[Federal Register Volume 81, Number 113 (Monday, June 13, 2016)]
[Proposed Rules]
[Pages 38516-38567]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-13655]



[[Page 38515]]

Vol. 81

Monday,

No. 113

June 13, 2016

Part VI





Department of Commerce





-----------------------------------------------------------------------





National Oceanic and Atmospheric Administration





-----------------------------------------------------------------------





50 CFR Part 219





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

  Federal Register / Vol. 81 , No. 113 / Monday, June 13, 2016 / 
Proposed Rules  

[[Page 38516]]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

50 CFR Part 219

[Docket No. 151027994-6421-01]
RIN 0648-BF47


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

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

ACTION: Proposed rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: NMFS' Office of Protected Resources has received a request 
from NMFS' Northwest Fisheries Science Center (NWFSC) for authorization 
to take marine mammals incidental to fisheries research conducted in 
the Pacific Ocean off the northwest United States, 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.

DATES: Comments and information must be received no later than July 13, 
2016.

ADDRESSES: You may submit comments on this document, identified by 
NOAA-NMFS-2016-0060, by any of the following methods:
     Electronic submission: Submit all electronic public 
comments via the federal e-Rulemaking Portal. Go to 
www.regulations.gov, enter 0648-BF47 in the ``Search'' box, click the 
``Comment Now!'' icon, complete the required fields, and enter or 
attach your comments.
     Mail: Comments should be addressed 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: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Attachments to electronic comments will be 
accepted in Microsoft Word or Excel or Adobe PDF file formats only. To 
help NMFS process and review comments more efficiently, please use only 
one method to submit comments. All comments received are a part of the 
public record and will generally be posted on www.regulations.gov 
without change. All personal identifying information (e.g., name, 
address) voluntarily submitted by the commenter may be publicly 
accessible. Do not submit confidential business information or 
otherwise sensitive or protected information. NMFS will accept 
anonymous comments (enter N/A in the required fields if you wish to 
remain anonymous).

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

SUPPLEMENTARY INFORMATION: 

Availability

    A copy of NWFSC's application and any supporting documents, as well 
as a list of the references cited in this document, may be obtained by 
visiting the Internet 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, to be issued under the authority of the Marine 
Mammal Protection Act (MMPA) (16 U.S.C. 1361 et seq.), would establish 
a framework for authorizing the take of marine mammals incidental to 
the NWFSC's fisheries research activities in the California Current and 
Pacific Northwest.
    The NWFSC collects a wide array of information necessary to 
evaluate the status of exploited fishery resources and the marine 
environment. NWFSC scientists conduct fishery-independent research 
onboard NOAA-owned and operated vessels or on chartered vessels. A few 
surveys are conducted onboard commercial fishing vessels, but the NWFSC 
designs and executes the studies and funds vessel time.
    We received an application from the NWFSC 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. The regulations would 
be valid from 2016 to 2021. 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, 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 Letters of Authorization. As directed by this legal 
authority, this proposed rule contains mitigation, monitoring, and 
reporting requirements.

Summary of Major Provisions Within the Proposed Rule

    The following provides a summary of some of the major provisions 
within the proposed rulemaking for the NWFSC fisheries research 
activities. We have preliminarily determined that the NWFSC's adherence 
to the proposed mitigation, monitoring, and reporting measures listed 
below would achieve the least practicable adverse impact on the 
affected marine mammals. They include:
     Required monitoring of the sampling areas to detect the 
presence of marine mammals before deployment of certain research gear.
     Required use of acoustic deterrent devices on surface 
trawl nets.
     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

    Paragraphs 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1371 
(a)(5)(A) and (D)) direct 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 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact

[[Page 38517]]

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.''
    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].

Summary of Request

    On August 10, 2015, we received an adequate and complete request 
from NWFSC for authorization to take marine mammals incidental to 
fisheries research activities. We received an initial draft of the 
request on January 2, 2015, followed by a revised draft on April 28, 
2015. On August 28, 2015 (80 FR 52256), we published a notice of 
receipt of NWFSC's application in the Federal Register, requesting 
comments and information related to the NWFSC request for thirty days. 
We received comments jointly from The Humane Society of the United 
States and Whale and Dolphin Conservation, which we considered in 
development of this proposed rule and which are available on the 
Internet at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm.
    NWFSC proposes to conduct fisheries research using trawl gear used 
at various levels in the water column, hook-and-line gears (including 
longlines with multiple hooks, rod and reel, and troll deployments), 
purse seine/tangle net gear, and other gear. If a marine mammal 
interacts with gear deployed by NWFSC, the outcome could potentially be 
Level A harassment, serious injury (i.e., any injury that will likely 
result in mortality), or mortality. Therefore, NWFSC has pooled the 
estimated number of incidents of take that could reasonably result from 
gear interactions, and we have assessed the potential impacts 
accordingly. NWFSC 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 NWFSC research. The proposed 
regulations would be valid for five years from the date of issuance.
    NWFSC requests authorization to take individuals of sixteen species 
by Level A harassment, serious injury, or mortality (hereafter referred 
to as M/SI + Level A) and of 34 species by Level B harassment.

Description of the Specified Activity

Overview

    The NWFSC collects a wide array of information necessary to 
evaluate the status of exploited fishery resources and the marine 
environment. NWFSC scientists conduct fishery-independent research 
onboard NOAA-owned and operated vessels or on chartered vessels. A few 
surveys are conducted onboard commercial fishing vessels, but the NWFSC 
designs and executes the studies and funds vessel time. The NWFSC 
proposes to administer and conduct approximately 36 survey programs 
over the five-year period. The gear types used fall into several 
categories: Towed nets fished at various levels in the water column, 
longline and other hook and line gear, seine nets, traps, and other 
gear. Only use of trawl nets, hook and line gears, and purse seine nets 
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 NWFSC is 
the research arm of NMFS in the northwest region of the United States. 
The NWFSC 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 
Pacific Fishery Management Council and numerous other domestic and 
international fisheries management organizations.

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 NWFSC, 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 NWFSC conducts research in the Pacific Northwest and California 
Current within three research areas: The California Current Research 
Area (CCRA), Puget Sound Research Area (PSRA), and Lower Columbia River 
Research Area (LCRRA). Please see Figures 1-2 through 1-4 in the NWFSC 
application for maps of the three research areas. We note here that, 
while the NWFSC specified geographical region extends outside of the 
U.S. Exclusive Economic Zone (EEZ), from the Mexican EEZ (not including 
Mexican territorial waters) north into the Canadian EEZ (not including 
Canadian territorial waters), the MMPA's authority does not extend into 
foreign territorial waters. In addition to general knowledge and other 
citations contained herein, this section relies upon 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 NWFSC conducts research surveys off the Pacific coast within 
the California Current Large Marine Ecosystem (CCE). This region is 
considered to be of moderately high

[[Page 38518]]

productivity. Sea surface temperature (SST) is fairly consistent, 
ranging from 9-14 [deg]C in winter and 13-15 [deg]C in summer. Major 
biogeographic breaks are found at Point Conception and Cape Mendocino, 
and the region includes major estuaries such as San Francisco Bay, the 
Columbia River, and Puget Sound. The latter two are areas of research 
focus for NWFSC and are described in further detail below. The shelf is 
generally narrow in the CCE, 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 is part of the North Pacific Gyre, 
related to the anticyclonic circulation of the central North Pacific 
and brings cool waters southward. In general, an area of divergence 
parallels the coast of California, with a zone of convergence 200-300 
km from the coastline. The current moves south along the western coast 
of North America, beginning off southern British Columbia and flowing 
southward past Washington, Oregon and California, before ending off 
southern Baja California (Bograd et al., 2010). Extensive seasonal 
upwelling of colder, nutrient-rich subsurface waters is predominant in 
the area south of Cape Mendocino and supports large populations of 
whales, seabirds and important fisheries. 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.
    On the shoreward side of the California Current, the California 
Current Front separates cold, low-salinity upwelled waters from the 
warmer, saltier waters close to shore. Offshore frontal filaments 
transport the frontal water across the entire ecosystem. In winter, the 
wind-driven Davidson Current is the dominant nearshore system, and its 
associated front forms along the boundary between inshore subtropical 
waters and colder offshore temperate and subarctic waters. Surface flow 
of the California Current appears to be diverted offshore at Point 
Conception and again at Punta Eugenia, while semi-permanent eddies 
exist south of these headlands.
    NWFSC conducts research programs specific to two major estuaries of 
the CCE: Puget Sound and the Columbia River. Offshore of these 
estuaries, the CCE is affected by the Heceta Bank, which rises to 
within 80 m of the ocean surface and causes coastal eddies, and 
underwater canyons (e.g., Juan de Fuca Canyon), which create upwelling 
conditions driving high biologic productivity. This portion of the 
region is also affected by high amounts of runoff from the Columbia and 
Fraser Rivers (the latter being the largest freshwater input to Puget 
Sound). The river plumes stimulate primary productivity, with the 
Columbia River plume creating a large surface lens of lower-salinity 
water in the spring and summer and the Fraser River plume carrying 
nutrients northwards past Vancouver Island year-round.
    Puget Sound, with more than 8,000 km\2\ of marine waters and 
estuarine environment and a watershed of more than 33,000 km\2\, is one 
of the largest estuaries in the United States and is the only inland 
sea with fjords in the continental United States. Puget Sound is a 
place of great physical and ecological complexity and productivity, 
with many diverse and important habitat types. Kelp beds and eelgrass 
meadows cover almost 1,000 km\2\, while other major habitat types 
include subtidal and intertidal wetlands, mudflats, and sandflats 
(Gustafson et al., 2000). Concentrations of nutrients (i.e., nitrates 
and phosphates) are consistently high throughout most of Puget Sound, 
largely due to the flux of oceanic water into the basin (Harrison et 
al., 1994), with circulation driven by tides, gravity, and freshwater 
influx. 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.
    The Columbia River is the largest in the Pacific Northwest, 
draining a watershed of 671,000 km\2\. The Columbia River estuary 
encompasses more than 325 km\2\ and is one of the largest on the west 
coast. Dams, diking, and dredging have dramatically altered the 
hydrologic processes that historically shaped the wetlands of the lower 
Columbia River. Prior to these alterations, many of the riverine 
islands and much of the floodplain were inundated several times a year, 
typically in December and again in May or June. Operation of dams has 
substantially reduced peak river flows and has nearly eliminated 
flooding in many low-lying areas. Dredging of shipping channels has 
required disposal of massive quantities of sediments, resulting in 
creation of new islands, filling of many former wetlands, and changing 
shoreline sediment types (OWJV, 1994).
    The LCRRA includes the Columbia River from its mouth, west of 
Astoria, OR, to the Bonneville Dam at river mile (RM) 145. Downstream 
of approximately RM 120, the river widens to include a broad floodplain 
and elongated islands that divide the river and form sloughs and side-
channels in the formerly marshy lowlands. The floodplain expands around 
the confluence with the Willamette River (which accounts for 
approximately fifteen percent of Columbia River flow) at RM 101. 
Downstream of approximately RM 35 the channel is dotted with low 
islands of deposited sediments and widens into several broad bays 
(OWJV, 1994).

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 Magnuson-Stevens Fishery 
Conservation and Management Act, the Pacific Salmon Treaty Act, and the 
Endangered Species Act, as well as under treaties with Native American 
tribes inside the EEZ off the Washington Coast.
    Within NMFS, six regional fisheries science centers direct and 
coordinate the collection of scientific information needed to inform 
fisheries management decisions. Each Fisheries Science Center is a 
distinct entity and is the scientific focal point for a particular 
region. NWFSC conducts research and provides scientific advice to 
manage fisheries and conserve protected species along the U.S. west 
coast, including estuaries and freshwater systems of Puget Sound and 
the major rivers in Washington and Oregon. NWFSC provides scientific 
information to support the Pacific Fishery Management Council and other

[[Page 38519]]

domestic and international fisheries management organizations.
    The NWFSC collects a wide array of information necessary to 
evaluate the status of exploited fishery resources and the marine 
environment. NWFSC scientists conduct fishery-independent research 
onboard NOAA-owned and operated vessels or on chartered vessels. A few 
surveys are conducted onboard commercial fishing vessels, but the NWFSC 
designs and executes the studies and funds vessel time. The NWFSC 
proposes to administer and conduct approximately 36 survey programs 
over the five-year period.
    The gear types used fall into several categories: Towed nets fished 
at various levels in the water column, longline and other hook and line 
gear, seine nets, traps, and other gear. Only use of trawl nets, hook 
and line gears, and purse seine nets 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 Bell M. Shimada, Reuben Lasker, 
and assorted other small vessels owned by NWFSC, aboard vessels owned 
and operated by cooperating agencies and institutions, or aboard 
charter vessels.
    In the following discussion, we first summarily describe various 
gear types used by NWFSC and then describe specific fisheries and 
ecosystem research activities conducted by the NWFSC. This is not an 
exhaustive list of gear and/or devices that may be utilized by NWFSC 
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 NWFSC survey activities, are described separately in a subsequent 
section. Please see Appendix A of NWFSC's draft EA for further 
description, pictures, and diagrams of research gear and vessels.
    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.
    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. Commercial trawl vessels 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 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 must be 
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. NWFSC 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.
    NWFSC 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. 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 are towed, one on each side of the 
vessel. NWFSC attaches video camera systems to some beam trawls. The 
trawls are towed along the seafloor at speeds of 1-1.5 kn.
    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.
    A commercial pelagic longline can be over 100 km long and have 
thousands of hooks attached, although longlines used for research 
surveys are shorter. The pelagic longline gear used for NWFSC research 
surveys typically use 500 hooks attached to a mainline less than 2 km 
long, with snap-on gangions less than 1 m long spaced at intervals of 
approximately 3 m. 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). Because pelagic longline gear is not anchored 
to the seafloor, it floats freely in the water and may drift 
considerable distances between the time of deployment and the time of 
retrieval. Bottom longlines used for commercial fishing can be up to 
several miles long, but those used for NWFSC research use shorter lines 
with approximately thirty hooks per line.
    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.
    Other hook and line gear--Hook and line is a general term used for 
a range of fishing methods that employ short fishing lines with hooks 
in one form or another (as opposed to longlines). This gear is similar 
to methods commonly used by recreational fishers and may generally 
include handlines, hand reels, powered reels, rod/pole and line, drop 
lines, and troll lines, all using bait or lures in various ways to 
attract target species. NWFSC uses barbed or barbless circle hooks used 
depending on the needs of the research (i.e., to retain fish

[[Page 38520]]

or release them with minimal injury) and would typically deploy 
multiple lines at once.
    Other nets--NWFSC 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 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, 
CTD, and pitch sensor.
    2. NWFSC 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).
    3. 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 with 1-mm mesh, 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. Plankton 
nets used by NWFSC generally employ 20 to 500-[mu]m mesh.
    4. 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.
    5. 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 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. In shallow areas, sampling protocol 
is adjusted to prevent contact between the bongo nets and the seafloor. 
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.
    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. NWFSC uses both purse seines and beach 
seines. Beach seines 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. The beach seines 
used in NWFSC research are 1.8-2.4 m in depth and 36-45 m in length, 
with mesh sizes of less than 25 mm. 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. The 
NWFSC pole seine is 12 x 2 m, with mesh smaller than 25 mm.
    Purse seines are typically much larger and are deployed from 
vessels. Commercial fishers use purse seines to capture schooling 
pelagic species by encircling the fish and then using a line at the 
bottom that enables the net to be closed like a purse. Commercial purse 
seines may be more than 2,000 m in length and 200 m in depth, varying 
in size according to vessel, mesh size, and target species. The purse 
seines employed by NWFSC are between 150-450 m in length, between 9-27 
m in depth and have mesh sizes ranging from 11-33 mm depending on the 
location in the net.
    Tangle net--Tangle nets are similar to gillnets (i.e., vertical 
panels of netting buoyed with floats at top and weighted at bottom) but 
are typically considered to be more selective and less lethal than 
gillnets, using smaller mesh sizes to allow fish to be caught by nose 
or jaw and thus able to be resuscitated. NWFSC uses a 180 x 12 m tangle 
net with 108-mm mesh.
    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. NWFSC uses fyke traps and sablefish (Anoplopoma fimbria) 
pots.
    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. NWFSC sets fyke traps with 6.4-mm mesh in 
estuarine channels that are approximately 1-5 m wide. NWFSC uses 
conical sablefish pots to catch fish. These pots consist of a conical-
frustum-shaped frame covered in nylon netting with one or more funnel-
shaped entrance tunnels and are 1.2 m in diameter.
    Conductivity, temperature, and depth profilers (CTD)--A CTD 
profiler is the primary research tool for determining chemical and 
physical properties of seawater (see Figure A-22 of NWFSC's EA for a 
photograph). 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

[[Page 38521]]

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.
    Other instruments--NWFSC uses a continuous water pump with a 
thermosalinograph to measure sea surface conductivity and temperature. 
The pump continuously pumps seawater from a depth of 3 m near the bow 
of the research vessel to the thermosalinograph which sends the 
temperature and conductivity data to a shipboard computer. To collect 
physical environmental data in riverine and estuarine habitats, NWFSC 
uses water level and temperature loggers. These devices are placed 
underwater at fixed locations where they continuously record data.
    Video cameras--The NWFSC uses several apparatuses to collect 
underwater videos of benthic habitats and organisms. These include a 
CamPod, a video camera sled, video beam trawls and a remotely operated 
vehicle (ROV). Each apparatus includes a video camera system consisting 
of a digital video camera, lights, and a power source. The CamPod is a 
lightweight, three-legged platform equipped with a video system and 
adequate illumination. The frame holds a 35-mm stills camera system and 
two video cameras--one that provides a forward-looking oblique view and 
a high-resolution video camera that faces downward. Designed primarily 
for making images of the benthic environment, the configuration of the 
device focuses on minimizing its hydrodynamic presence in the field of 
view of the cameras. The CamPod is deployed vertically through the 
water column on a cable and is intended to view one point on the 
bottom.
    A video camera sled consists of a video camera system mounted on a 
metal frame with runners to allow it to move along the benthic 
substrate. A research vessel tows the sled along the seafloor, allowing 
the camera to capture video footage of the benthic environment. NWFSC 
uses a video ROV to capture underwater footage of the benthic 
environment. The ROV is controlled and powered from a surface vessel. 
Electrical power is supplied through an umbilical or tether which also 
has fiber optics which carry video and data signals between the 
operator and the ROV. This enables researchers on the vessel to control 
the ROV's position in the water with joysticks while they view the 
video feed on a monitor.
    Section 1.6 of the NWFSC's application provides a detailed account 
of all surveys planned by NWFSC in the CCRA, PSRA, and LCRRA. We note 
here that active acoustic systems are used for data acquisition 
purposes only within the CCRA. 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. Table 1.1 
of NWFSC's application provides summary information related to these 
surveys. Please see those sections for full details of survey activity 
planned by NWFSC. Here we provide relevant information related to a 
subset of survey programs with potential for marine mammal 
interactions.
    1. Bycatch Reduction Research--Bycatch reduction research programs 
are conducted in the CCRA, from southern Oregon to Canada. This 
intermittent research is conducted aboard chartered commercial fishing 
vessels, involving thirty to ninety days at sea (DAS) from April to 
October, in order to test gear improvements in commercial trawls. 
Specific trawl gear tested varies based on survey objectives and vessel 
chartered. Projected annual effort is approximately forty bottom trawls 
per year (50-1,000 m depth; up to four hour tows), up to sixty midwater 
trawls per year (50-1,000 m depth; average two hour tow), and up to an 
additional sixty bottom trawls per year with a double-rigged shrimp 
trawl (100-300 m depth; thirty to eighty minute tows).
    2. Flatfish Broodstock Collection--In order to collect fish for 
aquaculture development, intermittent surveys are conducted aboard 
charter fishing vessels or small NOAA vessels. These surveys use 
commercial bottom trawls and hook and line and are conducted in Puget 
Sound and along the Washington coast for approximately twenty DAS. The 
hook and line portion involves approximately eighteen trips per year 
with up to twelve lines in the water at once, using barbed circle 
hooks. Total hook-hours are dependent on target species and catch per 
unit effort (CPUE). Trawls (6-24 per year) are deployed for 
approximately ten minutes each at depths greater than 10 m.
    3. Groundfish Bottom Trawl Survey--This survey is conducted 
annually from May to October for at least 190 DAS, extending throughout 
the U.S. west coast, and is designed to monitor groundfish distribution 
and biomass. Commercial fishing vessels are used to deploy Aberdeen 
bottom trawls (5 x 15 m mouth opening) for approximately 750 tows per 
year (55-1,280 m depth; fifteen minute tows).
    4. Hake Acoustic Survey/Camera Trawl Research--These surveys are 
conducted annually from March to September (up to 80 DAS) from southern 
California to southeast Alaska, following hake (Merluccius productus) 
distribution in order to measure abundance using active acoustic 
systems and trawl gear. NOAA vessels as well as commercial fishing 
vessels may be used, deploying Aleutian Wing midwater trawls (100 m 
headrope) for 225 trawls per year (30-1,500 m depth; variable tow 
duration) and Poly Nor'Easter bottom trawls (36 m footrope x 27 m 
headrope) for five to ten trawls per year (variable depth and 
duration). Results of the survey inform assessments of several rockfish 
(Sebastes spp.) populations and may be used in assessments of central 
California salmon productivity. It is either conducted on a NOAA ship 
or a charter vessel and requires about 45 survey days. The protocols 
for this survey include underway multi-frequency active acoustic 
devices, modified-Cobb midwater trawls, various plankton tows, and CTD 
profiles at fixed stations. The modified-Cobb trawl is deployed for 
fifteen-minute tows at 2 kn during dark hours at 15-30 m depth.
    5. Juvenile Salmon Pacific Northwest Coastal Survey--This survey 
complements similar surveys conducted by NMFS' Southwest Fisheries 
Science Center (SWFSC), is conducted annually in May, June, and 
September (36 DAS) from Newport, OR, to Cape Flattery, WA, aboard 
commercial fishing vessels, and is designed to assess ocean conditions 
and growth, relative abundance, and survival of juvenile salmon 
(Oncorhynchus spp.). The survey deploys the Nordic 264 surface trawl 
(30 m wide x 20 m deep) for 180 trawls per year (surface to 30 m depth; 
thirty minute tow).
    6. Marine Fish Broodstock Collection, Sampling, and Tagging--This 
variable research program occurs annually for approximately ten DAS 
aboard charter fishing vessels along the Washington coast. In order to 
collect fish, commercial bottom trawls (ten trawls per year; 50-1,000 m 
depth, up to four hour tow duration), pelagic longline, and hook and 
line gear are used. Approximately thirty longline sets per year, using 
five hundred barbed circle hooks per set, are set at approximately 215-
915 m depth (mainline length 1,370-1,830 m; soak time approximately 
three hours). Hook and line effort involves eight lines with barbed 
circle hooks deployed for six-hour fishing days for a total of ninety 
hours or 720 hook-hours per year.

[[Page 38522]]

    7. Northern Juvenile Rockfish Survey--This survey complements 
similar surveys conducted by SWFSC, is conducted annually from May to 
June from Cape Mendocino, CA, to Cape Flattery, WA, for fifteen to 
thirty DAS, and targets the pelagic phase of juvenile rockfish using a 
modified Cobb midwater trawl net (26 m headrope; 12 x 12 m opening). It 
is typically conducted on a charter vessel, with approximately one 
hundred trawls per year (fifteen-minute tows at night; 15-30 m depth).
    8. Video Beam Trawl Collaborative Research--This survey is 
conducted monthly along the continental shelf from Oregon to Washington 
aboard partner research vessels or chartered commercial vessels. The 
survey uses a 2-m beam trawl system with open codend outfitted with a 
digital video camera to assess the seasonal and interannual 
distribution of young-of-the-year groundfishes and the potential 
impacts of hypoxia and requires twenty DAS annually with twenty to 
forty trawl deployments of ten minutes each.
    9. Coastwide Groundfish Hook and Line Survey in Untrawlable 
Habitat--This survey to monitor groundfish distribution and abundance 
along the U.S. west coast is conducted annually from May to October 
aboard charter sportfishing vessels (250 DAS). Hook and line gear is 
deployed by rod and reel, with approximately 1,000 sites visited 
annually. At each site, each of three anglers deploys a line with five 
hooks for a five-minute soak and repeats this five times. Therefore, 75 
total hooks are deployed per site for five minutes each, yielding an 
annual total of 6,250 hook-hours.
    10. Near Coastal Ocean Purse Seining--This study of salmon habitat 
use is conducted monthly from May to September nearshore near the mouth 
of the Columbia River aboard chartered commercial vessels (12 DAS). 
Purse seines (228 x 18 m or 305 x 12 m) are deployed for 75 sets per 
year, with generally less than one hour set duration.
    11. Beam Trawl Survey to Evaluate Effects of Hypoxia--Conducted 
only in Puget Sound, with twenty DAS in summer and fall, this survey is 
designed to examine effects of hypoxia on demersal fish in Hood Canal. 
A 2-m beam trawl, primarily with open codend and outfitted with a video 
camera, is deployed for one tow per each of ten sites per season for a 
total of twenty tows (each tow at varying depths [30, 60, 90 m]; ten 
minute duration).
    12. Marine Fish Collections Including Flatfish--This survey, 
conducted only in Puget Sound aboard charter vessels with variable 
monthly effort (fifteen DAS), utilizes commercial bottom trawls. Annual 
effort is forty trawls at 50-1,000 m depth and tow duration is up to 
four hours.
    13. Movement Studies of Puget Sound Species--These surveys occur in 
Puget Sound aboard a variety of small boats, with year-round sampling 
totaling 25 DAS. Survey effort involves commercial bottom trawls 
(twelve tows per year at greater than 10 m depth and for ten minutes), 
hook and line (twenty trips per year with up to twelve barbless hooks 
in the water at once), and bottom longline (180-m mainline deployed to 
approximately 60 m depth). The latter involves three sets per year with 
thirty 16/0 circle hooks per set.
    14. Puget Sound Marine Pelagic Food Web--These surveys occur in 
Puget Sound only about every five years from April to October aboard 
charter vessels and totaling thirty DAS when it occurs. The survey 
deploys a Kodiak surface trawl (3.1 x 6.1 m) for five hundred tows of 
ten minute duration and depths greater than 10 m.
    15. Skagit Bay Juvenile Salmon Survey--This survey occurs in Puget 
Sound aboard chartered vessels annually from April to September for 
thirty DAS and uses the same Kodiak surface trawl with the same 
protocols as the Puget Sound marine pelagic food web survey (180 tows 
per year).
    16. Elwha Dam Removal--This Puget Sound study of the effects of dam 
removal on nearshore fish species includes use of a beach seine (43 x 
1.8 m). The survey is conducted monthly using a small vessel, totaling 
20 DAS and up to 140 samples per year (less than ten minutes per 
sample). Separate studies (``Snohomish Juvenile Salmon Studies'' [up to 
200 sets annually during 50 DAS; conducted monthly and twice-monthly 
from February to September] and ``Puget Sound Salmon Contaminant 
Study'' [up to 100 sets annually during 30 DAS from May to July]) use 
similar beach seines in similar ways. Additional surveys in the 
Columbia River (``Estuary Tidal Habitats'' [up to 100 sets annually 
during 25 DAS, quarterly to monthly] and ``LCR Ecosystem Monitoring'' 
[up to 200 sets annually during 16 DAS, monthly from February to 
December]) also use beach seines similarly.
    17. Rockfish Genetics--Hook and line fishing gear is used to 
capture bottomfish for biological sampling. Conducted in Puget Sound 
aboard charter boats from April to November (35-41 DAS), this survey 
uses baited hooks or bottom jigs for approximately 750 hook-hours per 
year.
    18. Marine Fish Research Including Broodstock Collection, Sampling, 
and Tagging--This research involves pelagic longline and hook and line 
survey effort conducted in Puget Sound aboard charter vessels for 
approximately 15 DAS with effort varying monthly. The gear 
specifications and effort are similar to those described previously 
(for pelagic longline and hook and line only) for marine fish 
broodstock collection in the California Current.
    19. Eulachon Arrival Timing--This survey uses a modified Cobb 
midwater trawl net 26-m headrope; 12 x 12 m opening) in the Columbia 
River estuary and plume to determine the arrival timing and 
distribution of spawning eulachon. The survey is conducted from January 
to March (15 DAS) aboard NOAA vessels, with sixty trawls per year 
(fifteen-minute tow duration at 30-40 m depth).
    20. Pair Trawl Juvenile Salmon Survey--This trawl survey is 
conducted in the Columbia River between approximately RM 40-50 from 
March to August (80 DAS) aboard small vessels. A surface pair trawl 
(wings 92 x 92 m; trawl body 9 m wide x 6 m deep x 18 m long) modified 
with an open codend (2.4 x 3 m opening) is towed near the surface for 
eight to fifteen hours per trawl, totaling 800-1,200 tow-hours per 
year. The trawl is outfitted with a flow-through Passive Integrated 
Transponder (PIT) tag detector to assess passage of tagged juvenile 
salmon.
    21. Benefits of Wetland Restoration to Juvenile Salmon--This study, 
occurring throughout the LCRRA, uses purse seines (150 x 9 m), beach 
seines (46 x 1.8 m), and surface trawls (3 x 6 m opening) to study 
salmon habitat use. The surveys are typically conducted aboard small 
research vessels and/or skiffs, with purse seine effort occurring for 
32 DAS bi-weekly from March to October (ninety sets per year; typically 
less than one hour set duration) and beach seines and surface trawls 
(fifteen minute tows) occurring quarterly from March to December. The 
latter portion is conducted for 16 DAS, at two sites per day with two 
to three hauls of each type per site.
    22. Migratory Behavior of Adult Salmon--This LCRRA survey uses 
tangle nets to catch and tag fish. Tangle nets (180 x 12 m) are 
deployed from commercial fishing vessels for 32 DAS from spring to 
fall, with up to 75 sets per year deployed for 25-45 minutes each.
    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

[[Page 38523]]

inasmuch as the information is relevant to NWFSC'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 NWFSC.
    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 hertz (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 decibel (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 duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy contained within a pulse, and considers 
both intensity and duration of exposure. For a single pulse, the 
numerical value of the SEL measurement is usually 5-15 dB lower than 
the rms sound pressure in dB re 1 [mu]Pa, with the comparative 
difference between measurements of rms and SEL measurements often 
tending to decrease with increasing range (Greene, 1997; McCauley et 
al., 1998). Peak sound pressure 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 (p-p), 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. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and the sound level 
of a region is defined by the total acoustical energy being generated 
by known and unknown sources. These sources may include physical (e.g., 
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 the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient sound for frequencies between 200 Hz and 50 
kHz (Mitson, 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf sound becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions.
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total sound at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times.
     Biological: 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.
     Anthropogenic: Sources of ambient sound related to human 
activity include transportation (surface vessels), dredging and 
construction, oil and gas drilling and production, seismic surveys, 
sonar, explosions, and ocean acoustic studies. 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. Sound from identifiable anthropogenic sources other than the 
activity of interest (e.g., a passing vessel) is sometimes termed 
background sound, as opposed to ambient sound.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the source levels (as 
determined by current weather conditions and levels of biological and 
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 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.
    Pulsed sound sources (e.g., explosions, gunshots, sonic booms,

[[Page 38524]]

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 non-continuous (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 (such as 
those used by the U.S. Navy). 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 (see Table 1) to determine 
when an activity that produces sound might result in impacts to a 
marine mammal such that a take by 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 lacking and we consider these thresholds as step 
functions. NMFS is currently revising these acoustic guidelines; for 
more information on that process, please visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. NMFS has determined that the 160-dB threshold 
for impulsive sources is most appropriate for use in considering the 
potential effects of the NWFSC's activities.

               Table 1--Current Acoustic Exposure Criteria
------------------------------------------------------------------------
           Criterion                 Definition           Threshold
------------------------------------------------------------------------
Level A harassment (underwater)  Injury (PTS--any   180 dB (cetaceans)/
                                  level above that   190 dB (pinnipeds)
                                  which is known     (rms).
                                  to cause TTS).
Level B harassment (underwater)  Behavioral         160 dB (impulsive
                                  disruption.        source)/120 dB
                                                     (continuous source)
                                                     (rms).
------------------------------------------------------------------------

    A wide range of active acoustic devices are used in NWFSC 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. NWFSC 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. NWFSC 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, 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 recent studies (Deng et al., 2014; Hastie et 
al., 2014) demonstrating some behavioral reaction by marine mammals to 
acoustic signals at frequencies above 180 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' 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 
the threshold for behavioral 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

[[Page 38525]]

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 and are 
not considered further in this document.
    Category 2 acoustic sources, which are present on most NWFSC 
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 NWFSC. 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 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. Characteristics of 
these sources are summarized in Table 2.
    (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 NWFSC 
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. The NWFSC 
operates the Simrad EK60 system, which typically transmits and receives 
at four frequencies ranging from 38-200 kHz.
    (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. The NWFSC operates the Simrad 
ME70 system, which is mounted to the hull of the research vessel and 
emits frequencies in the 70-120 kHz range.
    (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. NWFSC operates the Simrad SX90 
system.
    (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

[[Page 38526]]

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. NWFSC 
uses the Simrad ITI Catch Monitoring System, which allows monitoring of 
the exact position of the gear and of what is happening in and around 
the trawl, and the Simrad FS70 Third Wire Net Sonde, which allows 
monitoring of the trawl opening.

                                           Table 2--Operating Characteristics of NWFSC Active Acoustic Sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                       Operating
      Active acoustic system          frequencies    Maximum source level    Single ping duration (ms) and        Orientation/        Nominal beamwidth
                                         (kHz)                                   repetition rate (Hz)            directionality
--------------------------------------------------------------------------------------------------------------------------------------------------------
Simrad EK60 narrow beam               38, 70, 120,  224 dB...............  1 ms at 1 Hz....................  Downward looking.....  11[deg].
 echosounder.                                  200
Simrad ME70 multibeam echosounder.          70-120  205 dB...............  2 ms at 1 Hz....................  Downward looking.....  140[deg].
Simrad SX90 omnidirectional                 70-120  206 dB...............  2 ms at 1 Hz....................  Downward               0[deg]-90[deg] tilt
 multibeam sonar.                                                                                             omnidirectional.       angle from vertical
                                                                                                                                     (average).
Teledyne RD Instruments ADCP,                   75  224 dB...............  External trigger................  Downward looking       40[deg] x 100[deg].
 Ocean Surveyor.                                                                                              (30[deg] tilt).
Simrad ITI Trawl Monitoring System           27-33  <200 dB..............  0.05-0.5 Hz.....................  Downward looking.....  40[deg] x 100[deg].
Simrad FS70 trawl sonar...........             330  216..................  1 ms at 120 kHz.................  Third wire trawl       40[deg].
                                                                                                              sonar for monitoring
                                                                                                              net opening and
                                                                                                              fishing conditions.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Proposed Mitigation

    In order to issue an incidental take authorization 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 subsistence uses.'' Note that taxonomic information for 
certain species mentioned in this section is provided in the following 
section (``Description of Marine Mammals in the Area of the Specified 
Activity'').
    The NWFSC 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 NWFSC 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 
trawl gear, as well as use of a marine mammal excluder device (MMED) in 
Nordic 264 midwater trawls.

Development of Mitigation Measures

    In survey year 2008 in the CCE, NMFS' SWFSC had dramatically more 
incidental takes of marine mammals in research gear, in terms of both 
interactions and animals captured, than in any other year. The SWFSC 
had previously conducted over a thousand midwater trawl survey tows 
over more than 25 years, with very few incidents of marine mammal 
interactions (Hewitt, 2009), but the number of incidental takes in 2008 
exceeded the aggregate total over all preceding years. Following the 
first SWFSC survey cruise in April 2008, during which a number of 
marine mammals were captured in trawl gear, the SWFSC convened a 
workshop involving SWFSC staff with expertise in survey design and 
operations and marine mammal bycatch mitigation (Hewitt, 2009). 
Participants worked to determine appropriate mitigation measures and to 
consider changes to sampling protocols in an effort to reduce marine 
mammal interactions.
    The SWFSC also allocated resources towards the design, 
construction, and testing of a MMED that could be incorporated into the 
Nordic 264 trawl net, use of which had resulted in a large portion of 
takes. In 2009, the MMED was tested and use of the device added to 
SWFSC standard survey protocol for the Nordic 264 net (Dotson et al., 
2010).
    These efforts resulted in the consideration of many potential 
mitigation measures for all NMFS Science Centers, including those the 
NWFSC has determined to be feasible and relevant to their operations. 
These measures include the move-on rule, protected species visual 
watches and use of acoustic pingers on certain trawl gear, as well as 
use of the MMED in Nordic 264 trawls.

General Measures

    Coordination and communication--When NWFSC 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 NWFSC 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 NWFSC survey effort is conducted aboard 
cooperative platforms (i.e., non-NOAA vessels), ultimate responsibility 
and decision authority again rests with non-NWFSC 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 NWFSC survey effort is composed, in part or whole, of 
NWFSC staff and is led by a Chief Scientist (CS). Therefore, because 
the NWFSC--not OMAO or any other entity that may have authority over 
survey platforms used by NWFSC--is the applicant to whom any incidental 
take authorization issued under the authority of these proposed 
regulations would be issued, we require that the NWFSC take all 
necessary measures to

[[Page 38527]]

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. NWFSC 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.
    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). At any time during a survey or in transit, if a crew member 
standing watch or dedicated marine mammal observer 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 NWFSC 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 NWFSC 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--The NWFSC will implement a number of handling 
protocols to 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. Because incidental take of marine mammals in fishing 
gear is similar for commercial fisheries and research surveys, NWFSC 
proposes to adopt these protocols, which are expected to increase post-
release survival. 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. NWFSC 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.

Trawl Survey Visual Monitoring and Operational Protocols

    Specific mitigation protocols are required for all trawl operations 
conducted by the NWFSC using Nordic 264 surface trawl gear, midwater 
trawl gear (modified Cobb, Aleutian Wing, and various commercial nets), 
and bottom trawl gear (double-rigged shrimp, Poly Nor'easter, modified 
Aberdeen, beam, and various commercial nets). Separate protocols 
(described below) are in place for the Kodiak surface trawl and pair 
trawl gear. Marine mammal watches will be conducted for at least ten 
minutes prior to the beginning of the planned set and throughout the 
tow and net retrieval, by scanning the surrounding waters with the 
naked eye and rangefinding binoculars (or monocular). 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. The CS must confirm with the OOD that no marine mammals have 
been seen within 500 m (or as far as may be observed if less than 500 
m) of the ship or appear to be approaching the ship during the pre-set 
watch period prior to the deployment of any trawl gear. During 
nighttime operations, visual observation may be conducted using the 
naked eye and available vessel lighting but effectiveness is limited. 
The visual observation period typically occurs during transit leading 
up to arrival at the sampling station, rather than upon arrival on 
station. However, in some cases it may be necessary to conduct a 
plankton tow or other small net cast prior to deploying trawl gear. In 
these cases, the visual watch will continue until trawl gear is ready 
to be deployed. Aside from pre-trawl monitoring, the OOD/CS and crew 
standing watch will visually scan for marine mammals during all daytime 
operations.
    It is important to note that the 500 m distance is provided only as 
a frame of reference for marine mammal observations that would 
nominally be of greater concern as regards the potential for 
interaction with research fishing gear. The primary concern is to avoid 
all marine mammal interactions (regardless of the numbers of takes 
proposed for authorization here), and the most appropriate course of 
action to achieve this goal in any given instance is likely to be 
related more to event-specific elements than to an arbitrary distance 
from the vessel. Depending on unpredictable contextual elements, 
animals sighted at distances greater than 500 m could provoke 
mitigation action or, conversely, animals sighted at closer range could 
be determined to not be at risk of interacting with research fishing 
gear. The NWFSC considers 500 m to be the average effective observation 
distance, but the actual effective range is determined by numerous 
factors related to the weather, ship observations, and the species 
observed.
    The primary purpose of conducting pre-trawl visual monitoring is to 
implement the move-on rule. If marine mammals are sighted within 500 m 
(or as far as may be observed if less than 500 m) of the vessel 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, NWFSC may elect to either remain onsite to see if the 
animals move off or may move on to another sampling location. When 
remaining onsite, the set is delayed (typically for at least ten 
minutes) and, if the animals depart or appear to no longer be at risk 
of interacting with the vessel or gear, a further ten minute 
observation period is 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,

[[Page 38528]]

move-on rule mitigation protocols would begin anew. If, after moving 
on, marine mammals remain at risk of interaction, the CS or watch 
leader may decide to move again or to skip the station. Marine mammals 
that are sighted further than 500 m from the vessel would be monitored 
to determine their position and movement in relation to the vessel. If 
they appear to be closing on the vessel, the move-on rule protocols may 
be implemented even if they are initially further than 500 m from the 
vessel.
    For surface trawl surveys (i.e., those surveys deploying the Nordic 
264 net), which have historically presented the greatest risk of marine 
mammal interaction, dedicated crew are assigned to marine mammal 
monitoring duty (i.e., have no other tasks) and care is taken to 
provide some rest periods for observers to avoid fatigue. At least two 
pairs of binoculars are available for verification of potential 
sightings. As the vessel approaches the station, the OOD and at least 
one assigned member of the scientific party monitor for marine mammals. 
Within several minutes of arriving on station and finishing their 
sampling duties, two additional members of the scientific party are 
assigned to monitor for marine mammals and, for the remainder of the 
tow, there would be a minimum of three members of the scientific party 
watching for marine mammals. Depending on the situational context 
(e.g., numbers of marine mammals seen during the station approach or 
expected at that particular place and season), additional crew may be 
assigned to stand watch as necessary to provide full monitoring 
coverage around the vessel. Up to eight observers in total (including 
ship's crew standing watch) may be on duty during active trawling. The 
focus on the full area around the ship continues until trawl retrieval 
begins, at which point observational focus turns to the stern and the 
trawl net itself.
    For midwater and bottom trawl surveys, the pre-set watch period is 
conducted by the OOD and bridge crew and typically occurs during 
transit prior to arrival at the sampling station, but may also include 
time on station if other types of gear or equipment (e.g., bongo nets) 
are deployed before the trawl. For these trawls, risk of interaction 
during the tow is lower and monitoring effort is reduced to the bridge 
crew until trawl retrieval.
    For all surveys, although the minimum pre-set watch period is ten 
minutes, the actual monitoring period is typically longer. During 
standard trawl operations, at least some of the trackline to be towed 
is typically traversed prior to setting gear in order to check for 
hazards. On surface trawl surveys, CTD casts and plankton/bongo net 
hauls are made prior to setting the trawl. These activities can take 
25-35 minutes after the vessel arrives on station, depending on water 
depth, and monitoring for marine mammals continues throughout these 
activities. Midwater trawls and bottom trawls do not typically deploy 
other gears before deploying trawl gear but reconnaissance of the 
trackline often takes ten to fifteen minutes after arriving on station. 
In addition, once the decision is made to deploy the trawl gear, 
monitoring continues while the net is unspooled, which may take about 
ten minutes. Before the trawl doors are deployed, the net floats closed 
on the surface behind the vessel, and appropriate actions can be taken 
if marine mammals are sighted near the ship. Therefore, the marine 
mammal monitoring period--which begins before the vessel arrives on 
station and extends continuously through gear deployment--typically 
extends for over thirty minutes for all trawl types.
    The effectiveness of visual monitoring may be limited depending on 
weather and lighting conditions. The OOD, CS or watch leader will 
determine the best strategy to avoid potential takes of marine mammals 
based on the species encountered and their numbers and behavior, 
position, and vector relative to the vessel, as well as any other 
factors. For example, a whale transiting through the sampling area in 
the distance may only require a short move from the designated station, 
whereas a pod of dolphins in close proximity to the vessel may require 
a longer move from the station or possibly cancellation of the planned 
tow if the group follows the vessel.
    In general, trawl operations will be conducted immediately upon 
arrival on station (and on conclusion of the pre-watch period) in order 
to minimize the time during which marine mammals (particularly 
pinnipeds) may become attracted to the vessel. However, in some cases 
it will be necessary to conduct small net tows (e.g., bongo net) prior 
to deploying trawl gear.
    Once the trawl net is in the water, the OOD, CS, and/or crew 
standing watch will continue to visually monitor the surrounding waters 
and will maintain a lookout for marine mammal presence as far away as 
environmental conditions allow. If marine mammals are sighted before 
the gear is fully retrieved, the most appropriate response to avoid 
marine mammal interaction will be determined by the professional 
judgment of the CS, watch leader, OOD and other experienced crew as 
necessary. This judgment will be based on past experience operating 
trawl gears around marine mammals (i.e., best professional judgment) 
and on NWFSC training sessions that will facilitate dissemination of 
expertise operating in these situations (e.g., factors that contribute 
to marine mammal gear interactions and those that aid in successfully 
avoiding such events). Best professional judgment takes into 
consideration the species, numbers, and behavior of the animals, the 
status of the trawl net operation (e.g., 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. 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 
consider 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 NWFSC 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 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 tow durations of not more than thirty 
minutes at the target depth will typically be implemented, excluding 
deployment and retrieval time (which may require an additional thirty 
minutes, depending on target depth), to reduce the likelihood of 
attracting and incidentally taking marine mammals. Short tow durations 
decrease the opportunity for marine mammals to find the vessel and 
investigate. Trawl tow distances will be less than 3 nm--typically 1-2 
nm, depending on the specific survey and trawl speed--which is expected 
to reduce the likelihood of attracting and incidentally taking marine 
mammals. In addition, care will be taken when

[[Page 38529]]

emptying the trawl to avoid damage to marine mammals that may be caught 
in the gear but are not visible upon retrieval. The gear will be 
emptied as quickly as possible after retrieval in order to determine 
whether or not marine mammals are present. The vessel's crew will clean 
trawl nets prior to deployment to remove prey items that might attract 
marine mammals. Catch volumes are typically small with every attempt 
made to collect all organisms caught in the trawl.
    Marine mammal excluder device--Excluder devices are specialized 
modifications, typically used in trawl nets, which are designed to 
reduce bycatch by allowing non-target taxa to escape the net. These 
devices generally consist of a grid of bars fitted into the net that 
allow target species to pass through the bars into the codend while 
larger, unwanted taxa (e.g., turtles, sharks, mammals) strike the bars 
and are ejected through an opening in the net. Marine turtle bycatch in 
the commercial shrimp trawl industry led to the development of turtle 
excluder devices (TED) (e.g., Mitchell et al., 1995) in the 1970s. TEDs 
are perhaps the most commonly used excluder devices, but devices 
designed specifically for the exclusion of marine mammals have also 
been developed for various fisheries around the world where marine 
mammal interactions are problematic (e.g., Gibson and Isakssen, 1998; 
Northridge, 2003).
    Similar to TEDs, MMEDs generally consist of a large aluminum grate 
positioned in the intermediate portion of the net forward of the codend 
and below an escape opening constructed into the upper net panel above 
the grate. These devices enable target species to pass through a grid 
or mesh barrier and into the codend while preventing the passage of 
marine mammals, which are ejected out through an escape opening or swim 
back out of the mouth of the net. The angled aluminum grate is intended 
to guide marine mammals through the escape opening. For full details of 
design and testing of the MMED designed by the SWFSC for the Nordic 264 
net, please see Dotson et al. (2010).
    MMEDs have not been proven to be fully effective at preventing 
marine mammal capture in trawl nets (e.g., Chilvers, 2008) and are not 
expected to prevent marine mammal capture in NWFSC trawl surveys. It is 
difficult to effectively test such devices, in terms of effectiveness 
in excluding marine mammals as opposed to effects on target species 
catchability, because realistic field trials would necessarily involve 
marine mammal interactions with trawl nets. Use of artificial 
surrogates in field trials has not been shown to be a realistic 
substitute (Gibson and Isakssen, 1998). Nevertheless, we believe it 
reasonable to assume that use of MMEDs may reduce the likelihood of a 
given marine mammal interaction with trawl gear resulting in mortality. 
We do not infer causality, but note that annual marine mammal 
interactions with the Nordic 264 trawl net have been much reduced for 
the SWFSC (relative to 2008) since use of the MMED began.
    Multiple types of midwater trawl nets are used in NWFSC trawl 
surveys. The Nordic 264 trawl net, used as a surface trawl by NWFSC, is 
generally much larger than the midwater trawls, is fished at faster 
speeds, and has a different shape and functionality than these nets. 
Very few marine mammal interactions with NWFSC pelagic trawl gear have 
involved nets other than the Nordic 264 (one of 37 total incidents 
since 1999; Table 4). Therefore, MMED use is not proposed for nets 
other than the Nordic 264.
    The NWFSC has tested the MMED design used by the SWFSC and found 
that it caused a significant loss of some salmon species that were the 
target of their research. More recent experiments have used video 
cameras attached to the net opening and near the excluder device to 
test different configurations of the excluder device to minimize loss 
of target species. The experiments have looked at adding weight and 
stiffeners to the flap covering the escape hatch to keep it closed and 
flipping the MMED so the escape hatch faces down rather than up. Based 
on preliminary results, this downward-pointing escape hatch appears to 
be the best design for minimizing loss of target species. Additional 
research will be necessary to calibrate catch levels in tows with the 
excluder device compared to past tows that did not contain the excluder 
(i.e., to align the new catchability rates with historical data sets). 
During these configuration and calibration experiments some nets will 
be fished without the MMED in order to provide controls for 
catchability. Once the NWFSC completes these experiments the MMED will 
be used in all future trawls with the Nordic 264. Please see ``Proposed 
Monitoring and Reporting'' for additional discussion.
    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 (which are historically one of the most frequently captured 
species in NWFSC surveys; see Table 4) 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.

[[Page 38530]]

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., 2015a) 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 NWFSC trawl gear.
    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 NWFSC 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.'' NWFSC use of pingers as 
a deterrent device, which may cause Level B harassment of marine 
mammals, is intended solely for the avoidance of potential marine 
mammal interactions with NWFSC 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 NWFSC use of pingers is not discussed further in this document.
    Pingers will be deployed during all surface trawl operations (i.e., 
using the Nordic 264 net), with two pairs of pingers installed near the 
net opening. The vessel's crew will ensure that pingers are operational 
prior to deployment. Pinger brands typically used by NWFSC include the 
Aquatec Subsea Limited model AQUAmark and Fumunda Marine models F10 and 
F70, with the following attributes: (1) Operational depth of 10-200 m; 
(2) tones range from 200-400 ms in duration, repeated every five to six 
seconds; (3) variable frequency of 10-160 kHz; and (4) maximum source 
level of 145 dB rms re 1 [mu]Pa. Please see ``Marine Mammal Hearing'' 
below for reference to functional and best hearing ranges for marine 
mammals present in the CCE.
    Kodiak surface trawl and pair trawl gear--The Kodiak surface trawl, 
used only in Puget Sound, has only limited potential for marine mammal 
interaction. This gear type is a small net towed at slow speeds (about 
2 kn) as close to shore as the net can be fished, and these 
characteristics mean that marine mammals would likely be able to avoid 
the net or swim out of it if necessary. However, rules for cetaceans 
would be similar as for other net types (i.e., delay and/or move-on if 
cetaceans observed within approximately 500 m or clearly approaching 
from greater distance). If killer whales are observed at any distance, 
the net would not be deployed and the move-on rule invoked.
    The pair trawl is used only in the Columbia River, and is fished 
with an open codend. Although unlikely, there is some potential for 
pinnipeds to become entangled in the net material. NWFSC's practice, 
which would be allowed under section 109(h) of the MMPA, is to deter 
pinnipeds from encountering the net using pyrotechnic devices and other 
measures. Therefore, separate mitigation is not warranted, and we do 
not discuss NWFSC deterrence of pinnipeds associated with pair trawl 
surveys further in this document. Please see the NWFSC's draft 
Programmatic Environmental Assessment for further information about 
this practice.

Longline and Other Hook and Line 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 during the thirty-minute 
period prior to arrival on station; (2) implement the move-on rule if 
marine mammals are observed within the area around the vessel and maybe 
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. If killer whales are 
observed at any distance, the set would not occur and the move-on rule 
would be invoked.
    Other types of hook and line surveys (e.g., rod and reel) generally 
use the same protocols as longline surveys.

[[Page 38531]]

However, for hook and line surveys in Puget Sound the move-on rule is 
not required for pinnipeds because they are commonly abundant on shore 
nearby hook and line sampling locations. Use of the move-on rule in 
these circumstances would represent an impracticable impact on NWFSC 
survey operations, and we note that no marine mammals have ever been 
captured in NWFSC hook and line surveys (Table 4). However, the NWFSC 
would implement the move-on rule for hook and line surveys in Puget 
Sound for any cetaceans that are within 500 m and may be at risk of 
interaction with the survey operation. If killer whales are observed at 
any distance, fishing would not occur.
    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. NWFSC longline protocols specifically 
prohibit chumming (releasing additional bait to attract target species 
to the gear) and spent bait and offal is retained on the vessel until 
all gear has been retrieved. Some hook and line surveys use barbless 
hooks, which are less likely to injure a hooked animal.

Seine Survey Visual Monitoring and Operational Protocols

    Visual monitoring and operational protocols for seine 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. 
For purse seine operations, visual monitoring is focused on avoidance 
of cetaceans and aggregations of pinnipeds. Individual or small numbers 
of pinnipeds may be attracted to purse seine operations, especially in 
Puget Sound, and are frequently observed to enter operational purse 
seines to depredate the catch and exit the net unharmed. Use of the 
move-on rule in these circumstances would represent an impracticable 
impact on NWFSC survey operations, and we note that no marine mammals 
have ever been captured in NWFSC seine surveys (Table 4).
    If pinnipeds are in the immediate vicinity of a purse seine survey, 
the set may be delayed until animals move away or the move-on rule is 
determined to be appropriate, but the net would not be opened if 
already deployed and pinnipeds enter it. However, delay would not be 
invoked if only few pinnipeds are present (e.g., less than five), and 
they do not appear to obviously be at risk.
    If any dolphins or porpoises are observed within approximately 500 
m of the purse seine survey location, the set would be delayed. If any 
dolphins or porpoises are observed in the net, the net would be 
immediately opened to free the animals. If killer whales or other large 
whales are observed at any distance the net would not be set, and the 
move-on rule would be invoked.
    Beach seines are typically set nearshore by small boat crews, who 
visually survey the area prior to the set. The set would not be made 
within 200 m of any hauled pinnipeds. Otherwise, marine mammals are 
unlikely to be at risk of interaction with NWFSC beach seine 
operations, as the nets are relatively small and deployed and retrieved 
slowly. If a marine mammal is observed attempting to interact with the 
beach seine gear, the gear would immediately be lifted and removed from 
the water.
    Tangle net protocols--Tangle nets are used only in the Columbia 
River. NWFSC attempts to avoid pinnipeds by rotating sampling locations 
on a daily basis and by avoiding fishing near haulout areas. However, 
as was described for NWFSC use of pair trawl gear in the LCRRA, NWFSC 
also deters pinnipeds from interacting with tangle net gear as 
necessary using pyrotechnic devices and visual presence, a practice 
allowed under section 109(h) of the MMPA. Therefore, we do not discuss 
NWFSC deterrence of pinnipeds associated with tangle net surveys 
further in this document. Please see the NWFSC's draft Programmatic 
Environmental Assessment for further information about this practice. 
If pinniped presence in the vicinity of tangle net surveys is so 
abundant as to be uncontrollable through deterrence, sampling would be 
discontinued for a given day.
    We have carefully evaluated the NWFSC'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. Our evaluation of potential measures included 
consideration of the following factors in relation to one another: (1) 
The manner in which, and the degree to which, the successful 
implementation of the measure is expected to minimize adverse impacts 
to marine mammals, (2) the proven or likely efficacy of the specific 
measure to minimize adverse impacts as planned; and (3) the 
practicability of the measure for applicant implementation.
    Any mitigation measure(s) we prescribe should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    (1) Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    (2) A reduction in the number (total number or number at 
biologically important time or location) of individual marine mammals 
exposed to stimuli expected to result in incidental take (this goal may 
contribute to 1, above, or to reducing takes by behavioral harassment 
only).
    (3) A reduction in the number (total number or number at a 
biologically important time or location) of times any individual marine 
mammal would be exposed to stimuli expected to result in incidental 
take (this goal may contribute to 1, above, or to reducing takes by 
behavioral harassment only).
    (4) A reduction in the intensity of exposure to stimuli expected to 
result in incidental take (this goal may contribute to 1, above, or to 
reducing the severity of behavioral harassment only).
    (5) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying particular attention to the prey base, blockage or 
limitation of passage to or from biologically important areas, 
permanent destruction of habitat, or temporary disturbance of habitat 
during a biologically important time.
    (6) For monitoring directly related to mitigation, an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of the NWFSC's proposed measures, as well 
as other measures we considered, 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.

Description of Marine Mammals in the Area of the Specified Activity

    We have reviewed NWFSC's species descriptions--which summarize 
available information regarding status and trends, distribution and 
habitat preferences, behavior and life history, and auditory 
capabilities of the

[[Page 38532]]

potentially affected species--for accuracy and completeness and refer 
the reader to Sections 3 and 4 of NWFSC's application, as well as to 
NMFS' Stock Assessment Reports (SARs; www.nmfs.noaa.gov/pr/sars/), 
instead of reprinting the information here. Table 3 lists all species 
with expected potential for occurrence in the specified geographical 
region where NWFSC proposes to conduct the specified activity and 
summarize information related to the population or stock, including 
potential biological removal (PBR). For taxonomy, we follow Committee 
on Taxonomy (2015). 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 Analyses''). Species that could 
potentially occur in the proposed research areas but are not expected 
to have the potential for interaction with NWFSC research gear or that 
are not likely to be harassed by NWFSC'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. For status of 
species, we provide information regarding U.S. regulatory status under 
the MMPA and ESA.
    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 area. NMFS' stock 
abundance estimates for most species represent the total estimate of 
individuals within the geographic area, if known, that comprises that 
stock. For some species, this geographic area may extend beyond U.S. 
waters. Survey abundance (as compared to stock or species abundance) is 
the total number of individuals estimated within the survey area, which 
may or may not align completely with a stock's geographic range as 
defined in the SARs. These surveys may also extend beyond U.S. waters.
    Thirty-four species (with 43 managed stocks) are considered to have 
the potential to co-occur with NWFSC activities. Extralimital species 
or stocks in the California Current include the Bryde's whale 
(Balaenoptera edeni brydei) and the North Pacific right whale 
(Eubalaena japonica). In addition, the sea otter is found in coastal 
waters, with the southern sea otter (Enhydra lutris nereis) found in 
California and the northern (or eastern) sea otter (E. l. kenyoni; 
Washington stock only) found in Washington. However, sea otters are 
managed by the U.S. Fish and Wildlife Service and are not considered 
further in this document. All stocks are assessed in NMFS' U.S. Pacific 
SARs (Carretta et al., 2015a,b), with the exception of the west coast 
transient and northern resident stocks of killer whales, the eastern 
North Pacific stock of the northern fur seal, and the eastern stock of 
the Steller sea lion, which are considered in the U.S. Alaska SARs 
(Allen and Angliss, 2015; Muto and Angliss, 2015). Values presented in 
Table 3 reflect the most recent information available (i.e., final 2014 
and draft 2015 reports, as appropriate).
    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, recent 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), and WNP animals comprised 8.1 percent of 
gray whales identified during a recent field season off of Vancouver 
Island (Weller et al., 2012). In addition, two genetic matches of WNP 
whales have been recorded off of Santa Barbara, CA (Lang et al., 2011). 
More recently, 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 NWFSC 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 NWFSC 
research activity would be one of the approximately twenty WNP whales 
that have been documented in the eastern Pacific. The likelihood that a 
WNP whale would interact with NWFSC research gear is insignificant and 
discountable, and WNP gray whales are omitted from further analysis.

                                Table 3--Marine Mammals Potentially Present in the Vicinity of NWFSC Research Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                  Occurrence          ESA/MMPA      Stock abundance
                                                                           ------------------------    status;      (CV, Nmin, most             Annual M/
           Common name              Scientific name           Stock                                 strategic (Y/  recent abundance      PBR     SI \3\
                                                                              CC      LCR     PS       N) \1\         survey) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Family Eschrichtiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale......................  Eschrichtius         Eastern North            X   ......      X   -; N          20,990 (0.05;            624       132
                                   robustus.            Pacific.                                                   20,125; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale..................  Megaptera            California/Oregon/       X   ......      X   E/D; Y        1,918 (0.03;         \12\ 11     >=5.5
                                   novaeangliae         Washington (CA/OR/                                         1,855; 2011).
                                   kuzira.              WA).
Minke whale.....................  Balaenoptera         CA/OR/WA...........      X   ......      X   -; N          478 (1.36; 202;            2         0
                                   acutorostrata                                                                   2008).
                                   scammoni.
Sei whale.......................  B. borealis          Eastern North            X   ......  ......  E/D; Y        126 (0.53; 83;          0.17         0
                                   borealis.            Pacific.                                                   2008).
Fin whale.......................  B. physalus          CA/OR/WA...........      X   ......  ......  E/D; Y        3,051 (0.18;              16       2.2
                                   physalus.                                                                       2,598; 2008).

[[Page 38533]]

 
Blue whale......................  B. musculus          Eastern North            X   ......  ......  E/D; Y        1,647 (0.07;        \12\ 2.3       0.9
                                   musculus.            Pacific.                                                   1,551; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Family Physeteridae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale.....................  Physeter             CA/OR/WA...........      X   ......  ......  E/D; Y        2,106 (0.58;             2.7       1.7
                                   macrocephalus.                                                                  1,332; 2008).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                     Family Kogiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy sperm whale...............  Kogia breviceps....  CA/OR/WA...........      X   ......  ......  -; N          579 (1.02; 271;          2.7         0
                                                                                                                   2008).
Dwarf sperm whale...............  K. sima............  CA/OR/WA \5\.......      X   ......  ......  -; N          Unknown...........    Undet.         0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Family Ziphiidae (beaked whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale...........  Ziphius cavirostris  CA/OR/WA...........      X   ......  ......  -; Y          6,590 (0.55;              45         0
                                                                                                                   4,481; 2008).
Baird's beaked whale............  Berardius bairdii..  CA/OR/WA...........      X   ......  ......  -; N          847 (0.81; 466;          4.7         0
                                                                                                                   2008).
Hubbs' beaked whale.............  Mesoplodon           CA/OR/WA \6\.......      X   ......  ......  -; Y          694 (0.65; 389;          3.9         0
                                   carlhubbsi.                                                                     2008).
Blainville's beaked whale.......  M. densirostris....  ...................      X   ......  ......
Ginkgo-toothed beaked whale.....  M. ginkgodens......  ...................      X   ......  ......
Perrin's beaked whale...........  M. perrini.........  ...................      X   ......  ......
Lesser (pygmy) beaked whale.....  M. peruvianus......  ...................      X   ......  ......
Stejneger's beaked whale........  M. stejnegeri......  ...................      X   ......  ......  ............  ..................  ........  ........
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Common bottlenose dolphin.......  Tursiops truncatus   CA/OR/WA Offshore..      X   ......  ......  -; N          1,006 (0.48; 684;        5.5       >=2
                                   truncatus.                                                                      2008).
                                  ...................  California Coastal.      X   ......  ......  -; N          323 (0.13; 290;          2.4       0.2
                                                                                                                   2005).
Striped dolphin.................  Stenella             CA/OR/WA...........      X   ......  ......  -; N          10,908 (0.34;             82         0
                                   coeruleoalba.                                                                   8,231; 2008).
Long-beaked common dolphin......  Delphinus capensis   California.........      X   ......  ......  -; N          107,016 (0.42;           610      13.8
                                   capensis.                                                                       76,224; 2009).
Short-beaked common dolphin.....  D. delphis delphis.  CA/OR/WA...........      X   ......  ......  -; N          411,211 (0.21;         3,440        64
                                                                                                                   343,990; 2008).
Pacific white-sided dolphin.....  Lagenorhynchus       CA/OR/WA...........      X   ......      X   -; N          26,930 (0.28;            171      17.8
                                   obliquidens.                                                                    21,406; 2008).
Northern right whale dolphin....  Lissodelphis         CA/OR/WA...........      X   ......  ......  -; N          8,334 (0.4; 6,019;        48       4.8
                                   borealis.                                                                       2008).
Risso's dolphin.................  Grampus griseus....  CA/OR/WA...........      X   ......  ......  -; N          6,272 (0.3; 4,913;        39       1.6
                                                                                                                   2008).
Killer whale....................  Orcinus orca \4\...  West Coast               X       X       X   -; N          243 (n/a; 2009)...       2.4         0
                                                        Transient \7\.
                                  ...................  Eastern North            X   ......  ......  -; N          240 (0.49; 162;          1.6         0
                                                        Pacific Offshore.                                          2008).
                                  ...................  Eastern North            X   ......      X   E/D; Y        78\10\ (n/a; 2014)      0.14         0
                                                        Pacific Southern
                                                        Resident.
                                  ...................  Eastern North            X   ......      X   -; N          261 (n/a; 2011)...      1.96         0
                                                        Pacific Northern
                                                        Resident.
Short-finned pilot whale........  Globicephala         CA/OR/WA...........      X   ......  ......  -; N          760 (0.64; 465;          4.6         0
                                   macrorhynchus.                                                                  2008).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise.................  Phocoena phocoena    Morro Bay..........      X   ......  ......  -; N          2,917 (0.41;              21     >=0.6
                                   vomerina.                                                                       2,102; 2012).
                                  ...................  Monterey Bay.......      X   ......  ......  -; N          3,715 (0.51;              25         0
                                                                                                                   2,480; 2011).
                                  ...................  San Francisco-           X   ......  ......  -; N          9,886 (0.51;              66         0
                                                        Russian River.                                             6,625; 2011).
                                  ...................  Northern CA/             X   ......  ......  -; N          35,769 (0.52;            475     >=0.6
                                                        Southern OR.                                               23,749; 2011).
                                  ...................  Northern OR/WA           X       X   ......  -; N          21,487 (0.44;            151       >=3
                                                        Coast.                                                     15,123; 2011).
                                  ...................  Washington Inland    ......  ......      X   -; N          10,682 (0.38;             63     >=2.2
                                                        Waters.                                                    7,841; 2003).
Dall's porpoise.................  Phocoenoides dalli   CA/OR/WA...........      X       X       X   -; N          42,000 (0.33;            257     >=0.4
                                   dalli.                                                                          32,106; 2008).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Guadalupe fur seal..............  Arctocephalus        ...................      X   ......  ......  T/D; Y        7,408 (n/a; 3,028;        91    \13\ 0
                                   philippii                                                                       1993).
                                   townsendi.

[[Page 38534]]

 
Northern fur seal...............  Callorhinus ursinus  Pribilof Islands/        X   ......  ......  D; Y          648,534 (0.2;         11,802       439
                                                        Eastern Pacific.                                           548,919; 2012).
                                  ...................  California.........      X   ......  ......  -; N          14,050\10\ (n/a;         451       1.8
                                                                                                                   7,524; 2013).
California sea lion.............  Zalophus             United States......      X       X       X   -; N          296,750 (n/a;          9,200       389
                                   californianus.                                                                  153,337; 2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion................  Eumetopias jubatus   Eastern U.S.\9\....      X       X       X   D; Y          60,131-74,448 (n/      1,645      92.3
                                   monteriensis.                                                                   a; 36,551; 2013)
                                                                                                                   \11\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal.....................  Phoca vitulina       California.........      X   ......  ......  -; N          30,968 (n/a;           1,641        43
                                   richardii.                                                                      27,348; 2012).
                                  ...................  OR/WA Coast \8\....      X       X   ......  -; N          24,732 (0.12;         Undet.      10.6
                                                                                                                   22,380; 1999).
                                  ...................  Washington Northern  ......  ......      X   -; N          11,036 (0.15;         Undet.       9.8
                                                        Inland Waters.\8\                                          7,213; 1999).
                                  ...................  Southern Puget       ......  ......      X   -; N          1,568 (0.15;          Undet.       3.4
                                                        Sound \8\.                                                 1,025; 1999).
                                  ...................  Hood Canal \8\.....  ......  ......      X   -; N          1,088 (0.15; 711;     Undet.       0.2
                                                                                                                   1999).
Northern elephant seal..........  Mirounga             California Breeding      X   ......      X   -; N          179,000 (n/a;          4,882       8.8
                                   angustirostris.                                                                 81,368; 2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of stock
  abundance. In some cases, CV is not applicable. For three stocks of killer whales, the abundance values represent direct counts of individually
  identifiable animals; therefore there is only a single abundance estimate with no associated CV. For certain stocks of pinnipeds, abundance estimates
  are based upon observations of animals (often pups) ashore multiplied by some correction factor derived from knowledge of the species' (or similar
  species') life history to arrive at a best abundance estimate; therefore, there is no associated CV. In these cases, the minimum abundance may
  represent actual counts of all animals ashore.
\3\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value. All
  M/SI values are as presented in the draft 2015 SARs (Carretta et al., 2015b; Muto and Angliss, 2015).
\4\ Transient and resident killer whales are considered unnamed subspecies (Committee on Taxonomy, 2015).
\5\ No information is available to estimate the population size of dwarf sperm whales off the U.S. west coast, as no sightings of this species have been
  documented despite numerous vessel surveys of this region (Carretta et al., 2015a). Dwarf and pygmy sperm whales are difficult to differentiate at sea
  but, based on previous sighting surveys and historical stranding data, it is thought that recent ship survey sightings were of pygmy sperm whales.
\6\ The six species of Mesoplodont beaked whales occurring in the CCE are managed as a single stock due to the rarity of records and the difficulty in
  distinguishing these animals to species in the field. Based on bycatch and stranding records, it appears that M. carlhubbsi is the most commonly
  encountered of these species (Carretta et al., 2008; Moore and Barlow, 2013). Additional managed stocks in the Pacific include M. stejnegeri in
  Alaskan waters and M. densirostris in Hawaiian waters.
\7\ The abundance estimate for this stock includes only animals from the ``inner coast'' population occurring in inside waters of southeastern Alaska,
  British Columbia, and Washington--excluding animals from the ``outer coast'' subpopulation, including animals from California--and therefore should be
  considered a minimum count. For comparison, the previous abundance estimate for this stock, including counts of animals from California that are now
  considered outdated, was 354.
\8\ Abundance estimates for these stocks are not considered current. PBR is therefore considered undetermined for these stocks, as there is no current
  minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates, as these represent the best available
  information for use in this document.
\9\ The eastern distinct population segment of the Steller sea lion, previously listed as threatened, was delisted under the ESA on December 4, 2013 (78
  FR 66140; November 4, 2013).
\10\ These are provisional abundance estimates presented in the draft 2015 SARs.
\11\ Best abundance is calculated as the product of pup counts and a factor based on the birth rate, sex and age structure, and growth rate of the
  population. A range is presented because the extrapolation factor varies depending on the vital rate parameter resulting in the growth rate (i.e.,
  high fecundity or low juvenile mortality).
\12\ These stocks are known to spend a portion of their time outside the U.S. EEZ. Therefore, the PBR presented here is the allocation for U.S. waters
  only and is a portion of the total. The total PBR for blue whales is 9.3 (one-quarter allocation for U.S. waters), and the total for humpback whales
  is 22 (one half allocation for U.S. waters). Annual M/SI presented for these species is for U.S. waters only.
\13\ This represents annual M/SI in U.S. waters. However, the vast majority of M/SI for this stock--the level of which is unknown--would likely occur in
  Mexican waters.

    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.
    For marine mammals in the California Current Ecosystem, 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 all CCE 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, and none of these species were taken in the fishery in 2012-13. 
More information is available on the Internet at: www.nmfs.noaa.gov/pr/interactions/trt/poctrp.htm. Of the stocks of concern, the NWFSC has 
requested the authorization of

[[Page 38535]]

incidental M/SI + Level A for the short-finned pilot whale only (see 
``Estimated Take by Incidental Harassment'' later in this document). 
The most recent reported average annual human-caused mortality for 
short-finned pilot whales (2004-08) is zero animals. The NWFSC does not 
use drift gillnets in its fisheries research program; therefore, take 
reduction measures applicable to the CA DGN fisheries are not relevant 
to the NWFSC.
    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 sixteen formally recognized UMEs on the 
U.S. west coast involving species under NMFS' jurisdiction. The most 
recent of these, and the only ones involving currently ongoing 
investigations, involve Guadalupe fur seals and California sea lions. 
Increased strandings of Guadalupe fur seals (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. 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 December 3, 2015).
    Additional UMEs in the past ten years include those involving 
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). There is also an ongoing UME in the 
western Gulf of Alaska that involves elevated large whale mortalities 
and may be affecting eastern North Pacific gray whales, which also 
occur in the NWFSC's research areas. For more information on UMEs, 
please visit the Internet at: www.nmfs.noaa.gov/pr/health/mmume/events.html.

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 by Incidental Harassment'' 
section later in this document will include a quantitative analysis of 
the number of individuals that are expected to be taken by this 
activity. The ``Negligible Impact Analysis'' section will include an 
analysis of how this specific activity will impact marine mammals and 
will consider the content of this section, the ``Estimated Take by 
Incidental Harassment'' section, and the ``Proposed Mitigation'' 
section, to draw conclusions regarding the likely impacts of this 
activity on the reproductive success or survivorship of individuals and 
from that on the affected marine mammal populations 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. More superficial strikes may not kill or 
result in the death of the animal. These interactions are typically 
associated with large whales (e.g., fin 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 ninety 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 eighty percent at 15 kn to 
approximately twenty 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 eighty 
to ninety percent.
    For vessels used in NWFSC research activities, transit speeds 
average 10 kn (but vary from 6-14 kn), while vessel speed during active 
sampling 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 fifty percent. However, the likelihood of a 
strike actually happening is again discountable. Ship strikes, as 
analyzed in the studies cited above, generally involve commercial 
shipping, which is

[[Page 38536]]

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 NOAA-chartered survey vessel traveling at low 
speed (5.5 kn) while conducting multi-beam 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. This strike represents the only such incident in 
approximately 540,000 hours of similar coastal mapping activity (p = 
1.9 x 10-6; 95% CI = 0-5.5 x 10-6; 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 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.
    In summary, we anticipate that vessel collisions involving NWFSC 
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 NWFSC in any of the three research areas. 
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, 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 NWFSC 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 other hook and line gear, seines (primarily purse 
seines), and tangle nets.
    Trawl nets, longlines, and purse seines deployed by NWFSC 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 (a gear type not generally used by 
NWFSC), 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 (gear used by NWFSC), 
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, 2014). 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,

[[Page 38537]]

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 
(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 seventeen 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,'' 
NWFSC has recorded marine mammal interactions primarily with the Nordic 
264 surface trawl net but also has one recorded interaction with the 
modified Cobb midwater trawl. No marine mammal interactions have been 
recorded for any bottom trawl survey.
    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. Pelagic longlines, which notionally fish near the surface 
with the use of floats, may be deployed in such a way as to fish at 
different depths in the water column. For example, deep-set longlines 
targeting tuna may have a target depth of 400 m, while a shallow-set 
longline targeting swordfish is set at 30-90 m depth. We refer here to 
bottom and pelagic longlines. 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. Pelagic longlines 
are generally composed of various diameter monofilament line and are 
generally much longer, and with more hooks, than are bottom longlines. 
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

[[Page 38538]]

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. Hook and line (e.g., rod and reel) gear also 
carries some lesser potential for marine mammal interaction, as the use 
of baited hooks in the presence of inquisitive marine mammals 
necessarily carries some risk. However, the scale of hook and line 
operations in relation to longline operations and the lack of extended, 
unattended soak times mean that use of other hook and line gear is much 
less likely to result in marine mammal interactions. However, due to 
the limited potential risk we carry this gear forward for further 
analysis with longline in a general category of hook and line gear.
    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. NWFSC has not recorded marine mammal 
interactions with any longline survey. 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.
    Tangle nets and other set gear--As noted previously, tangle nets 
operate in similar fashion to 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 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 NWFSC use of tangle nets, as described 
below in ``Estimated Take by Incidental Harassment, Serious Injury, or 
Mortality.'' However, this risk is limited by the fact that NWFSC uses 
tangle nets only in the LCRRA, for up to 75 sets of 25-45 minutes 
duration each.
    The NWFSC also uses fyke traps and modified sablefish 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, all fyke traps used by the NWFSC are wetland systems designed 
to target small fish, and are fished in areas where pinnipeds are rare 
(estuarine, wetland channels typically 1-5 m wide, including brackish 
and freshwater habitats) and only limited deployments (up to one 
hundred sets per year). Sablefish pots are likewise used in only very 
limited fashion, with modified pots deployed in some Puget Sound 
estuaries to collect herring eggs. The doors are sewed shut such that 
marine mammals cannot enter the pot itself, and are unlikely to become 
entangled in the line. Therefore, we do not believe that there is a 
reasonable potential for marine mammal interaction with fyke traps or 
pots used by the NWFSC, and these gears are not considered further in 
this document.
    Seine nets--Purse seine gear is well-known as a potential source of 
marine mammal mortality due to its use in tuna fisheries of the eastern 
tropical Pacific Ocean (ETP), where incidental take of dolphins was 
very high from the late 1950s into the 1970s (Perrin, 1969). Because 
large yellowfin tuna (Thunnus albacares) and several species of dolphin 
associate together, dolphins were often captured along with the target 
species, resulting in the deaths of hundreds of thousands of dolphins. 
Through a series of combined actions, including passage of the MMPA in 
1972, subsequent amendments, regulations, and mitigation measures, 
dolphin bycatch in the ETP has since decreased 99 percent in the 
international fishing fleet, and was eliminated by the U.S. fleet 
(Gerrodette and Forcada, 2005). As in the ETP tuna fisheries, the most 
significant risk associated with use of purse seines are when marine 
mammals and target species associate together, which is not the case 
for any NWFSC use of purse seines. Similar to longline gear, NWFSC 
purse seines are much smaller than those typically used in commercial 
fisheries. However, there is some risk associated with use of purse 
seines (and to a lesser extent, seine nets in general), and we 
therefore carry seine nets forward for further consideration.
    Other research gear--The only NWFSC research gears with any record 
of marine mammal interactions are pelagic trawl nets (i.e., Nordic 264 
and modified Cobb). Because of ample evidence from commercial fishing 
operations, we assume that there is also risk of marine mammal 
interaction due to NWFSC use of bottom trawl nets, hook and line gear 
(primarily longlines but also including other hook and line gear), and 
seine gear (primarily purse seine gear but also including beach 
seines). All other gears used in NWFSC fisheries research (e.g., a 
variety of plankton nets, CTDs, 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, water pump/thermosalinograph, ROVs, small surface 
trawls, plankton nets, 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 NWFSC (see ``Description of Active 
Acoustic Sound Sources''). Here, we first provide background 
information on marine mammal hearing before discussing the potential 
effects of NWFSC use of active acoustic sources on marine mammals.

[[Page 38539]]

    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 low-frequency cetaceans. 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):
     Low-frequency cetaceans (mysticetes): Functional hearing 
is estimated to occur between approximately 7 Hz and 25 kHz (up to 30 
kHz in some species), with best hearing estimated to be from 100 Hz to 
8 kHz (Watkins, 1986; Ketten, 1998; Houser et al., 2001; Au et al., 
2006; Lucifredi and Stein, 2007; Ketten et al., 2007; Parks et al., 
2007a; Ketten and Mountain, 2009; Tubelli et al., 2012);
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Functional hearing is estimated to occur 
between approximately 150 Hz and 160 kHz, with best hearing from 10 to 
less than 100 kHz (Johnson, 1967; White, 1977; Richardson et al., 1995; 
Szymanski et al., 1999; Kastelein et al., 2003; Finneran et al., 2005a, 
2009; Nachtigall et al., 2005, 2008; Yuen et al., 2005; Popov et al., 
2007; Au and Hastings, 2008; Houser et al., 2008; Pacini et al., 2010, 
2011; Schlundt et al., 2011);
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, including the hourglass dolphin, on the 
basis of recent echolocation data and genetic data [May-Collado and 
Agnarsson, 2006; Kyhn et al. 2009, 2010; Tougaard et al. 2010]): 
Functional hearing is estimated to occur between approximately 200 Hz 
and 180 kHz (Popov and Supin, 1990a,b; Kastelein et al., 2002; Popov et 
al., 2005); and
     Pinnipeds in water; Phocidae (true seals): Functional 
hearing is estimated to occur between approximately 75 Hz to 100 kHz, 
with best hearing between 1-50 kHz (M[oslash]hl, 1968; Terhune and 
Ronald, 1971, 1972; Richardson et al., 1995; Kastak and Schusterman, 
1999; Reichmuth, 2008; Kastelein et al., 2009);
     Pinnipeds in water; Otariidae (eared seals): Functional 
hearing is estimated to occur between 100 Hz and 48 kHz for Otariidae, 
with best hearing between 2-48 kHz (Schusterman et al., 1972; Moore and 
Schusterman, 1987; Babushina et al., 1991; Richardson et al., 1995; 
Kastak and Schusterman, 1998; Kastelein et al., 2005a; Mulsow and 
Reichmuth, 2007; Mulsow et al., 2011a, b).
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    Thirty-four marine mammal species (28 cetacean and six pinniped 
[four otariid and two phocid] species) have the potential to co-occur 
with NWFSC research activities. Please refer to Table 3. Of the 28 
cetacean species that may be present, six 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 underwater sound--Please refer to the 
information given previously (``Description of Active Acoustic 
Sources'') regarding sound, characteristics of sound types, and metrics 
used in this document. Anthropogenic sounds cover a broad range of 
frequencies and sound levels and can have a range of highly variable 
impacts on marine life, from none or minor to potentially severe 
responses, depending on received levels, duration of exposure, 
behavioral context, and various other factors. The potential effects of 
underwater sound from active acoustic sources can potentially result in 
one or more of the following: Temporary or permanent hearing 
impairment, non-auditory physical or physiological effects, behavioral 
disturbance, stress, and masking (Richardson et al., 1995; Gordon et 
al., 2004; Nowacek et al., 2007; Southall et al., 2007; 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 NWFSC'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 NWFSC 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 (Kastak et al., 1999; Schlundt 
et al., 2000; Finneran et al., 2002, 2005b). 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).

[[Page 38540]]

    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals--PTS data exists only for a single harbor seal 
(Kastak et al., 2008)--but are assumed to be similar to those in humans 
and other terrestrial mammals. PTS typically occurs at exposure levels 
at least several decibels above (a 40-dB threshold shift approximates 
PTS onset; e.g., Kryter et al., 1966; Miller, 1974) that inducing mild 
TTS (a 6-dB threshold shift approximates TTS onset; e.g., Southall et 
al. 2007). Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS thresholds for impulse sounds (such as 
impact pile driving pulses as received close to the source) are at 
least 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). NWFSC 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, and 
none of the data published at the time of this writing concern TTS 
elicited by exposure to multiple pulses of sound.
    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 [Delphinapterus leucas], 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 
(e.g., Finneran et al., 2002; Nachtigall et al., 2004; Kastak et al., 
2005; Lucke et al., 2009; Popov et al., 2011). In general, harbor seals 
(Kastak et al., 2005; Kastelein et al., 2012a) and harbor porpoises 
(Lucke et al., 2009; Kastelein et al., 2012b) have a lower TTS onset 
than other measured pinniped or cetacean species. Additionally, the 
existing marine mammal TTS data come from a limited number of 
individuals within these species. There are no data available on noise-
induced hearing loss for mysticetes. For summaries of data on TTS in 
marine mammals or for further discussion of TTS onset thresholds, 
please see Southall et al. (2007) and Finneran and Jenkins (2012).
    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

[[Page 38541]]

that are resting may show greater behavioral change in response to 
disturbing sound levels than animals that are highly motivated to 
remain in an area for feeding (Richardson et al., 1995; NRC, 2003; 
Wartzok et al., 2003). Controlled experiments with captive marine 
mammals have showed pronounced behavioral reactions, including 
avoidance of loud sound sources (Ridgway et al., 1997; Finneran et al., 
2003). Observed responses of wild marine mammals to loud 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).
    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, b). 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, 2005b, 2006; Gailey et 
al., 2007).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007b). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors, and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from seismic surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
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

[[Page 38542]]

dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    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., 2007b; Di Iorio and Clark, 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore, 2014). Masking can be tested 
directly in captive species (e.g., Erbe, 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most

[[Page 38543]]

of the increase from distant commercial shipping (Hildebrand, 2009). 
All anthropogenic sound sources, but especially chronic and lower-
frequency signals (e.g., from vessel traffic), contribute to elevated 
ambient sound levels, thus intensifying masking.
    Potential effects of NWFSC activity--As described previously (see 
``Description of Active Acoustic Sound Sources''), the NWFSC 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 NWFSC 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 NWFSC. 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, NMFS' 
acoustics experts believe that 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 NWFSC, 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 NWFSC 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 NWFSC 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 NWFSC, 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

[[Page 38544]]

data that the chance of TTS is only in a small volume immediately under 
the 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 sea ways--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 NWFSC use of the multibeam echosounder, on the basis of a 2008 
mass stranding of approximately one hundred melon-headed whales 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 NWFSC 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 NWFSC 
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.

[[Page 38545]]

    Based on the source operating characteristics, most of these 
sources may be detected by odontocete cetaceans (and particularly high-
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 NWFSC 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. 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, 2005b, 2008a, b; 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 NWFSC surveys conducted in coastal areas, including rivers 
and estuaries, 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. Such circumstances 
are expected in Puget Sound and in the Columbia River. NWFSC 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. However, NWFSC 
surveys would be unlikely to disturb any sea lion pups, and any 
disturbance of harbor seal pups would be unlikely to result in 
abandonment. The eastern stock of Steller sea lions breeds in rookeries 
located in southeast Alaska, British Columbia, Oregon, and California; 
there are no known breeding rookeries in Washington or in the Columbia 
River. California sea lions breed in the Gulf of California, western 
Baja California, and southern California. Harbor seal pups could be 
present at times during NWFSC research effort (harbor seal pupping in 
Washington inland waters occurs from approximately June through 
September, depending on location), but 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 NWFSC research would interrupt the brief 
mother-pup bonding period within which disturbance could result in 
separation. In addition, NWFSC 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 moving sample site locations to avoid consistent haulout areas.
    Disturbance of pinnipeds caused by NWFSC 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

[[Page 38546]]

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 NWFSC research surveys, with 
primary species of concern being hake, salmonids, and small, energy-
rich, schooling species such as Pacific sardine, anchovies, and jack 
mackerel.
    However, the total amount of these species taken in research 
surveys is very small relative to their overall biomass in the area 
(See Section 4.2.3 of the NWFSC EA for more information on fish catch 
during research surveys). For example, the average annual catch of 
Pacific hake in the course of all NWFSC research surveys during 2008-12 
was approximately 1,181 metric tons (mt). Research catch is therefore 
negligible compared to the average commercial harvest for the same 
period (63,974 mt). For salmonids, in all cases the research take as a 
percent of either the average spawning population estimate or the 
average total juveniles produced is less than one tenth of one percent. 
For most commercial species, the average annual research catch is less 
than one percent of the overfishing limit (a fisheries management 
metric used to prevent overfishing). 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.
    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. 
This is especially true for pinnipeds, which are opportunistic 
predators that consume a wide assortment of fish and squid, and judging 
by their increasing populations throughout their range and expanding 
range into the Pacific Northwest (Caretta et al., 2015a), food 
availability does not appear to be a limiting factor (Baraff and 
Loughlin, 2000; Scordino, 2010). 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 NWFSC'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 see also the 
previous discussion on masking under ``Acoustic Effects''), 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 NWFSC active acoustic sources are 
generally high frequency, of short 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. NWFSC 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 NWFSC use of these sources would, on their 
own, have any appreciable effect on acoustic habitat. Sounds emitted by 
NWFSC vessels would be of lower frequency and continuous, but would 
also be widely dispersed in both space and time. NWFSC 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--NWFSC 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 (Morgan and Chuenpagdee, 2003; Stevenson et al., 
2004). 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. In general, physical damage to the 
seafloor would be expected to recover within eighteen months through 
the action of water currents and natural sedimentation, with the 
exception of rocks and boulders which may be permanently displaced 
(Stevenson et al., 2004). Biological damage would likely recover within 
the same timeframe, although repeated disturbance of an area can 
prolong the recovery time (Stevenson et al., 2004), and recovery of 
corals may take significantly longer. However, NWFSC catch records show 
that only minimal amounts of coral are captured (annual average of 55 
kg of coral in all

[[Page 38547]]

surveys from 2008-12). Relatively small areas would be impacted by 
NWFSC 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. NWFSC 
activities would not be expected to have any other impacts on physical 
habitat.
    As described in the preceding, the potential for NWFSC 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 by Incidental Harassment, Serious Injury, or Mortality

    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]. Serious injury means any injury that 
will likely result in mortality (50 CFR 216.3).
    Take of marine mammals incidental to NWFSC 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).

Estimated Take Due to Gear Interaction

Historical Interactions

    In order to estimate the number of potential incidents of take that 
could occur by M/SI + Level A through gear interaction, we first 
consider NWFSC's record of past such incidents, and then consider in 
addition other species that may have similar vulnerabilities to NWFSC 
trawl gear as those species for which we have historical interaction 
records. Historical interactions with NWFSC research gear are described 
in Table 4. Available records are for the years 1999 through present. 
All historical interactions have taken place in the CCRA, offshore 
Washington and Oregon, and have occurred during use of the Nordic 264 
surface trawl net, with a few exceptions. There is one historical 
interaction in the PSRA (also using the Nordic 264 surface trawl) and 
one CCRA historical interaction using the modified Cobb midwater trawl. 
NWFSC has no historical interactions for any bottom trawl, hook and 
line, or seine gear, and has no historical interactions in the LCRRA. 
Please see Figure 6-1 in the NWFSC request for authorization for 
specific locations of these incidents.

                               Table 4--Historical Interactions With Research Gear
----------------------------------------------------------------------------------------------------------------
                                                                            Number        Number
       Gear \1\              Survey           Date          Species         killed    released alive     Total
----------------------------------------------------------------------------------------------------------------
Pelagic trawl........  Juvenile Salmon      5/24/1999  Pacific white-              4  ..............           4
                        Coastal (JSC).                  sided dolphin.
Pelagic trawl........  JSC..............    9/29/1999  Steller sea lion.           1  ..............           1
Pelagic trawl........  JSC..............    10/1/1999  Steller sea lion.           3  ..............           3
Pelagic trawl........  JSC..............    5/18/2000  Northern fur seal           1  ..............           1
Pelagic trawl........  Piscine Predator     7/19/2001  California sea              1  ..............           1
                        and Forage Fish                 lion.
                        (PPFF) \2\.
Pelagic trawl........  JSC..............    9/22/2002  Steller sea lion.           1  ..............           1
Pelagic trawl........  JSC..............    9/23/2002  Steller sea lion.           1  ..............           1
Pelagic trawl........  JSC..............    9/24/2002  Steller sea lion.           2  ..............           2
Pelagic trawl........  JSC..............    6/25/2003  Pacific white-              1  ..............           1
                                                        sided dolphin.
Pelagic trawl........  JSC..............    6/30/2003  Harbor seal......           1  ..............           1
Pelagic trawl........  JSC..............    6/30/2003  Pacific white-              2  ..............           2
                                                        sided dolphin.
Pelagic trawl........  JSC..............    6/18/2005  Pacific white-              3  ..............           3
                                                        sided dolphin.
Pelagic trawl........  PPFF \2\.........     6/1/2006  Pacific white-              3  ..............           3
                                                        sided dolphin.
Pelagic trawl........  PPFF \2\.........    8/28/2006  Pacific white-              2  ..............           2
                                                        sided dolphin.
Pelagic trawl........  JSC..............    9/28/2007  California sea              1  ..............           1
                                                        lion.
Pelagic trawl........  Skagit Bay           5/16/2009  Harbor seal......  ..........               1           1
                        Juvenile Salmon
                        \3\.
Pelagic trawl........  JSC..............    5/23/2009  Unidentified                2  ..............           2
                                                        small cetacean
                                                        \4\.
Pelagic trawl \5\....  Northern Juvenile    5/26/2009  California sea              1               1           2
                        Rockfish.                       lion.
Pelagic trawl........  JSC..............    5/24/2010  Harbor seal......           1  ..............           1
Pelagic trawl........  JSC..............    6/28/2012  Pacific white-              3  ..............           3
                                                        sided dolphin.
Pelagic trawl........  JSC..............    6/21/2014  Pacific white-              6  ..............           6
                                                        sided dolphin.
------------------------------------------------------
    Total individuals captured (total number of        Northern fur seal           1  ..............           1
     interactions given in parentheses).                (1).
                                                       California sea              3               1           4
                                                        lion (3).
                                                       Pacific white-             24  ..............          24
                                                        sided dolphin
                                                        (8).
                                                       Harbor seal (3)..           2               1           3
                                                       Steller sea lion            8  ..............           8
                                                        (5).
----------------------------------------------------------------------------------------------------------------
\1\ All incidents involved use of the Nordic 264 surface trawl, except as noted below.
\2\ Survey discontinued.
\3\ This incident occurred in Puget Sound; all other incidents occurred in waters offshore Washington and
  Oregon.
\4\ Animals not identified before fishing crew returned carcasses to sea.
\5\ This incident involved use of the modified Cobb midwater trawl.

    Although some historical interactions resulted in the animal(s) 
being released alive, no serious injury determinations (NMFS, 2012a; 
2012b) were made, and it is possible that some of these animals later 
died. In order to use these historical interaction records in a 
precautionary manner as the basis for the take estimation process, and 
because

[[Page 38548]]

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. Over 
the past seventeen years, NWFSC has had only infrequent interactions 
with marine mammals, with 0.1-0.5 animals captured per year for the 
pinniped species and 1.4 animals captured per year for the Pacific 
white-sided dolphin. No Steller sea lion has been captured since 2002, 
northern fur seals have been involved in only one incident (none since 
2000), and only a few California sea lions and harbor seals have been 
involved in interactions with research fishing gear. However, we assume 
that any of these species could be captured in any year.
    In order to produce the most precautionary take estimates possible, 
we consider all of the data available to us (i.e., since 1999). In 
consideration of these interaction records, we assume that one 
individual of each species of otariid pinniped could be captured per 
year over the course of the five-year period of validity for these 
proposed regulations, that two individual harbor seals could be 
captured per year, and that the worst case event could happen each year 
for Pacific white-sided dolphins (i.e., six dolphins could be captured 
in a single trawl in each year). Table 5 shows the projected five-year 
total captures of these five species for this proposed rule, as 
described above, for trawl gear only. Although more than one individual 
of the two sea lion species has been captured in a single tow, 
interactions with these species have historically occurred only 
infrequently, and we believe that the above assumption appropriately 
reflects the likely total number of individuals involved in research 
gear interactions over a five-year period. We assume that two total 
harbor seals could be captured per year in recognition of the 
demonstrated vulnerability to capture in the PSRA (all other species 
have been captured only in the CCRA). 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 not exceed the annual 
effort during prior years for which we have interaction records.

             Table 5--Projected Five-Year Total Take in Trawl Gear for Historically Captured Species
----------------------------------------------------------------------------------------------------------------
                                                                   CCRA average    PSRA average
                Gear                           Species              annual take     annual take    Projected 5-
                                                                      (total)         (total)     year total \1\
----------------------------------------------------------------------------------------------------------------
Trawl..............................  Pacific white-sided dolphin          6 (30)  ..............              30
                                     California sea lion........           1 (5)  ..............               5
                                     Harbor seal................           1 (5)           1 (5)              10
                                     Northern fur seal..........           1 (5)  ..............               5
                                     Steller sea lion...........           1 (5)  ..............               5
----------------------------------------------------------------------------------------------------------------
\1\ Because there are no historical take records from the LCRRA, we incorporate all projected LCRRA takes in
  Table 7 below.

    In order to estimate the total potential number of incidents of M/
SI + Level A that could occur incidental to the NWFSC's use of trawl, 
hook and line, and seine gear over the five-year period of validity for 
these proposed regulations (i.e., takes additional to those described 
in Table 4), we first consider whether there are additional species 
that may have similar vulnerability to capture in trawl 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.
    As background to the process of determining which species not 
historically taken may have sufficient vulnerability to capture in 
NWFSC 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 LCRRA), 
we note that the NWFSC is NMFS' research arm in the northwest portion 
of the West Coast Region 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 NWFSC, and we have 
concurred with these decisions.
    In order to evaluate the potential vulnerability of additional 
species to trawl and of all species to hook and line and seine gear, we 
first consulted NMFS' List of Fisheries (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 2015 LOF (79 FR 77919; December 29, 
2014), 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 NWFSC 
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 2015 LOF. 
For specific numbers of marine mammal takes associated with these 
fisheries, please see the relevant SARs. More information is available 
on the Internet at www.nmfs.noaa.gov/pr/interactions/lof/ and 
www.nmfs.noaa.gov/pr/sars/.

[[Page 38549]]



                      Table 6--U.S. Commercial Fisheries Interactions for Trawl, Hook and Line, and Seine Gear for Relevant Species
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           Vulnerability   Hook and line   Vulnerability                   Vulnerability
                       Species \1\                           Trawl \2\     inferred? \3\        \2\        inferred? \3\     Seine \2\     inferred? \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale..............................................               Y               N               N             n/a               N             n/a
Humpback whale..........................................               Y               N               Y               N               Y               N
Balaenoptera spp........................................               Y               N               Y               N               N             n/a
Sperm whale.............................................               N             n/a               Y               N               N             n/a
Kogia spp...............................................               N             n/a               Y               Y               N             n/a
Cuvier's beaked whale...................................               N             n/a               Y               N               N             n/a
Baird's beaked whale....................................               N             n/a               N             n/a               N             n/a
Mesoplodon spp..........................................               N             n/a               Y               N               N             n/a
Common bottlenose dolphin...............................               Y               Y               Y               Y               Y               N
Stenella spp............................................               N             n/a               Y               Y               N             n/a
Delphinus spp...........................................               Y               Y               Y               Y               Y               Y
Lagenorhynchus spp.\4\..................................             n/a             n/a               N             n/a               N             n/a
Northern right whale dolphin............................           Y \6\               Y               N             n/a               N             n/a
Risso's dolphin.........................................               Y               Y               Y               Y               N             n/a
Killer whale............................................               Y               N               Y               N               N             n/a
Globicephala spp........................................               Y               N               Y               Y               Y               N
Harbor porpoise.........................................               Y               Y               N             n/a               N             n/a
Dall's porpoise.........................................               Y               Y               Y               N               N             n/a
Guadalupe fur seal \5\..................................               N             n/a               N             n/a               N             n/a
Northern fur seal \4\...................................             n/a             n/a               Y               N               N             n/a
California sea lion \4\.................................             n/a             n/a           Y \6\               Y               Y               Y
Steller sea lion \4\....................................             n/a             n/a               Y               Y               N             n/a
Phoca spp.\4\...........................................             n/a             n/a               N             n/a               Y               Y
Northern elephant seal..................................               Y               N               N             n/a               N             n/a
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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.
\3\ Where there are no documented incidents of M/SI incidental to relevant commercial fisheries, this is not applicable.
\4\ This exercise is considered ``not applicable'' for trawl gear for those species historically captured by NWFSC gear. Historical record, rather than
  analogy, is considered the best information upon which to base a take estimate.
\5\ It is likely that Guadalupe fur seals are taken in Mexican fisheries, but there are no records available to us.
\6\ There are no records of take for California sea lions in commercial hook and line fisheries, but there have been multiple takes of California sea
  lions in longline surveys conducted by the SWFSC. There are no records of take for northern right whale dolphins in commercial trawl fisheries, but
  this species has been captured in a trawl survey conducted by the SWFSC. We therefore infer vulnerability for those species to those research gears.

    Information related to incidental M/SI in relevant commercial 
fisheries is not, however, the sole determinant of whether it may be 
appropriate to authorize M/SI + Level A incidental to NWFSC survey 
operations. A number of factors (e.g., species-specific knowledge 
regarding animal behavior, overall abundance in the geographic region, 
density relative to NWFSC survey effort, feeding ecology, propensity to 
travel in groups commonly associated with other species historically 
taken) were taken into account by the NWFSC 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 NWFSC research gear. Similarly, we have determined that some 
species groups with documented M/SI are not likely to be vulnerable to 
capture in NWFSC gear. In these instances, we provide further 
explanation below. Those species with no records of historical 
interaction with NWFSC research gear and no documented M/SI in relevant 
commercial fisheries, and for which the NWFSC has not requested the 
authorization of incidental take, are not considered further in this 
section. The NWFSC 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 NWFSC 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. These species are limited to a few 
species delphinid species that we believe may have similar risk of 
capture as that displayed by the Pacific white-sided dolphin. For these 
species, we assume it is possible that a worst-case scenario of 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. The former 
assumption also accounts for the likelihood that, for species that 
often travel in groups, an incident involving capture of that species 
is likely to involve more than one individual.
    For example, we believe that the Risso's dolphin is potentially 
vulnerable to capture in trawl gear and may have similar propensity to 
capture in that gear as does the Pacific white-sided dolphin. Because 
the greatest number of Pacific white-sided dolphins captured in any one 
trawl tow was six individuals, we assume that six Risso's dolphins 
could also be captured in a single incident. However, in recognition of 
the fact that any incident involving the capture of Risso's dolphins 
would likely be a rare event, we propose a total take authorization 
over the five-year period of the number that may result from a single, 
worst-case incident (six dolphins). While we do not necessarily believe 
that six Risso's dolphins would be captured in a single incident--and 
that more capture incidents involving fewer individuals could occur, as 
opposed to a single, worst-case incident--we believe that this is a 
reasonable approach to estimating

[[Page 38550]]

potential incidents of M/SI + Level A while balancing what could happen 
in a worst-case scenario with the potential likelihood that no 
incidents of capture would actually occur. The SWFSC historical capture 
of northern right whale dolphins in 2008 provides an instructive 
example of a situation where a worst-case scenario (six dolphins 
captured in a single trawl tow) did occur, but overall capture of this 
species was very rare (no other capture incidents before or since).
    Separately, for those species that we believe may have a 
vulnerability to capture in given gear but that we do not believe may 
have a similar propensity to capture in that gear as a historically 
captured species, we assume that capture would be a rare event such 
that authorization of a single take over the five-year period is likely 
sufficient to capture the risk of interaction. For example, from the 
LOF we infer vulnerability to capture in trawl gear for the Dall's 
porpoise but do not believe that this species has a similar propensity 
for interaction in trawl gear as the Pacific white-sided dolphin.
    NWFSC requested authorization of incidental take for bottlenose 
dolphin, for either the offshore or coastal stock. However, we have had 
clarifying conversations with NWFSC to more explicitly understand the 
interaction risk posed by NWFSC survey operations. Coastal stock 
dolphins are generally found within 1 km of shore, from San Francisco 
Bay south to Mexican waters. This distribution has very little overlap 
with NWFSC research survey activity and, when coupled with the limited 
effort involved in NWFSC survey operations in that range and the 
mitigation measure proposed to be implemented, we do not believe that 
incidental take of coastal stock bottlenose dolphins is reasonably 
likely and do not propose to authorize take from this stock.
    Trawl--From the 2015 LOF and SWFSC historical gear interactions, we 
infer vulnerability to trawl gear in the CCRA for the Risso's dolphin, 
short- and long-beaked common dolphins, northern right whale dolphin, 
Dall's porpoise, harbor porpoise, and bottlenose dolphin. We consider 
some of these species to have a similar propensity for interaction with 
trawl gear as that demonstrated by the Pacific white-sided dolphin 
(Risso's dolphin, northern right whale dolphin) and the rest to have 
lower risk of interaction.
    Due to their likely presence in the relevant areas and inference 
based on historical interactions and the LOF, we assume additional 
vulnerability and therefore potential take for some of these species in 
trawl gear used in the PSRA and LCRRA. In the PSRA, these include the 
harbor porpoise and Dall's porpoise and the California sea lion and 
Steller sea lion. In the LCRRA these include the harbor porpoise and 
the harbor seal, California sea lion, and Steller sea lion.
    For the striped dolphin, 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. The 
proposed take authorization for this species was determined to be 
appropriate based on analogy to other similar species that have been 
taken either in NWFSC operations or in analogous commercial fishery 
operations. We believe that the striped dolphin has a similar 
propensity for interaction with trawl gear as that demonstrated by the 
Pacific white-sided dolphin.
    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. This is only likely to occur in 
the CCRA due to the greater diversity of pinniped and small cetacean 
species likely to be encountered in that area. Therefore, the NWFSC has 
requested the authorization of incidental M/SI + Level A for one 
unidentified pinniped and one unidentified small cetacean over the 
course of the five-year period of proposed authorization.
    Hook and line--The process is the same as is described above for 
trawl gear. From the 2015 LOF and SWFSC historical interactions, we 
infer vulnerability to hook and line gear in the CCRA for the Risso's 
dolphin, bottlenose dolphin, striped dolphin, pygmy and dwarf sperm 
whale (i.e., Kogia spp.), short- and long-beaked common dolphins, 
short-finned pilot whale, and California and Steller sea lions.
    Due to their likely presence in the relevant areas and inference 
based on historical interactions and the LOF, we assume additional 
vulnerability and therefore potential take for some of these species in 
hook and line gear used in the PSRA (hook and line gear is not used in 
the LCRRA). These include the California sea lion and harbor seal.
    Seine--The process is the same as is described above for trawl 
gear. From the 2015 LOF, we infer vulnerability to seine and tangle net 
gear in the CCRA and/or LCRRA for the short-beaked common dolphin, 
harbor seal, and California sea lion. Long-beaked common dolphin is not 
included because they are much rarer in Oregon and Washington where 
seine surveys are conducted. Seine gear is used infrequently in the 
PSRA (e.g., twelve purse seine sets per year) and the move-on rule 
applied if any small cetacean is seen within 500 m of the planned set. 
We do not believe that any take in seine gear is likely in the PSRA.
    We also believe that there is a reasonable potential of seine gear 
interaction for a number of species in the CCRA and/or LCRRA for which 
there are no LOF records of interaction in commercial fisheries gears. 
These proposed authorizations reflect the NWFSC's expert judgment 
regarding the distribution of these species in relation to NWFSC use of 
seine gear offshore Oregon and Washington. For example, several of 
these species have the potential to interact with NWFSC purse seine 
surveys in the Columbia River plume, where there are no corresponding 
commercial seine fisheries. Therefore, we would not expect the LOF to 
adequately reflect the risk of marine mammal interaction posed by NWFSC 
survey activities. Species for which we propose to authorize take in 
seine gear in the CCRA and/or LCRRA with no LOF interaction records 
include the Dall's porpoise, Pacific white-sided dolphin, Risso's 
dolphin, northern right whale dolphin, Steller sea lion, and harbor 
porpoise. For the harbor porpoise, we expect that there is greater 
vulnerability to take in these gears (i.e., we expect it could be taken 
in both the CCRA and LCRRA) and have increased the proposed take 
authorization relative to the other species accordingly. NWFSC 
considers the delphinid species to be at risk because of their 
occurrence in coastal waters offshore Oregon and Washington, and 
because they often occur in mixed schools and could be caught together 
in purse seines.

[[Page 38551]]



                    Table 7--Total Estimated M/SI + Level A Due to Gear Interaction, 2016-21
----------------------------------------------------------------------------------------------------------------
                                                           Estimated 5-year
             Species                 Estimated 5-year    total, hook and line    Estimated 5-year     Total, all
                                     total, trawl \1\             \1\            total, seine \1\       gears
----------------------------------------------------------------------------------------------------------------
Kogia spp.\2\....................  ....................  1...................  ....................            1
Bottlenose dolphin \3\...........  1...................  1...................  ....................            2
Striped dolphin..................  6...................  1...................  ....................            7
Short-beaked common dolphin......  1...................  1...................  1...................            3
Long-beaked common dolphin.......  1...................  1...................  ....................            2
Pacific white-sided dolphin......  30..................  ....................  1...................           31
Northern right whale dolphin.....  6...................  ....................  1...................            7
Risso's dolphin..................  6...................  1...................  1...................            8
Short-finned pilot whale.........  ....................  1...................  ....................            1
Harbor porpoise \4\..............  3 (CCRA/PSRA/LCRRA).  ....................  2 (CCRA/LCRRA)......            5
Dall's porpoise..................  2 (CCRA/PSRA).......  ....................  1...................            3
Northern fur seal \5\............  5...................  ....................  ....................            5
California sea lion..............  7 (5 CCRA/PSRA/       2 (CCRA/PSRA).......  1 (LCRRA)...........           10
                                    LCRRA).
Steller sea lion.................  7 (5 CCRA/PSRA/       1...................  1 (LCRRA)...........            9
                                    LCRRA).
Harbor seal \4\..................  11 (5 CCRA/5 PSRA/    1 (PSRA)............  1 (LCRRA)...........           13
                                    LCRRA.
Unidentified pinniped............  1...................  ....................  ....................            1
Unidentified small cetacean......  1...................  ....................  ....................            1
----------------------------------------------------------------------------------------------------------------
\1\ Please see Table 6 and preceding text for derivation of take estimates. Takes proposed for authorization are
  not specific to any area, but our estimates are informed by area-specific vulnerability. All takes are
  expected to occur in the CCRA, except where the gear-specific breakdown of expected takes per area is
  provided. Note that hook and line surveys are not proposed for LCRRA and only limited seine surveys are
  proposed for PSRA.
\2\ We expect that only one Kogia spp. may be taken over the five-year timespan and that it could be either a
  pygmy or dwarf sperm whale.
\3\ Incidental take is expected only from the offshore stock.
\4\ Incidental take for these species may be of animals from any stock in California, Oregon, or Washington, but
  expected vulnerability may be assigned to CCE or Washington inland waters stocks according to the expected
  take proportions shown.
\5\ Incidental take may be of animals from either the eastern Pacific or California stock.

    For large whales, beaked whales, and killer whales, observed M/SI 
is extremely rare for trawl and seine gear and, for most of these 
species, only slightly more common in longline gear. Although large 
whale species could become captured or entangled in NWFSC 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 from 2007-11. This fishery has 129 
participants, and the fishery as a whole exerts substantially greater 
effort in a given year than does the NWFSC. In a very rough estimate, 
we can say that these three estimated incidents between 2007-11 
represent an insignificant per-participant interaction rate of 0.005 
per year, despite the greater effort. Similarly, there were zero 
documented interactions from 2007-11 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 average soak time of ten to 
fourteen hours, this represents an approximate minimum of almost sixty 
million hook hours. For reference, an approximate maximum estimate of 
NWFSC effort in the CCRA is 52,000 hook-hours per year. Other large 
whales, beaked whales and killer whales have similarly low rates of 
interaction with commercial fisheries, despite the significantly 
greater effort. In addition, large whales, beaked whales, and killer 
whales generally have, with few exceptions, very low densities in the 
CCE relative to other species (see Table 10). We believe it extremely 
unlikely that any large whale, beaked whale, or killer whale would be 
captured or entangled in NWFSC research gear.
    There are a number of additional species with various LOF 
interaction records where we do not infer vulnerability to NWFSC use of 
that gear. Pilot whales have demonstrated vulnerability to midwater 
trawl gear in Atlantic fisheries and to purse seine gear, but we do not 
infer vulnerability to capture during NWFSC use of these gears because 
of the species is not abundant in the CCRA (Table 10). Bottlenose 
dolphins have been captured in purse seines, but they are also very 
rare in the areas where NWFSC conducts seine surveys. Similarly, we do 
not infer vulnerability to hook and line gear for Dall's porpoise or 
fur seals or to trawl gear for elephant seals given the amount of 
research effort conducted (for hook and line) or the rare nature of 
fisheries interactions for elephant seals.

Estimated Take Due to Acoustic Harassment

    As described previously (``Potential Effects of the Specified 
Activity on Marine Mammals''), we believe that NWFSC 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 NWFSC 
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.
    The operating frequencies of active acoustic systems used by NWFSC 
sources only go down to 27-33 kHz for the trawl monitoring system, 
which is not one of the predominant sources, and to 38 kHz for the EK60 
echosounder (see Table 2 and Table 8). These frequencies are above the 
hearing range of baleen whales (i.e., mysticetes); therefore, baleen 
whales would not be expected to perceive signals from NWFSC active 
acoustic sources, and we would not expect any exposures to these 
signals to

[[Page 38552]]

result in behavioral harassment. Baleen whales are not considered 
further in this section.
    The assessment paradigm for active acoustic sources used in NWFSC 
fisheries research is relatively straightforward and has a number of 
key simplifying assumptions. NMFS' 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. For use of these active acoustic systems, the appropriate 
threshold is 160 dB re 1 [mu]Pa (rms). 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 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. 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 NWFSC only uses active acoustic systems for data acquisition 
purposes in the CCRA.
    Sound source characteristics--An initial characterization of the 
general source parameters for the primary active acoustic sources 
operated by the NWFSC was conducted, enabling a full assessment of all 
sound sources used by the NWFSC 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 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.

           Table 8--Effective Exposure Areas for Predominant Acoustic Sources Across Two Depth Strata
----------------------------------------------------------------------------------------------------------------
                                                                                            Effective exposure
                                                                   Effective exposure      area: Sea surface to
                    Active acoustic system                        area: Sea surface to    depth at which 160-dB
                                                                  200 m depth (km\2\)      threshold is reached
                                                                                                 (km\2\)
----------------------------------------------------------------------------------------------------------------
Simrad EK60 narrow beam echosounder...........................                   0.0142                   0.1411
Simrad ME70 multibeam echosounder.............................                   0.0201                   0.0201
Simrad FS70 trawl sonar.......................................                    0.008                    0.008
Simrad SX90 narrow beam sonar \1\.............................                   0.0654                   0.1634
Teledyne RD Instruments ADCP, Ocean Surveyor..................                   0.0086                   0.0187
Simrad ITI trawl monitoring system............................                   0.0032                   0.0032
----------------------------------------------------------------------------------------------------------------
\1\ Exposure area varies greatly depending on the tilt angle setting of the SX90. To approximate the varied
  usage this system might receive, the exposure area for each depth strata was averaged by assuming equal usage
  at tilt angles of 5, 20, 45, and 80 degrees.

    Among Category 2 sources (Table 2), six 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 (i.e., frequency, beamwidth, source level, tilt angle, 
and horizontal and vertical resolution; 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 NWFSC'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

[[Page 38553]]

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; SX90, 
EK60, and ME70) 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 (0-200 
m and greater than 200 m), 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 that would be 
surveyed was determined, as was the relative percentage of surveyed 
linear kilometers associated with each source type. The total line-
kilometers for each vessel, the effective percentages associated with 
each of the resulting three predominant source types (SX90, EK60, and 
ME70), and the effective total line-kilometers of operation for each 
source type are given below.
    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, and accounted for the frequency-
dependent absorption coefficient ([alpha] at 8 [deg]C and 34 ppt) 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 (0-200 m and surface to range at 
which the on-axis received level reaches 160 dB rms). These results, 
shown in Table 8, 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 NWFSC's application) 
multiplied by the total distance traveled by the ship. Where different 
sources operating simultaneously would be predominant in each different 
depth strata (e.g., ME70 and EK60 operating simultaneously may be 
predominant in the shallow stratum and deep stratum, respectively), 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 (e.g., Navy, 2013). 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 
(Allen and Angliss, 2015; Carretta et al., 2015a) and other sources 
(Barlow and Forney, 2007; ManTech-SRS Technologies, 2007). 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 NWFSC fisheries surveys (detailed 
previously in ``Detailed Description of Activities'').
    (2) 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

[[Page 38554]]

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 the depth at which 
this received level condition occurs (i.e., corresponding to the 0 to 
greater than 200 m depth stratum).
    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 either the extent of a depth boundary or the 160 dB rms received 
sound level; 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 portion of the total line-kilometers for which it is 
used and the volumetric density of animals for each species. These 
annual estimates are given below.
    We first provide information related to relative annual usage 
patterns of predominant active acoustic sources. For example, the use 
of the ME70 and EK60 account for predominant sources during all surveys 
on the R/V Bell M. Shimada, with the EK60 used during one hundred 
percent of distance traveled (Table 9). When the ME70 is on, it is the 
dominant source in the 0-200 m depth stratum (0.0201 km\2\ cross-
sectional ensonified area versus 0.0142 km\2\ cross-sectional 
ensonified area for the EK60; Table 8); therefore, the ME70 is the 
dominant active acoustic source for twenty percent of the line-
kilometers and the EK60 is the dominant active acoustic source for the 
other eighty percent. However, in the deeper depth stratum, the EK60 is 
always the dominant source when compared with the ME70 (0.1411 km\2\ 
cross-sectional ensonified area versus 0.0201 km\2\ cross-sectional 
ensonified area for the ME70; Table 8); therefore, the EK60 is the 
dominant active acoustic source in the deeper depth stratum at all 
times for the Shimada. However, of the total line-kilometers of NWFSC 
survey activity aboard the Shimada, only forty percent are in waters 
greater than 200 m.

                      Table 9--Annual Linear Survey Kilometers for Each Vessel and Its Predominant Sources Within Two Depth Strata
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             Line-km/                        Line-km/
                                                             Line-kms/                     % time source     dominant      % time source     dominant
                         Vessel                               vessel          Source       dominant (0-    source (0-200  dominant (>200   source (>200
                                                                                              200 m)            m)              m)              m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Lasker..................................................           4,500            SX90             100           4,500              50           2,250
Shimada.................................................          18,494            ME70              20           3,699               0               0
                                                          ..............            EK60              80          14,795              40           7,398
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Next, we provide volumetric densities for marine mammals in the 
CCRA and total estimated takes by Level B harassment, by dominant 
source and total, for each species in the CCRA (Table 10). We also 
provide a sample calculation.
    We first determine the source-specific ensonified volume of water 
(i.e., the ensonified volume where we consider a specific source to be 
predominant and therefore have the potential to harass marine mammals) 
and then determine source- and species-specific exposure estimates for 
the shallow and deep (if applicable; Table 10) 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 when a given source would be predominant in each 
stratum and use these values to derive an estimated source-specific 
ensonified volume. In order to estimate the additional volume of 
ensonified water in the deep stratum, we first subtract the cross-
sectional ensonified area of the shallow stratum (which is already 
accounted for) from that of the deep stratum. Source- 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.
    (1) EK60 ensonified volume; 0-200 m: 0.0142 km\2\ * 14,795 km = 
210.1 km\3\
    (2) EK60 ensonified volume; >200 m: (0.1411 km\2\ - 0.0142 km\2\) * 
7,398 km = 938.8 km\3\
    (3) Estimated exposures to sound >=160 dB rms; sperm whale; EK60: 
(0.003 sperm whales/km\3\ * 210.1 km\3\ = 0.7 [rounded to 1]) + (0.003 
sperm whales/km\3\ * 938.8 km\3\ = 3.2 [rounded to 3]) = 4 estimated 
sperm whale exposures to SPLs >=160 dB rms resulting from use of the 
EK60.

                    Table 10--Densities and Estimated Source-, Stratum-, and Species-Specific Annual Estimates of Level B Harassment
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Area      Volumetric        Estimated Level B        Estimated Level B
                                                                      density      density         harassment, 0-200 m      harassment, >200 m
                   Species                     Shallow      Deep     (animals/    (animals/  --------------------------------------------------   Total
                                                                     km\2\) \1\   km\3\) \2\    EK60      ME70      SX90      EK60      SX90
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale.................................  .........         X         0.002        0.003         1         0         1         3         1         6

[[Page 38555]]

 
Kogia spp...................................  .........         X         0.001        0.002         0         0         1         2         0         3
Cuvier's beaked whale.......................  .........         X         0.004        0.008         2         1         2         7         2        14
Baird's beaked whale........................  .........         X         0.001        0.002         0         0         1         2         0         3
Mesoplodont beaked whales...................  .........         X         0.001        0.002         0         0         1         2         0         3
Bottlenose dolphin..........................         X   .........        0.002        0.009         2         1         3         0         0         6
Striped dolphin.............................         X   .........        0.017        0.083        18         6        25         0         0        49
Long-beaked common dolphin..................         X   .........        0.019        0.096        20         7        28         0         0        55
Short-beaked common dolphin.................         X   .........        0.309        1.547       325       115       455         0         0       895
Pacific white-sided dolphin.................         X   .........        0.021        0.105        22         8        31         0         0        61
Northern right whale dolphin................         X   .........        0.010        0.049        10         4        14         0         0        28
Risso's dolphin.............................         X   .........        0.010        0.052        11         4        15         0         0        30
Killer whale................................         X   .........        0.001        0.004         1         0         1         0         0         2
Short-finned pilot whale....................  .........         X        0.0003        0.001         0         0         0         1         0         1
Harbor porpoise.............................         X   .........    \4\ 0.038        0.189        40        14        56         0         0       110
Dall's porpoise.............................         X   .........        0.076        0.378        79        28       111         0         0       218
Guadalupe fur seal..........................         X   .........    \3\ 0.007        0.037         8         3        11         0         0        22
Northern fur seal...........................         X   .........    \3\ 0.649        3.245       682       241       955         0         0     1,878
California sea lion.........................         X   .........    \3\ 0.297        1.484       312       110       437         0         0       859
Steller sea lion............................         X   .........    \3\ 0.060        0.301        63        22        89         0         0       174
Harbor seal.................................         X   .........    \3\ 0.056        0.279        59        21        82         0         0       162
Northern elephant seal......................  .........         X     \3\ 0.179        0.358        75        27       105       336        79       622
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ All density estimates from Barlow and Forney (2007) unless otherwise indicated.
\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\ Density estimates derived by NWFSC from SAR abundance estimates and notional study area of 1,000,000 km\2\.
\4\ ManTech-SRS Technologies (2007) estimated a harbor porpoise density for coastal and inland waters of Washington, which is used as the best available
  proxy here. There are no known density estimates for harbor porpoises in NWFSC survey areas in the CCRA.

Estimated Take Due to Physical Disturbance

    Estimated take due to physical disturbance could potentially happen 
in the PSRA and LCRRA, and would result in no greater than Level B 
harassment. 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 
NWFSC vessels or researchers, as a result of unintentional approach 
during survey activity. Behavioral responses may be considered 
according to the scale shown in Table 11 and based on the method 
developed by Mortenson (1996). We consider responses corresponding to 
Levels 2-3 to constitute Level B harassment.

                 Table 11--Seal 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 NWFSC has estimated potential incidents of Level B harassment 
due to physical disturbance (Table 12) by considering the number of 
seals believed to potentially be present at affected haul-outs and the 
number of visits expected to be made by NWFSC researchers. The number 
of haul-outs disturbed and number of animals assumed to be on those 
haul-outs was determined by NWFSC on the basis of anecdotal evidence 
from researchers. 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.

[[Page 38556]]



      Table 12--Estimated Annual Level B Harassment of Pinnipeds Associated With Disturbance by Researchers
----------------------------------------------------------------------------------------------------------------
                                                                     Estimated
                                                                   total number
                                                                   of animals on     Number of       Estimated
                Species                         Location            potentially     visits per    annual Level B
                                                                  disturbed haul-      year         harassment
                                                                       outs
----------------------------------------------------------------------------------------------------------------
Harbor seal...........................  Puget Sound.............           1,440               8          11,520
                                        Columbia River..........           3,000              25          75,000
California sea lion...................  Puget Sound.............             350               8           2,800
----------------------------------------------------------------------------------------------------------------

Summary of Estimated Incidental Take

    Here we provide a summary of the total proposed incidental take 
authorization on an annual basis, as well other information relevant to 
the negligible impact analysis. Table 13 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. As footnoted in Table 13, the indicated level of take could 
occur to any species or stock for those species with multiple stocks 
(e.g., Northern fur seal) or considered as a group (e.g., Mesoplodont 
beaked whales). However, the harbor porpoise and harbor seal each have 
multiple stocks spanning the three NWFSC research areas, and we provide 
further detail regarding our consideration of potential take specific 
to stocks that may occur in the PSRA and LCRRA. Many stocks do not 
occur in those research areas and, therefore, would not be vulnerable 
to interaction with research gear deployed in those areas.
    For harbor porpoise, we propose to authorize a total of five takes 
by M/SI + Level A for all stocks combined over the five-year period of 
validity for these proposed regulations. 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 intended for assessment 
of the significance of harassment. These takes could occur to any 
stock; however, our proposed take authorization is informed by 
reasonable expectation regarding species vulnerability to gear used in 
the three research areas. Of the five total takes, we expect that two 
might occur in the CCRA, one in the PSRA, and two in the LCRRA. 
Therefore, corresponding with the relationship between stock ranges and 
the location of NWFSC research activities, the likely maximum takes 
that could accrue to any harbor porpoise stock from California to 
southern Oregon would be two, while the northern Oregon/Washington 
coast stock could potentially accrue four takes because it is 
vulnerable to the takes expected in either the CCRA or LCRRA. In Table 
13 below, the proposed total take authorization column reflects the 
total of four takes that could occur in either the CCRA or LCRRA (and 
the one take expected in the PSRA, which would occur to the Washington 
inland waters stock). However, the estimated maximum annual take column 
reflects the annualized stock-specific risk, i.e., any stock in the CA-
southern OR grouping is expected to be vulnerable to a maximum of two 
takes over the five-year period (0.4/year) while the northern OR/WA 
coast stock could be vulnerable to as many as four takes over the five 
years (0.8/year). This stock-specific accounting does not change our 
expectation that a total of five takes would occur for all stocks 
combined but informs our stock-specific negligible impact analysis.
    Similarly, the harbor seal has separate designated stocks that may 
occur in all three research areas. We propose to authorize a total of 
thirteen takes by M/SI + Level A for all harbor seal stocks combined, 
and expect that five of these may occur in the CCRA, six in the PSRA, 
and two in the LCRRA. Therefore, while we would expect that a maximum 
of five takes could accrue to the California stock, as many as seven 
takes could occur for the Oregon/Washington coastal stock (which is the 
only stock that may occur in the LCRRA). Although NMFS has split the 
former Washington inland waters stock of harbor seals into three 
separate stocks, we do not have sufficient information to assess stock-
specific risk in the PSRA. Separately, we have estimated that 162 
incidents of acoustic harassment may occur for harbor seals due to 
NWFSC use of active acoustic systems (in the CCRA only) and that, due 
to the physical presence of researchers, individual harbor seals on 
haul-outs (as many as 3,000) may be disturbed up to 25 times per year 
in the LCRRA. Therefore, as shown in Table 13, the California stock of 
harbor seals is vulnerable to only the estimated 162 acoustic 
harassment takes, but the OR/WA coast stock would be vulnerable to both 
the acoustic harassment takes as well as the physical disturbance 
takes. However, note that the percent of estimated population is 
calculated considering the number of individuals anticipated to be 
disturbed rather than the number of incidents of disturbance.
    We previously authorized take of marine mammals incidental to 
fisheries research operations conducted by the SWFSC (see 80 FR 58982 
and 80 FR 68512). This take would occur to some of the same stocks for 
which we propose to authorize take incidental to NWFSC 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 for SWFSC. 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 NWFSC 
and previously authorized for SWFSC 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 13 and in the following 
discussion). PBR and annual M/SI values considered in Table 13 reflect 
the most recent information available (i.e., final 2014 and draft 2015 
SARs, as appropriate).

[[Page 38557]]



                               Table 13--Summary Information Related to NWFSC Proposed Annual Take Authorization, 2016-21
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                    Proposed total
                                    annual Level B      Percent of     Proposed total M/ SWFSC total M/SI      Estimated
           Species \1\                harassment         estimated          SI \3\        authorization,   maximum annual M/ PBR minus annual    Stock
                                     authorization      population      authorization,        2015-20           SI \4\         M/SI (%) \5\    trend \6\
                                          \2\            abundance          2016-21
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale......................                 6               0.3                 0                 0                 0               n/a         ?
Kogia spp........................                 3               0.5                 1                 1               0.4        2.7 (14.8)         ?
Cuvier's beaked whale............                14               0.2                 0                 0                 0               n/a    [darr]
Baird's beaked whale.............                 3               0.4                 0                 0                 0               n/a         ?
Mesoplodont beaked whales........                 3               0.4                 0                 0                 0               n/a    [darr]
Bottlenose dolphin (offshore                      6               0.6                 2                 9               2.6        3.5 (74.3)         ?
 stock)..........................
Striped dolphin..................                49               0.4                 7                12               4.2          82 (5.1)         ?
Long-beaked common dolphin.......                55               0.1                 2                12               3.2       596.2 (0.5)    [uarr]
Short-beaked common dolphin......               895               0.2                 3                12               3.4       3,376 (0.1)         ?
Pacific white-sided dolphin......                61               0.2                31                35              13.6       159.2 (8.5)         ?
Northern right whale dolphin.....                28               0.3                 7                10               3.8        44.4 (8.6)         ?
Risso's dolphin..................                30               0.5                 8                12               4.4       37.4 (11.8)         ?
Killer whale \7\.................                 2               0.8                 0                 0                 0               n/a         ?
Short-finned pilot whale.........                 1               0.1                 1                 1               0.4         4.6 (8.7)         ?
Harbor porpoise (CA-southern OR                 110               3.8                 4                 5               1.8        20.4 (8.8)         ?
 stocks) \7\.....................
Harbor porpoise (Northern OR/WA    ................  ................  ................  ................               2.2         148 (1.5)         ?
 coast)..........................
Harbor porpoise (WA inland                        0               n/a                 1                 0               0.2        60.8 (0.3)         ?
 waters).........................
Dall's porpoise..................               218               0.5                 3                 5                 2       256.6 (0.8)         ?
Guadalupe fur seal...............                22               0.3                 0                 0                 0               n/a    [uarr]
Northern fur seal \6\............         \8\ 1,878               0.3                 5                 5               2.4       449.4 (0.5)    [uarr]
California sea lion..............             3,659               0.4                10                25               7.6       8,815 (0.1)    [uarr]
Steller sea lion.................               174           \8\ 0.3                 9                10               4.4     1,552.7 (0.3)    [uarr]
Harbor seal (CA).................            75,162               0.6                 5                 9               3.2       1,598 (0.2)    [rarr]
Harbor seal (OR/WA coast)........  ................              12.8                 2  ................               1.8           Unknown    [rarr]
Harbor seal (WA inland waters)...            11,520              10.5                 6                 0               1.2           Unknown    [rarr]
Northern elephant seal...........               622               0.3                 5                 5               2.2     4,873.2 (0.1)    [uarr]
Unidentified small cetacean......               n/a               n/a                 1                 1               n/a               n/a       n/a
Unidentified pinniped............               n/a               n/a                 1                 2               n/a               n/a       n/a
--------------------------------------------------------------------------------------------------------------------------------------------------------
Please see Tables 7, 10, and 12 and preceding text for details.
\1\ For species with multiple stocks or for species groups (Kogia spp. and Mesoplodont beaked whales), indicated level of take could occur to
  individuals from any stock or species except as indicated in table.
\2\ Level B harassment totals include estimated take due to acoustic harassment and, for harbor seals and California sea lions, estimated take due to
  physical disturbance. Active acoustic devices are not used for data acquisition in the PSRA; therefore, no takes by acoustic harassment are expected
  for stocks that occur entirely or largely in inland waters (e.g., resident killer whales). Takes by physical disturbance for pinniped species
  represent repeated takes of smaller numbers of individuals (e.g., we expect as many as 1,440 harbor seals in the PSRA to be harassed on as many as
  eight occasions). The ``percent of estimated population'' column represents this smaller number of individuals taken rather than the total number of
  take incidents.
\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 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'
  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 or cetacean that may be captured in trawl gear in the CCRA. 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.
\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). For the Pacific-white sided dolphin, harbor seal, and California sea lion, we subtract the annual
  average of mortalities occurring incidental to NWFSC fisheries research during 2007-11 from the total human-caused M/SI prior to calculating this
  value, as we explicitly account for predicted future mortalities incidental to NWFSC fisheries research via the estimated maximum annual M/SI + Level
  A column. In parentheses, we provide the estimated maximum annual M/SI expressed as a percentage of this value.
\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\ These species have multiple stocks that may be affected. Values for ``percent of estimated population'' and ``PBR--annual M/SI'' (where relevant)
  calculated for the stock with the lowest population abundance and/or PBR (as appropriate). This approach assumes that all indicated takes would accrue
  to the stock in question, which is a very conservative assumption. Stocks in question are the offshore killer whale, Morro Bay harbor porpoise, and
  California northern fur seal.
\8\ A range is provided for Steller sea lion abundance. We have used the lower bound of the given range for calculation of this value.
\8\ Calculated on the basis of relative abundance; i.e., of 1,878 total estimated incidents of Level B harassment, we would expect on the basis of
  relative abundance in the study area that 98 percent would accrue to the Pribilof Islands/Eastern Pacific stock and two percent would accrue to the
  California stock.


[[Page 38558]]

Analyses and Preliminary Determinations

Negligible Impact Analysis

    Introduction--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.'' 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. We also assess the number, intensity, and context of estimated 
takes by evaluating this information relative to population status 
(i.e., the environmental baseline).
    Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into these 
analyses 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, other ongoing sources of human-caused 
mortality, and specific consideration of take by M/SI + Level A 
previously authorized for other NMFS research activities).
    In 1988, Congress amended the MMPA, with provisions for the 
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 set 
allowable take levels incidental to commercial fishing operations led 
NMFS to suggest a new conceptual means for assuring that incidental 
take does not cause any marine mammal species or stock to be reduced or 
to be maintained below the lower limit of its Optimum Sustainable 
Population (OSP) level. That concept, potential biological removal 
(PBR), was incorporated in the 1994 amendments to the MMPA, wherein 
Congress enacted MMPA sections 117 and 118, establishing a new regime 
governing the incidental taking of marine mammals in commercial fishing 
operations and stock assessments.
    PBR, which is defined by 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,'' is one tool 
that can be used to help evaluate the effects of M/SI on a marine 
mammal stock. 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 stock of marine mammal either does not have a level of human-
caused M/SI that is likely to cause the stock to be reduced below its 
OSP level or, if the stock is depleted (i.e., below its OSP level), 
does not have a level of human-caused mortality and serious injury that 
is likely to delay restoration of the stock to OSP level by more than 
ten percent in comparison with recovery time in the absence of human-
caused M/SI.
    PBR, a parametric concept that relates survivorship to population 
size, was developed in consideration of the principle given by Holt and 
Talbot (1978): ``Management decisions should include a safety factor to 
allow for the facts that knowledge is limited and institutions are 
imperfect'' (Taylor, 1993). 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 (Nmin); 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 Nmin 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 was not designed as an absolute threshold limiting human 
activities, but as a means to evaluate the relative impacts of those 
activities on marine mammal stocks. Specifically, assessing M/SI 
relative to a stock's PBR may signal to NMFS the need to establish take 
reduction teams in commercial fisheries and may assist NMFS and 
existing take reduction teams in the identification of measures to 
reduce and/or minimize the taking of marine mammals by commercial 
fisheries to a level below a 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 may prioritize 
working with a take reduction team to further mitigate the effects of 
fishery activities via additional bycatch reduction measures. In 
addition, PBR alone is not used to authorize or deny authorization of 
commercial fisheries that may incidentally take marine mammals.
    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, 
including those within section 101(a)(5)(E) related to the taking of 
ESA-listed marine mammals incidental to commercial fisheries (64 FR 
28800; May 27, 1999). 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. Although NMFS has not historically applied PBR outside the 
context of sections 117, 118, and 101(a)(5)(E), NMFS recognizes that as 
a quantitative tool, PBR may be useful in certain instances for 
evaluating the impacts of other human-caused activities on marine 
mammal stocks.
    Our use of PBR here (for NWFSC fisheries research activities) does 
not make up the entirety of our impact assessment, but rather is being 
utilized as a known, quantitative metric for evaluating whether the 
proposed activities are likely to have a population-level effect on the 
affected

[[Page 38559]]

marine mammal stocks. Here, we calculate a metric that incorporates 
information regarding ongoing anthropogenic mortality into the PBR 
value; i.e., PBR minus the reported annual anthropogenic mortality 
estimate (also referred to as ``residual PBR''; Wood et al., 2012). We 
first consider maximum potential incidental M/SI for NMFS research 
relative to this metric for each affected stock (see Table 13), in 
consideration of NMFS' defined significance threshold for M/SI (ten 
percent of PBR [69 FR 43338; July 20, 2004]). By considering the 
maximum potential incidental M/SI in relation to PBR and other ongoing 
sources of anthropogenic mortality, we ensure that the potential 
incremental addition of M/SI through NMFS' fisheries research 
activities does not pose a risk to the stock that bears further 
consideration here. We also consider the interaction of those removals 
with incidental taking of that stock by harassment pursuant to the 
specified activity (i.e., NWFSC fisheries research activities).
    Therefore, for those stocks with total incidental M/SI less than 
the significance threshold (i.e., ten percent of residual PBR), we 
consider the effects of the specified activity to represent an 
insignificant incremental increase in ongoing anthropogenic M/SI and 
need not consider other factors in making a negligible impact 
determination except in combination with additional incidental take by 
harassment. For those stocks with incidental M/SI exceeding the 
significance threshold, we will consider additional factors that may 
either increase or reduce the level of concern related to the 
significance of a given level of taking--such as implementation of 
mitigation measures or additional population stressors--in addition to 
considering the interaction of those removals with incidental taking of 
that stock by harassment.
    Analysis--Please see Table 13 for information related to this 
analysis. The large majority of stocks that may potentially be taken by 
M/SI + Level A (18 of 21) fall below the significance threshold, while 
an additional four 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 significance threshold. Next, we consider those stocks above 
the significance threshold (i.e., Kogia spp.; the offshore stock of 
bottlenose dolphin, and Risso's dolphin) and those without PBR values 
(harbor seals along the Oregon and Washington coasts and in Washington 
inland waters).
    As described in greater depth previously (see ``Acoustic 
Effects''), we do not believe that NWFSC use of active acoustic sources 
has the likely potential to cause any effect exceeding Level B 
harassment of marine mammals. In addition, for the majority of species, 
the proposed annual take by Level B harassment is very low in relation 
to the population abundance estimate (less than one percent). We have 
produced what we believe to be precautionary estimates of potential 
incidents of Level B harassment. The procedure for producing these 
estimates, described in detail in ``Estimated Take Due to Acoustic 
Harassment,'' represents NMFS' best effort towards balancing the need 
to quantify the potential for occurrence of Level B harassment due to 
production of underwater sound with 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 NWFSC 
operates. The sources considered here have moderate to high output 
frequencies (10 to 180 kHz), 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.
    In addition, otariid pinnipeds are less likely than other taxa to 
perceive acoustic signals generated by NWFSC or, given perception, to 
react to these signals than the quantitative estimates indicate. This 
group of pinnipeds has reduced functional hearing at the higher 
frequencies produced by active acoustic sources considered here (e.g., 
primary operating frequencies of 40-180 kHz) and, based purely on their 
auditory capabilities, the potential impacts are likely much less than 
we have calculated as these relevant factors are not taken into 
account.
    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., 
Southall et al., 2007). 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 NWFSC 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 + Level A for any species.
    Similarly, disturbance of pinnipeds on haul-outs by researchers 
approaching on foot or in small vessels (as is expected for harbor 
seals in the lower Columbia River and Puget Sound and for California 
sea lions in Puget Sound) 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 (less than fifteen percent) of the estimated population 
abundance of the affected stocks would be expected to experience the 
disturbance.
    For Kogia spp. and Risso's dolphin, maximum total potential M/SI 
due to NMFS' fisheries research activity (SWFSC and NWFSC combined) 
approaches fifteen and twelve percent of residual PBR, respectively. 
There are no other known sources of anthropogenic M/SI for Kogia spp. 
The only known source of other anthropogenic mortality for Risso's 
dolphin is in commercial fisheries, but such take is considered to be 
insignificant and approaching zero mortality and serious injury. For 
example, PBR for Risso's dolphin is currently set at 39 and the annual 
average of known ongoing anthropogenic M/SI is 1.6, yielding a residual 
PBR value of 37.4. The

[[Page 38560]]

maximum combined annual average M/SI incidental to NMFS fisheries 
research activity is 4.4, or 11.8 percent of residual PBR.
    M/SI incidental to NMFS' fisheries research activities could be as 
much as 74 percent of residual PBR for the offshore stock of bottlenose 
dolphin, assuming a worst-case scenario in which take of an 
unidentified cetacean is applied to this stock. Fisheries bycatch of 
this stock occurs on an annual basis, though this ongoing level of M/SI 
is accounted for. The majority of takes in commercial fisheries from 
2007-11 were due to interactions with the California drift gillnet 
fishery, and it is possible that these interactions have declined since 
the use of acoustic pingers was required. Any level of removals up to 
PBR could occur while still allowing the stock to reach or maintain its 
optimum sustainable population, as indicated in the definition of the 
PBR metric. Nevertheless, given the small PBR value, fluctuation in the 
amount of incidental take could result in unsustainable levels of 
removal from the stock. If bycatch in commercial fisheries increases, 
or other sources of mortality are recorded for this stock, we will use 
the adaptive management provisions of the proposed regulations to 
prescribe increased mitigation sufficient to reduce the likelihood of 
incidental take in NMFS fisheries research activities. No population 
trends are known for these three stocks.
    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 
(1.8 and 1.2, respectively) is a small fraction of any sustainable take 
level that might be calculated for either stock. For the reasons stated 
above, we do not consider the proposed level of take by acoustic and 
physical disturbance for harbor seals to represent a significant 
additional population stressor when considered in context with the 
proposed level of take by M/SI.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the planned mitigation measures, we 
preliminarily find that the total marine mammal take from NWFSC's 
fisheries research activities will have a negligible impact on the 
affected marine mammal species or stocks. In summary, this finding of 
negligible impact 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 (i.e., below ten percent of residual PBR) for a 
majority of affected stocks; (4) consideration of additional factors 
for Kogia spp. and Risso's dolphin do not reveal cause for concern; (5) 
total maximum potential M/SI incidental to NMFS fisheries research 
activity for bottlenose dolphin, considered in conjunction with other 
sources of ongoing mortality, is currently sustainable because it is 
below the residual PBR level; (6) available information regarding two 
harbor seal stocks 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 addition, no M/SI is proposed 
for authorization for any species or stock that is listed under the ESA 
or considered depleted under the MMPA. 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.

Small Numbers Analysis

    Please see Table 13 for information relating to this small numbers 
analysis. The total amount of taking proposed for authorization is less 
than one percent for a large majority of stocks. The total amount of 
taking for remaining stocks ranges from four to thirteen percent.
    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 mitigation measures, 
we preliminarily find that small numbers of marine mammals will be 
taken relative to the populations of the affected species or stocks.

Proposed Monitoring and Reporting

    In order to issue an incidental take authorization 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 such 
taking.'' The MMPA implementing regulations at 50 CFR 216.104 (a)(13) 
indicate that requests for incidental take authorizations must include 
the suggested means of accomplishing the necessary monitoring and 
reporting that will result in increased knowledge of the species and of 
the level of taking or impacts on populations of marine mammals that 
are expected to be present in the proposed action area.
    Any monitoring requirement we prescribe should improve our 
understanding of one or more of the following:
     Occurrence of marine mammal species in action area (e.g., 
presence, abundance, distribution, density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving, or feeding areas).
     Individual responses to acute stressors, or impacts of 
chronic exposures (behavioral or physiological).
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of an individual; or (2) population, 
species, or stock.
     Effects on marine mammal habitat and resultant impacts to 
marine mammals.
     Mitigation and monitoring effectiveness.
    NWFSC plans to make more systematic its training, operations, data 
collection, animal handling and

[[Page 38561]]

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 NWFSC personnel with no other 
responsibilities 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 NWFSC 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.
    In the PSRA and LCRRA only, the NWFSC will monitor any potential 
disturbance of hauled-out pinnipeds, 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 
11.

Training

    NWFSC anticipates that additional information on practices to avoid 
marine mammal interactions can be gleaned from training sessions and 
more systematic data collection standards. The NWFSC will conduct 
annual trainings 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, recording of count and disturbance observations 
(relevant to AMLR surveys), completion of datasheets, and use of 
equipment. Some of these topics may be familiar to NWFSC staff, who may 
be professional biologists; the NWFSC shall determine the agenda for 
these trainings and ensure that all relevant staff have necessary 
familiarity with these topics. The first training such will include 
three primary elements:
    First, the course will provide an overview of the purpose and need 
for the authorization, including mandatory mitigation measures by gear 
and the purpose for each, and species that NWFSC is authorized to 
incidentally take.
    Second, the training will provide detailed descriptions of 
reporting, data collection, and sampling protocols. This portion of the 
training 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 biological data collection 
and sampling training module will include the same sampling and 
necropsy training that is used for the West Coast Regional Observer 
training.
    NWFSC will also dedicate a portion of training to discussion of 
best professional judgment (which is recognized as an integral 
component of mitigation implementation; see ``Proposed Mitigation''), 
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. 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 
NWFSC 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 NWFSC 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, NWFSC believes adopting these 
protocols for data collection will also increase the information on 
which ``serious injury'' determinations (NMFS, 2012a, b) are based and 
improve scientific knowledge about marine mammals that interact with 
fisheries research gears and the factors that contribute to these 
interactions. NWFSC 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 level of consciousness, remove fishing gear, return an individual 
to water and log activities pertaining to the interaction.
    NWFSC will record interaction information on either existing data 
forms created by other NMFS programs or will develop their own 
standardized forms. To aid in serious injury determinations and comply 
with the current NMFS Serious Injury Guidelines (NMFS, 2012a, b), 
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 NWFSC DEA, ``Protected Species Handling Procedures 
for NWFSC Fisheries Research Vessels.''

Reporting

    As is normally the case, NWFSC 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 NWFSC will follow a 
phased approach with regard to the cessation of its activities and/or 
reporting of such events, as

[[Page 38562]]

described in the proposed regulatory texts following this preamble. In 
addition, Chief Scientists (or cruise leader, CS) will provide reports 
to NWFSC 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 
NWFSC 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 NWFSC will submit annual summary reports to OPR including: (1) 
Annual line-kilometers surveyed during which the EK60, ME70, SX90 (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 hook and line, seine, and 
trawl gear, including number of sets, hook hours, 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 
11, and distance of closest approach; and (5) a written evaluation of 
the effectiveness of NWFSC 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.
    NWFSC 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. NWFSC 
will require that the CS complete data forms and address supplemental 
questions, both of which have been developed to aid in SI 
determinations. NWFSC 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 NWFSC 
will perform all necessary reporting to ensure that any incidental M/SI 
is incorporated as appropriate into relevant SARs.

Adaptive Management

    The regulations governing the take of marine mammals incidental to 
NWFSC 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 
NWFSC 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 
NWFSC 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.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

    There are no relevant subsistence uses of marine mammals implicated 
by these actions. Therefore, we have determined that the total taking 
of affected species or stocks would not have an unmitigable adverse 
impact on the availability of such species or stocks for taking for 
subsistence purposes.

Endangered Species Act (ESA)

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

National Environmental Policy Act (NEPA)

    The NWFSC has prepared a Draft Environmental Assessment (EA; Draft 
Programmatic Environmental Assessment for Fisheries Research Conducted 
and Funded by the Northwest Fisheries Science Center) in accordance 
with NEPA and the regulations published by the Council on Environmental 
Quality. It is posted on the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm. We have independently evaluated the Draft EA 
and are proposing to adopt it. We may prepare a separate NEPA analysis 
and incorporate relevant portions of NWFSC's EA by reference. 
Information in NWFSC's application, EA and this notice collectively 
provide the environmental information related to proposed issuance of 
these regulations for public review and comment. We will review all 
comments submitted in response to this notice as we complete the NEPA 
process, including a decision

[[Page 38563]]

of whether to sign a Finding of No Significant Impact, prior to a final 
decision on the incidental take authorization request.

Request for Information

    NMFS requests interested persons to submit comments, information, 
and suggestions concerning the NWFSC 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: June 6, 2016.
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.

Subpart D [Reserved]

0
2. Add and reserve subpart D.
0
3. Add subpart E to part 219 to read as follows:
Subpart E--Taking Marine Mammals Incidental to Northwest Fisheries 
Science Center Fisheries Research in the California Current
Sec.
219.41 Specified activity and specified geographical region.
219.42 Effective dates.
219.43 Permissible methods of taking.
219.44 Prohibitions.
219.45 Mitigation requirements.
219.46 Requirements for monitoring and reporting.
219.47 Letters of Authorization.
219.48 Renewals and modifications of Letters of Authorization.
219.49 [Reserved]
219.50 [Reserved]


Sec.  219.41  Specified activity and specified geographical region.

    (a) Regulations in this subpart apply only to the National Marine 
Fisheries Service's (NMFS) Northwest Fisheries Science Center (NWFSC) 
and those persons it authorizes or funds to conduct activities on its 
behalf for the taking of marine mammals that occurs in the area 
outlined in paragraph (b) of this section and that occurs incidental to 
research survey program operations.
    (b) The taking of marine mammals by NWFSC may be authorized in a 
Letter of Authorization (LOA) only if it occurs within the California 
Current Ecosystem, including Puget Sound and the Columbia River.


Sec.  219.42  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.  219.43  Permissible methods of taking.

    (a) Under LOAs issued pursuant to Sec. Sec.  216.106 and 219.47 of 
this chapter, the Holder of the LOA (hereinafter ``NWFSC'') may 
incidentally, but not intentionally, take marine mammals within the 
area described in Sec.  219.41(b) of this chapter 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 seine gear, provided the activity is in compliance with all 
terms, conditions, and requirements of the regulations in this subpart 
and the appropriate LOA.


Sec.  219.44  Prohibitions.

    Notwithstanding takings contemplated in Sec.  219.41 and authorized 
by a LOA issued under Sec. Sec.  216.106 and 219.47 of this chapter, no 
person in connection with the activities described in Sec.  219.41 of 
this chapter may:
    (a) Violate, or fail to comply with, the terms, conditions, and 
requirements of this subpart or a LOA issued under Sec. Sec.  216.106 
and 219.47 of this chapter;
    (b) Take any marine mammal not specified in such LOAs;
    (c) Take any marine mammal specified in such LOAs in any manner 
other than as specified;
    (d) Take a marine mammal specified in such LOAs 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 LOAs 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.  219.45  Mitigation requirements.

    When conducting the activities identified in Sec.  219.41(a) of 
this chapter, the mitigation measures contained in any LOA issued under 
Sec. Sec.  216.106 and 219.47 of this chapter must be implemented. 
These mitigation measures shall include but are not limited to:
    (a) General conditions: (1) NWFSC 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.

[[Page 38564]]

    (2) NWFSC 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.
    (3) NWFSC 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.
    (4) When deploying any type of sampling gear at sea, NWFSC 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.
    (5) NWFSC shall implement handling and/or disentanglement protocols 
as specified in the guidance that shall be provided to NWFSC survey 
personnel.
    (b) For all research surveys using trawl, hook and line, or seine 
gear in Puget Sound, the move-on rule mitigation protocol described in 
paragraph (c)(3) shall be implemented upon observation of killer whales 
at any distance.
    (c) Trawl survey protocols: (1) NWFSC shall conduct trawl 
operations as soon as is practicable upon arrival at the sampling 
station.
    (2) NWFSC shall initiate marine mammal watches (visual observation) 
a minimum of ten minutes prior to beginning of net deployment, but 
shall also conduct monitoring during 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) NWFSC shall implement the move-on rule mitigation protocol, as 
described in this paragraph. If one or more marine mammals are observed 
within 500 m of the planned location in the ten minutes before setting 
the trawl gear, 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, NWFSC 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 ten minute 
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 NWFSC shall move again or skip the station. Marine 
mammals that are sighted further than 500 m from the vessel 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. NWFSC may use best professional judgment in making 
these decisions.
    (4) NWFSC 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, NWFSC shall take the 
most appropriate action to avoid marine mammal interaction. NWFSC may 
use best professional judgment in making this decision.
    (5) If trawling operations have been suspended because of the 
presence of marine mammals, NWFSC may resume trawl operations when 
practicable only when the animals are believed to have departed the 
area. NWFSC may use best professional judgment in making this 
determination.
    (6) When conducting surface trawls using the Nordic 264 net, 
dedicated crew with no other tasks shall conduct required marine mammal 
monitoring. Marine mammal monitoring shall be staffed in a stepwise 
process, with a minimum of two observers beginning pre-set monitoring 
and increasing to a minimum of four observers prior to and during gear 
deployment. During the tow, a minimum of three observers shall conduct 
required monitoring.
    (7) NWFSC 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. Trawl nets must 
be cleaned prior to deployment.
    (8) NWFSC must install and use a marine mammal excluder device at 
all times when the Nordic 264 trawl net is used.
    (9) NWFSC must install and use acoustic deterrent devices whenever 
the Nordic 264 trawl net is used, with two pairs of the devices 
installed near the net opening. NWFSC must ensure that the devices are 
operating properly before deploying the net.
    (10) For use of the Kodiak surface trawl in Puget Sound, trawl 
survey protocols described in this section apply only to cetaceans.
    (11) Trawl survey protocols described in this section do not apply 
to use of pair trawl gear in the Columbia River.
    (d) Hook and line (including longline) survey protocols: (1) NWFSC 
shall deploy hook and line gear as soon as is practicable upon arrival 
at the sampling station.
    (2) NWFSC shall initiate marine mammal watches (visual observation) 
no less than thirty 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.
    (3) NWFSC shall implement the move-on rule mitigation protocol, as 
described in this paragraph. If one or more marine mammals are observed 
within 500 m of the planned location in the ten minutes 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, NWFSC 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 thirty minute 
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 NWFSC shall move again or skip the station. Marine 
mammals that are sighted further than 500 m from the vessel 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. NWFSC may use best professional judgment in making 
these decisions.
    (4) NWFSC 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,

[[Page 38565]]

NWFSC shall take the most appropriate action to avoid marine mammal 
interaction. NWFSC may use best professional judgment in making this 
decision.
    (5) If deployment or retrieval operations have been suspended 
because of the presence of marine mammals, NWFSC may resume such 
operations when practicable only when the animals are believed to have 
departed the area. NWFSC may use best professional judgment in making 
this decision.
    (6) NWFSC shall implement standard survey protocols, including 
maximum soak durations and a prohibition on chumming.
    (7) For hook and line surveys in Puget Sound, but not including 
longline surveys, hook and line survey protocols described in this 
section apply only to cetaceans.
    (e) Seine survey protocols: (1) NWFSC shall conduct seine 
operations as soon as is practicable upon arrival at the sampling 
station.
    (2) NWFSC 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) NWFSC shall implement the move-on rule mitigation protocol, as 
described in this paragraph for use of purse seine gear. If one or more 
small cetaceans (i.e., dolphin or porpoise) or five or more pinnipeds 
are observed within 500 m of the planned location before setting the 
seine gear, 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, NWFSC 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 ten minute 
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 NWFSC shall move 
again or skip the station. Marine mammals that are sighted further than 
500 m from the vessel 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. NWFSC may use best 
professional judgment in making these decisions.
    (4) NWFSC shall maintain visual monitoring effort during the entire 
period of time that seine 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, NWFSC shall take the 
most appropriate action to avoid marine mammal interaction. NWFSC may 
use best professional judgment in making this decision.
    (5) If seine operations have been suspended because of the presence 
of marine mammals, NWFSC may resume seine operations when practicable 
only when the animals are believed to have departed the area. NWFSC may 
use best professional judgment in making this determination.
    (6) If any cetaceans are observed in a purse seine net, NWFSC shall 
immediately open the net and free the animals.
    (7) NWFSC shall not make beach seine sets within 200 m of any 
hauled-out pinniped, and shall immediately remove the gear from the 
water upon observation of any marine mammal attempting to interact with 
the gear.


Sec.  219.46  Requirements for monitoring and reporting.

    (a) NWFSC shall designate a compliance coordinator who shall be 
responsible for ensuring compliance with all requirements of any LOA 
issued pursuant to Sec. Sec.  216.106 and 219.47 of this chapter and 
for preparing for any subsequent request(s) for incidental take 
authorization.
    (b) Visual monitoring program: (1) Marine mammal visual monitoring 
shall occur prior to deployment of trawl, seine, and hook and line 
gear, respectively; throughout deployment of gear and active fishing of 
research gears (not including longline soak time); prior to retrieval 
of longline gear; and throughout retrieval of all research gear.
    (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.
    (c) Training: (1) NWFSC 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. NWFSC may determine the agenda for 
these trainings.
    (2) NWFSC 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) NWFSC shall coordinate with NMFS' Southwest Fisheries Science 
Center (SWFSC) regarding surveys conducted in the California Current 
Ecosystem, such that training and guidance related to handling 
procedures and data collection is consistent.
    (d) Handling procedures and data collection: (1) NWFSC must develop 
and implement standardized marine mammal handling, disentanglement, and 
data collection procedures. These standard procedures will be subject 
to approval by NMFS' Office of Protected Resources (OPR).
    (2) When practicable, for any marine mammal interaction involving 
the release of a live animal, NWFSC shall collect necessary data to 
facilitate a serious injury determination.
    (3) NWFSC 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.
    (4) NWFSC shall record such data on standardized forms, which will 
be subject to approval by OPR. NWFSC shall also answer a standard 
series of supplemental questions regarding the details of any marine 
mammal interaction.
    (e) Reporting: (1) NWFSC shall report all incidents of marine 
mammal interaction to NMFS' Protected Species Incidental Take database 
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) NWFSC shall submit an annual summary 
report to OPR not later than ninety days following the end of a given 
year. NWFSC 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:

[[Page 38566]]

    (A) Annual line-kilometers surveyed during which the EK60, ME70, 
SX90 (or equivalent sources) were predominant and associated pro-rated 
estimates of actual take;
    (B) Summary information regarding use of all hook and line, seine, 
and trawl gear, including number of sets, hook hours, tows, etc., 
specific to each gear;
    (C) 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;
    (D) A written evaluation of the effectiveness of NWFSC 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 NWFSC and any 
coordination with SWFSC or NMFS' West Coast Regional Office.
    (f) Reporting of injured or dead marine mammals:
    (1) In the unanticipated event that the activity defined in Sec.  
219.41(a) clearly causes the take of a marine mammal in a prohibited 
manner, NWFSC 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 NWFSC 
Director (or designee). The incident must be reported immediately to 
OPR and the West Coast Regional Stranding Coordinator, NMFS. OPR will 
review the circumstances of the prohibited take and work with NWFSC to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. The immediate 
decision made by NWFSC 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 NWFSC 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), NWFSC shall immediately report the incident to OPR 
and the West Coast 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 NWFSC to determine whether additional 
mitigation measures or modifications to the activities are appropriate.
    (3) In the event that NWFSC 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.  219.41(a) (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, scavenger damage), NWFSC shall report the incident to 
OPR and the West Coast Regional Stranding Coordinator, NMFS, within 24 
hours of the discovery. NWFSC shall provide photographs or video 
footage or other documentation of the stranded animal sighting to OPR.


Sec.  219.47  Letters of Authorization.

    (a) To incidentally take marine mammals pursuant to these 
regulations, NWFSC must apply for and obtain an LOA.
    (b) An LOA, unless suspended or revoked, may be effective for a 
period of time not to exceed the expiration date of these regulations.
    (c) If an LOA expires prior to the expiration date of these 
regulations, NWFSC 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, NWFSC must apply 
for and obtain a modification of the LOA as described in Sec.  219.48 
of this chapter.
    (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.  219.48  Renewals and modifications of Letters of Authorization.

    (a) An LOA issued under Sec. Sec.  216.106 and 219.47 of this 
chapter for the activity identified in Sec.  219.41(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. Sec.  216.106 and 219.47 of this 
chapter for the activity identified in Sec.  219.41(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 NWFSC 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 NWFSC's monitoring from the previous year(s).
    (B) Results from other marine mammal and/or sound research or 
studies.

[[Page 38567]]

    (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. Sec.  216.106 
and 219.47 of this chapter, 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.  219.49  [Reserved]


Sec.  219.50  [Reserved]

[FR Doc. 2016-13655 Filed 6-10-16; 8:45 am]
 BILLING CODE 3510-22-P