Islands 
and Bering, Chukchi, and Beaufort Seas, encountered whales are most 
likely to be from the Hawaii DPS (86.5 percent), but could be from the 
Mexico DPS (11.3 percent) or WNP DPS (4.4 percent). The same pattern 
holds in the Gulf of Alaska, with the probability of encountering 
whales from these same DPSs expected to be 89 percent, 10.5 percent, 
and 0.5 percent, respectively, and in southeast Alaska (93.9 percent 
from Hawaii DPS and 6.1 percent from Mexico DPS). Off of Washington, 
whales remain most likely to be from the Hawaii DPS (52.9 percent), but 
are almost equally likely to be from the Mexico DPS (41.9 percent), and 
could also be from the Central America DPS (14.7 percent). Off of 
Oregon and California, whales are most likely to be from the Mexico DPS 
(89.6 percent), with a 19.7 percent probability of an encountered whale 
being from the Central America DPS. Note that these probabilities 
reflect the upper limit of the 95 percent confidence interval of the 
probability of occurrence; therefore, numbers may not sum to 100 
percent for a given area.
    Although no comprehensive abundance estimate is available for the 
Alaska stock of minke whales, recent surveys provide estimates for 
portions of the stock's range. A 2010 survey conducted on the eastern 
Bering Sea shelf produced a provisional abundance estimate of 2,020 (CV 
= 0.73) whales (Friday et al., 2013). This estimate is considered 
provisional because it has not been corrected for animals missed on the 
trackline, animals submerged when the ship passed, or responsive 
movement. Additionally, line-transect surveys were conducted in shelf 
and nearshore waters (within 30-45 nautical miles of land) in 2001-2003 
between the Kenai Peninsula (150[deg] W) and Amchitka Pass (178[deg] 
W). Minke whale abundance was estimated to be 1,233 (CV = 0.34) for 
this area (also not been corrected for animals missed on the trackline) 
(Zerbini et al., 2006). The majority of the sightings were in the 
Aleutian Islands, rather than in the Gulf of Alaska, and in water 
shallower than 200 m. These estimates cannot be used as an estimate of 
the entire Alaska stock of minke whales because only a portion of the 
stock's range was surveyed. Similarly, although a comprehensive 
abundance estimate is not available for the northeast Pacific stock of 
fin whales, provisional estimates representing portions of the range 
are available. The same 2010 survey of the eastern Bearing sea shelf 
provided an estimate of 1,061 (CV = 0.38) fin whales (Friday et al., 
2013). The estimate is not corrected for missed animals, but is 
expected to be robust as previous studies have shown that only small 
correction factors are needed for fin whales (Barlow, 1995). Zerbini et 
al. (2006) produced an estimate of 1,652 (95% CI: 1,142-2,389) fin 
whales for the area described above.
    Current and historical estimates of the abundance of sperm whales 
in the North Pacific are considered unreliable, and caution should be 
exercised in interpreting published estimates (Muto et al., 2017). 
However, Kato and Miyashita (1998) produced an abundance estimate of 
102,112 (CV = 0.155) sperm whales in the western North Pacific 
(believed to be positively biased). The number of sperm whales 
occurring within Alaska waters is unknown.
    Using 2010-2012 survey data for the inland waters of southeast 
Alaska, Dahlheim et al. (2015) calculated a combined abundance estimate 
for harbor porpoise in the northern (including Cross Sound, Icy Strait, 
Glacier Bay, Lynn Canal, Stephens Passage, and Chatham Strait) and 
southern (including Frederick Sound, Sumner Strait, Wrangell and 
Zarembo Islands, and Clarence Strait as far south as Ketchikan) regions 
of the inland waters of 975 (CV = 0.1). Because this abundance estimate 
has not been corrected for detection biases, which are expected to be 
high for harbor porpoise, the estimate is likely conservative (Muto et 
al., 2017). However, this estimate may be used to calculate a minimum 
abundance estimate of 896 harbor porpoise for the area, with a 
corresponding PBR value of 8.9.
    No estimate of population abundance is available for the entire 
Alaska stock of bearded seals (note that this stock corresponds with 
the Beringia DPS designated pursuant to the ESA and listed as 
threatened). However, during 2012-2013, U.S. and Russian researchers 
conducted aerial abundance and distribution surveys over the entire 
Bering Sea and Sea of Okhotsk (Moreland et al. 2013). A sub-sample of 
data from the U.S. portion of the Bering Sea were analyzed by Conn et 
al. (2014) to produce an abundance estimate of approximately 299,174 
(95% CI: 245,476-360,544) bearded seals in U.S. waters. However, this 
estimate does not include seals that were in the Chukchi and Beaufort 
seas at the time of the surveys and therefore must be considered an 
underestimate. Using this estimate, a minimum abundance of 273,676 
seals in the U.S. sector of the Bering Sea (and associated PBR of 
8,210) was calculated.
    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 
due to ongoing climate change. On March 11, 2016, the U.S. District 
Court for the District of Alaska issued a memorandum decision in a 
lawsuit challenging the listing of ringed seals under the ESA (Alaska 
Oil and Gas Association, et al. v. National Marine Fisheries Service, 
et al., Case No. 4:14-cv-00029-RRB). The decision vacated NMFS's 
listing of the Arctic subspecies of ringed seals as a threatened 
species. NMFS appealed that decision and on February 12, 2018, the 
Ninth Circuit U.S. Court of Appeals upheld the decision to list the 
ringed seal as threatened. The decision was affirmed and the listing 
reinstated on May 15, 2018.
    A comprehensive and reliable abundance estimate for the Alaska 
stock of ringed seals is not available. However, using data from 
surveys in the late 1990s and 2000 (Bengtson et al., 2005; Frost et 
al., 2004), Kelly et al. (2010) estimated the total population in the 
Alaska Chukchi and Beaufort seas to be at least 300,000 ringed seals. 
This is likely an underestimate since surveys in the Beaufort Sea were 
limited to within 40 km from shore (Muto et al., 2017). Using the same 
survey data described above for bearded seals, Conn et al. (2014) 
calculated an abundance estimate of about 170,000 ringed seals for the 
U.S. portion of the Bering Sea. This

[[Page 37656]]

estimate did not account for availability bias and did not include 
ringed seals in the shorefast ice zone, which were surveyed using a 
different method. Thus, the actual number of ringed seals in the U.S. 
sector of the Bering Sea is likely much higher, perhaps by a factor of 
two or more (Muto et al., 2017).
    Take Reduction Planning--Take reduction plans are designed to help 
recover and prevent the depletion of strategic marine mammal stocks 
that interact with certain U.S. commercial fisheries, as required by 
Section 118 of the MMPA. The immediate goal of a take reduction plan is 
to reduce, within six months of its implementation, the M/SI of marine 
mammals incidental to commercial fishing to less than the PBR level. 
The long-term goal is to reduce, within five years of its 
implementation, the M/SI of marine mammals incidental to commercial 
fishing to insignificant levels, approaching a zero serious injury and 
mortality rate, taking into account the economics of the fishery, the 
availability of existing technology, and existing state or regional 
fishery management plans. Take reduction teams are convened to develop 
these plans.
    There are no take reduction plans currently in effect for Alaskan 
fisheries. For marine mammals off the U.S. west coast, there is 
currently one take reduction plan in effect (Pacific Offshore Cetacean 
Take Reduction Plan). The goal of this plan is to reduce M/SI of 
several marine mammal stocks incidental to the California thresher 
shark/swordfish drift gillnet fishery (CA DGN). A team was convened in 
1996 and a final plan produced in 1997 (62 FR 51805; October 3, 1997). 
Marine mammal stocks of concern initially included the California, 
Oregon, and Washington stocks for beaked whales, short-finned pilot 
whales, pygmy sperm whales, sperm whales, and humpback whales. The most 
recent five-year averages of M/SI for these stocks are below PBR. More 
information is available online at: www.nmfs.noaa.gov/pr/interactions/trt/poctrp.htm. Of the stocks of concern, the AFSC has requested the 
authorization of incidental M/SI for the short-finned pilot whale only 
(on behalf of IPHC; see ``Estimated Take'' later in this document). The 
most recent reported average annual human-caused mortality for short-
finned pilot whales (2010-14) is 1.2 animals. The IPHC does not use 
drift gillnets in its fisheries research program; therefore, take 
reduction measures applicable to the CA DGN fisheries are not relevant.
    Unusual Mortality Events (UME)--A UME is defined under the MMPA as 
``a stranding that is unexpected; involves a significant die-off of any 
marine mammal population; and demands immediate response.'' From 1991 
to the present, there have been 19 formally recognized UMEs on the U.S. 
west coast or in Alaska involving species under NMFS' jurisdiction. The 
only currently ongoing investigations involve Guadalupe fur seals and 
California sea lions along the west coast. Increased strandings of 
Guadalupe fur seals (up to eight times the historical average) have 
occurred along the entire coast of California. These increased 
strandings were reported beginning in January 2015 and peaked from 
April through June 2015, but have remained well above average through 
2017. Findings from the majority of stranded animals include 
malnutrition with secondary bacterial and parasitic infections. 
Beginning in January 2013, elevated strandings of California sea lion 
pups were observed in southern California, with live sea lion 
strandings nearly three times higher than the historical average. 
Findings to date indicate that a likely contributor to the large number 
of stranded, malnourished pups was a change in the availability of sea 
lion prey for nursing mothers, especially sardines. These UMEs are 
occurring in the same areas and the causes and mechanisms of this 
remain under investigation (www.nmfs.noaa.gov/pr/health/mmume/guadalupefurseals2015.html; www.nmfs.noaa.gov/pr/health/mmume/californiasealions2013.htm; accessed November 24, 2017).
    Another recent, notable UME involved large whales and occurred in 
the western Gulf of Alaska and off of British Columbia, Canada. 
Beginning in May 2015, elevated large whale mortalities (primarily fin 
and humpback whales) occurred in the areas around Kodiak Island, 
Afognak Island, Chirikof Island, the Semidi Islands, and the southern 
shoreline of the Alaska Peninsula. Although most carcasses have been 
non-retrievable as they were discovered floating and in a state of 
moderate to severe decomposition, the UME is likely attributable to 
ecological factors, i.e., the 2015 El Ni[ntilde]o, ``warm water blob,'' 
and the Pacific Coast domoic acid bloom. While the UME remains under 
investigation at the time of this writing, the dates of the UME are 
considered to be from May 22, through December 31, 2015 (western Gulf 
of Alaska) and from April 23, 2015 through April 16, 2016 (British 
Columbia). More information is available online at www.nmfs.noaa.gov/pr/health/mmume/large_whales_2015.html.
    Additional UMEs in the past ten years include those involving 
ringed, ribbon, spotted, and bearded seals (collectively ``ice seals'') 
(2011; disease); harbor porpoises in California (2008; cause determined 
to be ecological factors); Guadalupe fur seals in the Northwest (2007; 
undetermined); large whales in California (2007; human interaction); 
cetaceans in California (2007; undetermined); and harbor porpoises in 
the Pacific Northwest (2006; undetermined). For more information on 
UMEs, please visit: www.nmfs.noaa.gov/pr/health/mmume/events.html.

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 (2016) 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 an exception 
for lower limits for low-frequency cetaceans where the result was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. The functional groups and the associated 
frequencies are indicated below (note that these frequency ranges 
correspond to the range for the composite group, with the entire range 
not necessarily reflecting the capabilities of every species within 
that group):
    <bullet> Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz, with best 
hearing estimated to be from 100 Hz to 8 kHz;

[[Page 37657]]

    <bullet> Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz, with best hearing from 10 to 
less than 100 kHz;
    <bullet> High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz;
    <bullet> Pinnipeds in water; Phocidae (true seals): Functional 
hearing is estimated to occur between approximately 50 Hz to 86 kHz, 
with best hearing between 1-50 kHz;
    <bullet> Pinnipeds in water; Otariidae (eared seals): Functional 
hearing is estimated to occur between 60 Hz and 39 kHz for Otariidae, 
with best hearing between 2-48 kHz.
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Forty marine mammal species (30 cetacean and ten pinniped (four otariid 
and six phocid) species) have the potential to co-occur with AFSC and 
IPHC research activities. Please refer to Table 3. Of the 30 cetacean 
species that may be present, eight are classified as low-frequency 
cetaceans (i.e., all mysticete species), eighteen are classified as 
mid-frequency cetaceans (i.e., all delphinid and ziphiid species and 
the sperm whale), and four are classified as high-frequency cetaceans 
(i.e., porpoises and Kogia spp.).

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity (e.g., gear deployment, use of 
active acoustic sources, visual disturbance) may impact marine mammals 
and their habitat. The ``Estimated Take'' section later in this 
document includes a quantitative analysis of the number of individuals 
that are expected to be taken by this activity. The ``Negligible Impact 
Analysis and Determination'' section considers the content of this 
section and the material it references, the ``Estimated Take'' section, 
and the ``Proposed Mitigation'' section, to draw conclusions regarding 
the likely impacts of these activities on the reproductive success or 
survivorship of individuals and how those impacts on individuals are 
likely to impact marine mammal species or stocks. In the following 
discussion, we consider potential effects to marine mammals from ship 
strike, physical interaction with the gear types described previously, 
use of active acoustic sources, and visual disturbance of pinnipeds.

Ship Strike

    Vessel collisions with marine mammals, or ship strikes, can result 
in death or serious injury of the animal. Wounds resulting from ship 
strike may include massive trauma, hemorrhaging, broken bones, or 
propeller lacerations (Knowlton and Kraus, 2001). An animal at the 
surface may be struck directly by a vessel, a surfacing animal may hit 
the bottom of a vessel, or an animal just below the surface may be cut 
by a vessel's propeller. Superficial strikes may not kill or result in 
the death of the animal. These interactions are typically associated 
with large whales, which are occasionally found draped across the 
bulbous bow of large commercial ships upon arrival in port. Although 
smaller cetaceans or pinnipeds are more maneuverable in relation to 
large vessels than are large whales, they may also be susceptible to 
strike. The severity of injuries typically depends on the size and 
speed of the vessel, with the probability of death or serious injury 
increasing as vessel speed increases (Knowlton and Kraus, 2001; Laist 
et al., 2001; Vanderlaan and Taggart, 2007; Conn and Silber, 2013). 
Impact forces increase with speed, as does the probability of a strike 
at a given distance (Silber et al., 2010; Gende et al., 2011).
    Pace and Silber (2005) found that the probability of death or 
serious injury increased rapidly with increasing vessel speed. 
Specifically, the predicted probability of serious injury or death 
increased from 45 to 75 percent as vessel speed increased from 10 to 14 
kn, and exceeded 90 percent at 17 kn. Higher speeds during collisions 
result in greater force of impact, but higher speeds also appear to 
increase the chance of severe injuries or death through increased 
likelihood of collision by pulling whales toward the vessel (Clyne, 
1999; Knowlton et al., 1995). In a separate study, Vanderlaan and 
Taggart (2007) analyzed the probability of lethal mortality of large 
whales at a given speed, showing that the greatest rate of change in 
the probability of a lethal injury to a large whale as a function of 
vessel speed occurs between 8.6 and 15 kn. The chances of a lethal 
injury decline from approximately 80 percent at 15 kn to approximately 
20 percent at 8.6 kn. At speeds below 11.8 kn, the chances of lethal 
injury drop below fifty percent, while the probability asymptotically 
increases toward one hundred percent above 15 kn.
    In an effort to reduce the number and severity of strikes of the 
endangered North Atlantic right whale (Eubalaena glacialis), NMFS 
implemented speed restrictions in 2008 (73 FR 60173; October 10, 2008). 
These restrictions require that vessels greater than or equal to 65 ft 
(19.8 m) in length travel at less than or equal to 10 kn near key port 
entrances and in certain areas of right whale aggregation along the 
U.S. eastern seaboard. Conn and Silber (2013) estimated that these 
restrictions reduced total ship strike mortality risk levels by 80 to 
90 percent.
    For vessels used in AFSC research activities, transit speeds 
average 10 kn (but vary from 6-14 kn), while vessel speed during active 
sampling with towed gear is typically only 2-4 kn. At sampling speeds, 
both the possibility of striking a marine mammal and the possibility of 
a strike resulting in serious injury or mortality are discountable. At 
average transit speed, the probability of serious injury or mortality 
resulting from a strike is less than 50 percent. However, the 
likelihood of a strike actually happening is again unlikely. Ship 
strikes, as analyzed in the studies cited above, generally involve 
commercial shipping, which is much more common in both space and time 
than is research activity. Jensen and Silber (2004) summarized ship 
strikes of large whales worldwide from 1975-2003 and found that most 
collisions occurred in the open ocean and involved large vessels (e.g., 
commercial shipping). Commercial fishing vessels were responsible for 
three percent of recorded collisions, while only one such incident 
(0.75 percent) was reported for a research vessel during that time 
period.
    It is possible for ship strikes to occur while traveling at slow 
speeds. For example, a hydrographic survey vessel traveling at low 
speed (5.5 kn) while conducting mapping surveys off the central 
California coast struck and killed a blue whale in 2009. The State of 
California determined that the whale had suddenly and unexpectedly 
surfaced beneath the hull, with the result that the propeller severed 
the whale's vertebrae, and that this was an unavoidable event. The 
strike represents the only such incident in approximately 540,000 hours 
of similar coastal mapping activity (p = 1.9 x 10 <SUP>-</SUP>\6\; 95% 
CI = 0-5.5 x 10 <SUP>-</SUP>\6\; NMFS, 2013). In addition, a research 
vessel reported a fatal strike in 2011 of a dolphin in the Atlantic, 
demonstrating that it is possible for strikes involving smaller

[[Page 37658]]

cetaceans or pinnipeds to occur. In that case, the incident report 
indicated that an animal apparently was struck by the vessel's 
propeller as it was intentionally swimming near the vessel. While 
indicative of the type of unusual events that cannot be ruled out, 
neither of these instances represents a circumstance that would be 
considered reasonably foreseeable or that would be considered 
preventable.
    Although the likelihood of vessels associated with research surveys 
striking a marine mammal are low, we require a robust ship strike 
avoidance protocol (see ``Proposed Mitigation''), which we believe 
eliminates any foreseeable risk of ship strike. We anticipate that 
vessel collisions involving AFSC research vessels, while not 
impossible, represent unlikely, unpredictable events for which there 
are no preventive measures. No ship strikes have been reported from any 
fisheries research activities conducted or funded by the AFSC. Given 
the relatively slow speeds of research vessels, the presence of bridge 
crew watching for obstacles at all times (including marine mammals), 
the presence of marine mammal observers on some surveys, and the small 
number of research cruises relative to commercial ship traffic, we 
believe that the possibility of ship strike is discountable and, 
further, that were a strike of a large whale to occur, it would be 
unlikely to result in serious injury or mortality. No incidental take 
resulting from ship strike is anticipated, and this potential effect of 
research will not be discussed further in the following analysis.

Research Gear

    The types of research gear used by AFSC were described previously 
under ``Detailed Description of Activity.'' Here, we broadly categorize 
these gears into those whose use we consider to have an extremely 
unlikely potential to result in marine mammal interaction and those 
whose use we believe may result in marine mammal interaction. Gears in 
the former category are not considered further, while those in the 
latter category are carried forward for further analysis. Gears with 
likely potential for marine mammal interaction include trawls, 
longlines, and gillnets.
    Trawl nets, longlines, and gillnets deployed by AFSC are similar to 
gear used in various commercial fisheries, and the potential for and 
history of marine mammal interaction with these gears through physical 
contact (i.e., capture or entanglement) is well-documented. Read et al. 
(2006) estimated marine mammal bycatch in U.S. fisheries from 1990-99 
and derived an estimate of global marine mammal bycatch by expanding 
U.S. bycatch estimates using data on fleet composition from the United 
Nations Food and Agriculture Organization (FAO). Although most U.S. 
bycatch for both cetaceans (84 percent) and pinnipeds (98 percent) 
occurred in gillnets, global marine mammal bycatch in trawl nets and 
longlines is likely substantial given that total global bycatch is 
thought to number in the hundreds of thousands of individuals (Read et 
al., 2006). In addition, global bycatch via longline has likely 
increased, as longlines have become the most common method of capturing 
swordfish and tuna since the U.N. banned the use of high seas driftnets 
over 2.5 km long in 1991 (high seas driftnets were previously often 40-
60 km long) (Read, 2008; FAO, 2001).
    Marine mammals are widely regarded as being quite intelligent and 
inquisitive, and when their pursuit of prey coincides with human 
pursuit of the same resources, it should be expected that physical 
interaction with fishing gear may occur (e.g., Beverton, 1985). 
Fishermen and marine mammals are both drawn to areas of high prey 
density, and certain fishing activities may further attract marine 
mammals by providing food (e.g., bait, captured fish, bycatch discards) 
or by otherwise making it easier for animals to feed on a concentrated 
food source. Provision of foraging opportunities near the surface may 
present an advantage by negating the need for energetically expensive 
deep foraging dives (Hamer and Goldsworthy, 2006). Trawling, for 
example, can make available previously unexploited food resources by 
gathering prey that may otherwise be too fast or deep for normal 
predation, or may concentrate calories in an otherwise patchy landscape 
(Fertl and Leatherwood, 1997). Pilot whales, which are generally 
considered to be teuthophagous (i.e., feeding primarily on squid), were 
commonly observed in association with Atlantic mackerel (Scomber 
scombrus) trawl fisheries from 1977-88 in the northeast U.S. EEZ 
(Waring et al., 1990). Not surprisingly, stomach contents of captured 
whales were observed to have high proportions of mackerel (68 percent 
of non-trace food items), indicating that the ready availability of a 
novel, concentrated, high-calorie prey item resulted in changed dietary 
composition (Read, 1994).
    These interactions can result in injury or death for the animal(s) 
involved and/or damage to fishing gear. Coastal animals, including 
various pinnipeds, bottlenose dolphins, and harbor porpoises, are 
perhaps the most vulnerable to these interactions and set or passive 
fishing gear (e.g., gillnets, traps) the most likely to be interacted 
with (e.g., Beverton, 1985; Barlow et al., 1994; Read et al., 2006; 
Byrd et al., 2014; Lewison et al., 2014). Although interactions are 
less common for use of trawl nets and longlines, they do occur with 
sufficient frequency to necessitate the establishment of required 
mitigation measures for multiple U.S. fisheries using both types of 
gear (NMFS, 2017). It is likely that no species of marine mammal can be 
definitively excluded from the potential for interaction with fishing 
gear (e.g., Northridge, 1984); however, the extent of interactions is 
likely dependent on the biology, ecology, and behavior of the species 
involved and the type, location, and nature of the fishery.
    Trawl Nets--As described previously, trawl nets are towed nets 
(i.e., active fishing) consisting of a cone-shaped net with a codend or 
bag for collecting the fish and can be designed to fish at the bottom, 
surface, or any other depth in the water column. Here we refer to 
bottom trawls and pelagic trawls (midwater or surface, i.e., any net 
not designed to tend the bottom while fishing). Trawl nets in general 
have the potential to capture or entangle marine mammals, which have 
been known to be caught in bottom trawls, presumably when feeding on 
fish caught therein, and in pelagic trawls, which may or may not be 
coincident with their feeding (Northridge, 1984).
    Capture or entanglement may occur whenever marine mammals are 
swimming near the gear, intentionally (e.g., foraging) or 
unintentionally (e.g., migrating), and any animal captured in a net is 
at significant risk of drowning unless quickly freed. Animals can also 
be captured or entangled in netting or tow lines (also called lazy 
lines) other than the main body of the net; animals may become 
entangled around the head, body, flukes, pectoral fins, or dorsal fin. 
Interaction that does not result in the immediate death of the animal 
by drowning can cause injury (i.e., Level A harassment) or serious 
injury. Constricting lines wrapped around the animal can immobilize the 
animal or injure by cutting into or through blubber, muscles and bone 
(i.e., penetrating injuries) or constricting blood flow to or severing 
appendages. Immobilization of the animal, if it does not result in 
immediate drowning, can cause internal injuries from prolonged stress 
and/or severe struggling and/or impede the animal's ability to feed

[[Page 37659]]

(resulting in starvation or reduced fitness) (Andersen et al., 2008).
    Marine mammal interactions with trawl nets, through capture or 
entanglement, are well-documented. Dolphins are known to attend 
operating nets in order to either benefit from disturbance of the 
bottom or to prey on discards or fish within the net. For example, 
Leatherwood (1975) reported that the most frequently observed feeding 
pattern for bottlenose dolphins in the Gulf of Mexico involved herds 
following working shrimp trawlers, apparently feeding on organisms 
stirred up from the benthos. Bearzi and di Sciara (1997) 
opportunistically investigated working trawlers in the Adriatic Sea 
from 1990-94 and found that ten percent were accompanied by foraging 
bottlenose dolphins. However, pelagic trawls have greater potential to 
capture cetaceans, because the nets may be towed at faster speeds, 
these trawls are more likely to target species that are important prey 
for marine mammals (e.g., squid, mackerel), and the likelihood of 
working in deeper waters means that a more diverse assemblage of 
species could potentially be present (Hall et al., 2000).
    Globally, at least 17 cetacean species are known to feed in 
association with trawlers and individuals of at least 25 species are 
documented to have been killed by trawl nets, including several large 
whales, porpoises, and a variety of delphinids (Perez, 2006; Young and 
Iudicello, 2007; Karpouzli and Leaper, 2004; Hall et al., 2000; Fertl 
and Leatherwood, 1997; Northridge, 1991; Song et al., 2010). At least 
eighteen species of seals and sea lions are known to have been killed 
in trawl nets (Wickens, 1995; Perez, 2006; Zeeberg et al., 2006). 
Generally, direct interaction between trawl nets and marine mammals 
(both cetaceans and pinnipeds) has been recorded wherever trawling and 
animals co-occur. A lack of recorded interactions where animals are 
known to be present may indicate simply that trawling is absent or an 
insignificant component of fisheries in that region or that 
interactions were not observed, recorded, or reported.
    In evaluating risk relative to a specific fishery (or comparable 
research survey), one must consider the size of the net as well as 
frequency, timing, and location of deployment. These considerations 
inform determinations of whether interaction with marine mammals is 
likely. Of the net types described previously under ``Trawl Nets,'' 
AFSC has recorded marine mammal interactions with the Cantrawl surface 
trawl net but also has one recorded interaction with a bottom trawl. 
Other midwater trawl nets, such as the Nordic 264 and Cobb trawl, have 
demonstrated potential for marine mammal interaction based on 
interaction records from other NMFS science centers.
    Longlines--Longlines are basically strings of baited hooks that are 
either anchored to the bottom, for targeting groundfish, or are free-
floating, for targeting pelagic species and represent a passive fishing 
technique (the latter not used by AFSC). Any longline generally 
consists of a mainline from which leader lines (gangions) with baited 
hooks branch off at a specified interval, and is left to passively 
fish, or soak, for a set period of time before the vessel returns to 
retrieve the gear. Longlines are marked by two or more floats that act 
as visual markers and may also carry radio beacons; aids to detection 
are of particular importance for pelagic longlines, which may drift a 
significant distance from the deployment location. Bottom longlines may 
be of monofilament or multifilament natural or synthetic lines.
    Marine mammals may be hooked or entangled in longline gear, with 
interactions potentially resulting in death due to drowning, 
strangulation, severing of carotid arteries or the esophagus, 
infection, an inability to evade predators, or starvation due to an 
inability to catch prey (Hofmeyr et al., 2002), although it is more 
likely that animals will survive being hooked if they are able to reach 
the surface to breathe. Injuries, which may include serious injury, 
include lacerations and puncture wounds. Animals may attempt to 
depredate either bait or catch, with subsequent hooking, or may become 
accidentally entangled. As described for trawls, entanglement can lead 
to constricting lines wrapped around the animals and/or immobilization, 
and even if entangling materials are removed the wounds caused may 
continue to weaken the animal or allow further infection (Hofmeyr et 
al., 2002). Large whales may become entangled in a longline and then 
break free with a portion of gear trailing, resulting in alteration of 
swimming energetics due to drag and ultimate loss of fitness and 
potential mortality (Andersen et al., 2008). Weight of the gear can 
cause entangling lines to further constrict and further injure the 
animal. Hooking injuries and ingested gear are most common in small 
cetaceans and pinnipeds, but have been observed in large cetaceans 
(e.g., sperm whales). The severity of the injury depends on the 
species, whether ingested gear includes hooks, whether the gear works 
its way into the gastrointestinal (GI) tract, whether the gear 
penetrates the GI lining, and the location of the hooking (e.g., 
embedded in the animal's stomach or other internal body parts) 
(Andersen et al., 2008). Bottom longlines pose less of a threat to 
marine mammals due to their deployment on the ocean bottom but can 
still result in entanglement in buoy lines or hooking as the line is 
either deployed or retrieved. The rate of interaction between longline 
fisheries and marine mammals depends on the degree of overlap between 
longline effort and species distribution, hook style and size, type of 
bait and target catch, and fishing practices (such as setting/hauling 
during the day or at night).
    As was noted for trawl nets, many species of cetaceans and 
pinnipeds are documented to have been killed by longlines, including 
several large whales, porpoises, a variety of delphinids, seals, and 
sea lions (Perez, 2006; Young and Iudicello, 2007; Northridge, 1984, 
1991; Wickens, 1995). Generally, direct interaction between longlines 
and marine mammals (both cetaceans and pinnipeds) has been recorded 
wherever longline fishing and animals co-occur. A lack of recorded 
interactions where animals are known to be present may indicate simply 
that longlining is absent or an insignificant component of fisheries in 
that region or that interactions were not observed, recorded, or 
reported.
    In evaluating risk relative to a specific fishery (or research 
survey), one must consider the length of the line and number of hooks 
deployed as well as frequency, timing, and location of deployment. 
These considerations inform determinations of whether interaction with 
marine mammals is likely. AFSC has not recorded marine mammal 
interactions with any longline survey, while the IPHC has recorded five 
interactions (all pinnipeds) from 1999-2016. While a lack of historical 
interactions does not in and of itself indicate that future 
interactions are unlikely, we believe that the historical record, 
considered in context with the frequency and timing of these 
activities, as well as mitigation measures employed indicate that 
future marine mammal interactions with these gears would be uncommon.
    Gillnets--Marine mammal interactions with gillnets are well-
documented, with a large proportion of species of all types of marine 
mammals (e.g., mysticetes, odontocetes, pinnipeds) recorded as gillnet 
bycatch (Reeves et al., 2013; Lewison et al., 2014; Zollett, 2009). 
Reeves et al. (2013) note that numbers of marine mammals killed in 
gillnets tend to be greatest for species that are widely distributed in

[[Page 37660]]

coastal and shelf waters. Because of the well-documented risk to marine 
mammals, and to coastally distributed pinnipeds and small cetaceans in 
particular, we believe there is some risk of interaction inherent to 
AFSC use of gillnets, as described below in ``Estimated Take.'' 
However, this risk is limited by AFSC's minimal use of gillnets, 
primarily at the Little Port Walter in southeast Alaska (see Table 1-1 
of AFSC's application), and by use of pingers on gillnets as a 
deterrent (see ``Proposed Mitigation'').
    The AFSC also uses some traps and pots, both of which are passive 
fishing gear that have limited species selectivity and may be set for 
long durations (FAO, 2001). Thus, these gears have the potential to 
capture non-targeted fauna that use the same habitat as targeted 
species, even without the use of bait. Mortality in fyke nets can arise 
from stress and injury associated with anoxia, abrasion, confinement, 
and starvation (Larocque, 2011). In 2010, NMFS Northeast Fisheries 
Science Center captured a harbor seal in a fyke trap. However, AFSC 
fyke traps are used in freshwater habitats with only limited 
deployments. Other traps and pots are likewise used in only very 
limited fashion, with some traps deployed without bait. Therefore, we 
do not believe that there is a reasonable potential for marine mammal 
interaction with fyke traps or pots used by the AFSC, and these gears 
are not considered further in this document.
    Other research gear--The only AFSC research gears with any record 
of marine mammal interactions are trawl nets, while IPHC has recorded 
marine mammal interactions with longlines. Because of ample evidence 
from commercial fishing operations, we assume that there is also risk 
of marine mammal interaction due to AFSC use of gillnets. All other 
gears used in AFSC fisheries research (e.g., a variety of plankton 
nets, CTDs, remotely operated vehicles (ROVs)) do not have the expected 
potential for marine mammal interactions and are not known to have been 
involved in any marine mammal interaction anywhere. Specifically, we 
consider CTDs, ROVs, small surface trawls, plankton nets, other small 
nets, camera traps, dredges, and vertically deployed or towed imaging 
systems to be no-impact gear types.
    Unlike trawl nets, seine nets, and longline gear, which are used in 
both scientific research and commercial fishing applications, these 
other gears are not considered similar or analogous to any commercial 
fishing gear and are not designed to capture any commercially salable 
species, or to collect any sort of sample in large quantities. They are 
not considered to have the potential to take marine mammals primarily 
because of their design or how they are deployed. For example, CTDs are 
typically deployed in a vertical cast on a cable and have no loose 
lines or other entanglement hazards. A Bongo net is typically deployed 
on a cable, whereas neuston nets (these may be plankton nets or small 
trawls) are often deployed in the upper one meter of the water column; 
either net type has very small size (e.g., two bongo nets of 0.5 m\2\ 
each or a neuston net of approximately 2 m\2\) and no trailing lines to 
present an entanglement risk. These other gear types are not considered 
further in this document.

Acoustic Effects

    We previously provided general background information on sound and 
the specific sources used by the AFSC (see ``Description of Active 
Acoustic Sound Sources''), as well as background information on marine 
mammal hearing (see ``Description of Marine Mammals in the Area of the 
Specified Activity''). Here, we discuss the potential effects of AFSC 
use of active acoustic sources on marine mammals.
    Potential Effects of Underwater Sound--Note that, in the following 
discussion, we refer in many cases to a review article concerning 
studies of noise-induced hearing loss conducted from 1996-2015 (i.e., 
Finneran, 2015). For study-specific citations, please see that work. 
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; G[ouml]tz 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. We first describe specific manifestations of acoustic 
effects before providing discussion specific to AFSC's use of active 
acoustic sources (e.g., echosounders).
    Richardson et al. (1995) described zones of increasing intensity of 
effect that might be expected to occur, in relation to distance from a 
source and assuming that the signal is within an animal's hearing 
range. First is the area within which the acoustic signal would be 
audible (potentially perceived) to the animal but not strong enough to 
elicit any overt behavioral or physiological response. The next zone 
corresponds with the area where the signal is audible to the animal and 
of sufficient intensity to elicit behavioral or physiological 
responsiveness. Third is a zone within which, for signals of high 
intensity, the received level is sufficient to potentially cause 
discomfort or tissue damage to auditory or other systems. Overlaying 
these zones to a certain extent is the area within which masking (i.e., 
when a sound interferes with or masks the ability of an animal to 
detect a signal of interest that is above the absolute hearing 
threshold) may occur; the masking zone may be highly variable in size.
    We describe the more severe effects (i.e., permanent hearing 
impairment, certain non-auditory physical or physiological effects) 
only briefly as we do not expect that there is a reasonable likelihood 
that AFSC use of active acoustic sources may result in such effects 
(see below for further discussion). 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).

[[Page 37661]]

Therefore, NMFS does not consider TTS to constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans, but such 
relationships 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 6 dB higher than 
the TTS threshold on a peak-pressure basis and PTS cumulative sound 
exposure level thresholds are 15 to 20 dB higher than TTS cumulative 
sound exposure level thresholds (Southall et al., 2007). Given the 
higher level of sound or longer exposure duration necessary to cause 
PTS as compared with TTS, it is considerably less likely that PTS could 
occur.
    Non-auditory physiological effects or injuries that theoretically 
might occur in marine mammals exposed to high level underwater sound or 
as a secondary effect of extreme behavioral reactions (e.g., change in 
dive profile as a result of an avoidance reaction) caused by exposure 
to sound include neurological effects, bubble formation, resonance 
effects, and other types of organ or tissue damage (Cox et al., 2006; 
Southall et al., 2007; Zimmer and Tyack, 2007). AFSC activities do not 
involve the use of devices such as explosives or mid-frequency active 
sonar that are associated with these types of effects.
    When a live or dead marine mammal swims or floats onto shore and is 
incapable of returning to sea, the event is termed a ``stranding'' (16 
U.S.C. 1421h(3)). Marine mammals are known to strand for a variety of 
reasons, such as infectious agents, biotoxicosis, starvation, fishery 
interaction, ship strike, unusual oceanographic or weather events, 
sound exposure, or combinations of these stressors sustained 
concurrently or in series (e.g., Geraci et al., 1999). However, the 
cause or causes of most strandings are unknown (e.g., Best, 1982). 
Combinations of dissimilar stressors may combine to kill an animal or 
dramatically reduce its fitness, even though one exposure without the 
other would not be expected to produce the same outcome (e.g., Sih et 
al., 2004). For further description of stranding events see, e.g., 
Southall et al., 2006; Jepson et al., 2013; Wright et al., 2013.
    1. 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. Few data on sound levels and durations 
necessary to elicit mild TTS have been obtained for marine mammals.
    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, beluga whale, harbor porpoise, and Yangtze finless 
porpoise (Neophocoena asiaeorientalis)) and three species of pinnipeds 
(northern elephant seal, harbor seal, and California sea lion) 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 (Finneran, 
2015). 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), Finneran (2015), and NMFS (2016).
    2. 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

[[Page 37662]]

et al., 2003). Observed responses of wild marine mammals to loud pulsed 
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). However, 
many delphinids approach low-frequency seismic airgun source vessels 
with no apparent discomfort or obvious behavioral change (e.g., 
Barkaszi et al., 2012), indicating the importance of frequency output 
in relation to the species hearing sensitivitiy.
    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, 
2005). 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., 2013a, 2013b). 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 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, 2005, 2006; Gailey et 
al., 2007; Gailey et al., 2016).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007). 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 airgun 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; 
Stone et al., 2000; 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; Teilmann 
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-

[[Page 37663]]

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.
    3. Stress Responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle, 1950; 
Moberg, 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg, 1987; Blecha, 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
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). For example, Rolland et al. (2012) found 
that noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003).
    4. 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; Erbe et al., 
2016). 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 man-made, 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., 2007; Di Iorio and Clark, 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore, 2014). Masking can be tested 
directly in captive species (e.g., Erbe, 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial

[[Page 37664]]

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 of AFSC Activity--As described previously (see 
``Description of Active Acoustic Sound Sources''), the AFSC proposes to 
use various active acoustic sources, including echosounders (e.g., 
multibeam systems), scientific sonar systems, positional sonars (e.g., 
net sounders for determining trawl position), and environmental sensors 
(e.g., current profilers). These acoustic sources, which are present on 
most AFSC fishery research vessels, include a variety of single, dual, 
and multi-beam echosounders (many with a variety of modes), sources 
used to determine the orientation of trawl nets, and several current 
profilers.
    Many typically investigated acoustic sources (e.g., seismic 
airguns, low- and mid-frequency active sonar used for military 
purposes, pile driving, vessel noise)--sources for which certain of the 
potential acoustic effects described above have been observed or 
inferred--produce signals that are either much lower frequency and/or 
higher total energy (considering output sound levels and signal 
duration) than the high-frequency mapping and fish-finding systems used 
by the AFSC. There has been relatively little attention given to the 
potential impacts of high-frequency sonar systems on marine life, 
largely because their combination of high output frequency and 
relatively low output power means that such systems are less likely to 
impact many marine species. However, some marine mammals do hear and 
produce sounds within the frequency range used by these sources and 
ambient noise is much lower at high frequencies, increasing the 
probability of signal detection relative to other sounds in the 
environment.
    As noted above, relatively high levels of sound are likely required 
to cause TTS in most pinnipeds and odontocete cetaceans. While 
dependent on sound exposure frequency, level, and duration, existing 
studies indicate that for the kinds of relatively brief exposures 
potentially associated with transient sounds such as those produced by 
the active acoustic sources used by the AFSC, SPLs in the range of 
approximately 180-220 dB rms might be required to induce onset TTS 
levels for most species (Southall et al., 2007). However, it should be 
noted that there may be increased sensitivity to TTS for certain 
species generally (harbor porpoise; Lucke et al., 2009) or specifically 
at higher sound exposure frequencies, which correspond to a species' 
best hearing range (20 kHz vs. 3 kHz for bottlenose dolphins; Finneran 
and Schlundt, 2010). However, for these animals, which are better able 
to hear higher frequencies and may be more sensitive to higher 
frequencies, exposures on the order of approximately 170 dB rms or 
higher for brief transient signals are likely required for even 
temporary (recoverable) changes in hearing sensitivity that would 
likely not be categorized as physiologically damaging (Lucke et al., 
2009). The corresponding estimates for PTS would be at very high 
received levels that would rarely be experienced in practice.
    Based on discussion provided by Southall et al. (2007), Lurton and 
DeRuiter (2011) modeled the potential impacts of conventional 
echosounders on marine mammals, estimating PTS onset at typical 
distances of 10-100 m for the kinds of sources considered here. Kremser 
et al. (2005) modeled the potential for TTS in blue, sperm, and beaked 
whales (please see Kremser et al. (2005) for discussion of assumptions 
regarding TTS onset in these species) from a multibeam echosounder, 
finding similarly that TTS would likely only occur at very close ranges 
to the hull of the vessel. The authors estimated ship movement at 12 kn 
(faster than AFSC vessels would typically move), which would result in 
an underestimate of the potential for TTS to occur, but the modeled 
system (Hydrosweep) operates at lower frequencies and with a wider beam 
pattern than do typical AFSC systems, which would result in a likely 
more significant overestimate of TTS potential. The results of both 
studies emphasize that these effects would very likely only occur in 
the cone ensonified below the ship and that animal responses to the 
vessel (sound or physical presence) at these extremely close ranges 
would very likely influence their probability of being exposed to these 
levels. At the same distances, but to the side of the vessel, animals 
would not be exposed to these levels, greatly decreasing the potential 
for an animal to be exposed to the most intense signals. For example, 
Kremser et al. (2005) note that SPLs outside the vertical lobe, or 
beam, decrease rapidly with distance, such that SPLs within the 
horizontal lobes are about 20 dB less than the value found in the 
center of the beam. For certain species (i.e., odontocete cetaceans and 
especially harbor porpoises), these ranges may be somewhat greater 
based on more recent data (Lucke et al., 2009; Finneran and Schlundt, 
2010) but are likely still on the order of hundreds of meters. In 
addition, potential behavioral responses further reduce the already low 
likelihood that an animal may approach close enough for any type of 
hearing loss to occur.
    Various other studies have evaluated the environmental risk posed 
by use of specific scientific sonar systems. Burkhardt et al. (2007) 
considered both the Hydrosweep system evaluated by Kremser et al. 
(2005) and the Simrad EK60, which is used by the AFSC, and concluded 
that direct injury (i.e., sound energy causes direct tissue damage) and 
indirect injury (i.e., self-damaging behavior as response to acoustic 
exposure) would be unlikely given source and operational use (i.e., 
vessel movement) characteristics, and that any behavioral responses 
would be unlikely to be significant. Similarly, Boebel et al. (2006) 
considered the Hydrosweep system in relation to the risk for direct or 
indirect injury, concluding that (1) risk of TTS (please see Boebel et 
al. (2006) for assumptions regarding TTS onset) would be less than two 
percent of the risk of ship strike and (2) risk of behaviorally-induced 
damage would be essentially nil due to differences in source 
characteristics between scientific sonars and sources typically 
associated with stranding events (e.g., mid-frequency active sonar, but 
see discussion of the 2008 Madagascar stranding event below). It should 
be noted that the risk of direct injury may be greater when a vessel 
operates sources while on station (i.e., stationary), as there is a 
greater chance for an animal to receive the signal when the vessel is 
not moving.
    Boebel et al. (2005) report the results of a workshop in which a 
structured, qualitative risk analysis of a range of acoustic technology 
was undertaken, specific to use of such technology in the Antarctic. 
The authors assessed a single-beam echosounder commonly used for 
collecting bathymetric data (12 kHz, 232 dB, 10[deg] beam width), an 
array of single-beam echosounders used for mapping krill (38, 70, 120, 
and 200 kHz; 230 dB; 7[deg] beam width), and a multibeam echosounder 
(30 kHz, 236 dB, 150[deg] x 1[deg] swath width). For each source, the 
authors produced a matrix displaying the severity of potential 
consequences (on a six-point scale) against the likelihood of 
occurrence for a given degree of severity. For the former two systems, 
the authors determined on the basis of the volume of water potentially 
affected by the system and comparisons between its output and available 
TTS data that the chance of TTS is only in a small volume immediately 
under the

[[Page 37665]]

transducers, and that consequences of level four and above were 
inconceivable, whereas level one consequences (``Individuals show no 
response, or only a temporary (minutes) behavior change'') would be 
expected in almost all instances. Some minor displacement of animals in 
the immediate vicinity of the ship may occur. For the multibeam 
echosounder, Boebel et al. (2005) note that the high output and broad 
width of the swath abeam of the vessel makes displacement of animals 
more likely. However, the fore and aft beamwidth is small and the pulse 
length very short, so the risk of ensonification above TTS levels is 
still considered quite small and the likelihood of auditory or other 
injuries low. In general, the authors reached the same conclusions 
described for the single-beam systems but note that more severe 
impacts--including fatalities resulting from herding of sensitive 
species in narrow seaways--are at least possible (i.e., may occur in 
exceptional circumstances). However, the probability of herding remains 
low not just because of the rarity of the necessary confluence of 
species, bathymetry, and likely other factors, but because the 
restricted beam shape makes it unlikely that an animal would be exposed 
more than briefly during the passage of the vessel (Boebel et al., 
2005). More recently, Lurton (2016) conducted a modeling exercise and 
concluded similarly that likely potential for acoustic injury from 
these types of systems is negligible, but that behavioral response 
cannot be ruled out.
    We have, however, considered the potential for severe behavioral 
responses such as stranding and associated indirect injury or mortality 
from AFSC use of the multibeam echosounder, on the basis of a 2008 mass 
stranding of approximately one hundred melon-headed whales 
(Peponocephala electra) in a Madagascar lagoon system. An investigation 
of the event indicated that use of a high-frequency mapping system (12-
kHz multibeam echosounder; it is important to note that all AFSC 
sources operate at higher frequencies (see Table 2)) was the most 
plausible and likely initial behavioral trigger of the event, while 
providing the caveat that there is no unequivocal and easily 
identifiable single cause (Southall et al., 2013). The panel's 
conclusion was based on (1) very close temporal and spatial association 
and directed movement of the survey with the stranding event; (2) the 
unusual nature of such an event coupled with previously documented 
apparent behavioral sensitivity of the species to other sound types 
(Southall et al., 2006; Brownell et al., 2009); and (3) the fact that 
all other possible factors considered were determined to be unlikely 
causes. Specifically, regarding survey patterns prior to the event and 
in relation to bathymetry, the vessel transited in a north-south 
direction on the shelf break parallel to the shore, ensonifying large 
areas of deep-water habitat prior to operating intermittently in a 
concentrated area offshore from the stranding site; this may have 
trapped the animals between the sound source and the shore, thus 
driving them towards the lagoon system.
    The investigatory panel systematically excluded or deemed highly 
unlikely nearly all potential reasons for these animals leaving their 
typical pelagic habitat for an area extremely atypical for the species 
(i.e., a shallow lagoon system). Notably, this was the first time that 
such a system has been associated with a stranding event.
    The panel also noted several site- and situation-specific secondary 
factors that may have contributed to the avoidance responses that led 
to the eventual entrapment and mortality of the whales. Specifically, 
shoreward-directed surface currents and elevated chlorophyll levels in 
the area preceding the event may have played a role (Southall et al., 
2013). The report also notes that prior use of a similar system in the 
general area may have sensitized the animals and also concluded that, 
for odontocete cetaceans that hear well in higher frequency ranges 
where ambient noise is typically quite low, high-power active sonars 
operating in this range may be more easily audible and have potential 
effects over larger areas than low frequency systems that have more 
typically been considered in terms of anthropogenic noise impacts. It 
is, however, important to note that the relatively lower output 
frequency, higher output power, and complex nature of the system 
implicated in this event, in context of the other factors noted here, 
likely produced a fairly unusual set of circumstances that indicate 
that such events would likely remain rare and are not necessarily 
relevant to use of lower-power, higher-frequency systems more commonly 
used for scientific applications. The risk of similar events recurring 
may be very low, given the extensive use of active acoustic systems 
used for scientific and navigational purposes worldwide on a daily 
basis and the lack of direct evidence of such responses previously 
reported.
    Characteristics of the sound sources predominantly used by AFSC 
further reduce the likelihood of effects to marine mammals, as well as 
the intensity of effect assuming that an animal perceives the signal. 
Intermittent exposures--as would occur due to the brief, transient 
signals produced by these sources--require a higher cumulative SEL to 
induce TTS than would continuous exposures of the same duration (i.e., 
intermittent exposure results in lower levels of TTS) (Mooney et al., 
2009a; Finneran et al., 2010). In addition, intermittent exposures 
recover faster in comparison with continuous exposures of the same 
duration (Finneran et al., 2010). Although echosounder pulses are, in 
general, emitted rapidly, they are not dissimilar to odontocete 
echolocation click trains. Research indicates that marine mammals 
generally have extremely fine auditory temporal resolution and can 
detect each signal separately (e.g., Au et al., 1988; Dolphin et al., 
1995; Supin and Popov, 1995; Mooney et al., 2009b), especially for 
species with echolocation capabilities. Therefore, it is likely that 
marine mammals would indeed perceive echosounder signals as being 
intermittent.
    We conclude here that, on the basis of available information on 
hearing and potential auditory effects in marine mammals, high-
frequency cetacean species would be the most likely to potentially 
incur temporary hearing loss from a vessel operating high-frequency 
sonar sources, and the potential for PTS to occur for any species is so 
unlikely as to be discountable. Even for high-frequency cetacean 
species, individuals would have to make a very close approach and also 
remain very close to vessels operating these sources in order to 
receive multiple exposures at relatively high levels, as would be 
necessary to cause TTS. Additionally, given that behavioral responses 
typically include the temporary avoidance that might be expected (see 
below), the potential for auditory effects considered physiological 
damage (injury) is considered extremely low in relation to realistic 
operations of these devices. Given the fact that fisheries research 
survey vessels are moving, the likelihood that animals may avoid the 
vessel to some extent based on either its physical presence or due to 
aversive sound (vessel or active acoustic sources), and the 
intermittent nature of many of these sources, the potential for TTS is 
probably low for high-frequency cetaceans and very low to zero for 
other species.
    Based on the source operating characteristics, most of these 
sources may be detected by odontocete cetaceans (and particularly high-

[[Page 37666]]

frequency specialists such as porpoises) but are unlikely to be audible 
to mysticetes (i.e., low-frequency cetaceans) and some pinnipeds. While 
low-frequency cetaceans and pinnipeds have been observed to respond 
behaviorally to low- and mid-frequency sounds (e.g., Frankel, 2005), 
there is little evidence of behavioral responses in these species to 
high-frequency sound exposure (e.g., Jacobs and Terhune, 2002; 
Kastelein et al., 2006). If a marine mammal does perceive a signal from 
a AFSC active acoustic source, it is likely that the response would be, 
at most, behavioral in nature. Behavioral reactions of free-ranging 
marine mammals to scientific sonars are likely to vary by species and 
circumstance. For example, Watkins et al. (1985) note that sperm whales 
did not appear to be disturbed by or even aware of signals from 
scientific sonars and pingers (36-60 kHz) despite being very close to 
the transducers, but Gerrodette and Pettis (2005) report that when a 
38-kHz echosounder and ADCP were on (1) the average size of detected 
schools of spotted dolphins and pilot whales was decreased; (2) 
perpendicular sighting distances increased for spotted and spinner 
dolphins; and (3) sighting rates decreased for beaked whales.
    Despite these observations, few experiments have been conducted to 
explicitly test for potential effects of echosounders on the behavior 
of wild cetaceans. Quick et al. (2017) describe an experimental 
approach to assess potential changes in short-finned pilot whale 
behavior during exposure to an echosounder (Simrad EK60 operated at 38 
kHz, which is commonly used by AFSC). Previous studies of the effects 
of military tactical sonars on pilot whales failed to document overt 
avoidance responses, but did show changes in heading variance, which 
may be indicative of avoidance (Miller et al., 2012; Quick et al., 
2017). In 2011, digital acoustic recording tags (DTAG) were attached to 
pilot whales off of North Carolina, with five of the whales exposed to 
signals from the echosounder over a period of eight days and four 
treated as control animals. DTAGS record both received levels of noise 
as well as orientation of the animal. Results did not show an overt 
response to the echosounder or a change to foraging behavior of tagged 
whales, but the whales did increase heading variance during exposure. 
The authors suggest that this response was not a directed avoidance 
response but was more likely a vigilance response, with animals 
maintaining awareness of the location of the echosounder through 
increased changes in heading variance (Quick et al., 2017). Visual 
observations of behavior did not indicate any dramatic response, 
unusual behaviors, or changes in heading, and cessation of biologically 
important behavior such as feeding was not observed. These less overt 
responses to sound exposure are difficult to detect by visual 
observation, but may have important consequences if the exposure does 
interfere with biologically important behavior. Given the transient 
nature of AFSC use of active acoustic sources, we do not expect any 
behavioral disturbance to carry meaningful biological consequences for 
individuals.
    As described above, behavioral responses of marine mammals are 
extremely variable, depending on multiple exposure factors, with the 
most common type of observed response being behavioral avoidance of 
areas around aversive sound sources. Certain odontocete cetaceans 
(particularly harbor porpoises and beaked whales) are known to avoid 
high-frequency sound sources in both field and laboratory settings 
(e.g., Kastelein et al., 2000, 2005, 2008a, 2008b; Culik et al., 2001; 
Johnston, 2002; Olesiuk et al., 2002; Carretta et al., 2008). There is 
some additional, low probability for masking to occur for high-
frequency specialists, but similar factors (directional beam pattern, 
transient signal, moving vessel) mean that the significance of any 
potential masking is probably inconsequential.

Potential Effects of Visual Disturbance

    During AFSC surveys conducted in coastal areas, pinnipeds are 
expected to be hauled out and at times experience incidental close 
approaches by researchers in small vessels during the course of 
fisheries research activities. AFSC expects some of these animals will 
exhibit a behavioral response to the visual stimuli (e.g., including 
alert behavior, movement, vocalizing, or flushing). NMFS does not 
consider the lesser reactions (e.g., alert behavior) to constitute 
harassment. These events are expected to be infrequent and cause only a 
temporary disturbance on the order of minutes. Monitoring results from 
other activities involving the disturbance of pinnipeds and relevant 
studies of pinniped populations that experience more regular vessel 
disturbance indicate that individually significant or population level 
impacts are unlikely to occur.
    In areas where disturbance of haul-outs due to periodic human 
activity (e.g., researchers approaching on foot, passage of small 
vessels, maintenance activity) occurs, monitoring results have 
generally indicated that pinnipeds typically move or flush from the 
haul-out in response to human presence or visual disturbance, although 
some individuals typically remain hauled-out (e.g., SCWA, 2012). The 
nature of response is generally dependent on species. For example, 
California sea lions and northern elephant seals have been observed as 
less sensitive to stimulus than harbor seals during monitoring at 
numerous sites. Monitoring of pinniped disturbance as a result of 
abalone research in the Channel Islands showed that while harbor seals 
flushed at a rate of 69 percent, California sea lions flushed at a rate 
of only 21 percent. The rate for elephant seals declined to 0.1 percent 
(VanBlaricom, 2010).
    Upon the occurrence of low-severity disturbance (i.e., the approach 
of a vessel or person as opposed to an explosion or sonic boom), 
pinnipeds typically exhibit a continuum of responses, beginning with 
alert movements (e.g., raising the head), which may then escalate to 
movement away from the stimulus and possible flushing into the water. 
Flushed pinnipeds typically re-occupy the haul-out within minutes to 
hours of the stimulus.
    In a popular tourism area of the Pacific Northwest where human 
disturbances occurred frequently, past studies observed stable 
populations of seals over a twenty-year period (Calambokidis et al., 
1991). Despite high levels of seasonal disturbance by tourists using 
both motorized and non-motorized vessels, Calambokidis et al. (1991) 
observed an increase in site use (pup rearing) and classified this area 
as one of the most important pupping sites for seals in the region. 
Another study observed an increase in seal vigilance when vessels 
passed the haul-out site, but then vigilance relaxed within ten minutes 
of the vessels' passing (Fox, 2008). If vessels passed frequently 
within a short time period (e.g., 24 hours), a reduction in the total 
number of seals present was also observed (Fox, 2008).
    Level A harassment, serious injury, or mortality could likely only 
occur as a result of trampling in a stampede (a potentially dangerous 
occurrence in which large numbers of animals succumb to mass panic and 
rush away from a stimulus) or abandonment of pups. Pups could be 
present at times during AFSC research effort, but AFSC researchers take 
precautions to minimize disturbance and prevent any possibility of 
stampedes, including choosing travel routes as far away from hauled 
pinnipeds as possible and by

[[Page 37667]]

moving sample site locations to avoid consistent haulout areas. In 
addition, harbor seal pups are extremely precocious, swimming and 
diving immediately after birth and throughout the lactation period, 
unlike most other phocids which normally enter the sea only after 
weaning (Lawson and Renouf, 1985; Cottrell et al., 2002; Burns et al., 
2005). Lawson and Renouf (1987) investigated harbor seal mother-pup 
bonding in response to natural and anthropogenic disturbance. In 
summary, they found that the most critical bonding time is within 
minutes after birth. As such, it is unlikely that infrequent 
disturbance resulting from AFSC research would interrupt the brief 
mother-pup bonding period within which disturbance could result in 
separation.
    Disturbance of pinnipeds caused by AFSC survey activities would be 
expected to last for only short periods of time, separated by 
significant amounts of time in which no disturbance occurred. Because 
such disturbance is sporadic, rather than chronic, and of low 
intensity, individual marine mammals are unlikely to incur any 
detrimental impacts to vital rates or ability to forage and, thus, loss 
of fitness. Correspondingly, even local populations, much less the 
overall stocks of animals, are extremely unlikely to accrue any 
significantly detrimental impacts.

Anticipated Effects on Marine Mammal Habitat

    Effects to Prey--In addition to direct, or operational, 
interactions between fishing gear and marine mammals, indirect (i.e., 
biological or ecological) interactions occur as well, in which marine 
mammals and fisheries both utilize the same resource, potentially 
resulting in competition that may be mutually disadvantageous (e.g., 
Northridge, 1984; Beddington et al., 1985; Wickens, 1995). Marine 
mammal prey varies by species, season, and location and, for some, is 
not well documented. There is some overlap in prey of marine mammals 
and the species sampled and removed during AFSC research surveys, with 
primary species of concern being walleye pollock (Gadus chalcogrammus), 
Pacific cod (G. macrocephalus), Atka mackerel (Pleurogrammus 
monopterygius), sablefish (Anoplopoma fimbria), salmonids (Oncorhynchus 
spp.), and small, energy-rich, forage fish species such as Pacific 
sandlance (Ammodytes spp.) and Pacific herring (Clupea pallasi).
    However, the total amount of these species taken in research 
surveys is very small relative to their overall biomass in the area 
(See Section 4.3.3 of the AFSC EA for more information on fish catch 
during research surveys). For example, AFSC research surveys are 
expected to catch approximately 433 metric tons (mt) of pollock per 
year in the GOARA. Research catch is therefore negligible compared to 
the allowable commercial harvest (111,530 mt in 2014) in the same area. 
For most commercial species, the average annual research catch is less 
than one percent of the allowable commercial catch. Other species of 
fish and invertebrates that are used as prey by marine mammals are 
taken in research surveys as well but, as indicated by these examples, 
the proportions of research catch compared to biomass and commercial 
harvest is very small.
    Several AFSC fisheries research projects target prey of endangered 
western DPS Steller sea lions within the GOARA and BSAIRA. These 
studies are, in part, designed to assess aspects of the seasonal 
abundance and distribution of sea lion prey as part of a comprehensive 
examination of how nutritional status and prey availability may affect 
the recovery of the species. Some of these studies may be conducted 
within designated critical habitat for Steller sea lions, no-transit 
zones around rookeries, and areas designated as fishery closure zones. 
The primary prey caught in critical habitat includes rockfishes, 
pollock, Atka mackerel, arrowtooth flounder, and Pacific cod. Table 9-1 
of AFSC's application shows the average annual AFSC fisheries research 
catch within Steller sea lion critical habitat. As described above, 
these amounts of prey are a small fraction of the commercial harvest 
total allowable catch, and an even smaller fraction of the biomass 
available to Steller sea lions. AFSC fisheries research catches are 
therefore anticipated to result in little to no effects on foraging sea 
lions in the general area or in their critical habitat. Prior ESA 
section 7 consultations conducted as part of the process for obtaining 
regional scientific research permits have not found any of the 
fisheries research prey removals to jeopardize listed species or to 
adversely modify critical habitat.
    In addition to the small total biomass taken, some of the size 
classes of fish targeted in research surveys are very small (e.g., 
juvenile salmonids are typically only centimeters long), and these 
small size classes are not known to be prey of marine mammals. Research 
catches are also distributed over a wide area because of the random 
sampling design covering large sample areas. Fish removals by research 
are therefore highly localized and unlikely to affect the spatial 
concentrations and availability of prey for any marine mammal species. 
The overall effect of research catches on marine mammals through 
competition for prey may therefore be considered insignificant for all 
species.
    Acoustic Habitat--Acoustic habitat is the soundscape--which 
encompasses all of the sound present in a particular location and time, 
as a whole--when considered from the perspective of the animals 
experiencing it. Animals produce sound for, or listen for sounds 
produced by, conspecifics (communication during feeding, mating, and 
other social activities), other animals (finding prey or avoiding 
predators), and the physical environment (finding suitable habitats, 
navigating). Together, sounds made by animals and the geophysical 
environment (e.g., produced by earthquakes, lightning, wind, rain, 
waves) make up the natural contributions to the total acoustics of a 
place. These acoustic conditions, termed acoustic habitat, are one 
attribute of an animal's total habitat.
    Soundscapes are also defined by, and acoustic habitat influenced 
by, the total contribution of anthropogenic sound. This may include 
incidental emissions from sources such as vessel traffic, or may be 
intentionally introduced to the marine environment for data acquisition 
purposes (as in the AFSC's use of active acoustic sources). 
Anthropogenic noise varies widely in its frequency content, duration, 
and loudness and these characteristics greatly influence the potential 
habitat-mediated effects to marine mammals (please also see the 
previous discussion on masking in the ``Acoustic Effects'' subsection), 
which may range from local effects for brief periods of time to chronic 
effects over large areas and for long durations. Depending on the 
extent of effects to habitat, animals may alter their communications 
signals (thereby potentially expending additional energy) or miss 
acoustic cues (either conspecific or adventitious). For more detail on 
these concepts see, e.g., Barber et al., 2010; Pijanowski et al., 2011; 
Francis and Barber, 2013; Lillis et al., 2014.
    Problems arising from a failure to detect cues are more likely to 
occur when noise stimuli are chronic and overlap with biologically 
relevant cues used for communication, orientation, and predator/prey 
detection (Francis and Barber, 2013). As described above (``Acoustic 
Effects''), the signals emitted by AFSC active acoustic sources are 
generally high frequency, of short

[[Page 37668]]

duration, and transient. These factors mean that the signals will 
attenuate rapidly (not travel over great distances), may not be 
perceived or affect perception even when animals are in the vicinity, 
and would not be considered chronic in any given location. AFSC use of 
these sources is widely dispersed in both space and time. In 
conjunction with the prior factors, this means that it is highly 
unlikely that AFSC use of these sources would, on their own, have any 
appreciable effect on acoustic habitat. Sounds emitted by AFSC vessels 
would be of lower frequency and continuous, but would also be widely 
dispersed in both space and time. AFSC vessel traffic--including both 
sound from the vessel itself and from the active acoustic sources--is 
of very low density compared to commercial shipping traffic or 
commercial fishing vessels and would therefore be expected to represent 
an insignificant incremental increase in the total amount of 
anthropogenic sound input to the marine environment.
    Physical Habitat--AFSC conducts some bottom trawling, which may 
physically damage seafloor habitat. Physical damage may include 
furrowing and smoothing of the seafloor as well as the displacement of 
rocks and boulders, and such damage can increase with multiple contacts 
in the same area (Schwinghamer et al., 1998; Kaiser et al., 2002; Malik 
and Mayer, 2007; NRC, 2002). The effects of bottom contact gear differ 
in each type of benthic environment. In sandy habitats with strong 
currents, the furrows created by mobile bottom contact gear quickly 
begin to erode because lighter weight sand at the edges of furrows can 
be easily moved by water back towards the center of the furrow (NRC, 
2002). Duration of effects in these environments therefore tend to be 
very short because the terrain and associated organisms are accustomed 
to natural disturbance. By contrast, the physical features of more 
stable hard bottom habitats are less susceptible to disturbance, but 
once damaged or removed by fishing gear, the organisms that grow on 
gravel, cobbles, and boulders can take years to recover, especially in 
deeper water where there is less natural disturbance (NRC, 2002). 
However, the area of benthic habitat affected by AFSC research each 
year would be a very small fraction of total area and effects are not 
expected to occur in areas of particular importance.
    Damage to seafloor habitat may also harm infauna and epifauna 
(i.e., animals that live in or on the seafloor or on structures on the 
seafloor), including corals (Schwinghamer et al., 1998; Collie et al., 
2000; Stevenson et al., 2004). In general, recovery of biological 
damage varies based on the type of fishing gear used, the type of 
seafloor surface (i.e., mud, sand, gravel, mixed substrate), and the 
level of repeated disturbances, but would be expected to occur within 
1-18 months. However, repeated disturbance of an area can prolong the 
recovery time (Stevenson et al., 2004), and recovery of corals may take 
significantly longer. However, AFSC catch records show that only 
minimal amounts of coral are captured (annual average of 100 kg of 
coral per year for most species groups). Relatively small areas would 
be impacted by AFSC bottom trawling and, because such surveys are 
conducted in the same areas but not in the exact same locations, they 
are expected to cause single rather than repeated disturbances in any 
given area. AFSC activities would not be expected to have any other 
impacts on physical habitat.
    As described in the preceding, the potential for AFSC research to 
affect the availability of prey to marine mammals or to meaningfully 
impact the quality of physical or acoustic habitat is considered to be 
insignificant for all species. Effects to habitat will not be discussed 
further in this document.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization, which will inform both NMFS's consideration 
of whether the number of takes is ``small'' and the negligible impact 
determination.
    Except with respect to certain activities not pertinent here, 
section 3(18) of the MMPA defines ``harassment'' as: any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Take of marine mammals incidental to AFSC research activities could 
occur as a result of (1) injury or mortality due to gear interaction 
(Level A harassment, serious injury, or mortality); (2) behavioral 
disturbance resulting from the use of active acoustic sources (Level B 
harassment only); or (3) behavioral disturbance of pinnipeds resulting 
from incidental approach of researchers (Level B harassment only). 
Below we describe how the potential take is estimated.

Estimated Take Due to Gear Interaction

    In order to estimate the number of potential incidents of take that 
could occur through gear interaction, we first consider AFSC's and 
IPHC's record of past such incidents, and then consider in addition 
other species that may have similar vulnerabilities to AFSC trawl and 
IPHC longline gear as those species for which we have historical 
interaction records. Historical interactions with research gear are 
described in Table 4, and we anticipate that all species that 
interacted with AFSC or IPHC fisheries research gear historically could 
potentially be taken in the future. Available records are for the years 
2004 through present (AFSC) and 1998 through present (IPHC). All 
historical AFSC interactions have taken place in the GOARA, and have 
occurred during use of either the Cantrawl surface trawl net or with a 
bottom trawl. Historical IPHC interactions have occurred during use of 
bottom longlines and were located in the GOARA (southeast Alaska) or 
west coast (offshore Oregon). AFSC has no historical interactions for 
any longline or gillnet gear, and there are no historical interactions 
in the BSAIRA or CSBSRA. Please see Figures 6-1 and C-6 in the AFSC 
request for authorization for specific locations of these incidents.

                                                   Table 4--Historical Interactions With Research Gear
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                      Number
               Gear                        Survey              Date             Location \1\              Species          Number    released    Total
                                                                                                                           killed     alive
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottom longline...................  IPHC setline........       7/17/1999  West coast.............  Harbor seal.........          1  .........          1
Bottom longline...................  IPHC setline........       7/23/2003  SE Alaska..............  Steller sea lion....          1  .........          1
Bottom longline...................  IPHC setline........       7/16/2007  SE Alaska..............  Steller sea lion....          1  .........          1

[[Page 37669]]

 
Bottom trawl......................  Gulf of Alaska             6/13/2009  GOARA..................  Northern fur seal             1  .........          1
                                     Biennial Shelf and                                             \2\.
                                     Slope Bottom Trawl
                                     Groundfish Survey.
Bottom longline...................  IPHC setline........       7/31/2011  West coast.............  Harbor seal.........          1  .........          1
Surface trawl (Cantrawl)..........  Gulf of Alaska             9/10/2011  GOARA..................  Dall's porpoise.....          1  .........          1
                                     Assessment.
Surface trawl (Cantrawl)..........  Gulf of Alaska             9/21/2011  GOARA..................  Dall's porpoise.....          1  .........          1
                                     Assessment.
Bottom trawl......................  ADFG Large Mesh             9/5/2014  GOARA..................  Harbor seal.........          1  .........          1
                                     Trawl Survey.
Bottom longline...................  IPHC setline........       7/22/2016  SE Alaska..............  Steller sea lion....          1  .........          1
    Total individuals captured....  ....................  ..............  .......................  Northern fur seal...          1  .........          1
                                    ....................  ..............  .......................  Dall's porpoise.....          2  .........          2
                                    ....................  ..............  .......................  Harbor seal.........          3  .........          3
                                    ....................  ..............  .......................  Steller sea lion....          3  .........          3
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ AFSC interactions are described by research area. IPHC research programs are not distributed according to AFSC research areas and so are described
  by geographic location. Specific locations of all interactions are shown in Figures 6-1 and C-6 of the application.
\2\ Based on the location of this incident, the captured animal was believed to be from the eastern Pacific stock of northern fur seal.

    In order to use these historical interaction records as the basis 
for the take estimation process, and because we have no specific 
information to indicate whether any given future interaction might 
result in M/SI versus Level A harassment, we conservatively assume that 
all interactions equate to mortality for these fishing gear 
interactions. AFSC and IPHC have historically had only infrequent 
interactions with marine mammals, e.g., from 2004-2015 AFSC conducted 
at least 1,250 trawl tows per year, with only three (a fourth occurred 
during a survey conducted by the Alaska Department of Fish and Game) 
marine mammal interactions (Table 4). However, we assume that any of 
the historically-captured species (northern fur seal, Dall's porpoise, 
harbor seal, Steller sea lion) could be captured in any year.
    We consider all of the interaction records available to us. In 
consideration of these data, we assume that one individual of each of 
the historically-captured species (Table 4) could be captured per year 
over the course of the five-year period of validity for these proposed 
regulations, specific to relevant survey operations where the species 
occur (e.g., one harbor seal taken per year specific to IPHC longline 
survey operations, one Dall's porpoise taken per year specific to AFSC 
trawl survey operations in GOARA, one Dall's porpoise taken per year 
specific to AFSC trawl survey operations in BSAIRA). Table 5 shows the 
projected five-year total captures of the historically-captured species 
for this proposed rule, as described above, for AFSC trawl gear and 
IPHC longline gear only. Although more than one individual Dall's 
porpoise has been captured in a single year, interactions have 
historically occurred only infrequently. Therefore, we believe that the 
above assumption appropriately reflects the likely total number of 
individuals involved in research gear interactions over a five-year 
period and that the assumption is precautionary in that it separately 
accounts for potential vulnerability of species to gear interaction in 
the different research areas. Harbor seals are expected to have less 
frequency of interaction than the fur seal or Steller sea lion due to 
its more inshore and coastal distribution. AFSC requests authorization 
of one take per harbor seal stock in each relevant research area over 
the 5-year period (note that these takes are not included in Table 5 
but are incorporated in Table 7). These estimates are based on the 
assumption that annual effort (e.g., total annual trawl tow time) over 
the proposed five-year authorization period will be approximately 
equivalent to the annual effort during prior years for which we have 
interaction records.

                                      Table 5--Projected Five-Year Total Take for Historically Captured Species \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          AFSC GOARA average      AFSC BSAIRA        IPHC average
                   Gear                                Species                annual take       average annual        annual take      Projected 5-year
                                                                                (total)          take (total)         (total) \2\            total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Trawl.....................................  Northern fur seal \3\.......               1 (5)               1 (5)  ..................                  10
                                            Dall's porpoise.............               1 (5)               1 (5)  ..................                  10
Longline..................................  Harbor seal.................  ..................  ..................               1 (5)                   5
                                            Steller sea lion............  ..................  ..................               1 (5)                   5
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Projected takes based on species interaction records in analogous commercial fisheries (versus historical records) are incorporated in Table 7
  below, as are all projected takes within the CSBSRA.
\2\ IPHC activities are not defined by the three AFSC research areas and may occur anywhere within the IPHC research areas off the U.S. west coast or in
  the Gulf of Alaska and Bering Sea. Projected IPHC harbor seal takes could occur to any stock of harbor seal. Historical IPHC takes of Steller sea lion
  have been of the eastern DPS (based on geographic location), but potential future takes could occur to either eastern or western DPS.
\3\ Referring to expected potential future takes of eastern Pacific stock northern fur seals in AFSC trawl gear on basis of historical record.
  Additional take of California stock northern fur seals, inferred based on vulnerability and geographic overlap, are incorporated in Table 7 below.


[[Page 37670]]

    As background to the process of determining which species not 
historically taken may have sufficient vulnerability to capture in AFSC 
gear to justify inclusion in the take authorization request (or whether 
species historically taken may have vulnerability to gears in which 
they have not historically been taken or additional vulnerability not 
reflected above due to activity in other areas such as the CSBSRA), we 
note that the AFSC is NMFS' research arm in Alaska and may be 
considered as a leading source of expert knowledge regarding marine 
mammals (e.g., behavior, abundance, density) in the areas where they 
operate. The species for which the take request was formulated were 
selected by the AFSC, and we have concurred with these decisions. We 
also note that, in addition to consulting NMFS's List of Fisheries 
(LOF; described below), the historical interaction records described 
above for the IPHC informed our consideration of risk of interaction 
due to AFSC's use of longline gear (for which there are no historical 
interaction records).
    In order to estimate the total potential number of incidents of 
takes that could occur incidental to the AFSC's use of trawl, longline, 
and gillnet gear, and IPHC's use of longline gear, over the five-year 
period of validity for these proposed regulations (i.e., takes 
additional to those described in Table 5), we first consider whether 
there are additional species that may have similar vulnerability to 
capture in trawl or longline gear as the five species described above 
that have been taken historically and then evaluate the potential 
vulnerability of these and other species to additional gears.
    We believe that the Pacific white-sided dolphin likely has similar 
vulnerability to capture in trawl gear as the Dall's porpoise, given 
similar habitat preferences and with documented vulnerability to 
capture in both commercial and research trawls. The harbor porpoise is 
also considered vulnerable to capture in trawl gear, but likely with 
less frequency of interaction given its inshore and coastal 
distribution. The Steller sea lion is considered to have similar 
vulnerability to capture in trawl gear as the northern fur seal, given 
similar habitat preferences and with documented vulnerability to 
capture in commercial trawls. In addition to the one northern fur seal 
per year from the eastern Pacific stock that could be captured in each 
relevant research area (Table 5), we assume that one additional 
northern fur seal from the California stock could be taken in trawl 
gear over the 5-year period. The assumed lesser frequency of 
interaction is due to presumed lower occurrence of California stock fur 
seals in AFSC research areas. Only approximately half of this 
relatively small stock of fur seals ranges to the eastern GOARA. 
Similar to the harbor porpoise, spotted seals are expected to have 
similar vulnerability to capture in trawl gear as historically captured 
pinnipeds, but with less frequency of interaction due to its more 
inshore and coastal distribution. AFSC requests authorization of one 
take of spotted seal in each relevant research area over the 5-year 
period. This assumption is supported by LOF records (Table 7).
    Historical IPHC take records also illustrate likely similar 
vulnerabilities to capture by AFSC longline gear. However, due to 
reduced use of longline gear by AFSC relative to IPHC activity, expects 
that one Steller sea lion from each DPS could be taken over the 5-year 
period in each relevant research area. Despite IPHC records of harbor 
seal capture in longline gear, we do not believe that AFSC use of 
longline gear presents similar risk, in part due to the relative 
infrequency of use but also because of a lack of expected geographic 
overlap between AFSC longline sets and harbor seal occurrence. IPHC 
conducts many more longline sets per year but also conducts survey 
effort further inshore than does IPHC (water depths of 18 m). No take 
of harbor seals incidental to AFSC longline survey effort is proposed. 
Northern fur seals and California sea lions are considered analogous to 
Steller sea lions due to similar vulnerability to capture in longline 
gear. AFSC has requested authorization of one take over the 5-year 
period for each fur seal stock in each research area where fur seals 
are found and, on behalf of IPHC, requests authorization of one fur 
seal per year (which could be from either stock) and one California sea 
lion over the 5-year period. Finally, the spotted seal may have similar 
vulnerability to interaction with longline gear as the harbor seal, but 
likely with less frequency given the limited overlap between the 
species range and survey effort. We propose to authorize one take over 
the 5-year period for IPHC survey effort, but none for AFSC given very 
little expected overlap. These assumptions are supported by LOF records 
(Table 7).
    In order to evaluate the potential vulnerability of additional 
species to trawl and longline and of all species to gillnet gear, we 
first consulted the LOF, which classifies U.S. commercial fisheries 
into one of three categories according to the level of incidental 
marine mammal M/SI that is known to occur on an annual basis over the 
most recent five-year period (generally) for which data has been 
analyzed: Category I, frequent incidental M/SI; Category II, occasional 
incidental M/SI; and Category III, remote likelihood of or no known 
incidental M/SI. We provide summary information, as presented in the 
2017 LOF (82 FR 3655; January 12, 2017), in Table 6. In order to 
simplify information presented, and to encompass information related to 
other similar species from different locations, we group marine mammals 
by genus (where there is more than one member of the genus found in 
U.S. waters). Where there are documented incidents of M/SI incidental 
to relevant commercial fisheries, we note whether we believe those 
incidents provide sufficient basis upon which to infer vulnerability to 
capture in AFSC or IPHC research gear. For a listing of all Category I, 
II, and II fisheries using relevant gears, associated estimates of 
fishery participants, and specific locations and fisheries associated 
with the historical fisheries takes indicated in Table 6 below, please 
see the 2017 LOF. For specific numbers of marine mammal takes 
associated with these fisheries, please see the relevant SARs. More 
information is available online at www.nmfs.noaa.gov/pr/interactions/fisheries/lof.html and www.nmfs.noaa.gov/pr/sars/.

                       Table 6--U.S. Commercial Fisheries Interactions for Trawl, Longline, and Gillnet Gear for Relevant Species
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Vulnerability                     Vulnerability                     Vulnerability
                    Species \1\                        Trawl \2\        inferred?       Longline \2\      inferred?       Gillnet \2\       inferred?
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale.........................               N                N                N                N                N                N
Bowhead whale.....................................               N                N                N                N                N                N
Gray whale........................................               Y                N                N                N                Y                N
Humpback whale....................................               Y                N                Y                N                Y                N

[[Page 37671]]

 
Balaenoptera spp..................................               Y                N                Y                N                Y                N
Sperm whale.......................................               N                N                Y                Y                N                N
Kogia spp.........................................             n/a              n/a                Y                N              n/a              n/a
Cuvier's beaked whale.............................               N                N                Y                N                N                N
Baird's beaked whale..............................               N                N                N                N                N                N
Mesoplodon spp....................................               N                N                Y                N                N                N
Beluga whale......................................               N                Y                N                N                Y                N
Common bottlenose dolphin.........................             n/a              n/a                Y                Y              n/a              n/a
Stenella spp......................................             n/a              n/a                Y                N              n/a              n/a
Delphinus spp.....................................             n/a              n/a                Y                Y              n/a              n/a
Lagenorhynchus spp................................               Y                Y                N                N                Y                Y
Northern right whale dolphin......................             n/a              n/a                N                N              n/a              n/a
Risso's dolphin...................................             n/a              n/a                Y                Y              n/a              n/a
Killer whale......................................               Y                N                Y                Y                N                N
Globicephala spp..................................             n/a              n/a                Y                Y              n/a              n/a
Harbor porpoise...................................               Y                Y                Y                N                Y                Y
Dall's porpoise \3\...............................             n/a              n/a                Y                Y                Y                Y
Guadalupe fur seal \4\............................             n/a              n/a                N                N              n/a              n/a
Northern fur seal \3\.............................             n/a              n/a                Y                Y                Y                Y
California sea lion \5\...........................             n/a              n/a                Y                Y              n/a              n/a
Steller sea lion \3\..............................               Y                Y              n/a              n/a                Y                Y
Bearded seal......................................               Y                Y                N                N                N                N
Phoca spp \3\.....................................               Y                Y              n/a              n/a                Y                Y
Ringed seal.......................................               Y                Y                Y                Y                N                N
Ribbon seal.......................................               Y                Y                N                N                N                N
Northern elephant seal............................               Y                Y                Y                N                Y                N
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Please refer to Table 3 for taxonomic reference.
\2\ Indicates whether any member of the genus has documented incidental M/SI in a U.S. fishery using that gear in the most recent five-year timespan for
  which data is available. For those species not expected to occur in Alaskan waters, trawl and gillnet gear are not applicable (these gears would only
  be used in Alaskan waters).
\3\ This exercise is considered ``not applicable'' for those species historically captured by AFSC or IPHC gear. Historical record, rather than analogy,
  is considered the best information upon which to base a take estimate.
\4\ It is likely that Guadalupe fur seals are taken in Mexican fisheries, but there are no records available to us.
\5\ There are no records of take for California sea lions in commercial longline fisheries, but there have been multiple takes of California sea lions
  in longline surveys conducted by NMFS's Southwest Fisheries Science Center. We therefore infer vulnerability for the species to research longline
  gear.

    Information related to incidental M/SI in relevant commercial 
fisheries is not, however, the sole determinant of whether it may be 
appropriate to authorize take incidental to AFSC survey operations. A 
number of factors (e.g., species-specific knowledge regarding animal 
behavior, overall abundance in the geographic region, density relative 
to AFSC survey effort, feeding ecology, propensity to travel in groups 
commonly associated with other species historically taken) were taken 
into account by the AFSC to determine whether a species may have a 
similar vulnerability to certain types of gear as historically taken 
species. In some cases, we have determined that species without 
documented M/SI may nevertheless be vulnerable to capture in AFSC 
research gear. Similarly, we have determined that some species groups 
with documented M/SI are not likely to be vulnerable to capture in AFSC 
gear. In these instances, we provide further explanation below. Those 
species with no records of historical interaction with AFSC research 
gear and no documented M/SI in relevant commercial fisheries, and for 
which the AFSC has not requested the authorization of incidental take, 
are not considered further in this section. The AFSC believes generally 
that any sex or age class of those species for which take authorization 
is requested could be captured.
    In order to estimate a number of individuals that could potentially 
be captured in AFSC research gear for those species not historically 
captured, we first determine which species may have vulnerability to 
capture in a given gear. Of those species, we then determine whether 
any may have similar propensity to capture in a given gear as a 
historically captured species. For these species, we assume it is 
possible that take could occur while at the same time contending that, 
absent significant range shifts or changes in habitat usage, capture of 
a species not historically captured would likely be a very rare event. 
Therefore, we assume that capture would be a rare event such that 
authorization of a single take over the five-year period, for each 
region where the gear is used and the species is present, is likely 
sufficient to capture the risk of interaction.
    Trawl--From the 2017 LOF, we infer vulnerability to trawl gear for 
the bearded seal, ringed seal, ribbon seal, and northern elephant seal. 
This is in addition to the species for which vulnerability is indicated 
by historical AFSC interactions (described above).
    For the beluga whale, we believe that there is a reasonable 
likelihood of incidental take in trawl gear although there are no 
records of incidental M/SI in relevant commercial fisheries. Commercial 
fisheries using trawl gear have largely been absent from areas where 
beluga whales occur and, in particular, there are no commercial trawl 
fisheries in the CSBSRA. AFSC examined the potential for incidental 
take of beluga whales by evaluating the areas of overlap between the 
proposed fisheries research activities and beluga whale distribution, 
considering the seasonality of both the research activities and the 
species distributions as well as other factors that may influence the 
degree of potential overlap

[[Page 37672]]

such as sea and shorefast ice occurrence. In considering the possible 
take of beluga whales, the AFSC considered that beluga whales show 
behavior similar to large dolphins and porpoises. While no belugas have 
been taken in AFSC research or commercial trawl fisheries, there have 
been takes of large dolphins elsewhere in trawls. Beluga whales may 
occur in summer periods within the Chukchi and Beaufort Sea regions 
where the AFSC may be conducting trawl surveys. Thus, AFSC has 
requested authorization of one take each from two stocks of beluga 
whale (eastern Chukchi stock and Beaufort Sea stock) in fisheries 
research trawl surveys over the 5-year authorization period. Potential 
spatiotemporal overlap between AFSC trawl survey activities and other 
beluga whale stocks was evaluated and determined to not support a take 
authorization request for other stocks of beluga whale.
    It is also possible that a captured animal may not be able to be 
identified to species with certainty. Certain pinnipeds and small 
cetaceans are difficult to differentiate at sea, especially in low-
light situations or when a quick release is necessary. For example, a 
captured delphinid that is struggling in the net may escape or be freed 
before positive identification is made. Therefore, the AFSC has 
requested the authorization of incidental take for one unidentified 
pinniped and one unidentified small cetacean in trawl gear for each 
research area over the course of the five-year period of proposed 
authorization. One exception is for small cetaceans in the CSBSRA, as 
no cetacean interactions with trawl gear are expected in that region 
(other than the aforementioned potential beluga whale interactions), as 
small cetaceans occur only rarely in this region.
    Longline--The process is the same as is described above for trawl 
gear. From the 2017 LOF, we infer vulnerability to longline gear for 
the Dall's porpoise, Risso's dolphin, bottlenose dolphin, common 
dolphin, short-finned pilot whale, and ringed seal. This is in addition 
to the species for which vulnerability is indicated by historical AFSC 
interactions (described above).
    Based on the 2017 LOF and historical observations of sperm whale 
and killer whale interactions with research longline gear, we also 
infer vulnerability to interaction with longline gear for killer whales 
(Alaska resident stock only) and sperm whales (North Pacific stock 
only). Although we generally believe that, despite records of 
interaction with analogous commercial fisheries, the potential for 
incidental take of any large whale (i.e., baleen whales or sperm 
whale), beaked whale, or killer whale in research gear is so unlikely 
as to be discountable, there is a long history of attempted depredation 
of longline gear by animals from these stocks in Alaska, with take of 
these species having occurred in commercial fisheries. Between 2010 and 
2014, five sperm whales are recorded as having been seriously injured 
in the Gulf of Alaska sablefish longline fishery, while there have been 
two instances of killer whale M/SI in BSAI longline fisheries (Helker 
et al., 2016). Cetaceans have never been caught or entangled in AFSC or 
IPHC longline research gear. If interactions occur, marine mammals 
depredate hooked fish from the gear, but typically leave the hooks 
attached although occasionally bent or broken (i.e., evidence of the 
interaction). Certain species, particularly killer whales in the Bering 
Sea and sperm whales in the Gulf of Alaska, are commonly attracted to 
longline fishing operations and are adept at removing fish from 
longline gear as it is retrieved. Although we consider it unlikely that 
AFSC or IPHC research activities would result in any takes of either 
sperm whales or killer whales, AFSC has requested the authorization of 
such take as a precautionary measure, given the observed interactions 
of these species with research longline gear. Since longline 
depredation by sperm whales is known to occur only in Alaskan waters, 
requested take is limited to the North Pacific stock. Commercial 
fishery takes have been reported for both transient and resident stocks 
of killer whale. However, the Alaska resident stock consumes fish 
(e.g., Herman et al., 2005) and is most likely to be involved in 
depredation of research catch. In contrast, transient killer whales 
feed on marine mammals and are less likely to interact with research 
longline gears, and the limited effort for AFSC and IPHC research 
surveys compared to commercial fisheries does not justify take 
authorization for transient whales.
    Although there are LOF interaction records in longlines for 
stenellid dolphin species, the harbor porpoise, and the northern 
elephant seal, we do not propose to authorize take of these species 
through use of longline. No take is anticipated for the striped dolphin 
or for the long-beaked stock of common dolphin and coastal stock of 
bottlenose dolphin because of their expected pelagic and southerly 
distributions (respectively) relative to expected IPHC survey effort. 
Harbor porpoise have only been recorded as taken in commercial 
fisheries through use of pelagic longline in the Atlantic Ocean; there 
are no records of incidental take of harbor porpoise in longline 
fisheries in Alaska or off the U.S. west coast. Similarly, the LOF 
indicates that elephant seal interaction occurred only in a Hawaiian 
pelagic longline fishery.
    As described for trawl gear, it is also possible that a captured 
animal may not be able to be identified to species with certainty. 
Although we expect that cetaceans would likely be able to be identified 
when captured in longline gear, pinnipeds are considered more likely to 
escape before the animal may be identified. Therefore, the AFSC has 
requested the authorization of incidental take for one unidentified 
pinniped for each relevant research area, in addition to one 
unidentified pinniped captured in IPHC surveys, over the course of the 
five-year period of proposed authorization.
    Gillnet--The process is the same as is described above for trawl 
gear. From the 2017 LOF, we infer vulnerability to gillnet gear for the 
Pacific white-sided dolphin, harbor porpoise, Dall's porpoise, harbor 
seal, northern fur seal, and Steller sea lion. Gillnets are used only 
in Prince William Sound and at Little Port Walter in southeast Alaska. 
Therefore, only one take is proposed for authorization for relevant 
stocks of the vulnerable species over the 5-year period. This includes 
both the eastern Pacific and California stocks of northern fur seal and 
the Prince William Sound and Sitka/Chatham Strait stocks of harbor 
seal. Although there are LOF interaction records in gillnets for the 
beluga whale and the northern elephant seal, we do not expect these 
species to be present in areas where AFSC proposes to use gillnet 
research gear and no take of these species through use of gillnet is 
proposed for authorization.
    AFSC also expects that there may be an interaction resulting in 
escape of an unidentified cetacean in gillnet gear, and has requested 
the authorization of incidental take for one unidentified cetacean over 
the course of the five-year period of proposed authorization.

[[Page 37673]]



                                           Table 7--Total Estimated Take Due to Gear Interaction, 2018-23 \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                               Estimated 5-year
             Species                 Estimated 5-year total,       Estimated 5-year total,      total, longline    Estimated 5-year    Total, all gears
                                              trawl                    longline (AFSC)            (IPHC) \2\        total, gillnet
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale (North Pacific).....  ............................  1 (GOARA)...................                   1  ..................                   2
Beluga whale (eastern Chukchi)..  1 (CSBSRA)..................  ............................  ..................  ..................                   1
Beluga whale (Beaufort Sea).....  1 (CSBSRA)..................  ............................  ..................  ..................                   1
Bottlenose dolphin (offshore)...  ............................  ............................                   1  ..................                   1
Common dolphin..................  ............................  ............................                   1  ..................                   1
Pacific white-sided dolphin.....  5 (GOARA)...................  ............................  ..................                   1                   6
Risso's dolphin.................  ............................  ............................                   1  ..................                   1
Killer whale (Alaska resident)..  ............................  1 (BSAIRA)..................                   1  ..................                   2
Short-finned pilot whale........  ............................  ............................                   1  ..................                   1
Harbor porpoise (Southeast        ............................  ............................  ..................  ..................                   1
 Alaska) \3\.
Harbor porpoise (Gulf of Alaska)  1...........................  ............................  ..................                   1                   2
Harbor porpoise (Bering Sea)....  1...........................  ............................  ..................  ..................                   1
Dall's porpoise.................  10 (5 GOARA/5 BSAIRA).......  2 (1 GOARA/1 BSAIRA)........                   1                   1                  14
Northern fur seal (eastern        10 (5 GOARA/5 BSAIRA).......  2 (1 GOARA/1 BSAIRA)........                   5                   1               13-18
 Pacific).
Northern fur seal (California)..  1 (GOARA)...................  1 (GOARA)...................  ..................                   1                 3-8
California sea lion.............  ............................  ............................                   1  ..................                   1
Steller sea lion (eastern)......  5...........................  1...........................                   5                   1                7-12
Steller sea lion (western)......  10 (5 GOARA/5 BSAIRA).......  2 (1 GOARA/1 BSAIRA)........  ..................                   1               13-18
Bearded seal....................  2 (1 BSAIRA/1 CSBSRA).......  ............................  ..................  ..................                   2
Harbor seal \4\.................  12..........................  ............................                   5                   2                  19
Spotted seal....................  2 (1 BSAIRA/1 CSBSRA).......  ............................                   1  ..................                   3
Ringed seal.....................  2 (1 BSAIRA/1 CSBSRA).......  1...........................                   1  ..................                   4
Ribbon seal.....................  2 (1 BSAIRA/1 CSBSRA).......  ............................  ..................  ..................                   2
Northern elephant seal..........  1...........................  ............................  ..................  ..................                   1
Unidentified pinniped \5\.......  3...........................  2...........................                   1  ..................                   6
Unidentified small cetacean \6\.  2...........................  ............................  ..................                   1                   3
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Please see Table 6 and preceding text for derivation of take estimates. Takes proposed for authorization are informed by area- and gear-specific
  vulnerability. However, IPHC longline takes are considered separately. AFSC use of gillnets occurs only in the GOARA. Only trawl gear is used in the
  CSBSRA.
\2\ Potential IPHC takes are not specific to any area or stock. For example, the one expected take of Dall's porpoise could occur to an individual of
  either the CA/OR/WA or Alaska stocks. For harbor seals, although five total takes may occur over the 5-year period of the proposed regulations, no
  more than one take is anticipated from any given stock.
\3\ For harbor porpoise in southeast Alaska, we propose to authorize take of one animal in all gears combined (i.e., trawl and gillnet) over the 5-year
  period. In general, harbor porpoise would be expected to have the same vulnerability to particular gears regardless of stock. However, AFSC proposes
  to use acoustic pingers on surface trawl nets in southeast Alaska, reducing the likelihood of porpoise interaction with that gear. Use of acoustic
  pingers is proposed for gillnets in both southeast Alaska and in the Gulf of Alaska.
\4\ For trawl gear, the numbers include one take during the 5-year period for each Alaskan harbor seal stock (three stocks in BSAIRA and nine stocks in
  GOARA). For gillnet gear, the numbers include one take during the 5-year period for the Prince William Sound and Sitka/Chatham Strait stocks. For IPHC
  longline surveys, the five takes proposed for authorization could occur for any harbor seal stock, though no more than one take would be expected to
  occur over the 5-year period for any given stock.
\5\ Includes one unidentified pinniped in each research area (trawl) and one unidentified pinniped in the GOARA and BSAIRA and for IPHC surveys
  (longline).
\6\ Includes one unidentified small cetacean in the GOARA and BSAIRA (trawl) and one unidentified cetacean in the GOARA (gillnet). This is not
  anticipated to apply to harbor porpoise in southeast Alaska, as the already low probability of gear interaction is further reduced through use of
  additional mitigation (described in footnote 3).

    Whales--For large whales (baleen whales and sperm whales) and small 
whales (considered here to be beaked whales, Kogia spp., and killer 
whales), observed M/SI is extremely rare for trawl and gillnet gear 
and, for most of these species, only slightly more common in longline 
gear. Furthermore, with the exception of sperm whales and killer whales 
(who attempt to depredate longline gear), most of these species 
longline interactions are with pelagic gear. Baleen whale interactions 
with longline gear represent entanglements in pelagic mainlines, while 
beaked whales and Kogia spp. typically have a pelagic distribution 
resulting in a lack of spatial overlap with bottom longline fisheries. 
Although whale species could become captured or entangled in AFSC gear, 
the probability of interaction is extremely low considering the lower 
level of effort relative to that of commercial fisheries. For example, 
there were estimated to be three total incidents of sperm whale M/SI in 
the Hawaii deep-set longline fishery over a five-year period. This 
fishery has 129 participants, and the fishery as a whole exerts 
substantially greater effort in a given year than does the AFSC. In a 
very rough estimate, we can say that these three estimated incidents 
represent an insignificant per-participant interaction rate of 0.005 
per year, despite the greater effort. Similarly, there were zero 
documented interactions over a five-year period in the Atlantic Ocean, 
Caribbean, Gulf of Mexico large pelagics longline fishery, despite a 
reported fishing effort of 8,044 sets and 5,955,800 hooks in 2011 alone 
(Garrison and Stokes, 2012). With an

[[Page 37674]]

average soak time of ten to fourteen hours, this represents an 
approximate minimum of almost sixty million hook hours. AFSC and IPHC 
effort would be a small fraction of this per year. Other large whales 
and small whales have similarly low rates of interaction with 
commercial fisheries, despite the significantly greater effort. In 
addition, most large whales and small whales generally have, with few 
exceptions, very low densities in areas where AFSC and IPHC research 
occurs relative to other species (see Tables 10-12). With exceptions 
for sperm whales and killer whales that are known to depredate research 
longline gear in particular locations, we believe it extremely unlikely 
that any large whale or small whale would be captured or entangled in 
AFSC research gear.

Estimated Take Due to Acoustic Harassment

    As described previously (``Potential Effects of the Specified 
Activity on Marine Mammals and Their Habitat''), we believe that AFSC 
use of active acoustic sources has, at most, the potential to cause 
Level B harassment of marine mammals. In order to attempt to quantify 
the potential for Level B harassment to occur, NMFS (including the AFSC 
and acoustics experts from other parts of NMFS) developed an analytical 
framework considering characteristics of the active acoustic systems 
described previously under ``Description of Active Acoustic Sound 
Sources,'' their expected patterns of use, and characteristics of the 
marine mammal species that may interact with them. We believe that this 
quantitative assessment benefits from its simplicity and consistency 
with current NMFS acoustic guidance regarding Level B harassment but 
caution that, based on a number of deliberately precautionary 
assumptions, the resulting take estimates may be seen as an 
overestimate of the potential for behavioral harassment to occur as a 
result of the operation of these systems. Additional details on the 
approach used and the assumptions made that result in these estimates 
are described below.
    In 2016, NMFS released updated ``Technical Guidance for Assessing 
the Effects of Anthropogenic Sound on Marine Mammal Hearing'' with 
revised metrics and thresholds to assess the potential for injury 
(e.g., permanent threshold shift) from acoustic sources. While the 
AFSC's documents refer to NMFS's historic guidelines, as the acoustic 
analysis was completed prior to the release of the technical guidance, 
the conclusions regarding the potential for injury remain the same. 
Most importantly, the technical guidance now explicitly takes into 
account the duration of the sound through the use of the sound exposure 
level (SEL) metric, as opposed to the previous use of root mean square 
(rms) sound pressure level (SPL). The effect of this different metric, 
in particular for the very short duration sounds used for these 
echosounders, is to largely reduce the exposure level of sound an 
animal is exposed to for short duration sounds (e.g., for a 1 ms ping, 
an SPL source level is reduced by 30 dB in the SEL metric) offsetting 
changes in the thresholds themselves. While energy is accumulated over 
time using SEL, the previous conclusion that an individual would have 
to remain exceptionally close to a sound source for unrealistic lengths 
of time holds, suggesting the likelihood of injury occurring is 
exceedingly small and is therefore not considered further in this 
analysis.
    The assessment paradigm for active acoustic sources used in AFSC 
fisheries research is relatively straightforward and has a number of 
key simplifying assumptions. NMFS's current acoustic guidance requires 
in most cases that we assume Level B harassment occurs when a marine 
mammal receives an acoustic signal at or above a simple step-function 
threshold. Sound produced by these sources are very short in duration 
(typically on the order of milliseconds), intermittent, have high rise 
times, and are operated from moving platforms. They are consequently 
considered most similar to impulsive sources, which are subject to the 
160 dB rms criterion. Estimating the number of exposures at the 
specified received level requires several determinations, each of which 
is described sequentially below:
    (1) A detailed characterization of the acoustic characteristics of 
the effective sound source or sources in operation;
    (2) The operational areas exposed to levels at or above those 
associated with Level B harassment when these sources are in operation;
    (3) A method for quantifying the resulting sound fields around 
these sources; and
    (4) An estimate of the average density for marine mammal species in 
each area of operation.
    Quantifying the spatial and temporal dimension of the sound 
exposure footprint (or ``swath width'') of the active acoustic devices 
in operation on moving vessels and their relationship to the average 
density of marine mammals enables a quantitative estimate of the number 
of individuals for which sound levels exceed the relevant threshold for 
each area. The number of potential incidents of Level B harassment is 
ultimately estimated as the product of the volume of water ensonified 
at 160 dB rms or higher (to a maximum depth of 500 m) and the 
volumetric density of animals determined from simple assumptions about 
their vertical stratification in the water column. Specifically, 
reasonable assumptions based on what is known about diving behavior 
across different marine mammal species were made to segregate those 
that predominately remain in the upper 200 m of the water column versus 
those that regularly dive deeper during foraging and transit. Because 
depths range dramatically along the margin of the continental slope 
that define the outer edge of the survey areas, but deeper surveyed 
depths rarely range over 500 m in practice, the depth range for 
determining volumes was set at 500 m for deep diving species. Methods 
for estimating each of these calculations are described in greater 
detail in the following sections, along with the simplifying 
assumptions made, and followed by the take estimates. Note that the 
IPHC does not use active acoustic systems for data acquisition 
purposes; therefore, potential Level B harassment is only considered 
for AFSC survey operations in the GOARA, BSAIRA, and CSBSRA.
    Sound Source Characteristics--An initial characterization of the 
general source parameters for the primary active acoustic sources 
operated by the AFSC was conducted, enabling a full assessment of all 
sound sources used by the AFSC and delineation of Category 1 and 
Category 2 sources, the latter of which were carried forward for 
analysis here (see Table 2). This auditing of the active acoustic 
sources also enabled a determination of the predominant sources that, 
when operated, would have sound footprints exceeding those from any 
other simultaneously used sources. These sources were effectively those 
used directly in acoustic propagation modeling to estimate the zones 
within which the 160 dB rms received level would occur.
    Many of these sources can be operated in different modes and with 
different output parameters. In modeling their potential impact areas, 
those features among those given previously in Table 2 (e.g., lowest 
operating frequency) that would lead to the most precautionary estimate 
of maximum received level ranges (i.e., largest ensonified area) were 
used. The effective beam patterns took into account the normal modes in 
which these sources are typically operated. While these signals are 
brief and intermittent, a conservative assumption was taken in ignoring 
the temporal

[[Page 37675]]

pattern of transmitted pulses in calculating Level B harassment events. 
Operating characteristics of each of the predominant sound sources were 
used in the calculation of effective line-kilometers and area of 
exposure for each source in each survey.
    Note that, for purposes of this analysis, the EK60 is assumed to 
operate at 18 kHz, the ES60 is assumed to operate at 38 kHz, and the 
7111 is assumed to operate at 100 kHz. Therefore, we assume that Level 
B harassment of low-frequency cetaceans may only occur in response to 
exposure to signals from the EK60, as signals from the other two 
systems are outside the generalized hearing range for this group. 
Similarly, we assume that pinnipeds would not experience harassment 
upon exposure to signals from the 7111, which produces signals outside 
the generalized hearing range of both otariid and phocid pinnipeds.

   Table 8--Effective Exposure Areas for Predominant Acoustic Sources
                         Across Two Depth Strata
------------------------------------------------------------------------
                                             Effective       Effective
                                          exposure area:  exposure area:
         Active acoustic system           Sea surface to  Sea surface to
                                            200 m depth     500 m depth
                                              (km\2\)         (km\2\)
------------------------------------------------------------------------
Simrad EK60/ME70 narrow beam echosounder          0.0173           0.056
Simrad ES60 multibeam echosounder.......          0.0112           0.036
Reson 7111 multibeam echosounder........          0.1419           0.914
------------------------------------------------------------------------

    Among Category 2 sources (Table 2), three predominant sources 
(Table 8) were identified as having the largest potential impact zones 
during operations, based on their relatively lower output frequency, 
higher output power, and their operational pattern of use. Estimated 
effective cross-sectional areas of exposure were estimated for each of 
the predominant sources using a commercial software package (MATLAB) 
and key input parameters including source-specific operational 
characteristics (e.g., frequency, beamwidth, source level; see Table 2) 
and environmental characteristics (i.e., temperature, salinity, pH, and 
latitude). Where relevant, calculations were performed for different 
notional operational scenarios and the largest cross-sectional area 
used in estimating take (e.g., see Figure 6-2 of AFSC's application, 
which displays a simple visualization of a two-dimensional slice of 
modeled sound propagation to illustrate the predicted area ensonified 
to the 160-dB threshold by the nominal EK60 beam pattern assuming side 
lobes of ensonification).
    In determining the effective line-kilometers for each of these 
predominant sources, the operational patterns of use relative to one 
another were further applied to determine which source was the 
predominant one operating at any point in time for each survey. When 
multiple sound sources are used simultaneously, the one with the 
largest potential impact zone in each relevant depth strata is 
considered for use in estimating exposures. For example, when species 
(e.g., sperm whales) regularly dive deeper than 200 m, the largest 
potential impact zone was calculated for both depth strata and in some 
cases resulted in a different source being predominant in one depth 
stratum or the other. This enabled a more comprehensive way of 
accounting for maximum exposures for animals diving in a complex sound 
field resulting from simultaneous sources with different spatial 
profiles. This overall process effectively resulted in three sound 
sources (Table 8; ES60, EK60/ME70, and 7111) comprising the total 
effective line-kilometers, their relative proportions depending on the 
nature of each survey.
    Calculating Effective Line-Kilometers--As described below, based on 
the operating parameters for each source type, an estimated volume of 
water ensonified at or above the 160 dB rms threshold was determined. 
In all cases where multiple sources are operated simultaneously, the 
one with the largest estimated acoustic footprint was considered to be 
the effective source. This was calculated for each depth stratum, which 
in some cases resulted in different sources being predominant in each 
depth stratum for all line-kilometers when multiple sources were in 
operation; this was accounted for in estimating overall exposures for 
species that utilize both depth strata (deep divers). The total number 
of line-kilometers associated with relevant surveys was determined, as 
was the relative percentage of surveyed linear kilometers associated 
with each depth stratum (equating to the proportion of each survey 
occurring on the shallower upper continental shelf versus those in 
deeper waters). The total line-kilometers for each survey, the 
predominant source, the effective percentages associated with each 
depth, and the effective total volume ensonified are given below (Table 
9).
    Calculating Volume of Water Ensonified--The cross-sectional area of 
water ensonified at or above the 160 dB rms threshold was calculated 
using a simple model of sound propagation loss, which accounts for the 
loss of sound energy over increasing range. We used a spherical 
spreading model (where propagation loss = 20 * log [range]; such that 
there would be a 6-dB reduction in sound level for each doubling of 
distance from the source), a reasonable approximation over the 
relatively short ranges involved. Spherical spreading is a reasonable 
assumption even in relatively shallow waters since, taking into account 
the beam angle, the reflected energy from the seafloor will be much 
weaker than the direct source and the volume influenced by the 
reflected acoustic energy would be much smaller over the relatively 
short ranges involved. We also accounted for the frequency-dependent 
absorption coefficient and beam pattern of these sound sources, which 
is generally highly directional. The lowest frequency was used for 
systems that are operated over a range of frequencies. The vertical 
extent of this area is calculated for two depth strata. These results, 
shown in Table 9, were applied differentially based on the typical 
vertical stratification of marine mammals (see Table 10).
    Following the determination of effective sound exposure area for 
transmissions considered in two dimensions, the next step was to 
determine the effective volume of water ensonified at or above 160 dB 
rms for the entirety of each survey. For each of the three predominant 
sound sources, the volume of water ensonified is estimated as the 
athwartship cross-sectional area (in square kilometers) of sound at or 
above 160 dB rms (as illustrated in Figure 6.2 of AFSC's

[[Page 37676]]

application) multiplied by the total distance traveled by the ship. 
Where different sources operating simultaneously would be predominant 
in each different depth strata, the resulting cross-sectional area 
calculated took this into account. Specifically, for shallow-diving 
species this cross-sectional area was determined for whichever was 
predominant in the shallow stratum, whereas for deeper-diving species 
this area was calculated from the combined effects of the predominant 
source in the shallow stratum and the (sometimes different) source 
predominating in the deep stratum. This creates an effective total 
volume characterizing the area ensonified when each predominant source 
is operated and accounts for the fact that deeper-diving species may 
encounter a complex sound field in different portions of the water 
column.
    Marine Mammal Densities--One of the primary limitations to 
traditional estimates of behavioral harassment from acoustic exposure 
is the assumption that animals are uniformly distributed in time and 
space across very large geographical areas, such as those being 
considered here. There is ample evidence that this is in fact not the 
case, and marine species are highly heterogeneous in terms of their 
spatial distribution, largely as a result of species-typical 
utilization of heterogeneous ecosystem features. Some more 
sophisticated modeling efforts have attempted to include species-
typical behavioral patterns and diving parameters in movement models 
that more adequately assess the spatial and temporal aspects of 
distribution and thus exposure to sound. While simulated movement 
models were not used to mimic individual diving or aggregation 
parameters in the determination of animal density in this estimation, 
the vertical stratification of marine mammals based on known or 
reasonably assumed diving behavior was integrated into the density 
estimates used.
    First, typical two-dimensional marine mammal density estimates 
(animals/km\2\) were obtained from various sources for each ecosystem 
area. These were estimated from marine mammal Stock Assessment Reports 
and other sources (please see Table 6-10d of AFSC's application). There 
are a number of caveats associated with these estimates:
    (1) They are often calculated using visual sighting data collected 
during one season rather than throughout the year. The time of year 
when data were collected and from which densities were estimated may 
not always overlap with the timing of AFSC fisheries surveys (detailed 
previously in ``Detailed Description of Activities'').
    (2) Marine mammal survey areas do not necessarily coincide 
spatially with the entire AFSC fisheries research area boundaries. 
Estimated densities from the survey areas are assumed to apply to the 
entire research area.
    (3) The densities used for purposes of estimating acoustic 
exposures do not take into account the patchy distributions of marine 
mammals in an ecosystem, at least on the moderate to fine scales over 
which they are known to occur. Instead, animals are considered evenly 
distributed throughout the assessed area, and seasonal movement 
patterns are not taken into account.
    In addition, and to account for at least some coarse differences in 
marine mammal diving behavior and the effect this has on their likely 
exposure to these kinds of often highly directional sound sources, a 
volumetric density of marine mammals of each species was determined. 
This value is estimated as the abundance averaged over the two-
dimensional geographic area of the surveys and the vertical range of 
typical habitat for the population. Habitat ranges were categorized in 
two generalized depth strata (0-200 m and 0 to greater than 200 m) 
based on gross differences between known generally surface-associated 
and typically deep-diving marine mammals (e.g., Reynolds and Rommel, 
1999; Perrin et al., 2009). Animals in the shallow-diving stratum were 
assumed, on the basis of empirical measurements of diving with 
monitoring tags and reasonable assumptions of behavior based on other 
indicators, to spend a large majority of their lives (i.e., greater 
than 75 percent) at depths shallower than 200 m. Their volumetric 
density and thus exposure to sound is therefore limited by this depth 
boundary. In contrast, species in the deeper-diving stratum were 
assumed to regularly dive deeper than 200 m and spend significant time 
at these greater depths. Their volumetric density and thus potential 
exposure to sound at or above the 160 dB rms threshold is extended from 
the surface to 500 m, i.e., nominal maximum water depth in regions 
where these surveys occur.
    The volumetric densities are estimates of the three-dimensional 
distribution of animals in their typical depth strata. For shallow-
diving species the volumetric density is the area density divided by 
0.2 km (i.e., 200 m). For deeper diving species, the volumetric density 
is the area density divided by a nominal value of 0.5 km (i.e., 500 m). 
The two-dimensional and resulting three-dimensional (volumetric) 
densities for each species in each ecosystem area are shown below.
    Using Area of Ensonification and Volumetric Density to Estimate 
Exposures--Estimates of potential incidents of Level B harassment 
(i.e., potential exposure to levels of sound at or exceeding the 160 dB 
rms threshold) are then calculated by using (1) the combined results 
from output characteristics of each source and identification of the 
predominant sources in terms of acoustic output; (2) their relative 
annual usage patterns for each operational area; (3) a source-specific 
determination made of the area of water associated with received sounds 
at the extent of a depth boundary; and (4) determination of a 
biologically-relevant volumetric density of marine mammal species in 
each area. Estimates of Level B harassment by acoustic sources are the 
product of the volume of water ensonified at 160 dB rms or higher for 
the predominant sound source for each relevant survey and the 
volumetric density of animals for each species. These annual estimates 
are given below.
    Most species designated as shallow divers (< 200 m depth) were 
considered to be shelf and inshore species, and their lineal distance 
was the extent of survey areas to 200 m in depth. However, some shallow 
diving species also occur in offshore waters so the density to 200 m 
depth was applied to the volumetric density of all survey tracks. These 
species included gray whale; harbor porpoise (GOARA only); northern fur 
seal; Steller sea lion; Dalls' porpoise; beluga whale (Bristol Bay 
stock only); humpback whale, killer whales, and sei whales (BSAIRA 
only); and bearded, ribbon, ringed, and spotted seals (BSAIRA only). 
Ensonified volumes for deep diving species were summed for the shallow 
inshore component and the deeper waters.

[[Page 37677]]



                       Table 9--Annual Linear Survey Kilometers for Each Vessel and its Predominant Source Within Two Depth Strata
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                              Volume          Volume
            Vessel                     Survey            Line-kms       Dominant source   Distance 0-200  Distance > 200  ensonified (0-    ensonified
                                                                                            m (percent)     m (percent)       200 m)        (200-500 m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
GOARA
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Oscar Dyson..................  Pollock summer                 17,558  EK60/ME70                       74              26           224.8           256.1
                                acoustic trawl.
Oscar Dyson..................  Pollock winter                  9,540  EK60/ME70                       31              69            51.2           369.3
                                acoustic trawl
                                (Shelikof Strait).
Oscar Dyson..................  Pollock winter                  4,520  EK60/ME70                       99               1            77.4             2.5
                                acoustic trawl
                                (Shumagin/Sanak
                                Islands).
Charter vessels..............  Shelf and slope                 9,189  ES60                            76              24            78.2            79.4
                                bottom trawl
                                groundfish.
--------------------------------------------------------------------------------------------------------------------------------------------------------
BSAIRA
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Oscar Dyson..................  Pollock summer                 25,460  EK60/ME70                       91               9           400.8           128.5
                                acoustic trawl
                                (Bering Sea).
Oscar Dyson..................  Pollock winter                  2,788  EK60/ME70                       15              85             7.2           132.9
                                acoustic trawl
                                (Bogoslof Island).
Charter vessels..............  Aleutian Islands                3,190  ES60                            61              39            21.8            44.8
                                shelf and slope
                                bottom trawl
                                groundfish.
Charter vessels..............  Arctic Ecosystem                2,599  ES60                           100               0            29.1               0
                                Integrated Survey.
Charter vessels..............  Bering Sea shelf               11,200  ES60                           100               0           125.4               0
                                bottom trawl.
Charter vessels..............  Eastern Bering Sea              1,125  ES60                             0             100               0            40.5
                                upper continental
                                slope trawl summer.
Charter vessels..............  Bering Aleutian                12,288  ES60                            95               5           130.7            34.5
                                Salmon International
                                Survey (BASIS).
Charter vessels..............  Northern Bering Sea             1,440  ES60                           100               0            16.1               0
                                bottom trawl.
Charter vessels..............  Response of fish to               259  ES60                           100               0             2.9               0
                                drop camera systems.
Fairweather..................  Acoustic research and             145  Reson 7111                     100               0            20.6               0
                                mapping to
                                characterize EFH
                                (FISHPAC).
--------------------------------------------------------------------------------------------------------------------------------------------------------
CSBSRA
rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
Charter vessels..............  Arctic Ecosystem                5,915  ES60                           100               0            66.2               0
                                Integrated Survey.
--------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 37678]]

    Next, we provide volumetric densities for marine mammals and total 
estimated takes by Level B harassment, by dominant source and total, 
for each stock in each of the three research areas (Tables 10-12). We 
also provide a sample calculation.
    We first determine the source-specific ensonified volume of water 
for each relevant survey and then determine species-specific exposure 
estimates for the shallow and deep (if applicable; Tables 10-12) depth 
strata. First, we know the estimated source-specific cross-sectional 
ensonified area within the shallow and deep strata (Table 8) and the 
number of annual line-kilometers for each survey and use these values 
to derive an estimated ensonified volume. Survey- and stratum-specific 
exposure estimates are the product of these ensonified volumes and the 
species-specific volumetric densities (Table 10).
    To illustrate the process, we focus on the EK60 and the sperm whale 
in the GOARA.
    (1) EK60 ensonified volume; 0-200 m: 0.0173 km\2\ * 17,558 km * 
0.74 = 224.8 km\3\.
    (2) EK60 ensonified volume; >200 m: 0.0561 km\2\ * 17,558 km * 0.26 
= 256.1 km\3\.
    (3) Repeat steps 1 and 2 for each relevant survey; sum total 
ensonified volumes in each depth stratum
    (4) Estimated exposures to sound >=160 dB rms; sperm whale; EK60: 
(0.002 sperm whales/km\3\ * 353.4 km\3\ (total ensonified volume; 0-200 
m) = 0.7) + (0.002 sperm whales/km\3\ * 627.9 km\3\ (total ensonified 
volume; 200-500 m) = 1.3) = 2 estimated sperm whale exposures to SPLs 
>=160 dB rms resulting from use of the EK60.
    (5) Repeat steps 1-4 for additional surveys with other predominant 
sound sources.
    Totals in Tables 10-12 represent sums across all relevant surveys/
sources rounded up to the nearest whole number. The AFSC has requested 
the authorization of take indicated by rounding.

              Table 10--Densities and Estimated Source-, Stratum-, and Species-Specific Annual Estimates of Level B Harassment in the GOARA
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Volumetric      Estimated level B     Estimated level B
                                                                    Area density       density      harassment, 0-200 m   harassment, >200 m
                 Species                     Shallow      Deep        (animals/       (animals/   --------------------------------------------   Total
                                                                     km\2\) \1\      km\3\) \2\       EK60       ES60       EK60       ES60
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale................          X   ..........           0.005           0.027        0.1  .........  .........  .........          1
Gray whale...............................          X   ..........           1.700           8.500    4,649.4  .........  .........  .........      4,650
Humpback whale (CNP).....................          X   ..........           0.065           0.327      115.4  .........  .........  .........        116
Humpback whale (WNP).....................          X   ..........           0.001           0.004        1.2  .........  .........  .........          2
Minke whale..............................          X   ..........           0.001           0.006        2.1  .........  .........  .........          3
Sei whale................................          X   ..........           0.000           0.000       0.01  .........  .........  .........          1
Fin whale................................          X   ..........           0.020           0.100       35.3  .........  .........  .........         36
Blue whale...............................          X   ..........           0.000           0.001        0.2  .........  .........  .........          1
Sperm whale..............................  ..........          X            0.001           0.002        0.7        0.2        1.3        0.2          3
Cuvier's beaked whale....................  ..........          X            0.000           0.000        0.1          0        0.1          0          1
Baird's beaked whale.....................  ..........          X            0.002           0.003        1.2        0.3        2.1        0.3          4
Stejneger's beaked whale.................  ..........          X            0.005           0.010        3.6        0.8        6.4        0.8         12
Beluga whale (Cook Inlet) \3\............          X   ..........           0.200           1.000  .........        2.5  .........  .........          3
Pacific white-sided dolphin..............          X   ..........           0.015           0.075       26.5        5.9  .........  .........         33
Killer whale (offshore)..................          X   ..........           0.011           0.055       19.4        4.3  .........  .........         24
Killer whale (west coast transient)......          X   ..........           0.006           0.028        9.9        2.2  .........  .........         13
Killer whale (AT1 transient).............          X   ..........           0.001           0.004        1.2        0.3  .........  .........          2
Killer whale (GOA/BSAI transient)........          X   ..........           0.001           0.004        1.2        0.3  .........  .........          2
Killer whale (northern resident).........          X   ..........           0.003           0.013        4.4        1.0  .........  .........          6
Killer whale (AK resident)...............          X   ..........           0.009           0.045       15.9        3.5  .........  .........         20
Harbor porpoise (GOA)....................          X   ..........           0.200           1.000      547.0      102.9  .........  .........        650
Harbor porpoise (SEAK)...................          X   ..........           0.110           0.550      300.8       56.6  .........  .........        358
Dall's porpoise..........................          X   ..........           1.600           8.000    4,375.9      823.3  .........  .........      5,200
Northern fur seal (CA) \4\...............          X   ..........           0.044           0.219      119.5       22.5  .........  .........        143
Northern fur seal (EP--winter) \5\.......          X   ..........           0.377           1.883      458.0  .........  .........  .........        459
Northern fur seal (EP--summer)...........          X   ..........           0.116           0.582      176.7       59.9  .........  .........        237
Steller sea lion (eastern; GOA-wide).....          X   ..........           0.059           0.294      160.8       30.3  .........  .........        192
Steller sea lion (eastern; E144).........          X   ..........           0.221           1.103      603.3      113.5  .........  .........        717
Steller sea lion (eastern; W144).........          X   ..........           0.001           0.006        3.3        0.6  .........  .........          4
Steller sea lion (western; GOA-wide).....          X   ..........           0.035           0.176       96.0       18.1  .........  .........        115

[[Page 37679]]

 
Steller sea lion (western; E144).........          X   ..........           0.003           0.015        7.9        1.5  .........  .........         10
Steller sea lion (western; W144).........          X   ..........           0.048           0.239      130.7       24.6  .........  .........        156
Harbor seal (Clarence Strait)............          X   ..........           0.099           0.494      174.6       38.7  .........  .........        214
Harbor seal (Dixon/Cape Decision)........          X   ..........           0.057           0.283       99.9       22.1  .........  .........        123
Harbor seal (Sitka/Chatham Strait).......          X   ..........           0.046           0.232       82.0       18.2  .........  .........        101
Harbor seal (Lynn Canal/Stephens Passage)          X   ..........           0.030           0.148       52.3       11.6  .........  .........         64
Harbor seal (Glacier Bay/Icy Strait).....          X   ..........           0.022           0.113       39.8        8.8  .........  .........         49
Harbor seal (Cook Inlet/Shelikof Strait).          X   ..........           0.031           0.156       54.9       12.2  .........  .........         68
Harbor seal (Prince William Sound).......          X   ..........           0.061           0.303      107.2       23.7  .........  .........        131
Harbor seal (South Kodiak)...............          X   ..........           0.022           0.109       38.6        8.5  .........  .........         48
Harbor seal (North Kodiak)...............          X   ..........           0.009           0.472       16.7        3.7  .........  .........         21
Northern elephant seal...................  ..........          X            0.020           0.045       15.9        3.5       28.3        3.6         52
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Sources and derivation of marine mammal density information are provided in Table 6-10d of AFSC's application.
\2\ Volumetric density estimates derived by dividing area density estimates by 0.2 km (for shallow species) or 0.5 km (for deep species), corresponding
  with defined depth strata.
\3\ The EK60 is not used in areas of Cook Inlet where beluga whales may be present.
\4\ Individuals from the California stock of northern fur seals are assumed to occur only east of 144[deg]W.
\5\The EK60 is not used in winter in areas where the northern fur seal may be present.


             Table 11--Densities and Estimated Source-, Stratum-, and Species-Specific Annual Estimates of Level B Harassment in the BSAIRA
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                          Volumetric    Estimated level B harassment, 0-   Estimated level B
                                                         Area density       density                  200 m                harassment, >200 m
            Species               Shallow      Deep        (animals/       (animals/   -------------------------------------------------------   Total
                                                          km\2\) \1\      km\3\) \2\       EK60       ES60       7111       EK60       ES60
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale.....          X   ..........           0.000           0.002        0.1  .........  .........  .........  .........          1
Bowhead whale.................          X   ..........           0.017           0.085       41.5  .........  .........  .........  .........         42
Gray whale....................          X   ..........           0.380           1.900      928.5  .........  .........  .........  .........        929
Humpback whale (CNP)..........          X   ..........           0.018           0.092       45.0  .........  .........  .........  .........         45
Humpback whale (WNP)..........          X   ..........           0.002           0.008        3.9  .........  .........  .........  .........          4
Minke whale...................          X   ..........           0.002           0.011        4.3  .........  .........  .........  .........          5
Sei whale.....................          X   ..........           0.000           0.001        0.4  .........  .........  .........  .........          1
Fin whale.....................          X   ..........           0.001           0.007        3.4  .........  .........  .........  .........          4
Sperm whale...................  ..........          X            0.008           0.016        6.5        5.5        0.3        4.2        1.9         19
Cuvier's beaked whale.........  ..........          X            0.000           0.000        0.1        0.1          0          0          0          1
Baird's beaked whale..........  ..........          X            0.002           0.003        1.4        1.2        0.1        0.9        0.4          4
Stejneger's beaked whale......  ..........          X            0.001           0.002        1.0        0.8          0        0.6        0.3          3
Beluga whale (Bristol Bay) \3\          X   ..........           0.700           3.500  .........  .........  .........  .........  .........          0
Beluga whale (eastern Bering            X   ..........           0.242           0.484      493.7      419.5       24.9  .........  .........        939
 Sea).........................
Pacific white-sided dolphin...          X   ..........           0.005           0.027       11.0        9.4        0.6  .........  .........         21
Killer whale (offshore).......          X   ..........           0.011           0.055       22.4       19.1        1.1  .........  .........         43
Killer whale (GOA/BSAI                  X   ..........           0.003           0.013        5.3        4.5        0.3  .........  .........         11
 transient)...................
Killer whale (AK resident)....          X   ..........           0.001           0.005        2.0        1.7        0.1  .........  .........          4
Harbor porpoise (Bering Sea)..          X   ..........           0.450           2.250      918.1      780.1       46.3  .........  .........      1,745
Dall's porpoise...............          X   ..........           0.033           0.164       79.9       58.8        3.4  .........  .........        143
Northern fur seal (EP--winter)          X   ..........           0.075           0.377       18.2  .........  .........  .........  .........         19
 \4\..........................
Northern fur seal (EP--summer)          X   ..........           0.215           1.075      473.6      386.6  .........  .........  .........        861
Steller sea lion (eastern)....          X   ..........           0.000           0.001        0.2        0.2  .........  .........  .........          1
Steller sea lion (western)....          X   ..........           0.012           0.060       29.1       21.4  .........  .........  .........         51
Bearded seal..................          X   ..........           0.394           1.968      961.5      707.4  .........  .........  .........      1,669
Harbor seal (Aleutian Islands)          X   ..........           0.003           0.014        5.9        5.0  .........  .........  .........         11
Harbor seal (Pribilof Islands)          X   ..........           0.000           0.001        0.2        0.2  .........  .........  .........          1
Harbor seal (Bristol Bay).....          X   ..........           0.015           0.072       29.5       25.1  .........  .........  .........         55
Spotted seal..................          X   ..........           0.601           3.006    1,125.1      827.8  .........  .........  .........      1,953
Ringed seal...................          X   ..........           0.349           1.746      853.3      627.7  .........  .........  .........      1,481

[[Page 37680]]

 
Ribbon seal...................          X   ..........           0.241           1.204      450.5      331.4  .........  .........  .........        782
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Sources and derivation of marine mammal density information are provided in Table 6-10d of AFSC's application.
\2\ Volumetric density estimates derived by dividing area density estimates by 0.2 km (for shallow species) or 0.5 km (for deep species), corresponding
  with defined depth strata.
\3\ Acoustic sources considered in this analysis are not used in areas of Bristol Bay where beluga whales may occur.
\4\ The ES60 is not used during winter in BSAIRA.


             Table 12--Densities and Estimated Source-, Stratum-, and Species-Specific Annual Estimates of Level B Harassment in the CSBSRA
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                             Estimated
                                                                                                            Volumetric        level B
                                                                                           Area density       density     harassment, 0-
                             Species                                Shallow      Deep        (animals/       (animals/         200 m           Total
                                                                                            km\2\) \1\      km\3\) \2\   ----------------
                                                                                                                               ES60
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bowhead whale...................................................          X   ..........           2.270          11.350  ..............               0
Gray whale......................................................          X   ..........           0.010           0.050  ..............               0
Humpback whale (CNP)............................................          X   ..........           0.000           0.001  ..............               0
Humpback whale (WNP)............................................          X   ..........           0.000           0.000  ..............               0
Minke whale.....................................................          X   ..........           0.000           0.001  ..............               0
Fin whale.......................................................          X   ..........           0.000           0.001  ..............               0
Beluga whale (Beaufort Sea).....................................          X   ..........           0.008           0.040             3.0               3
Beluga whale (eastern Chukchi Sea)..............................          X   ..........           0.008           0.040             3.0               3
Killer whale (GOA/BSAI transient)...............................          X   ..........           0.000           0.000           0.003               1
Harbor porpoise (Bering Sea)....................................          X   ..........           0.000           0.001            0.03               1
Bearded seal....................................................          X   ..........           0.175           0.875            58.0              58
Spotted seal....................................................          X   ..........           0.460           2.302           152.5             153
Ringed seal.....................................................          X   ..........           1.765           8.825           584.6             585
Ribbon seal.....................................................          X   ..........           0.184           0.922              75              62
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Sources and derivation of marine mammal density information are provided in Table 6-10d of AFSC's application.
\2\ Volumetric density estimates derived by dividing area density estimates by 0.2 km.

Estimated Take Due to Physical Disturbance

    Take due to physical disturbance could potentially happen, as it is 
likely that some pinnipeds will move or flush from known haul-outs into 
the water in response to the presence or sound of AFSC vessels or 
researchers. Such events could occur as a result of unintentional 
approach during survey activity, in the GOARA or BSAIRA only. Physical 
disturbance would result in no greater than Level B harassment. 
Behavioral responses may be considered according to the scale shown in 
Table 13 and based on the method developed by Mortenson (1996). We 
consider responses corresponding to Levels 2-3 to constitute Level B 
harassment.

               Table 13--Pinniped Response to Disturbance
------------------------------------------------------------------------
                   Type of
    Level          response                    Definition
------------------------------------------------------------------------
1............  Alert..........  Seal head orientation or brief movement
                                 in response to disturbance, which may
                                 include turning head towards the
                                 disturbance, craning head and neck
                                 while holding the body rigid in a u-
                                 shaped position, changing from a lying
                                 to a sitting position, or brief
                                 movement of less than twice the
                                 animal's body length.
2............  Movement.......  Movements away from the source of
                                 disturbance, ranging from short
                                 withdrawals at least twice the animal's
                                 body length to longer retreats over the
                                 beach.
3............  Flight.........  All retreats (flushes) to the water.
------------------------------------------------------------------------

    The AFSC has estimated potential incidents of Level B harassment 
due to physical disturbance (Table 14) by considering the number of 
seals believed to potentially be present at affected haul-outs or 
rookeries and the number of visits within a certain distance of the 
haul-out expected to be made by AFSC researchers. AFSC compared haul-
out and rookery locations and research survey station and track line 
locations. Analysis was limited to activities that occurred within a 5-
km buffer zone from the shoreline. For point data, a 2-km zone around 
the point was assumed to represent the extent of the vessel and survey 
activity around the point. For line data representing the Alaska 
longline survey and the Gulf of Alaska acoustic pollock survey, a 0.5 
nmi (0.9 km) buffer around the line was used to represent the potential 
interaction area. Take interactions where then tallied if the buffered 
line or point data from the research activities intersected within a 
0.5 nmi buffer zone around any identified rookery or haul-out. When on 
the basis of this analysis a ``disturbance'' was assumed, the number

[[Page 37681]]

of individuals expected to be present at the location are assumed to be 
disturbed. Number of individuals was determined based on count data for 
Steller sea lions and based on a density value multiplied by the 
buffered haul-out area for harbor seals. AFSC does not believe that any 
research activities would result in physical disturbance of pinnipeds 
other than Steller sea lions or harbor seals. Similarly, no disturbance 
is expected of eastern Steller sea lions due to a lack of overlap 
between known haul-outs or rookeries and research activities.
    Although not all individuals on ``disturbed'' haul-outs would 
necessarily actually be disturbed, and some haul-outs may experience 
some disturbance at distances greater than expected, we believe that 
this approach is a reasonable effort towards accounting for this 
potential source of disturbance. The results are likely overestimates, 
because some activities may only be one-time, sporadic, or biennial 
activities, but are assumed to happen on an annual basis.

  Table 14--Estimated Annual Level B Harassment of Pinnipeds Associated
                     With Disturbance by Researchers
------------------------------------------------------------------------
                                                             Estimated
            Species                       Stock           annual level B
                                                            harassment
------------------------------------------------------------------------
Harbor seal....................  Clarence Strait........              28
                                 Dixon/Cape Decision....              30
                                 Sitka/Chatham Strait...             864
                                 Lynn Canal/Stephens                  45
                                  Passage.
                                 Glacier Bay/Icy Strait.              20
                                 Cook Inlet/Shelikof               2,554
                                  Strait.
                                 Prince William Sound...           3,063
                                 South Kodiak...........           3,761
                                 North Kodiak...........             885
                                 Bristol Bay............             132
                                 Pribilof Islands.......              28
                                 Aleutian Islands.......             290
Steller sea lion...............  Western DPS (GOARA)....           3,082
                                 Western DPS (BSAIRA)...             112
------------------------------------------------------------------------

Effects of Specified Activities on Subsistence Uses of Marine Mammals

    The availability of the affected marine mammal stocks or species 
for subsistence uses may be impacted by this activity. The subsistence 
uses that may be affected and the potential impacts of the activity on 
those uses are described in section 8 of the AFSC's application. 
Measures included in this proposed rulemaking to reduce the impacts of 
the activity on subsistence uses are described in Appendix B of the 
AFSC's application. For full details, please see those documents. Last, 
the information from this section and the Proposed Mitigation section 
is analyzed to determine whether the necessary findings may be made in 
the Unmitigable Adverse Impact Analysis and Determination section.

Proposed Mitigation

    Under Section 101(a)(5)(A) of the MMPA, NMFS must set forth the 
permissible methods of taking pursuant to such activity, and other 
means of effecting the least practicable adverse 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 (``least practicable adverse impact''). NMFS does not 
have a regulatory definition for ``least practicable adverse impact.'' 
However, NMFS's implementing 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)).
    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 consider 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. 
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.
    (2) The practicability of the measure for applicant implementation. 
Practicability of implementation may consider such things as cost, 
impact on operations, personnel safety, and practicality of 
implementation.
    The following suite of mitigation measures and procedures, i.e., 
measures taken to monitor, avoid, or minimize the encounter and 
potential take of marine mammals, will be employed by the AFSC during 
research cruises and activities. These procedures are the same whether 
the survey is conducted AFSC, IPHC, or is an AFSC-supported survey, 
which may be conducted onboard a variety of vessels, e.g., on board a 
NOAA vessel or charter vessel. The procedures described are based on 
protocols used during previous research surveys and/or best practices 
developed for commercial fisheries using similar gear. The AFSC 
conducts a large variety of research operations, but only activities 
using trawl, longline, and gillnet gears are expected to present a 
reasonable likelihood of resulting in incidental take of marine 
mammals. AFSC's past survey operations have resulted in marine mammal 
interactions. These protocols are designed to continue the past record 
of few interactions while providing credible, documented, and safe 
encounters with observed or captured animals. Mitigation procedures 
will be focused on those situations where mammals, in the best 
professional judgement of the vessel operator and Chief Scientist (CS), 
pose a risk of incidental take. In many instances, the AFSC will use 
streamlined protocols and training for protected species

[[Page 37682]]

developed in collaboration with the North Pacific Groundfish and 
Halibut Observer Program.
    The AFSC has invested significant time and effort in identifying 
technologies, practices, and equipment to minimize the impact of the 
proposed activities on marine mammal species and stocks and their 
habitat. These efforts have resulted in the consideration of many 
potential mitigation measures, including those the AFSC has determined 
to be feasible and has implemented in recent years as a standard part 
of sampling protocols. These measures include the move-on rule 
mitigation protocol (also referred to in the preamble as the move-on 
rule), protected species visual watches and use of acoustic pingers on 
gillnet gear and on surface trawls in southeast Alaska.
    Effective monitoring is a key step in implementing mitigation 
measures and is achieved through regular marine mammal watches. Marine 
mammal watches are a standard part of conducting AFSC fisheries 
research activities, particularly those activities that use gears that 
are known to or potentially interact with marine mammals. Marine mammal 
watches and monitoring occur during daylight hours prior to deployment 
of gear (e.g., trawls, gillnets, and longline gear), and they continue 
until gear is brought back on board. If marine mammals are sighted in 
the area and are considered to be at risk of interaction with the 
research gear, then the sampling station is either moved or canceled or 
the activity is suspended until the marine mammals are no longer in the 
area. On smaller vessels, the CS and the vessel operator are typically 
those looking for marine mammals and other protected species. When 
marine mammal researchers are on board (distinct from marine mammal 
observers dedicated to monitoring for potential gear interactions), 
they will record the estimated species and numbers of animals present 
and their behavior using protocols similar or adapted from the North 
Pacific Groundfish and Halibut Observer Program. If marine mammal 
researchers are not on board or available, then the CS in cooperation 
with the vessel operator will monitor for marine mammals and provide 
training as practical to bridge crew and other crew to observe and 
record such information. Because marine mammals are frequently observed 
in Alaskan waters, marine mammal observations may be limited to those 
animals that directly interact with or are near to the vessel or gear. 
NOAA vessels, chartered vessels, and affiliated vessels or studies are 
required to monitor interactions with marine mammals but are limited to 
reporting direct interactions, dead animals, or entangled whales.

General Measures

    Coordination and Communication--When AFSC survey effort is 
conducted aboard NOAA-owned vessels, there are both vessel officers and 
crew and a scientific party. Vessel officers and crew are not composed 
of AFSC staff but are employees of NOAA's Office of Marine and Aviation 
Operations (OMAO), which is responsible for the management and 
operation of NOAA fleet ships and aircraft and is composed of uniformed 
officers of the NOAA Commissioned Corps as well as civilians. The 
ship's officers and crew provide mission support and assistance to 
embarked scientists, and the vessel's Commanding Officer (CO) has 
ultimate responsibility for vessel and passenger safety and, therefore, 
decision authority. When AFSC survey effort is conducted aboard 
cooperative platforms (i.e., non-NOAA vessels), ultimate responsibility 
and decision authority again rests with non-AFSC personnel (i.e., 
vessel's master or captain). Decision authority includes the 
implementation of mitigation measures (e.g., whether to stop deployment 
of trawl gear upon observation of marine mammals). The scientific party 
involved in any AFSC survey effort is composed, in part or whole, of 
AFSC staff and is led by a CS. Therefore, because the AFSC--not OMAO or 
any other entity that may have authority over survey platforms used by 
AFSC--is the applicant to whom any incidental take authorization issued 
under the authority of these proposed regulations would be issued, we 
require that the AFSC take all necessary measures to coordinate and 
communicate in advance of each specific survey with OMAO, or other 
relevant parties, to ensure that all mitigation measures and monitoring 
requirements described herein, as well as the specific manner of 
implementation and relevant event-contingent decision-making processes, 
are clearly understood and agreed-upon. This may involve description of 
all required measures when submitting cruise instructions to OMAO or 
when completing contracts with external entities. AFSC will coordinate 
and conduct briefings at the outset of each survey and as necessary 
between ship's crew (CO/master or designee(s), as appropriate) and 
scientific party in order to explain responsibilities, communication 
procedures, marine mammal monitoring protocol, and operational 
procedures. The CS will be responsible for coordination with the 
Officer on Deck (OOD; or equivalent on non-NOAA platforms) to ensure 
that requirements, procedures, and decision-making processes are 
understood and properly implemented.
    As described previously, for IPHC longline survey operations, 
applicable mitigation, monitoring, and reporting requirements would be 
conveyed from the AFSC to the IPHC via Letters of Acknowledgement 
issued by the AFSC pursuant to the MSA. Although IPHC survey effort is 
not conducted aboard NOAA platforms, the same communication and 
coordination requirements would apply to IPHC surveys.
    Vessel Speed--Vessel speed during active sampling rarely exceeds 5 
kn, with typical speeds being 2-4 kn. Transit speeds vary from 6-14 kn 
but average 10 kn. These low vessel speeds minimize the potential for 
ship strike (see ``Potential Effects of the Specified Activity on 
Marine Mammals and Their Habitat'' for an in-depth discussion of ship 
strike). In addition, when research vessels are operating in areas and 
times where greater risk is expected due to marine mammal presence, 
e.g., Seguam Pass during humpback whale migration, additional crew are 
brought up to the bridge to monitor for whales. In such cases vessel 
captains may also reduce speed to improve the chances of observing 
whales and avoiding them. At any time during a survey or in transit, if 
a crew member or designated marine mammal observer standing watch 
sights marine mammals that may intersect with the vessel course that 
individual will immediately communicate the presence of marine mammals 
to the bridge for appropriate course alteration or speed reduction, as 
possible, to avoid incidental collisions.
    Other Gears--The AFSC deploys a wide variety of gear to sample the 
marine environment during all of their research cruises. Many of these 
types of gear (e.g., plankton nets, video camera and ROV deployments) 
are not considered to pose any risk to marine mammals and are therefore 
not subject to specific mitigation measures. However, at all times when 
the AFSC is conducting survey operations at sea, the OOD and/or CS and 
crew will monitor for any unusual circumstances that may arise at a 
sampling site and use best professional judgment to avoid any potential 
risks to marine mammals during use of all research equipment.
    Handling Procedures--Handling procedures are those taken to return 
a live animal to the sea or process a dead animal. The AFSC will 
implement a number of handling protocols to

[[Page 37683]]

minimize potential harm to marine mammals that are incidentally taken 
during the course of fisheries research activities. In general, 
protocols have already been prepared for use on commercial fishing 
vessels; these have been adapted from the North Pacific Fishery 
Observer Manual. These procedures are expected to increase post-release 
survival and, in general, following a ``common sense'' approach to 
handling captured or entangled marine mammals will present the best 
chance of minimizing injury to the animal and of decreasing risks to 
scientists and vessel crew. Handling or disentangling marine mammals 
carries inherent safety risks, and using best professional judgment and 
ensuring human safety is paramount.
    Captured live or injured marine mammals are released from research 
gear and returned to the water as soon as possible with no gear or as 
little gear remaining on the animal as possible. Animals are released 
without removing them from the water if possible and data collection is 
conducted in such a manner as not to delay release of the animal(s) or 
endanger the crew. AFSC staff will be instructed on how to identify 
different species; handle and bring marine mammals aboard a vessel; 
assess the level of consciousness; remove fishing gear; and return 
marine mammals to water. For further information regarding proposed 
handling procedures, please see section 11.7 of AFSC's application.
    Other Measures--AFSC scientists are aware of the need to prevent or 
minimize disturbance of marine mammals when operating vessels nearshore 
around pinniped rookeries and haul-outs, and other places where marine 
mammals are aggregated. Minimum approaches shall be not less than 1 km 
from the aggregation area.

Trawl Survey Visual Monitoring and Operational Protocols

    Visual monitoring protocols, described above, are an integral 
component of trawl mitigation protocols. Observation of marine mammal 
presence and behaviors in the vicinity of AFSC trawl survey operations 
allows for the application of professional judgment in determining the 
appropriate course of action to minimize the incidence of marine mammal 
gear interactions.
    The OOD, CS or other designated member of the scientific party, and 
crew standing watch on the bridge visually scan surrounding waters with 
the naked eye and rangefinding binoculars (or monocular) for marine 
mammals prior to, during, and until all trawl operations are completed. 
Some sets may be made at night or other limited visibility conditions, 
when visual observation may be conducted using the naked eye and 
available vessel lighting with limited effectiveness.
    Most research vessels engaged in trawling will have their station 
in view for 15 minutes or 2 nmi prior to reaching the station, 
depending upon the sea state and weather. Many vessels will inspect the 
tow path before deploying the trawl gear, adding another 15 minutes of 
observation time and gear preparation prior to deployment. Lookouts 
immediately alert the OOD and CS as to their best estimate of the 
species and number of animals observed and any observed animal's 
distance, bearing, and direction of travel relative to the ship's 
position. If any marine mammals are sighted around the vessel before 
setting gear, the vessel may be moved away from the animals to a 
different section of the sampling area if the animals appear to be at 
risk of interaction with the gear. This is what is referred to as the 
``move-on'' rule.
    If marine mammals are observed at or near the station, the CS and 
the vessel operator will determine the best strategy to avoid potential 
takes based on the species encountered, their numbers and behavior, 
their position and vector relative to the vessel, and other factors. 
For instance, a whale transiting through the area and heading away from 
the vessel may not require any move, or may require only a short move 
from the initial sampling site, while a pod of dolphins gathered around 
the vessel may require a longer move from the initial sampling site or 
possibly cancellation of the station if the dolphins follow the vessel. 
After moving on, if marine mammals are still visible from the vessel 
and appear to be at risk, the CS may decide, in consultation with the 
vessel operator, to move again or to skip the station. In many cases, 
the survey design can accommodate sampling at an alternate site. In 
most cases, gear is not deployed if marine mammals have been sighted 
from the ship in its approach to the station unless those animals do 
not appear to be in danger of interactions with the gear, as determined 
by the judgment of the CS and vessel operator. The efficacy of the 
``move-on'' rule is limited during night time or other periods of 
limited visibility; although operational lighting from the vessel 
illuminates the water in the immediate vicinity of the vessel during 
gear setting and retrieval. In these cases, it is again the judgment of 
the CS as based on experience and in consultation with the vessel 
operator to exercise due diligence and to decide on appropriate course 
of action to avoid unintentional interactions.
    Once the trawl net is in the water, the OOD, CS or other designated 
scientist, and/or crew standing watch continue to monitor the waters 
around the vessel and maintain a lookout for marine mammals as 
environmental conditions allow (as noted previously, visibility can be 
limited for various reasons). If marine mammals are sighted before the 
gear is fully retrieved, the most appropriate response to avoid 
incidental take is determined by the professional judgment of the OOD, 
in consultation with the CS and vessel operator as necessary. These 
judgments take into consideration the species, numbers, and behavior of 
the animals, the status of the trawl net operation (net opening, depth, 
and distance from the stern), the time it would take to retrieve the 
net, and safety considerations for changing speed or course. If marine 
mammals are sighted during haul-back operations, there is the potential 
for entanglement during retrieval of the net, especially when the trawl 
doors have been retrieved and the net is near the surface and no longer 
under tension. The risk of catching an animal may be reduced if the 
trawling continues and the haul-back is delayed until after the marine 
mammal has lost interest in the gear or left the area. The appropriate 
course of action to minimize the risk of incidental take is determined 
by the professional judgment of the OOD, vessel operator, and the CS 
based on all situation variables, even if the choices compromise the 
value of the data collected at the station. We recognize that it is not 
possible to dictate in advance the exact course of action that the OOD 
or CS should take in any given event involving the presence of marine 
mammals in proximity to an ongoing trawl tow, given the sheer number of 
potential variables, combinations of variables that may determine the 
appropriate course of action, and the need to prioritize human safety 
in the operation of fishing gear at sea. Nevertheless, we require a 
full accounting of factors that shape both successful and unsuccessful 
decisions, and these details will be fed back into AFSC training 
efforts and ultimately help to refine the best professional judgment 
that determines the course of action taken in any given scenario (see 
further discussion in ``Proposed Monitoring and Reporting'').
    If trawling operations have been suspended because of the presence 
of marine mammals, the vessel will resume trawl operations (when 
practicable) only when the animals are

[[Page 37684]]

believed to have departed the area. This decision is at the discretion 
of the OOD/CS and is dependent on the situation.
    Standard survey protocols that are expected to lessen the 
likelihood of marine mammal interactions include standardized tow 
durations and distances. Standard bottom trawl tow durations of not 
more than 15-30 minutes at the target depth will typically be 
implemented, excluding deployment and retrieval time, to reduce the 
likelihood of attracting and incidentally taking marine mammals. Short 
tow durations, and the resulting short tow distances (typically 1-2 
nmi), decrease the opportunity for marine mammals to find the vessel 
and investigate. The scientific crew will avoid dumping previous 
catches when the net is being retrieved, especially when the net is at 
the surface at the trawl alley. This practice of dumping fish when the 
net is near the vessel may train marine mammals to expect food when the 
net is retrieved and may capture the protected species.
    In operations in areas of southeast Alaska deploying surface nets, 
several additional measures have been employed to minimize the 
likelihood of marine mammal encounters, including no offal discard 
prior to or during the trawling at a station, trawling of short 
duration and seldom at night, no trawling less than one kilometer from 
pinniped rookeries or haul-outs, and deployment of acoustic pingers 
attached on the trawl foot or head ropes. Pingers are acoustic 
deterrents that are intended to deter the presence of marine mammals 
and therefore decrease the probability of entanglement or unintended 
capture of marine mammals.
    Acoustic Deterrent Devices--Acoustic deterrent devices (pingers) 
are underwater sound-emitting devices that have been shown to decrease 
the probability of interactions with certain species of marine mammals 
when fishing gear is fitted with the devices. Multiple studies have 
reported large decreases in harbor porpoise mortality (approximately 
eighty to ninety percent) in bottom-set gillnets (nets composed of 
vertical panes of netting, typically set in a straight line and either 
anchored to the bottom or drifting) during controlled experiments 
(e.g., Kraus et al., 1997; Trippel et al., 1999; Gearin et al., 2000). 
Using commercial fisheries data rather than a controlled experiment, 
Palka et al. (2008) reported that harbor porpoise bycatch rates in the 
northeast U.S gillnet fishery when fishing without pingers was about 
two to three times higher compared to when pingers were used. After 
conducting a controlled experiment in a California drift gillnet 
fishery during 1996-97, Barlow and Cameron (2003) reported 
significantly lower bycatch rates when pingers were used for all 
cetacean species combined, all pinniped species combined, and 
specifically for short-beaked common dolphins (85 percent reduction) 
and California sea lions (69 percent reduction). While not a 
statistically significant result, catches of Pacific white-sided 
dolphins were reduced by seventy percent. Carretta et al. (2008) 
subsequently examined nine years of observer data from the same drift 
gillnet fishery and found that pinger use had eliminated beaked whale 
bycatch. Carretta and Barlow (2011) assessed the long-term 
effectiveness of pingers in reducing marine mammal bycatch in the 
California drift gillnet fishery by evaluating fishery data from 1990-
2009 (with pingers in use beginning in 1996), finding that bycatch 
rates of cetaceans were reduced nearly fifty percent in sets using a 
sufficient number of pingers. However, in contrast to the findings of 
Barlow and Cameron (2003), they report no significant difference in 
pinniped bycatch.
    To be effective, a pinger must emit a signal that is sufficiently 
aversive to deter the species of concern, which requires that the 
signal is perceived while also deterring investigation. In rare cases, 
aversion may be learned as a warning when an animal has survived 
interaction with gear fitted with pingers (Dawson, 1994). The 
mechanisms by which pingers work in operational settings are not fully 
understood, but field trials and captive studies have shown that sounds 
produced by pingers are aversive to harbor porpoises (e.g., Laake et 
al., 1998; Kastelein et al., 2000; Culik et al., 2001), and it is 
assumed that when marine mammals are deterred from interacting with 
gear fitted with pingers that it is because the sounds produced by the 
devices are aversive. Two primary concerns expressed with regard to 
pinger effectiveness in reducing marine mammal bycatch relate to 
habituation (i.e., marine mammals may become habituated to the sounds 
made by the pingers, resulting in increasing bycatch rates over time; 
Dawson, 1994; Cox et al., 2001; Carlstr[ouml]m et al., 2009) and the 
``dinner bell effect'' (Dawson, 1994; Richardson et al., 1995), which 
implies that certain predatory marine mammal species (e.g., sea lions) 
may come to associate pingers with a food source (e.g., fish caught in 
nets) with the result that bycatch rates may be higher in nets with 
pingers than in those without.
    Palka et al. (2008) report that habituation has not occurred on a 
level that affects the bycatch estimate for the northeast U.S. gillnet 
fishery, while cautioning that the data studied do not provide a direct 
method to study habituation. Similarly, Carretta and Barlow (2011) 
report that habituation is not apparent in the California drift gillnet 
fishery, with the proportion of pinger-fitted sets with bycatch not 
significantly different for either cetaceans or pinnipeds between the 
periods 1996-2001 and 2001-09; in fact, bycatch rates for both taxa 
overall were lower in the latter period. We are not aware of any long-
term behavioral studies investigating habituation. Bycatch rates of 
California sea lions, specifically, did increase during the latter 
period. However, the authors do not attribute the increase to pinger 
use (i.e., the ``dinner bell effect''); rather, they believe that 
continuing increases in population abundance for the species (Carretta 
et al., 2017) coincident with a decline in fishery effort are 
responsible for the increased rate of capture. Despite these potential 
limitations on the effectiveness of pingers, and while effectiveness 
has not been tested on trawl gear, we believe that the available 
evidence supports an assumption that use of pingers is likely to reduce 
the potential for marine mammal interactions with AFSC surface trawl 
gear in southeast Alaska.
    If one assumes that use of a pinger is effective in deterring 
marine mammals from interacting with fishing gear, one must therefore 
assume that receipt of the acoustic signal has a disturbance effect on 
those marine mammals (i.e., Level B harassment). However, Level B 
harassment that may be incurred as a result of AFSC use of pingers does 
not constitute take that must be authorized under the MMPA. The MMPA 
prohibits the taking of marine mammals by U.S. citizens or within the 
U.S. EEZ unless such taking is appropriately permitted or authorized. 
However, the MMPA provides several narrowly defined exemptions from 
this requirement (e.g., for Alaskan natives; for defense of self or 
others; for Good Samaritans (16 U.S.C. 1371(b)-(d))). Section 109(h) of 
the MMPA (16 U.S.C. 1379(h)) allows for the taking of marine mammals in 
a humane manner by Federal, state, or local government officials or 
employees in the course of their official duties if the taking is 
necessary for the protection or welfare of the mammal, the protection 
of the public health and welfare, or the non-lethal removal of nuisance 
animals. AFSC use of pingers as a deterrent device, which may cause 
Level B harassment of marine mammals, is intended solely for the 
avoidance of

[[Page 37685]]

potential marine mammal interactions with AFSC research gear (i.e., 
avoidance of Level A harassment, serious injury, or mortality). 
Therefore, use of such deterrent devices, and the taking that may 
result, is for the protection and welfare of the mammal and is covered 
explicitly under MMPA section 109(h)(1)(A). Potential taking of marine 
mammals resulting from AFSC use of pingers is not discussed further in 
this document.
    As described above, pingers (10 kHz, 132 dB, 300 ms every 4 s) 
would be deployed on surface trawl nets deployed in southeast Alaska. 
Pingers would also be deployed on gillnets. Please see ``Marine Mammal 
Hearing'' below for reference to functional and best hearing ranges for 
marine mammals.

Longline Survey Visual Monitoring and Operational Protocols

    Visual monitoring requirements for all longline surveys are similar 
to the general protocols described above for trawl surveys. Please see 
that section for full details of the visual monitoring protocol and the 
move-on rule mitigation protocol. In summary, requirements for longline 
surveys are to: (1) Conduct visual monitoring prior to arrival on 
station; (2) implement the move-on rule if marine mammals are observed 
within the area around the vessel and may be at risk of interacting 
with the vessel or gear; (3) deploy gear as soon as possible upon 
arrival on station (depending on presence of marine mammals); and (4) 
maintain visual monitoring effort throughout deployment and retrieval 
of the longline gear. As was described for trawl gear, the OOD, CS, or 
watch leader will use best professional judgment to minimize the risk 
to marine mammals from potential gear interactions during deployment 
and retrieval of gear. If marine mammals are detected during setting 
operations and are considered to be at risk, immediate retrieval or 
suspension of operations may be warranted. If operations have been 
suspended because of the presence of marine mammals, the vessel will 
resume setting (when practicable) only when the animals are believed to 
have departed the area. If marine mammals are detected during retrieval 
operations and are considered to be at risk, haul-back may be 
postponed. These decisions are at the discretion of the OOD/CS and are 
dependent on the situation.
    As for trawl surveys, some standard survey protocols are expected 
to minimize the potential for marine mammal interactions. Soak times 
are typically short relative to commercial fishing operations, measured 
from the time the last hook is in the water to when the first hook is 
brought out of the water. AFSC longline protocols specifically prohibit 
chumming (releasing additional bait to attract target species to the 
gear). Spent bait and offal are discarded away from the longline 
retrieval area but not retained until completion of longline retrieval. 
Due to the volume of fish caught with each set and the length of time 
it takes to retrieve the longline (up to eight hours), the retention of 
spent bait and offal until the gear is completely retrieved is not 
possible.
    Whales, particularly killer whales in the Bering Sea and sperm 
whales in the Gulf of Alaska, are commonly attracted to longline 
fishing operations and have learned how to remove fish from longline 
gear as it is retrieved. Such depredation of fish off the longline by 
whales can significantly affect catch rate and species composition of 
data collected by the survey. The effect of depredation activity on 
survey results has been a research subject for many years and many 
aspects are therefore recorded as part of normal survey protocols, 
including the amount of catch potentially depredated (percent of empty 
hooks or damaged fish), number of whales visible, behavior of whales, 
whale proximity to the vessel, and any whale/vessel interactions. Sperm 
whale depredation can be difficult to determine because they can 
alternate between diving deep to depredate the line and swimming at the 
surface eating offal (see below). The presence of sperm whales at the 
surface does not mean they are actively depredating the line.
    The Alaska Longline Survey uses bottom longline gear with a 16-km 
mainline. Sets are made in the morning if no killer whales or sperm 
whales are present and the longline gear is allowed to soak for three 
hours before haul-back begins. Due to the length of the mainline and 
numbers of hooks involved, it takes up to eight hours to complete the 
haul-back. Whales have learned to associate particular sounds with 
longline operations and typically arrive on scene as the gear is being 
retrieved. Efforts have been made to avoid depredation by allowing the 
line to sink back down but such strategies have proved impractical as 
whales can wait in the area for days and fish caught on the line are 
then eaten by other demersal marine organisms. The only practical way 
to minimize depredation if whales find the vessel is to continue 
retrieving the gear as quickly as possible. As killer whales may also 
follow the survey vessel between stations, the station order has been 
altered to disrupt the survey pattern as a means to dissuade the 
animals from this behavior and to avoid continued interactions.

Gillnet Survey Visual Monitoring and Operational Protocols

    Visual monitoring and operational protocols for gillnet surveys are 
similar to those described previously for trawl surveys, with a focus 
on visual observation in the survey area and avoidance of marine 
mammals that may be at risk of interaction with survey vessels or gear. 
Gillnets are not deployed if marine mammals have been sighted on 
arrival at the sample site. The exception is for animals that, because 
of their behavior, travel vector or other factors, do not appear to be 
at risk of interaction with the gillnet gear. If no marine mammals are 
present, the gear is set and monitored continuously during the soak. If 
a marine mammal is sighted during the soak and appears to be at risk of 
interaction with the gear, then the gear is pulled immediately. As 
noted above, pingers would be deployed on gillnets, which are used only 
at the Little Port Walter Research Station in southeast Alaska and in 
Prince William Sound.
    We have carefully evaluated the AFSC's proposed mitigation measures 
and considered a range of other measures in the context of ensuring 
that we prescribed the means of effecting the least practicable adverse 
impact on the affected marine mammal species and stocks and their 
habitat. Based on our evaluation of these measures, we have 
preliminarily determined that the proposed mitigation measures provide 
the means of effecting the least practicable adverse impact on marine 
mammal species or stocks and their habitat, paying particular attention 
to rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for subsistence uses.

Proposed Monitoring and Reporting

    In order to issue an LOA for an activity, Section 101(a)(5)(A) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of the authorized taking. NMFS's MMPA 
implementing regulations further describe the information that an 
applicant should provide when requesting an authorization (50 CFR 
216.104(a)(13)), including the means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and the level of taking or impacts on populations of marine 
mammals.
    Monitoring and reporting requirements prescribed by NMFS

[[Page 37686]]

should contribute to improved understanding of one or more of the 
following:
    <bullet> Occurrence of significant interactions with marine mammal 
species in action area (e.g., animals that came close to the vessel, 
contacted the gear, or are otherwise rare or displaying unusual 
behavior).
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
    <bullet> How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or important physical components of marine 
mammal habitat).
    <bullet> Mitigation and monitoring effectiveness.
    AFSC plans to make more systematic its training, operations, data 
collection, animal handling and sampling protocols, etc. in order to 
improve its ability to understand how mitigation measures influence 
interaction rates and ensure its research operations are conducted in 
an informed manner and consistent with lessons learned from those with 
experience operating these gears in close proximity to marine mammals. 
It is in this spirit that we propose the monitoring requirements 
described below.

Visual Monitoring

    Marine mammal watches are a standard part of conducting fisheries 
research activities, and are implemented as described previously in 
``Proposed Mitigation.'' Dedicated marine mammal visual monitoring 
occurs as described (1) for some period prior to deployment of most 
research gear; (2) throughout deployment and active fishing of all 
research gears; (3) for some period prior to retrieval of longline 
gear; and (4) throughout retrieval of all research gear. This visual 
monitoring is performed by trained AFSC personnel or other trained crew 
during the monitoring period. Observers record the species and 
estimated number of animals present and their behaviors, which may be 
valuable information towards an understanding of whether certain 
species may be attracted to vessels or certain survey gears. 
Separately, marine mammal watches are conducted by watch-standers 
(those navigating the vessel and other crew; these will typically not 
be AFSC personnel) at all times when the vessel is being operated. The 
primary focus for this type of watch is to avoid striking marine 
mammals and to generally avoid navigational hazards. These watch-
standers typically have other duties associated with navigation and 
other vessel operations and are not required to record or report to the 
scientific party data on marine mammal sightings, except when gear is 
being deployed or retrieved.
    AFSC will also monitor disturbance of hauled-out pinnipeds 
resulting from the presence of researchers, paying particular attention 
to the distance at which different species of pinniped are disturbed. 
Disturbance will be recorded according to the three-point scale, 
representing increasing seal response to disturbance, shown in Table 
13.

Training

    AFSC anticipates that additional information on practices to avoid 
marine mammal interactions can be gleaned from training sessions and 
more systematic data collection standards. The AFSC will conduct annual 
trainings for all chief scientists and other personnel who may be 
responsible for conducting marine mammal visual observations or 
handling incidentally captured marine mammals to explain mitigation 
measures and monitoring and reporting requirements, mitigation and 
monitoring protocols, marine mammal identification, recording of count 
and disturbance observations, completion of datasheets, and use of 
equipment. Some of these topics may be familiar to AFSC staff, who may 
be professional biologists; the AFSC shall determine the agenda for 
these trainings and ensure that all relevant staff have necessary 
familiarity with these topics. The AFSC will work with the North 
Pacific Fisheries Groundfish and Halibut Observer Program to customize 
a new training program. The first such training will include three 
primary elements: (1) An overview of the purpose and need for the 
authorization, including mandatory mitigation measures by gear and the 
purpose for each, and species that AFSC is authorized to incidentally 
take; (2) detailed descriptions of reporting, data collection, and 
sampling protocols; and (3) discussion of best professional judgment 
(which is recognized as an integral component of mitigation 
implementation; see ``Proposed Mitigation'').
    The second topic will include instruction on how to complete new 
data collection forms such as the marine mammal watch log, the 
incidental take form (e.g., specific gear configuration and details 
relevant to an interaction with protected species), and forms used for 
species identification and biological sampling.
    The third topic will include use of professional judgment in any 
incidents of marine mammal interaction and instructive examples where 
use of best professional judgment was determined to be successful or 
unsuccessful. We recognize that many factors come into play regarding 
decision-making at sea and that it is not practicable to simplify what 
are inherently variable and complex situational decisions into rules 
that may be defined on paper. However, it is our intent that use of 
best professional judgment be an iterative process from year to year, 
in which any at-sea decision-maker (i.e., responsible for decisions 
regarding the avoidance of marine mammal interactions with survey gear 
through the application of best professional judgment) learns from the 
prior experience of all relevant AFSC personnel (rather than from 
solely their own experience). The outcome should be increased 
transparency in decision-making processes where best professional 
judgment is appropriate and, to the extent possible, some degree of 
standardization across common situations, with an ultimate goal of 
reducing marine mammal interactions. It is the responsibility of the 
AFSC to facilitate such exchange.

Handling Procedures and Data Collection

    Improved standardization of handling procedures were discussed 
previously in ``Proposed Mitigation.'' In addition to the benefits 
implementing these protocols are believed to have on the animals 
through increased post-release survival, AFSC believes adopting these 
protocols for data collection will also increase the information on 
which ``serious injury'' determinations (NMFS, 2012a, 2012b) are based 
and improve scientific knowledge about marine mammals that interact 
with fisheries research gears and the factors that contribute to these 
interactions. AFSC personnel will be provided standard guidance and 
training regarding handling of marine mammals, including how to 
identify different species, bring an individual aboard a vessel, assess 
the

[[Page 37687]]

level of consciousness, remove fishing gear, return an individual to 
water and log activities pertaining to the interaction.
    AFSC will record interaction information on their own standardized 
forms. To aid in serious injury determinations and comply with the 
current NMFS Serious Injury Guidelines (NMFS, 2012a, 2012b), 
researchers will also answer a series of supplemental questions on the 
details of marine mammal interactions.
    Finally, for any marine mammals that are killed during fisheries 
research activities, scientists will collect data and samples pursuant 
to Appendix D of the AFSC DEA, ``Protected Species Mitigation and 
Handling Procedures for AFSC Fisheries Research Vessels.''

Reporting

    As is normally the case, AFSC will coordinate with the relevant 
stranding coordinators for any unusual marine mammal behavior and any 
stranding, beached live/dead, or floating marine mammals that are 
encountered during field research activities. The AFSC will follow a 
phased approach with regard to the cessation of its activities and/or 
reporting of such events, as described in the proposed regulatory texts 
following this preamble. In addition, Chief Scientists (or cruise 
leader, CS) will provide reports to AFSC leadership and to the Office 
of Protected Resources (OPR). As a result, when marine mammals interact 
with survey gear, whether killed or released alive, a report provided 
by the CS will fully describe any observations of the animals, the 
context (vessel and conditions), decisions made and rationale for 
decisions made in vessel and gear handling. The circumstances of these 
events are critical in enabling AFSC and OPR to better evaluate the 
conditions under which takes are most likely occur. We believe in the 
long term this will allow the avoidance of these types of events in the 
future.
    The AFSC will submit annual summary reports to OPR including: (1) 
Annual line-kilometers surveyed during which the EK60, ME70, ES60, 7111 
(or equivalent sources) were predominant (see ``Estimated Take by 
Acoustic Harassment'' for further discussion), specific to each region; 
(2) summary information regarding use of all longline, gillnet, and 
trawl gear, including number of sets, tows, etc., specific to each 
research area and gear; (3) accounts of all incidents of marine mammal 
interactions, including circumstances of the event and descriptions of 
any mitigation procedures implemented or not implemented and why; (4) 
summary information related to any disturbance of pinnipeds, including 
event-specific total counts of animals present, counts of reactions 
according to the three-point scale shown in Table 13, and distance of 
closest approach; and (5) a written evaluation of the effectiveness of 
AFSC mitigation strategies in reducing the number of marine mammal 
interactions with survey gear, including best professional judgment and 
suggestions for changes to the mitigation strategies, if any. The 
period of reporting will be annually, beginning one year post-issuance 
of any LOA, and the report must be submitted not less than ninety days 
following the end of a given year. Submission of this information is in 
service of an adaptive management framework allowing NMFS to make 
appropriate modifications to mitigation and/or monitoring strategies, 
as necessary, during the proposed five-year period of validity for 
these regulations.
    NMFS has established a formal incidental take reporting system, the 
Protected Species Incidental Take (PSIT) database, requiring that 
incidental takes of protected species be reported within 48 hours of 
the occurrence. The PSIT generates automated messages to NMFS 
leadership and other relevant staff, alerting them to the event and to 
the fact that updated information describing the circumstances of the 
event has been inputted to the database. The PSIT and CS reports 
represent not only valuable real-time reporting and information 
dissemination tools but also serve as an archive of information that 
may be mined in the future to study why takes occur by species, gear, 
region, etc.
    AFSC will also collect and report all necessary data, to the extent 
practicable given the primacy of human safety and the well-being of 
captured or entangled marine mammals, to facilitate serious injury (SI) 
determinations for marine mammals that are released alive. AFSC will 
require that the CS complete data forms and address supplemental 
questions, both of which have been developed to aid in SI 
determinations. AFSC understands the critical need to provide as much 
relevant information as possible about marine mammal interactions to 
inform decisions regarding SI determinations. In addition, the AFSC 
will perform all necessary reporting to ensure that any incidental M/SI 
is incorporated as appropriate into relevant SARs.

Negligible Impact Analysis and Determination

    Introduction--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'' by mortality, serious injury, 
and Level A or Level B harassment, we consider other factors, such as 
the likely nature of any behavioral responses (e.g., intensity, 
duration), the context of any such responses (e.g., critical 
reproductive time or location, migration), as well as effects on 
habitat, and the likely effectiveness of 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, and specific consideration of take 
by M/SI previously authorized for other NMFS research activities).
    We note here that the takes from potential gear interactions 
enumerated below could result in non-serious injury, but their worse 
potential outcome (mortality) is analyzed for the purposes of the 
negligible impact determination. We discuss here the connection between 
the mechanisms for authorizing incidental take under section 101(a)(5) 
for activities, such as AFSC's research activities, and for authorizing 
incidental take from commercial fisheries. In 1988, Congress amended 
the MMPA's provisions for addressing incidental take of marine mammals 
in commercial fishing operations. Congress directed NMFS to develop and 
recommend a new long-term regime to govern such incidental taking (see 
MMC, 1994). The need to develop a system suited to the unique 
circumstances of commercial fishing operations led NMFS to suggest a 
new conceptual means and associated regulatory framework. That concept, 
Potential Biological Removal (PBR), and

[[Page 37688]]

a system for developing plans containing regulatory and voluntary 
measures to reduce incidental take for fisheries that exceed PBR were 
incorporated as sections 117 and 118 in the 1994 amendments to the 
MMPA.
    PBR is defined in the MMPA (16 U.S.C. 1362(20)) 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, and is a measure to be 
considered when evaluating the effects of M/SI on a marine mammal 
species or stock. Optimum sustainable population (OSP) is defined by 
the MMPA (16 U.S.C. 1362(9)) as the number of animals which will result 
in the maximum productivity of the population or the species, keeping 
in mind the carrying capacity of the habitat and the health of the 
ecosystem of which they form a constituent element. A primary goal of 
the MMPA is to ensure that each species or stock of marine mammal is 
maintained at or returned to its OSP.
    PBR values are calculated by NMFS as the level of annual removal 
from a stock that will allow that stock to equilibrate within OSP at 
least 95 percent of the time, and is the product of factors relating to 
the minimum population estimate of the stock (N<INF>min</INF>); the 
productivity rate of the stock at a small population size; and a 
recovery factor. Determination of appropriate values for these three 
elements incorporates significant precaution, such that application of 
the parameter to the management of marine mammal stocks may be 
reasonably certain to achieve the goals of the MMPA. For example, 
calculation of N<INF>min</INF> incorporates the precision and 
variability associated with abundance information and is intended to 
provide reasonable assurance that the stock size is equal to or greater 
than the estimate (Barlow et al., 1995). In general, the three factors 
are developed on a stock-specific basis in consideration of one another 
in order to produce conservative PBR values that appropriately account 
for both imprecision that may be estimated as well as potential bias 
stemming from lack of knowledge (Wade, 1998).
    PBR can be used as a consideration of the effects of M/SI on a 
marine mammal stock but was applied specifically to work within the 
management framework for commercial fishing incidental take. PBR cannot 
be applied appropriately outside of the section 118 regulatory 
framework for which it was designed without consideration of how it 
applies in section 118 and how other statutory management frameworks in 
the MMPA differ. PBR was not designed as an absolute threshold limiting 
commercial fisheries, but rather as a means to evaluate the relative 
impacts of those activities on marine mammal stocks. Even where 
commercial fishing is causing M/SI at levels that exceed PBR, the 
fishery is not suspended. When M/SI exceeds PBR, NMFS may develop a 
take reduction plan, usually with the assistance of a take reduction 
team. The take reduction plan will include measures to reduce and/or 
minimize the taking of marine mammals by commercial fisheries to a 
level below the stock's PBR. That is, where the total annual human-
caused M/SI exceeds PBR, NMFS is not required to halt fishing 
activities contributing to total M/SI but rather utilizes the take 
reduction process to further mitigate the effects of fishery activities 
via additional bycatch reduction measures. PBR is not used to grant or 
deny authorization of commercial fisheries that may incidentally take 
marine mammals.
    Similarly, to the extent consideration of PBR may be relevant to 
considering the impacts of incidental take from activities other than 
commercial fisheries, using it as the sole reason to deny incidental 
take authorization for those activities would be inconsistent with 
Congress's intent under section 101(a)(5) and the use of PBR under 
section 118. The standard for authorizing incidental take under section 
101(a)(5) continues to be, among other things, whether the total taking 
will have a negligible impact on the species or stock. When Congress 
amended the MMPA in 1994 to add section 118 for commercial fishing, it 
did not alter the standards for authorizing non-commercial fishing 
incidental take under section 101(a)(5), acknowledging that negligible 
impact under section 101(a)(5) is a separate standard from PBR under 
section 118. In fact, in 1994 Congress also amended section 
101(a)(5)(E) (a separate provision governing commercial fishing 
incidental take for species listed under the Endangered Species Act) to 
add compliance with the new section 118 but kept the requirement for a 
negligible impact finding, showing that the determination of negligible 
impact and application of PBR may share certain features but are 
different.
    Since the introduction of PBR, NMFS has used the concept almost 
entirely within the context of implementing sections 117 and 118 and 
other commercial fisheries management-related provisions of the MMPA. 
The MMPA requires that PBR be estimated in stock assessment reports and 
that it be used in applications related to the management of take 
incidental to commercial fisheries (i.e., the take reduction planning 
process described in section 118 of the MMPA and the determination of 
whether a stock is ``strategic'' (16 U.S.C. 1362(19))), but nothing in 
the MMPA requires the application of PBR outside the management of 
commercial fisheries interactions with marine mammals.
    Nonetheless, NMFS recognizes that as a quantitative metric, PBR may 
be useful in certain instances as a consideration when evaluating the 
impacts of other human-caused activities on marine mammal stocks. 
Outside the commercial fishing context, and in consideration of all 
known human-caused mortality, PBR can help inform the potential effects 
of M/SI caused by activities authorized under 101(a)(5)(A) on marine 
mammal stocks. As noted by NMFS and the USFWS in our implementation 
regulations for the 1986 amendments to the MMPA (54 FR 40341, September 
29, 1989), the Services consider many factors, when available, in 
making a negligible impact determination, including, but not limited 
to, the status of the species or stock relative to OSP (if known), 
whether the recruitment rate for the species or stock is increasing, 
decreasing, stable, or unknown, the size and distribution of the 
population, and existing impacts and environmental conditions. To 
specifically use PBR, along with other factors, to evaluate the effects 
of M/SI, we first calculate a metric for each species or stock that 
incorporates information regarding ongoing anthropogenic M/SI into the 
PBR value (i.e., PBR minus the total annual anthropogenic mortality/
serious injury estimate), which is called ``residual PBR'' (Wood et 
al., 2012). We then consider how the anticipated potential incidental 
M/SI from the activities being evaluated compares to residual PBR. 
Anticipated or potential M/SI that exceeds residual PBR is considered 
to have a higher likelihood of adversely affecting rates of recruitment 
or survival, while anticipated M/SI that is equal to or less than 
residual PBR has a lower likelihood (both examples given without 
consideration of other types of take, which also factor into a 
negligible impact determination). In such cases where the anticipated 
M/SI is near, at, or above residual PBR, consideration of other 
factors, including those outlined above as well as mitigation and other 
factors (positive or negative), is especially important to assessing 
whether the M/SI will have a negligible impact on the stock. As 
described above, PBR is a conservative metric and

[[Page 37689]]

is not intended to be used as a solid cap on mortality--accordingly, 
impacts from M/SI that exceed residual PBR may still potentially be 
found to be negligible in light of other factors that offset concern, 
especially when robust mitigation and adaptive management provisions 
are included.
    Alternately, for a species or stock with incidental M/SI less than 
10 percent of residual PBR, we consider M/SI from the specified 
activities to represent an insignificant incremental increase in 
ongoing anthropogenic M/SI that alone (i.e., in the absence of any 
other take) cannot affect annual rates of recruitment and survival. In 
a prior incidental take rulemaking and in the commercial fishing 
context, this threshold is identified as the significance threshold, 
but it is more accurately an insignificance threshold outside 
commercial fishing because it represents the level at which there is no 
need to consider other factors in determining the role of M/SI in 
affecting rates of recruitment and survival. Assuming that any 
additional incidental take by harassment would not exceed the 
negligible impact level, the anticipated M/SI caused by the activities 
being evaluated would have a negligible impact on the species or stock. 
This 10 percent was identified as a workload simplification 
consideration to avoid the need to provide unnecessary additional 
information when the conclusion is relatively obvious; but as described 
above, values above 10 percent have no particular significance 
associated with them until and unless they approach residual PBR.
    Our evaluation of the M/SI for each of the species and stocks for 
which mortality could occur follows. In addition, all mortality 
authorized for some of the same species or stocks over the next several 
years pursuant to our final rulemakings for the NMFS Southwest 
Fisheries Science Center and the NMFS Northwest Fisheries Science 
Center has been incorporated into the residual PBR.
    We first consider maximum potential incidental M/SI for each stock 
(Table 6) in consideration of NMFS's threshold for identifying 
insignificant M/SI take (10 percent of residual PBR (69 FR 43338; July 
20, 2004)). By considering the maximum potential incidental M/SI in 
relation to PBR and ongoing sources of anthropogenic mortality, we 
begin our evaluation of whether the potential incremental addition of 
M/SI through AFSC research activities may affect the species' or 
stock's annual rates of recruitment or survival. We also consider the 
interaction of those mortalities with incidental taking of that species 
or stock by harassment pursuant to the specified activity.

Summary of Estimated Incidental Take

    Here we provide a summary of the total proposed incidental take 
authorization on an annual basis, as well as other information relevant 
to the negligible impact analysis. Table 15 shows information relevant 
to our negligible impact analysis concerning the total annual taking 
that could occur for each stock from NMFS' scientific research 
activities when considering incidental take previously authorized for 
SWFSC (80 FR 58982; September 30, 2015) and take proposed for 
authorization for NWFSC (81 FR 38516; June 13, 2016) and AFSC. 
Scientific research activities conducted by the SWFSC and/or NWFSC may 
impact the same populations of marine mammals expected to be impacted 
by IPHC survey activities occurring off of the U.S. west coast. We 
propose to authorize take by M/SI over the five-year period of validity 
for these proposed regulations as indicated in Table 15 below. For the 
purposes of the negligible impact analysis, we assume that all of these 
takes could potentially be in the form of M/SI; PBR is not appropriate 
for direct assessment of the significance of harassment.
    For some stocks, a range is provided in the ``Total M/SI 
Authorization'' columns of Table 15 (below). In these cases, the worst 
case potential outcome is used to derive the value presented in the 
``Estimated Maximum Annual M/SI'' column (Table 15, below). For 
example, we present ranges of 13-18 and 3-8 as the total take 
authorization proposed over five years for the eastern Pacific and 
California stocks of northern fur seal, respectively. These ranges 
reflect that, as part of the overall proposed take authorization for 
AFSC, a total of five takes of northern fur seals are expected to occur 
as a result specifically of IPHC longline operations. These five takes 
are considered as potentially accruing to either stock; therefore, we 
assess the consequences of the proposed take authorization for these 
stocks as though the maximum could occur to both. The ten total takes 
expected to potentially occur as a result of SWFSC and/or NWFSC survey 
operations could also occur to individuals from either stock. 
Similarly, we assume that IPHC survey operations specifically could 
result in incidental take of up to five harbor seals over the five 
years, and that these takes could occur for any stock of harbor seal 
(but that no more than one take would be expected from any given 
stock). Therefore, although only five takes are expected from IPHC 
activities, we assume that one take accrues to each of the 17 harbor 
seal stocks that may overlap with the IPHC surveys. For the NWFSC, we 
assumed that nine total takes of harbor seal could occur over five 
years, and that these takes could occur to either the California or 
Oregon/Washington coast stocks. Over five years, six total takes were 
expected to result from NWFSC/SWFSC survey operations within Washington 
inland waters--potentially occurring to any of the three stocks of 
harbor seals occurring in those waters. The value presented for 
``Estimated Maximum Annual M/SI'' for each stock reflects these 
considerations. Similar considerations result in the ranges given for 
Steller sea lions (Table 15). This stock-specific accounting does not 
change our expectations regarding the combined total number of takes 
that would actually occur for each stock, but informs our stock-
specific negligible impact analysis.
    We previously authorized take of marine mammals incidental to 
fisheries research operations conducted by the SWFSC (see 80 FR 58982 
and 80 FR 68512), and proposed to authorize take incidental to 
fisheries research operations conducted by the NWFSC (see 81 FR 38516). 
This take would occur to some of the same stocks for which we propose 
to authorize take incidental to AFSC fisheries research operations. 
Therefore, in order to evaluate the likely impact of the take by M/SI 
proposed for authorization in this rule, we consider not only other 
ongoing sources of human-caused mortality but the potential mortality 
authorized or proposed for authorization for SWFSC/NWFSC. As used in 
this document, other ongoing sources of human-caused (anthropogenic) 
mortality refers to estimates of realized or actual annual mortality 
reported in the SARs and does not include authorized or unknown 
mortality. Below, we consider the total taking by M/SI proposed for 
authorization for AFSC and previously authorized or proposed for 
authorization for SWFSC/NWFSC together to produce a maximum annual M/SI 
take level (including take of unidentified marine mammals that could 
accrue to any relevant stock) and compare that value to the stock's PBR 
value, considering ongoing sources of anthropogenic mortality (as 
described in footnote 4 of Table 15 and in the following discussion). 
PBR and annual M/SI values considered in Table 15 reflect the most 
recent information available (i.e., final 2016 SARs).

[[Page 37690]]



                                Table 15--Summary Information Related to AFSC Proposed Annual Take Authorization, 2018-23
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Proposed total                   Proposed AFSC/
                                                     annual Level B     Percent of     IPHC total M/    SWFSC/NWFSC   Estimated    PBR minus     Stock
           Species 1                    Stock          harassment       estimated           SI          total M/SI     maximum    annual M/SI   trend 6
                                                      authorization     population    authorization,   authorization  annual M/      (%) 5
                                                            2           abundance        2018-23 3                       SI 4
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Pacific right whale......  ENP...............               2  6.5............               0               0          0           n/a          ?
Bowhead whale..................  Western Arctic....              42  0.2............               0               0          0           n/a     [uarr]
Gray whale.....................  ENP...............           5,579  26.6...........               0               0          0           n/a     [rarr]
Humpback whale.................  CNP...............             161  1.6............               0               0          0           n/a     [uarr]
                                 WNP...............               6  0.5............               0               0          0           n/a     [uarr]
Minke whale....................  Alaska............               8  0.2 \8\........               0               0          0           n/a          ?
Sei whale......................  ENP...............               2  0.4............               0               0          0           n/a     [uarr]
Fin whale......................  Northeast Pacific.              40  3.9 \8\........               0               0          0           n/a     [uarr]
Blue whale.....................  ENP...............               1  0.1............               0               0          0           n/a     [rarr]
Sperm whale....................  North Pacific.....              22  Unknown........               2               0        0.4             ?          ?
Cuvier's beaked whale..........  Alaska............               2  Unknown........               0               0          0           n/a          ?
Baird's beaked whale...........  Alaska............               8  Unknown........               0               0          0           n/a          ?
Stejneger's beaked whale.......  Alaska............              15  Unknown........               0               0          0           n/a          ?
Beluga whale...................  Beaufort Sea......               3  0.0............               1               0        0.2     510 (0.0)  [uarr] or
                                                                                                                                                  [rarr]
                                 Eastern Chukchi                  3  0.1............               1               0        0.2     177 (0.1)          ?
                                  Sea.
                                 Eastern Bering Sea             939  4.9............               0               0          0           n/a          ?
                                 Bristol Bay.......               0  n/a............               0               0          0           n/a     [uarr]
                                 Cook Inlet........               3  1.0............               0               0          0           n/a     [darr]
Bottlenose dolphin.............  CA/OR/WA Offshore.               0  n/a............               1              11        2.8    9.4 (29.8)          ?
Common dolphin.................  CA/OR/WA..........               0  n/a............               1              15        3.6   8,353 (0.0)     [uarr]
Pacific white-sided dolphin....  NP................              54  0.2............               6               0        1.6             ?          ?
Risso's dolphin................  CA/OR/WA..........               0  n/a............               1              20        4.6   42.3 (10.9)          ?
Killer whale...................  ENP Offshore......              67  27.9...........               0               0        n/a           n/a          ?
                                 West Coast                      13  5.3............               0               0        n/a           n/a     [uarr]
                                  Transient.
                                 AT1 Transient.....               2  28.6...........               0               0        n/a           n/a     [darr]
                                 ENP Gulf of                     14  2.4............               0               0        n/a           n/a     [rarr]
                                  Alaska, Aleutian
                                  Islands, and
                                  Bering Sea
                                  Transient.
                                 ENP Northern                     6  2.3............               0               0        n/a           n/a     [uarr]
                                  Resident.
                                 ENP Alaska                      24  1.0............               2               0        0.4      23 (1.7)     [uarr]
                                  Resident.
Short-finned pilot whale.......  CA/OR/WA..........               0  n/a............               1               2        0.6    3.3 (18.2)          ?
Harbor porpoise................  Southeast Alaska..             358  12.4 \8\.......               1               0        0.2             ?  [darr] or
                                                                                                                                                  [rarr]
                                 Gulf of Alaska....             650  2.1............               2               0        0.8             ?          ?
                                 Bering Sea........           1,746  3.6............               1               0        0.4             ?          ?
Dall's porpoise................  CA/OR/WA..........               0  n/a............               1               8        2.2   171.7 (1.3)          ?
                                 Alaska............           5,343  6.4............              14               0        3.4             ?          ?
Northern fur seal..............  Pribilof Islands/            1,576  0.3............           13-18              10        7.0  11,166 (0.1)     [darr]
                                  Eastern Pacific.
                                 California........             143  1.0............             3-8  ..............        4.6   449.2 (1.0)     [uarr]
California sea lion............  United States.....               0  n/a............               1              35        8.0   8,811 (0.1)     [uarr]
Steller sea lion...............  Eastern U.S.......             914  2.2............            7-12              19        7.4   2,390 (0.3)     [uarr]
                                 Western U.S.......           3,526  6.9............           13-18               0        4.6      79 (5.8)      ? \7\
Bearded seal...................  Alaska (Beringia             1,727  0.6............               2               0        0.8   7,819 (0.0)          ?
                                  DPS).
Harbor seal....................  California........               0  n/a............               1            5-14        3.6   1,598 (0.2)     [rarr]
                                 OR/WA Coast.......               0  n/a............               1            2-11        2.2             ?     [rarr]
                                 Washington Inland                0  n/a............               1               6        1.6             ?     [rarr]
                                  Waters.
                                 Clarence Strait...             242  0.8............               2               0        0.8   1,181 (0.1)     [uarr]
                                 Dixon/Cape                     153  0.8............               2               0        0.8     634 (0.1)     [uarr]
                                  Decision.
                                 Sitka/Chatham                  965  6.5............               3               0        1.0     483 (0.2)     [uarr]
                                  Strait.
                                 Lynn Canal/                    109  1.2............               2               0        0.8     105 (0.8)     [darr]
                                  Stephens Passage.
                                 Glacier Bay/Ice                 69  1.0............               2               0        0.8      65 (1.2)     [uarr]
                                  Strait.
                                 Cook Inlet/                  2,622  9.6............               2               0        0.8     536 (0.1)     [uarr]
                                  Shelikof Strait.
                                 Prince William               3,194  10.7...........               3               0        1.0     559 (0.2)     [darr]
                                  Sound.
                                 South Kodiak......           3,809  19.8...........               2               0        0.8     186 (0.4)     [darr]
                                 North Kodiak......             906  10.9...........               2               0        0.8     261 (0.3)     [uarr]
                                 Bristol Bay.......             187  0.6............               2               0        0.8   1,040 (0.1)     [uarr]
                                 Pribilof Islands..              29  12.5...........               2               0        0.8      7 (11.4)     [rarr]
                                 Aleutian Islands..             301  4.7............               2               0        0.8      83 (1.0)     [uarr]
Spotted seal...................  Alaska............           2,106  0.5............               3               0        1.2  12,368 (0.0)          ?
Ringed seal....................  Alaska............           2,066  1.2 \8\........               4               0        1.6             ?          ?
Ribbon seal....................  Alaska............           1,404  0.8............               2               0        0.8       9,781.2          ?
                                                                                                                                        (0.0)
Northern elephant seal.........  California                      52  0.0............               1              10        2.6       4,873.2     [uarr]
                                  Breeding.                                                                                             (0.1)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Please see Tables 7, 10, 11, 12, and 14 and preceding text for details.
\1\ For some species with multiple stocks, indicated level of take could occur to individuals from any stock (as indicated in table). For some stocks, a
  range is presented.
\2\ Level B harassment totals include estimated take due to acoustic harassment and, for harbor seals and Steller sea lions, estimated take due to
  physical disturbance. Active acoustic devices are not used for data acquisition by IPHC; therefore, no takes by acoustic harassment are expected for
  stocks that occur entirely outside of Alaskan waters.
\3\ As explained earlier in this document, gear interaction could result in mortality, serious injury, or Level A harassment. Because we do not have
  sufficient information to enable us to parse out these outcomes, we present such take as a pool. For purposes of this negligible impact analysis we
  assume the worst case scenario (that all such takes incidental to research activities result in mortality).
\4\ This column represents the total number of incidents of M/SI that could potentially accrue to the specified species or stock as a result of NMFS's
  fisheries research activities and is the number carried forward for evaluation in the negligible impact analysis (later in this document). To reach
  this total, we add one to the total for each pinniped that may be captured in trawl gear in each of the three AFSC research areas; one to the total
  for each pinniped that may be captured in AFSC longline gear in the GOARA and BSAIRA; and one to the total for each pinniped that may be captured in
  IPHC longline gear. We also add one to the total of each small cetacean that may be captured in trawl gear in the GOARA and BSAIRA and one to the
  total of each small cetacean that may be captured in gillnet gear (GOARA only). This represents the potential that the take of an unidentified
  pinniped or small cetacean could accrue to any given stock captured in that gear in that area. The proposed take authorization is formulated as a five-
  year total; the annual average is used only for purposes of negligible impact analysis. We recognize that portions of an animal may not be taken in a
  given year.

[[Page 37691]]

 
\5\ This value represents the calculated PBR less the average annual estimate of ongoing anthropogenic mortalities (i.e., total annual human-caused M/
  SI, which is presented in the SARs) (see Table 3). In parentheses, we provide the estimated maximum annual M/SI expressed as a percentage of this
  value. For some stocks, a minimum population abundance value (and therefore PBR) is unavailable. In these cases, the proportion of estimated
  population abundance represented by the Level B harassment total and/or the proportion of residual PBR represented by the estimated maximum annual M/
  SI cannot be calculated.
\6\ See relevant SARs for more information regarding stock status and trends. Interannual increases may not be interpreted as evidence of a trend. Based
  on the most recent abundance estimates, harbor seal stocks may have reached carrying capacity and appear stable. A time series of stock-specific
  abundance estimates for harbor porpoise shows either increasing or stable estimates, but it is not statistically valid to infer a trend.
\7\ For western Steller sea lions, it is not appropriate to identify a single trend. Using data collected through 2015, there is strong evidence that
  non-pup and pup counts increased at ~2 percent per year between 2000 and 2015. However, there are strong regional differences across the range in
  Alaska, with positive trends east of Samalga Pass (~170[deg] W) in the Gulf of Alaska and eastern Bering Sea and negative trends to the west in the
  Aleutian Islands. For more information, please see Muto et al. (2017).
\8\ No official abundance estimate is provided for these stocks; however, we use the best available information regarding population abundance for
  comparison with the proposed total annual Level B harassment authorization. For the minke whale, surveys covering portions of the stock range provide
  a partial abundance estimate of 2,020 (CV = 0.73) + 1,233 (CV = 0.34) whales. For the fin whale, we use the minimum abundance estimate provided for a
  portion of the stock range (1,036 whales). Surveys in 2010-2012 provide an abundance estimate of 398 (CV = 0.12) + 577 (CV = 0.14) harbor porpoises in
  southeast Alaska. However, the resulting total of 975 is not corrected for observer perception bias and porpoise availability at the surface, which is
  particularly influential for estimates of porpoise abundance. Therefore, we apply a previously estimated correction factor of 2.96 (Hobbs and Waite,
  2010) to this estimate for a provisional abundance estimate of 2,886. For the ringed seal, a partial abundance estimate (that does not account for
  availability bias) of 170,000 seals is given. For more information, please see the relevant SARs.

    Analysis--The majority of stocks that may potentially be taken by 
M/SI (25 of 41) fall below the insignificance threshold (i.e., 10 
percent of residual PBR), while an additional 11 stocks do not have 
current PBR values and therefore are evaluated using other factors. We 
first consider stocks expected to be affected only by behavioral 
harassment and those stocks that fall below the insignificance 
threshold. Next, we consider those stocks above the insignificance 
threshold (i.e., the offshore stock of bottlenose dolphin, Risso's 
dolphin, short-finned pilot whale, and the Pribilof Islands stock of 
harbor seal) and those without PBR values (harbor seal stocks along the 
Oregon and Washington coasts and in Washington inland waters; three 
stocks of harbor porpoise; sperm whale; Pacific white-sided dolphin; 
the Alaska stock of Dall's porpoise; and the ringed seal).
    As described in greater depth previously (see ``Acoustic 
Effects''), we do not believe that AFSC use of active acoustic sources 
has the likely potential to cause any effect exceeding Level B 
harassment of marine mammals. We have produced what we believe to be 
precautionary estimates of potential incidents of Level B harassment. 
There is a general lack of information related to the specific way that 
these acoustic signals, which are generally highly directional and 
transient, interact with the physical environment and to a meaningful 
understanding of marine mammal perception of these signals and 
occurrence in the areas where AFSC operates. The procedure for 
producing these estimates, described in detail in ``Estimated Take Due 
to Acoustic Harassment,'' represents NMFS's best effort towards 
balancing the need to quantify the potential for occurrence of Level B 
harassment with this general lack of information. The sources 
considered here have moderate to high output frequencies, generally 
short ping durations, and are typically focused (highly directional) to 
serve their intended purpose of mapping specific objects, depths, or 
environmental features. In addition, some of these sources can be 
operated in different output modes (e.g., energy can be distributed 
among multiple output beams) that may lessen the likelihood of 
perception by and potential impacts on marine mammals in comparison 
with the quantitative estimates that guide our proposed take 
authorization. We also produced estimates of incidents of potential 
Level B harassment due to disturbance of hauled-out pinnipeds that may 
result from the physical presence of researchers; these estimates are 
combined with the estimates of Level B harassment that may result from 
use of active acoustic devices.
    Here, we consider authorized Level B take less than five percent of 
population abundance to be de minimis, while authorized Level B taking 
between 5-15 percent is low. A moderate amount of authorized taking by 
Level B harassment would be from 15-25 percent, and high above 25 
percent. Of the 49 stocks that may be subject to Level B harassment, 
the level of taking proposed for authorization would represent a de 
minimis impact for 31 stocks and a low impact for an additional ten 
stocks. We do not consider these impacts further for these 41 stocks. 
The level of taking by Level B harassment would represent a moderate 
impact on one additional stock, the South Kodiak stock of harbor seals; 
and, therefore, we consider these potential impacts in conjunction with 
the level of taking by M/SI. The annual taking by M/SI projected for 
this stock equates to less than one percent of residual PBR; therefore 
we do not consider this stock further. The total taking by Level B 
harassment represents a high level of impact for three stocks (gray 
whale and the offshore and AT1 stocks of killer whale). We discuss 
these in further detail below. For an additional four stocks (sperm 
whale and Alaska stocks of three beaked whale species), there is no 
abundance estimate upon which to base a comparison. However, we note 
that the anticipated number of incidents of take by Level B harassment 
are very low (2-22 for these four stocks) and likely represent a de 
minimis impact on these stocks.
    As described previously, there is some minimal potential for 
temporary effects to hearing for certain marine mammals, but most 
effects would likely be limited to temporary behavioral disturbance. 
Effects on individuals that are taken by Level B harassment will likely 
be limited to reactions such as increased swimming speeds, increased 
surfacing time, or decreased foraging (if such activity were 
occurring), reactions that are considered to be of low severity (e.g., 
Ellison et al., 2012). Individuals may move away from the source if 
disturbed; but, because the source is itself moving and because of the 
directional nature of the sources considered here, there is unlikely to 
be even temporary displacement from areas of significance and any 
disturbance would be of short duration. Although there is no 
information on which to base any distinction between incidents of 
harassment and individuals harassed, the same factors, in conjunction 
with the fact that AFSC survey effort is widely dispersed in space and 
time, indicate that repeated exposures of the same individuals would be 
very unlikely. For these reasons, we do not consider the proposed level 
of take by acoustic disturbance to represent a significant additional 
population stressor when considered in context with the proposed level 
of take by M/SI for any species, including those for which no abundance 
estimate is available.
    There are no additional impacts other than Level B harassment 
expected for the three stocks listed above for which Level B harassment 
is expected to be at a relatively high level, i.e., the gray whale and 
offshore and AT1 stocks of killer whale (Level B harassment incidents 
equate to approximately 27, 28, and 29 percent of the stock abundances, 
respectively). It should be noted that the AT1 stock of transient 
killer whales has a critically low population abundance of seven 
whales.

[[Page 37692]]

Although the estimate of take by Level B harassment is at 29 percent, 
this represents only two estimated incidents of temporary and 
insignificant behavioral disruption, which would not be expected to 
affect annual rates of recruitment or survival for the stock. We do not 
discuss these three stocks further.
    Similarly, disturbance of pinnipeds on haul-outs by researchers 
(expected for harbor seals and Steller sea lions in the GOARA and 
BSAIRA) are expected to be infrequent and cause only a temporary 
disturbance on the order of minutes. As noted previously, monitoring 
results from other activities involving the disturbance of pinnipeds 
and relevant studies of pinniped populations that experience more 
regular vessel disturbance indicate that individually significant or 
population level impacts are unlikely to occur. When considering the 
individual animals likely affected by this disturbance, only a small 
fraction of the estimated population abundance of the affected stocks 
would be expected to experience the disturbance.
    For Risso's dolphin, short-finned pilot whale, and the offshore 
stock of bottlenose dolphin, maximum total potential M/SI due to NMFS' 
fisheries research activity (SWFSC, NWFSC, and AFSC combined) is 
approximately 11, 18, and 30 percent of residual PBR, respectively. For 
example, PBR for Risso's dolphin is currently set at 46 and the annual 
average of known ongoing anthropogenic M/SI is 3.7, yielding a residual 
PBR value of 42.3. The maximum combined annual average M/SI incidental 
to NMFS fisheries research activity is 4.6, or 10.9 percent of residual 
PBR. The only known source of other anthropogenic mortality for these 
species is in commercial fisheries. For the Risso's dolphin and 
offshore stock of bottlenose dolphin, such take is considered to be 
insignificant and approaching zero mortality and serious injury. This 
is not the case for the short-finned pilot whale; however, the annual 
take from fisheries (1.2) and from NMFS's fisheries research (0.6) are 
both very low. There are no other factors that would lead us to believe 
that take by M/SI of 18 percent of residual PBR would be problematic 
for this species. Total potential M/SI due to NMFS' fisheries research 
activity is approximately 11 percent of residual PBR for the Pribilof 
Islands stock of harbor seals. However, there are no other known 
sources of anthropogenic M/SI for this stock or other known significant 
stressors; therefore, there is no indication that the take by M/SI of 
11 percent of residual PBR would be problematic for this stock.
    PBR is unknown for harbor seals on the Oregon and Washington coasts 
and in Washington inland waters (comprised of the Hood Canal, southern 
Puget Sound, and Washington northern inland waters stocks). The Hood 
Canal, southern Puget Sound, and Washington northern inland waters 
stocks were formerly a single inland waters stock. Both the Oregon/
Washington coast and Washington inland waters stocks of harbor seal 
were considered to be stable following the most recent abundance 
estimates (in 1999, stock abundances were estimated at 24,732 and 
13,692, respectively). However, a Washington Department of Fish and 
Wildlife expert (S. Jeffries) stated an unofficial abundance of 32,000 
harbor seals in Washington (Mapes, 2013). Therefore, it is reasonable 
to assume that at worst, the stocks have not declined since the last 
abundance estimates. Ongoing anthropogenic mortality is estimated at 
10.6 harbor seals per year for the coastal stock and 13.4 for inland 
waters seals; therefore, we reasonably assume that the maximum 
potential annual M/SI incidental to NMFS' fisheries research activities 
(2.2 and 1.6, respectively) is a small fraction of any sustainable take 
level that might be calculated for either stock.
    As noted above, PBR is also undetermined for the sperm whale, 
Pacific white-sided dolphin, three stocks of harbor porpoise, Alaska 
stock of Dall's porpoise, and the ringed seal. We follow a similar 
approach as for harbor seals (see above) in evaluating the significance 
of the proposed M/SI by describing available information regarding 
population abundance and other sources of anthropogenic M/SI.
    <bullet> Rice (1989) estimated that there were 930,000 sperm whales 
in the North Pacific following the conclusion of commercial whaling. 
However, this estimate included areas beyond the range of the U.S. 
North Pacific stock of sperm whales. Kato and Miyashita (1998) produced 
an estimate of 102,112 (CV = 0.155) sperm whales in the western North 
Pacific. However, this estimate is considered to be positively biased, 
and includes whales outside of Alaskan waters. Commercial fishing is 
the only other source of ongoing anthropogenic M/SI, which is estimated 
to be 3.7 whales per year. When considered in conjunction with the 
maximum total annual M/SI anticipated as a result of NMFS fisheries 
research activities (0.4), we expect that the resulting total annual M/
SI (4.1) is a small fraction of any sustainable take level that might 
be calculated for the stock.
    <bullet> Historically, the minimum population estimate for the 
Central North Pacific stock of Pacific white-sided dolphin was 26,880, 
based on the sum of abundance estimates for four separate survey blocks 
north of 45[deg] N from surveys conducted during 1987-1990, reported in 
Buckland et al. (1993). This was considered a minimum estimate because 
the abundance of animals in a fifth block, which straddled the boundary 
of the two stocks for this species, was not included in the estimate 
for the North Pacific stock. In addition, much of the potential habitat 
for this stock was not surveyed between 1987 and 1990 (Muto et al., 
2017). Using this minimum abundance estimate in the PBR equation, 
assuming the default 4 percent productivity rate and a recovery factor 
of 0.5 (as recommended for stocks of unknown status), produces a PBR 
value of 268.8. There are no other sources of anthropogenic M/SI for 
this stock. The maximum total annual M/SI anticipated as a result of 
NMFS fisheries research activities (1.6) would represent 0.6 percent of 
residual PBR.
    <bullet> For the Alaska stock of Dall's porpoise, no current 
estimate of minimum population abundance is available. However, an 
abundance estimate of 83,400 was estimated on the basis of data 
collected form 1987-1991 (Hobbs and Lerczak, 1993). Using this 
population estimate and its associated CV of 0.097, the minimum 
abundance would be 76,874. Using this estimate with the default 
productivity rate and the recovery factor for stocks expected to be 
within the OSP level (Buckland et al., 1993), a PBR value of 1,537.5 
may be calculated. Accounting for ongoing M/SI due to commercial 
fisheries, the maximum total annual M/SI anticipated as a result of 
NMFS fisheries research activities (3.4) would represent 0.2 percent of 
residual PBR.
    <bullet> For the Bering Sea stock of harbor porpoise, a minimum 
abundance estimate of 40,039 was calculated by Hobbs and Waite (2010) 
on the basis of a partial abundance estimate, derived from 1999 aerial 
surveys of Bristol Bay. Although this estimate is formally considered 
outdated for use in calculating PBR values, we use it here in the same 
way as the Pacific white-sided dolphin and Dall's porpoise, addressed 
above. As for the Pacific white-sided dolphin, we use the default 
productivity rate and recovery factor for stocks of unknown status to 
calculate a PBR value of 400.4. Accounting for minimal fisheries 
mortality, the maximum total annual M/SI anticipated as a result of 
NMFS fisheries research

[[Page 37693]]

activities (0.4) would represent 0.1 percent of residual PBR.
    <bullet> For the Gulf of Alaska stock of harbor porpoise, an 
minimum abundance estimate of 25,987 was calculated by Hobbs and Waite 
(2010) on the basis of an abundance estimate derived from 1998 aerial 
surveys of the western Gulf of Alaska. Using the default productivity 
rate and recovery factor for stocks of unknown status to calculate a 
PBR value of 259.9. Accounting for relatively significant ongoing 
fisheries mortality, the maximum total annual M/SI anticipated as a 
result of NMFS fisheries research activities (0.8) would represent 0.4 
percent of residual PBR.
    <bullet> A negatively biased minimum abundance estimate of 896 was 
calculated for the southeast Alaska stock of harbor porpoise on the 
basis of 2010-2012 aerial surveys (Muto et al., 2017). The estimate is 
negatively biased because it does not account for observer perception 
bias and porpoise availability at the surface. However, use of a widely 
accepted correction factor (2.96) provides a minimum abundance estimate 
of 2,652 and a corresponding PBR value of 26.5. This PBR value is less 
than estimated annual ongoing mortality due to commercial fisheries 
(34). However, the maximum total annual M/SI anticipated as a result of 
NMFS fisheries research activities (0.2) represents a minimum potential 
take of one animal over the 5-year period and would represent an 
insignificant incremental addition to the total annual M/SI (0.6 
percent).
    <bullet> Although NMFS does not provide a formal PBR value for the 
ringed seal, Muto et al. (2017) provide a minimum abundance estimate of 
170,000 seals in the U.S. sector of the Bering Sea. This is not 
considered a reliable estimate for the stock because it does not 
account for seals in the Chukchi and Beaufort Seas. However, as this is 
a conservative minimum abundance estimate, we use the corresponding PBR 
value of 5,100 given by Muto et al. (2017). Accounting for minimal 
ongoing M/SI due to commercial fisheries, as well as ongoing 
subsistence harvest of ringed seals, the maximum total annual M/SI 
anticipated as a result of NMFS fisheries research activities (1.6) 
would represent 0.04 percent of residual PBR.
    In summary, our negligible impact analysis is founded on the 
following factors: (1) The possibility of injury, serious injury, or 
mortality from the use of active acoustic devices may reasonably be 
considered discountable; (2) the anticipated incidents of Level B 
harassment from the use of active acoustic devices and physical 
disturbance of pinnipeds consist of, at worst, temporary and relatively 
minor modifications in behavior; (3) the predicted number of incidents 
of potential mortality are at insignificant levels for a majority of 
affected stocks; (4) consideration of additional factors for Risso's 
dolphin, short-finned pilot whale, the offshore stock of bottlenose 
dolphin, and the Pribilof Isalnds stock of harbor seal do not reveal 
cause for concern; (5) total maximum potential M/SI incidental to NMFS 
fisheries research activity for southeast Alaska harbor porpoise, 
considered in conjunction with other sources of ongoing mortality, 
presents only a minimal incremental additional to total M/SI; (6) 
available information regarding stocks for which no current PBR 
estimate is available indicates that total maximum potential M/SI is 
sustainable; and (7) the presumed efficacy of the planned mitigation 
measures in reducing the effects of the specified activity to the level 
of least practicable adverse impact. In combination, we believe that 
these factors demonstrate that the specified activity will have only 
short-term effects on individuals (resulting from Level B harassment) 
and that the total level of taking will not impact rates of recruitment 
or survival sufficiently to result in population-level impacts.
    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, we preliminarily find that the total marine mammal 
take from the proposed activities will have a negligible impact on the 
affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(A) of the MMPA for specified 
activities. The MMPA does not define small numbers and so, in practice, 
where estimated numbers are available, NMFS compares the number of 
individuals taken to the most appropriate estimation of abundance of 
the relevant species or stock in our determination of whether an 
authorization is limited to small numbers of marine mammals. 
Additionally, other qualitative factors may be considered in the 
analysis, such as the temporal or spatial scale of the activities.
    Please see Table 15 for information relating to this small numbers 
analysis. The total amount of taking proposed for authorization is less 
than five percent for a majority of stocks, and the total amount of 
taking proposed for authorization is less than one-third of the stock 
abundance for all stocks.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    In order to issue an LOA, NMFS must find that the specified 
activity will not have an ``unmitigable adverse impact'' on the 
subsistence uses of the affected marine mammal species or stocks by 
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50 
CFR 216.103 as an impact resulting from the specified activity that:
    (1) Is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by:
    (i) Causing the marine mammals to abandon or avoid hunting areas;
    (ii) Directly displacing subsistence users; or
    (iii) Placing physical barriers between the marine mammals and the 
subsistence hunters; and
    (2) Cannot be sufficiently mitigated by other measures to increase 
the availability of marine mammals to allow subsistence needs to be 
met.
    As described in this preamble, the AFSC has requested authorization 
of take incidental to fisheries research activities within Alaskan 
waters. The proposed activities have the potential to result in M/SI of 
marine mammals as a result of incidental interaction with research 
gear, and have the potential to result in incidental Level B harassment 
of marine mammals as a result of the use of active acoustic devices or 
because of the physical presence of researchers at locations where 
pinnipeds may be hauled out. These activities also have the potential 
to result in impacts on the availability of marine mammals for 
subsistence uses. The AFSC is aware of this potential and is committed 
to implementing actions to avoid or to minimize any such effects to 
Alaska Native subsistence communities. The AFSC addresses the potential 
for their proposed research activities to impact subsistence uses on 
the following factors:

[[Page 37694]]

Actions That May Cause Marine Mammals To Abandon or Avoid Hunting Areas

    Some AFSC fisheries research efforts use high-frequency mapping and 
fish-finding sonars to assess abundance and distribution of target 
stocks of fish. The high frequency transient sound sources operated by 
the AFSC are used for a wide variety of environmental and remote-object 
sensing in the marine environment. These acoustic sources, which are 
present on most AFSC fishery research vessels, include a variety of 
single, dual, and multi-beam echosounders, sources used to determine 
the orientation of trawl nets, and several current profilers. Some of 
these acoustic sources are likely to be audible to some marine mammal 
species. Among the marine mammals, most of these sources are unlikely 
to be audible to whales and most pinnipeds, whereas they may be 
detected by odontocete cetaceans (and particularly high frequency 
specialists such as harbor porpoise). There is relatively little direct 
information about behavioral responses of marine mammals, including the 
odontocete cetaceans to these devices, but the responses that have been 
measured in a variety of species to audible sounds suggest that the 
most likely behavioral responses (if any) would be localized short-term 
avoidance behavior (See ``Potential Effects of Specified Activities on 
Marine Mammals and their Habitat''). As a general conclusion, while 
some of the active acoustic sources used during AFSC fisheries research 
surveys are likely to be detected by some marine species (particularly 
phocid pinnipeds and odontocete cetaceans), the sound sources with 
potential for disturbance would be temporary and transient in any 
particular location as the research vessels move through an area. Any 
changes in marine mammal behavior in response to the sound sources or 
physical presence of the research vessel would likely involve temporary 
avoidance behavior in the vicinity of the research vessel and would 
return to normal after the vessel passed. Given the small number of 
research vessels involved and their infrequent and inconsistent 
presence in any given area from day to day, it is unlikely that the 
proposed activity would cause animals to avoid any particular area.
    Most AFSC fisheries research activities occur well away from land 
and, in cases where they do approach land, include mitigation measures 
to minimize the risk of disturbing pinnipeds hauled out on land. Any 
incidental disturbance of pinnipeds on haul-outs would likely be 
infrequent and result in temporary or short term changes in behavior. 
This sporadic and temporary type of disturbance is not likely to result 
in a change in use or abandonment of a known haul-out.
    AFSC fisheries research activities generally are highly transient 
and short term (e.g., several hours to a day in any one location) in 
duration and take place well out to sea, far from coastal or ice pack 
subsistence hunting activities. It is possible, albeit unlikely, for 
these fisheries research sound sources to interact with migratory 
species hunted for subsistence such that there could be short term 
alterations in migratory pathways. However, as described in the AFSC 
Communication Plan (Appendix B of AFSC's application), the AFSC will 
work with subsistence users to identify important areas for marine 
mammals and subsistence hunters early in the planning process as well 
as in real time to identify the potential for overlap between migratory 
pathways, key hunting regions and seasons, and proposed fisheries 
research. This communication should lead to avoidance of any issues of 
displacement of marine mammals and their prey.

Activities That May Directly Displace Subsistence Users

    AFSC fisheries research primarily utilizes ocean-going ships 
generally suited for offshore work. These vessels are not designed to 
work in or near sea ice where much of the subsistence harvest of 
pinnipeds occurs; thus research activities are most likely to occur 
outside of periods when this type of hunting occurs. Due to the desire 
to avoid disturbing pinnipeds hauled out on land, these ships largely 
avoid nearshore routes that might otherwise put them in the path of 
seal hunters.
    Bowhead whale hunts may occur near sea ice in the spring or in open 
water in the fall. AFSC fisheries research is only conducted during the 
open water season in the Arctic so there is no risk of potential 
interference with subsistence hunts in the spring. However, AFSC 
fisheries research vessels may be present in whale hunting areas in the 
fall and could potentially interfere with subsistence activities. The 
communications plan is designed to minimize the risk of any such 
interference by advance planning and communication between AFSC 
scientists and subsistence hunting organizations (e.g., Alaska Eskimo 
Whaling Commission) and real-time communication between AFSC research 
vessels as they approach subsistence areas and nearby coastal community 
contacts. The AFSC is committed to alter its research plans to address 
any concerns about potential interference and to avoid any such 
interference in the field.
    AFSC fisheries research vessels make port calls in established 
harbors and ports, thus reducing the chances for interaction with the 
transit of hunters to and from coastal villages to nearby hunting 
regions. As described in the Communication Plan provided as Appendix B 
of AFSC's application, in those rare cases where a research vessel may 
need to anchor offshore from a subsistence community, AFSC personnel 
will, within the limits of maritime safety, direct the ship to a 
predetermined location in coordination with the local subsistence 
community so as to avoid interfering with those activities.

Activities That May Place Physical Barriers (Vessels and Gear) Between 
the Marine Mammals and the Subsistence Hunters

    The AFSC uses a variety of towed nets and sampling gear to conduct 
its fisheries and ecosystem research. However, current operational 
guidelines designed to reduce incidental catch of marine mammals 
include measures that direct activities away from marine mammals near 
the research vessel (move-on rule). These measures will reduce the 
possibility for placing any barriers between subsistence hunters and 
their marine mammal prey. As outlined in the Communication Plan, AFSC 
will not deploy such research gear when subsistence hunters have been 
visually observed in the area.
    AFSC fisheries research will also strive to avoid working in any 
areas when migrating species are present in the immediate vicinity. Per 
the Communication Plan, the AFSC will coordinate both in advance and in 
real time with known marine mammal hunting communities within the 
immediate vicinity of research to avoid any interactions between 
hunting activity and fisheries research vessels or gear.
    The AFSC has provided a draft Communication Plan as Appendix B to 
their application, and we invite comment on that document. The AFSC is 
committed to conduct its proposed activities in ways that do not affect 
the availability of marine mammals to subsistence hunters. The AFSC 
will implement standard operational procedures and mitigation measures 
to minimize direct impacts on marine mammals and will work with Alaska 
Native organizations and coastal communities to develop effective

[[Page 37695]]

communication protocols to minimize the risk of potential interference 
with subsistence activities. The AFSC will thus work to ensure that its 
research activities do not negatively impact the availability of marine 
mammals to Alaska Native subsistence users.
    Based on the description of the specified activity, the measures 
described to minimize adverse effects on the availability of marine 
mammals for subsistence purposes, and the proposed mitigation and 
monitoring measures, we have preliminarily determined that there will 
not be an unmitigable adverse impact on subsistence uses from AFSC's 
proposed activities.

Adaptive Management

    The regulations governing the take of marine mammals incidental to 
AFSC fisheries research survey operations would contain an adaptive 
management component. The inclusion of an adaptive management component 
will be both valuable and necessary within the context of five-year 
regulations for activities that have been associated with marine mammal 
mortality.
    The reporting requirements associated with this proposed rule are 
designed to provide OPR with monitoring data from the previous year to 
allow consideration of whether any changes are appropriate. OPR and the 
AFSC will meet annually to discuss the monitoring reports and current 
science and whether mitigation or monitoring modifications are 
appropriate. The use of adaptive management allows OPR to consider new 
information from different sources to determine (with input from the 
AFSC regarding practicability) on an annual or biennial basis if 
mitigation or monitoring measures should be modified (including 
additions or deletions). Mitigation measures could be modified if new 
data suggests that such modifications would have a reasonable 
likelihood of reducing adverse effects to marine mammals and if the 
measures are practicable.
    The following are some of the possible sources of applicable data 
to be considered through the adaptive management process: (1) Results 
from monitoring reports, as required by MMPA authorizations; (2) 
results from general marine mammal and sound research; and (3) any 
information which reveals that marine mammals may have been taken in a 
manner, extent, or number not authorized by these regulations or 
subsequent LOAs.

Endangered Species Act (ESA)

    There are multiple marine mammal species listed under the ESA with 
confirmed or possible occurrence in the proposed specified geographical 
regions (see Table 3). The proposed authorization of incidental take 
pursuant to the AFSC's specified activity would not affect any 
designated critical habitat. OPR has initiated consultation with NMFS's 
Alaska Regional Office under section 7 of the ESA on the promulgation 
of five-year regulations and the subsequent issuance of LOAs to AFSC 
under section 101(a)(5)(A) of the MMPA. This consultation will be 
concluded prior to issuing any final rule.

Request for Information

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning the AFSC request and the proposed 
regulations (see ADDRESSES). All comments will be reviewed and 
evaluated as we prepare final rules and make final determinations on 
whether to issue the requested authorizations. This notice and 
referenced documents provide all environmental information relating to 
our proposed action for public review.

Classification

    Pursuant to the procedures established to implement Executive Order 
12866, the Office of Management and Budget has determined that this 
proposed rule is not significant.
    Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA), 
the Chief Counsel for Regulation of the Department of Commerce has 
certified to the Chief Counsel for Advocacy of the Small Business 
Administration that this proposed rule, if adopted, would not have a 
significant economic impact on a substantial number of small entities. 
NMFS is the sole entity that would be subject to the requirements in 
these proposed regulations, and NMFS is not a small governmental 
jurisdiction, small organization, or small business, as defined by the 
RFA. Because of this certification, a regulatory flexibility analysis 
is not required and none has been prepared.
    This proposed rule does not contain a collection-of-information 
requirement subject to the provisions of the Paperwork Reduction Act 
(PRA) because the applicant is a Federal agency. Notwithstanding any 
other provision of law, no person is required to respond to nor shall a 
person be subject to a penalty for failure to comply with a collection 
of information subject to the requirements of the PRA unless that 
collection of information displays a currently valid OMB control 
number. These requirements have been approved by OMB under control 
number 0648-0151 and include applications for regulations, subsequent 
LOAs, and reports.

List of Subjects in 50 CFR Part 219

    Exports, Fish, Imports, Indians, Labeling, Marine mammals, 
Penalties, Reporting and recordkeeping requirements, Seafood, 
Transportation.

    Dated: July 24, 2018.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine 
Fisheries Service.

    For reasons set forth in the preamble, 50 CFR part 219 is proposed 
to be amended as follows:

PART 219--REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE 
MAMMALS

0
1. The authority citation for part 219 continues to read as follows:

    Authority: 16 U.S.C. 1361 et seq.

0
2. Add subpart F to part 219 to read as follows:
Subpart F--Taking Marine Mammals Incidental to Alaska Fisheries Science 
Center Fisheries Research
Sec.
219.51 Specified activity and specified geographical region.
219.52 Effective dates.
219.53 Permissible methods of taking.
219.54 Prohibitions.
219.55 Mitigation requirements.
219.56 Requirements for monitoring and reporting.
219.57 Letters of Authorization.
219.58 Renewals and modifications of Letters of Authorization.
219.59-219.60 [Reserved]

Subpart F--Taking Marine Mammals Incidental to Alaska Fisheries 
Science Center Fisheries Research


Sec.  219.51   Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the National Marine 
Fisheries Service's (NMFS) Alaska Fisheries Science Center (AFSC) and 
those persons it authorizes, including the International Pacific 
Halibut Commission (IPHC) or funds to conduct activities on its behalf 
for the taking of marine mammals that occurs in the areas outlined in 
paragraph (b) of this section and that occurs incidental to research 
survey program operations.
    (b) The taking of marine mammals by AFSC may be authorized in a 
Letter of Authorization (LOA) only if it occurs within the Gulf of 
Alaska, Bering Sea and Aleutian Islands, Chukchi Sea and Beaufort Sea, 
or is conducted by the IPHC in the Bering Sea and Aleutian

[[Page 37696]]

Islands, Gulf of Alaska, or off the U.S. West Coast.


Sec.  219.52   Effective dates.

    Regulations in this subpart are effective from [EFFECTIVE DATE OF 
FINAL RULE] through [DATE 5 YEARS AFTER EFFECTIVE DATE OF FINAL RULE].


Sec.  219.53  Permissible methods of taking.

    Under LOAs issued pursuant to Sec.  216.106 of this chapter and 
Sec.  219.57, the Holder of the LOA (hereinafter ``AFSC'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  219.51(b) by Level B harassment associated with 
use of active acoustic systems and physical or visual disturbance of 
hauled-out pinnipeds and by Level A harassment, serious injury, or 
mortality associated with use of hook and line gear, trawl gear, and 
gillnet gear, provided the activity is in compliance with all terms, 
conditions, and requirements of the regulations in this subpart and the 
appropriate LOA.


Sec.  219.54  Prohibitions.

    Notwithstanding takings contemplated in Sec.  219.51 and authorized 
by a LOA issued under Sec.  216.106 of this chapter and Sec.  219.57, 
no person in connection with the activities described in Sec.  219.51 
may:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec.  216.106 of 
this chapter and Sec.  219.57;
    (b) Take any marine mammal not specified in such LOA;
    (c) Take any marine mammal specified in such LOA in any manner 
other than as specified;
    (d) Take a marine mammal specified in such LOA if NMFS determines 
such taking results in more than a negligible impact on the species or 
stocks of such marine mammal; or
    (e) Take a marine mammal specified in such LOA if NMFS determines 
such taking results in an unmitigable adverse impact on the species or 
stock of such marine mammal for taking for subsistence uses.


Sec.  219.55  Mitigation requirements.

    When conducting the activities identified in Sec.  219.51(a), the 
mitigation measures contained in any LOA issued under Sec.  216.106 of 
this chapter and Sec.  219.57 must be implemented. These mitigation 
measures shall include but are not limited to:
    (a) General conditions: (1) AFSC shall convey relevant mitigation, 
monitoring, and reporting requirements to the IPHC, as indicated in the 
following subparts.
    (2) AFSC shall take all necessary measures to coordinate and 
communicate in advance of each specific survey with the National 
Oceanic and Atmospheric Administration's (NOAA) Office of Marine and 
Aviation Operations (OMAO) or other relevant parties on non-NOAA 
platforms to ensure that all mitigation measures and monitoring 
requirements described herein, as well as the specific manner of 
implementation and relevant event-contingent decision-making processes, 
are clearly understood and agreed upon. AFSC shall convey this 
requirement to IPHC.
    (2) AFSC shall coordinate and conduct briefings at the outset of 
each survey and as necessary between ship's crew (Commanding Officer/
master or designee(s), as appropriate) and scientific party in order to 
explain responsibilities, communication procedures, marine mammal 
monitoring protocol, and operational procedures. AFSC shall convey this 
requirement to IPHC.
    (3) AFSC shall coordinate as necessary on a daily basis during 
survey cruises with OMAO personnel or other relevant personnel on non-
NOAA platforms to ensure that requirements, procedures, and decision-
making processes are understood and properly implemented. AFSC shall 
convey this requirement to IPHC.
    (4) When deploying any type of sampling gear at sea, AFSC shall at 
all times monitor for any unusual circumstances that may arise at a 
sampling site and use best professional judgment to avoid any potential 
risks to marine mammals during use of all research equipment. AFSC 
shall convey this requirement to IPHC.
    (5) AFSC shall implement handling and/or disentanglement protocols 
as specified in the guidance that shall be provided to AFSC survey 
personnel. AFSC shall convey this requirement to IPHC.
    (6) AFSC shall not approach within 1 km of locations where marine 
mammals are aggregated, including pinniped rookeries and haul-outs.
    (7) AFSC shall adhere to a final Communication Plan. In summary and 
in accordance with the Plan, AFSC shall:
    (i) Notify and provide potentially affected Alaska Native 
subsistence communities with the Communication Plan through a series of 
mailings, direct contacts, and planned meetings throughout the regions 
where AFSC fisheries research is expected to occur;
    (ii) Meet with potentially affected subsistence communities to 
discuss planned activities and to resolve potential conflicts regarding 
any aspects of either the fisheries research operations or the 
Communication Plan;
    (iii) Develop field operations plans as necessary, which shall 
address how researchers will consult and maintain communication with 
contacts in the potentially affected subsistence communities when in 
the field, including a list of local contacts and contact mechanisms, 
and which shall describe operational procedures and actions planned to 
avoid or minimize the risk of interactions between AFSC fisheries 
research and local subsistence activities;
    (iv) Schedule post-season informational sessions with subsistence 
contacts from the study areas to brief them on the outcome of the AFSC 
fisheries research and to assess performance of the Communication Plan 
and individual field operations or cruise plans in working to minimize 
effects to subsistence activities; and
    (v) Evaluate overall effectiveness of the Communications Plan in 
year four of any LOA issued pursuant to Sec.  216.106 of this chapter 
and Sec.  219.57.
    (b) Trawl survey protocols: (1) AFSC shall conduct trawl operations 
as soon as is practicable upon arrival at the sampling station.
    (2) AFSC shall initiate marine mammal watches (visual observation) 
at least 15 minutes prior to beginning of net deployment, but shall 
also conduct monitoring during any pre-set activities including 
trackline reconnaissance, CTD casts, and plankton or bongo net hauls. 
Marine mammal watches shall be conducted by scanning the surrounding 
waters with the naked eye and rangefinding binoculars (or monocular). 
During nighttime operations, visual observation shall be conducted 
using the naked eye and available vessel lighting.
    (3) AFSC shall implement the move-on rule mitigation protocol, as 
described in this paragraph. If one or more marine mammals are observed 
and are considered at risk of interacting with the vessel or research 
gear, or appear to be approaching the vessel and are considered at risk 
of interaction, AFSC shall either remain onsite or move on to another 
sampling location. If remaining onsite, the set shall be delayed. If 
the animals depart or appear to no longer be at risk of interacting 
with the vessel or gear, a further observation period shall be 
conducted. If no further observations are made or the animals still do 
not appear to be at risk of interaction, then the set may be made. If 
the vessel is moved to a different section of the sampling area, the 
move-on rule

[[Page 37697]]

mitigation protocol would begin anew. If, after moving on, marine 
mammals remain at risk of interaction, the AFSC shall move again or 
skip the station. Marine mammals that are sighted shall be monitored to 
determine their position and movement in relation to the vessel to 
determine whether the move-on rule mitigation protocol should be 
implemented. AFSC may use best professional judgment in making these 
decisions.
    (4) AFSC shall maintain visual monitoring effort during the entire 
period of time that trawl gear is in the water (i.e., throughout gear 
deployment, fishing, and retrieval). If marine mammals are sighted 
before the gear is fully removed from the water, AFSC shall take the 
most appropriate action to avoid marine mammal interaction. AFSC may 
use best professional judgment in making this decision.
    (5) If trawling operations have been suspended because of the 
presence of marine mammals, AFSC may resume trawl operations when 
practicable only when the animals are believed to have departed the 
area. AFSC may use best professional judgment in making this 
determination.
    (6) AFSC shall implement standard survey protocols to minimize 
potential for marine mammal interactions, including maximum tow 
durations at target depth and maximum tow distance, and shall carefully 
empty the trawl as quickly as possible upon retrieval.
    (7) Whenever surface trawl nets are used in southeast Alaska, AFSC 
must install and use acoustic deterrent devices, with two pairs of the 
devices installed near the net opening. AFSC must ensure that the 
devices are operating properly before deploying the net.
    (c) Longline survey protocols: (1) AFSC shall deploy longline gear 
as soon as is practicable upon arrival at the sampling station. AFSC 
shall convey this requirement to IPHC.
    (2) AFSC shall initiate marine mammal watches (visual observation) 
no less than 30 minutes (or for the duration of transit between set 
locations, if shorter than 30 minutes) prior to both deployment and 
retrieval of longline gear. Marine mammal watches shall be conducted by 
scanning the surrounding waters with the naked eye and rangefinding 
binoculars (or monocular). During nighttime operations, visual 
observation shall be conducted using the naked eye and available vessel 
lighting. AFSC shall convey this requirement to IPHC.
    (3) AFSC shall implement the move-on rule mitigation protocol, as 
described in this paragraph. If one or more marine mammals are observed 
in the vicinity of the planned location before gear deployment, and are 
considered at risk of interacting with the vessel or research gear, or 
appear to be approaching the vessel and are considered at risk of 
interaction, AFSC shall either remain onsite or move on to another 
sampling location. If remaining onsite, the set shall be delayed. If 
the animals depart or appear to no longer be at risk of interacting 
with the vessel or gear, a further observation period shall be 
conducted. If no further observations are made or the animals still do 
not appear to be at risk of interaction, then the set may be made. If 
the vessel is moved to a different section of the sampling area, the 
move-on rule mitigation protocol would begin anew. If, after moving on, 
marine mammals remain at risk of interaction, the AFSC shall move again 
or skip the station. Marine mammals that are sighted shall be monitored 
to determine their position and movement in relation to the vessel to 
determine whether the move-on rule mitigation protocol should be 
implemented. AFSC may use best professional judgment in making these 
decisions. AFSC shall convey this requirement to IPHC.
    (4) AFSC shall maintain visual monitoring effort during the entire 
period of gear deployment and retrieval. If marine mammals are sighted 
before the gear is fully deployed or retrieved, AFSC shall take the 
most appropriate action to avoid marine mammal interaction. AFSC may 
use best professional judgment in making this decision. AFSC shall 
convey this requirement to IPHC.
    (5) If deployment or retrieval operations have been suspended 
because of the presence of marine mammals, AFSC may resume such 
operations when practicable only when the animals are believed to have 
departed the area. AFSC may use best professional judgment in making 
this decision. AFSC shall convey this requirement to IPHC.
    (d) Gillnet survey protocols: (1) AFSC shall conduct gillnet 
operations as soon as is practicable upon arrival at the sampling 
station.
    (2) AFSC shall conduct marine mammal watches (visual observation) 
prior to beginning of net deployment. Marine mammal watches shall be 
conducted by scanning the surrounding waters with the naked eye and 
rangefinding binoculars (or monocular).
    (3) AFSC shall implement the move-on rule mitigation protocol. If 
one or more marine mammals are observed in the vicinity of the planned 
location before gear deployment, and are considered at risk of 
interacting with research gear, AFSC shall either remain onsite or move 
on to another sampling location. If remaining onsite, the set shall be 
delayed. If the animals depart or appear to no longer be at risk of 
interacting with the gear, a further observation period shall be 
conducted. If no further observations are made or the animals still do 
not appear to be at risk of interaction, then the set may be made. If 
the vessel is moved to a different area, the move-on rule mitigation 
protocol would begin anew. If, after moving on, marine mammals remain 
at risk of interaction, the AFSC shall move again or skip the station. 
Marine mammals that are sighted shall be monitored to determine their 
position and movement in relation to the vessel to determine whether 
the move-on rule mitigation protocol should be implemented. AFSC may 
use best professional judgment in making these decisions.
    (4) AFSC shall maintain visual monitoring effort during the entire 
period of time that gillnet gear is in the water (i.e., throughout gear 
deployment, fishing, and retrieval). If marine mammals are sighted 
before the gear is fully removed from the water, and appear to be at 
risk of interaction with the gear, AFSC shall pull the gear 
immediately. AFSC may use best professional judgment in making this 
decision.
    (5) If gillnet operations have been suspended because of the 
presence of marine mammals, AFSC may resume gillnet operations when 
practicable only when the animals are believed to have departed the 
area. AFSC may use best professional judgment in making this 
determination.
    (6) AFSC must install and use acoustic deterrent devices whenever 
gillnets are used. AFSC must ensure that the devices are operating 
properly before deploying the net.


Sec.  219.56  Requirements for monitoring and reporting.

    (a) AFSC shall designate a compliance coordinator who shall be 
responsible for ensuring compliance with all requirements of any LOA 
issued pursuant to Sec.  216.106 of this chapter and Sec.  219.57 and 
for preparing for any subsequent request(s) for incidental take 
authorization. AFSC shall convey this requirement to IPHC.
    (b) Visual monitoring program: (1) Marine mammal visual monitoring 
shall occur prior to deployment of trawl, longline, and gillnet gear, 
respectively; throughout deployment of gear and active fishing of 
research gears (not including longline soak time); prior to

[[Page 37698]]

retrieval of longline gear; and throughout retrieval of all research 
gear. AFSC shall convey this requirement to IPHC.
    (2) Marine mammal watches shall be conducted by watch-standers 
(those navigating the vessel and/or other crew) at all times when the 
vessel is being operated. AFSC shall convey this requirement to IPHC.
    (c) Training: (1) AFSC must conduct annual training for all chief 
scientists and other personnel who may be responsible for conducting 
dedicated marine mammal visual observations to explain mitigation 
measures and monitoring and reporting requirements, mitigation and 
monitoring protocols, marine mammal identification, completion of 
datasheets, and use of equipment. AFSC may determine the agenda for 
these trainings.
    (2) AFSC shall also dedicate a portion of training to discussion of 
best professional judgment, including use in any incidents of marine 
mammal interaction and instructive examples where use of best 
professional judgment was determined to be successful or unsuccessful.
    (3) AFSC shall convey these training requirements to IPHC.
    (d) Handling procedures and data collection: (1) AFSC must develop 
and implement standardized marine mammal handling, disentanglement, and 
data collection procedures. These standard procedures will be subject 
to approval by NMFS's Office of Protected Resources (OPR). AFSC shall 
convey these procedures to IPHC.
    (2) When practicable, for any marine mammal interaction involving 
the release of a live animal, AFSC shall collect necessary data to 
facilitate a serious injury determination. AFSC shall convey this 
requirement to IPHC.
    (3) AFSC shall provide its relevant personnel with standard 
guidance and training regarding handling of marine mammals, including 
how to identify different species, bring an individual aboard a vessel, 
assess the level of consciousness, remove fishing gear, return an 
individual to water, and log activities pertaining to the interaction. 
AFSC shall convey this requirement to IPHC.
    (4) AFSC shall record such data on standardized forms, which will 
be subject to approval by OPR. AFSC shall also answer a standard series 
of supplemental questions regarding the details of any marine mammal 
interaction. AFSC shall convey this requirement to IPHC.
    (e) Reporting: (1) AFSC shall report all incidents of marine mammal 
interaction to NMFS's Protected Species Incidental Take database, 
including those resulting from IPHC activities, within 48 hours of 
occurrence and shall provide supplemental information to OPR upon 
request. Information related to marine mammal interaction (animal 
captured or entangled in research gear) must include details of survey 
effort, full descriptions of any observations of the animals, the 
context (vessel and conditions), decisions made, and rationale for 
decisions made in vessel and gear handling.
    (2) Annual reporting: (i) AFSC shall submit an annual summary 
report to OPR not later than ninety days following the end of a given 
year. AFSC shall provide a final report within thirty days following 
resolution of comments on the draft report.
    (ii) These reports shall contain, at minimum, the following:
    (A) Annual line-kilometers surveyed during which the EK60, ME70, 
ES60, 7111 (or equivalent sources) were predominant and associated pro-
rated estimates of actual take;
    (B) Summary information regarding use of all longline, gillnet, and 
trawl gear, including number of sets, tows, etc., specific to each 
gear;
    (C) Accounts of all incidents of significant marine mammal 
interactions, including circumstances of the event and descriptions of 
any mitigation procedures implemented or not implemented and why;
    (D) A written evaluation of the effectiveness of AFSC mitigation 
strategies in reducing the number of marine mammal interactions with 
survey gear, including best professional judgment and suggestions for 
changes to the mitigation strategies, if any;
    (E) Final outcome of serious injury determinations for all 
incidents of marine mammal interactions where the animal(s) were 
released alive; and
    (F) A summary of all relevant training provided by AFSC and any 
coordination with NMFS' Alaska Regional Office.
    (3) AFSC shall convey these reporting requirements to IPHC and 
shall provide IPHC reports to OPR subject to the same schedule.
    (f) Reporting of injured or dead marine mammals:
    (1) In the unanticipated event that the activity defined in Sec.  
219.51(a) of this chapter clearly causes the take of a marine mammal in 
a prohibited manner, AFSC personnel engaged in the research activity 
shall immediately cease such activity until such time as an appropriate 
decision regarding activity continuation can be made by the AFSC 
Director (or designee). The incident must be reported immediately to 
OPR and the Alaska Regional Stranding Coordinator, NMFS. OPR will 
review the circumstances of the prohibited take and work with AFSC to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. The immediate 
decision made by AFSC regarding continuation of the specified activity 
is subject to OPR concurrence. The report must include the following 
information:
    (i) Time, date, and location (latitude/longitude) of the incident;
    (ii) Description of the incident;
    (iii) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, visibility);
    (iv) Description of all marine mammal observations in the 24 hours 
preceding the incident;
    (v) Species identification or description of the animal(s) 
involved;
    (vi) Status of all sound source use in the 24 hours preceding the 
incident;
    (vii) Water depth;
    (viii) Fate of the animal(s); and
    (ix) Photographs or video footage of the animal(s).
    (2) In the event that AFSC discovers an injured or dead marine 
mammal and determines that the cause of the injury or death is unknown 
and the death is relatively recent (e.g., in less than a moderate state 
of decomposition), AFSC shall immediately report the incident to OPR 
and the Alaska Regional Stranding Coordinator, NMFS. The report must 
include the information identified in paragraph (f)(1) of this section. 
Activities may continue while OPR reviews the circumstances of the 
incident. OPR will work with AFSC to determine whether additional 
mitigation measures or modifications to the activities are appropriate.
    (3) In the event that AFSC discovers an injured or dead marine 
mammal and determines that the injury or death is not associated with 
or related to the activities defined in Sec.  219.51(a) of this chapter 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, scavenger damage), AFSC shall report the incident to OPR 
and the Alaska Regional Stranding Coordinator, NMFS, within 24 hours of 
the discovery. AFSC shall provide photographs or video footage or other 
documentation of the stranded animal sighting to OPR.
    (4) AFSC shall convey these requirements to IPHC.


Sec.  219.57  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to these 
regulations, AFSC must apply for and obtain an LOA.
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of

[[Page 37699]]

time not to exceed the expiration date of these regulations.
    (c) If an LOA expires prior to the expiration date of these 
regulations, AFSC may apply for and obtain a renewal of the LOA.
    (d) In the event of projected changes to the activity or to 
mitigation and monitoring measures required by an LOA, AFSC must apply 
for and obtain a modification of the LOA as described in Sec.  219.58.
    (e) The LOA shall set forth:
    (1) Permissible methods of incidental taking;
    (2) Means of effecting the least practicable adverse impact (i.e., 
mitigation) on the species, its habitat, and on the availability of the 
species for subsistence uses; and
    (3) Requirements for monitoring and reporting.
    (f) Issuance of the LOA shall be based on a determination that the 
level of taking will be consistent with the findings made for the total 
taking allowable under these regulations.
    (g) Notice of issuance or denial of an LOA shall be published in 
the Federal Register within thirty days of a determination.


Sec.  219.58  Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec.  216.106 of this chapter and Sec.  
219.57 for the activity identified in Sec.  219.51(a) shall be renewed 
or modified upon request by the applicant, provided that:
    (1) The proposed specified activity and mitigation, monitoring, and 
reporting measures, as well as the anticipated impacts, are the same as 
those described and analyzed for these regulations (excluding changes 
made pursuant to the adaptive management provision in paragraph (c)(1) 
of this section), and
    (2) OPR determines that the mitigation, monitoring, and reporting 
measures required by the previous LOA under these regulations were 
implemented.
    (b) For an LOA modification or renewal requests by the applicant 
that include changes to the activity or the mitigation, monitoring, or 
reporting (excluding changes made pursuant to the adaptive management 
provision in paragraph (c)(1) of this section) that do not change the 
findings made for the regulations or result in no more than a minor 
change in the total estimated number of takes (or distribution by 
species or years), OPR may publish a notice of proposed LOA in the 
Federal Register, including the associated analysis of the change, and 
solicit public comment before issuing the LOA.
    (c) An LOA issued under Sec.  216.106 of this chapter and Sec.  
219.57 for the activity identified in Sec.  219.51(a) may be modified 
by OPR under the following circumstances:
    (1) Adaptive Management--OPR may modify (including augment) the 
existing mitigation, monitoring, or reporting measures (after 
consulting with AFSC regarding the practicability of the modifications) 
if doing so creates a reasonable likelihood of more effectively 
accomplishing the goals of the mitigation and monitoring set forth in 
the preamble for these regulations.
    (i) Possible sources of data that could contribute to the decision 
to modify the mitigation, monitoring, or reporting measures in an LOA:
    (A) Results from AFSC's monitoring from the previous year(s).
    (B) Results from other marine mammal and/or sound research or 
studies.
    (C) Any information that reveals marine mammals may have been taken 
in a manner, extent or number not authorized by these regulations or 
subsequent LOAs.
    (ii) If, through adaptive management, the modifications to the 
mitigation, monitoring, or reporting measures are substantial, OPR will 
publish a notice of proposed LOA in the Federal Register and solicit 
public comment.
    (2) Emergencies--If OPR determines that an emergency exists that 
poses a significant risk to the well-being of the species or stocks of 
marine mammals specified in LOAs issued pursuant to Sec.  216.106 of 
this chapter and Sec.  219.57, an LOA may be modified without prior 
notice or opportunity for public comment. Notice would be published in 
the Federal Register within thirty days of the action.


Sec.  Sec.  219.59-219.60  [Reserved]

[FR Doc. 2018-16114 Filed 7-31-18; 8:45 am]
 BILLING CODE 3510-22-P