[Federal Register Volume 82, Number 140 (Monday, July 24, 2017)]
[Notices]
[Pages 34352-34382]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-15455]



[[Page 34351]]

Vol. 82

Monday,

No. 140

July 24, 2017

Part II





Department of Commerce





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





National Oceanic and Atmospheric Administration





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





Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to a Geophysical Survey in the Central 
Pacific Ocean; Notices

  Federal Register / Vol. 82 , No. 140 / Monday, July 24, 2017 / 
Notices  

[[Page 34352]]


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

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF330


Takes of Marine Mammals Incidental To Specified Activities; 
Taking Marine Mammals Incidental to a Geophysical Survey in the Central 
Pacific Ocean

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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

SUMMARY: NMFS has received a request from the University of Hawaii (UH) 
for authorization to take marine mammals incidental to a marine 
geophysical survey in the Central Pacific Ocean. Pursuant to the Marine 
Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an incidental harassment authorization (IHA) to 
incidentally take marine mammals during the specified activities. NMFS 
will consider public comments prior to making any final decision on the 
issuance of the requested MMPA authorization and agency responses will 
be summarized in the final notice of our decision.

DATES: Comments and information must be received no later than August 
23, 2017.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at www.nmfs.noaa.gov/pr/permits/incidental/research.htm without change. All personal 
identifying information (e.g., name, address) voluntarily submitted by 
the commenter may be publicly accessible. Do not submit confidential 
business information or otherwise sensitive or protected information.

FOR FURTHER INFORMATION CONTACT: Jordan Carduner, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: www.nmfs.noaa.gov/pr/permits/incidental/research.htm. In case of problems accessing these documents, 
please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce (as delegated to NMFS) to allow, upon 
request, the incidental, but not intentional, taking of small numbers 
of marine mammals by U.S. citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment. Accordingly, NMFS is preparing an 
Environmental Assessment (EA) to consider the environmental impacts 
associated with the issuance of the proposed IHA. NMFS' EA is available 
at www.nmfs.noaa.gov/pr/permits/incidental/research.htm. We will review 
all comments submitted in response to this notice prior to concluding 
our NEPA process or making a final decision on the IHA request.

Summary of Request

    On March 15, 2016, NMFS received a request from the UH for an IHA 
to take marine mammals incidental to conducting a marine geophysical 
survey in the Central Pacific Ocean. On May 16, 2017, we deemed UH's 
application for authorization to be adequate and complete. UH's request 
is for take of a small number of 24 species of marine mammals by Level 
B harassment and Level A harassment. Neither UH nor NMFS expects 
mortality to result from this activity, and, therefore, an IHA is 
appropriate. The planned activity is not expected to exceed one year, 
hence, we do not expect subsequent MMPA incidental harassment 
authorizations would be issued for this particular activity.

Description of Proposed Activity

Overview

    UH, in collaboration with the Japan Agency for Marine-Earth Science 
and Technology (JAMSTEC), proposes to conduct a marine seismic survey 
north of Hawaii in the Central Pacific Ocean over the course of five 
and a half days in September 2017. The proposed survey would occur 
north of the Hawaiian Islands, in the approximate area 22.6-25.0[deg] 
N. and 153.5-157.4[deg] W. (See Figure 1 in IHA application). The 
project area is partly within the exclusive economic zone (EEZ) of the 
United States and partly in adjacent international waters. Water depths 
in the area range from 4000 to 5000 m. The survey would involve one 
source vessel, the Japan-flagged R/V (research vessel) Kairei. The 
Kairei would deploy a 32-airgun array with a total volume of ~7800 
cubic inches (in\3\) as an energy source.

[[Page 34353]]

Dates and Duration

    The seismic survey would be carried out for approximately five and 
a half days, including three and half days within the Hawaiian Islands 
EEZ and two days in international waters. The survey would start on 
approximately September 15, 2017. Exact dates of the activities are not 
known as they are dependent on logistics and weather conditions. 
Seismic activities would occur 24 hours per day during the proposed 
survey.

Specific Geographic Region

    The survey would encompass the approximate area 22.6-25.0[deg] N. 
and 153.5-157.4[deg] W. in the central Pacific Ocean north of Hawaii, 
partly within the Hawaiian Islands EEZ and partly in international 
waters. Water depth in the survey area ranges from approximately 4000 
to 5000 m. Representative survey track lines are shown in Figure 1 in 
the IHA application. However, some deviation in actual track lines 
could be necessary for reasons such as poor data quality, inclement 
weather, or mechanical issues with the research vessel and/or 
equipment. The Kairei would likely depart from Honolulu, Hawaii and 
return to Honolulu.

Detailed Description of Specific Activity

    Conventional seismic methodology would be used to image a typical/
stable oceanic crust, mantle, and the boundary between the Earth's 
crust and the mantle (called the Mohorovi[ccaron]i[cacute] 
discontinuity (Moho)). The data obtained from the survey would be used 
to help better inform and further refine planning efforts for a 
proposed ``Project Mohole'' under consideration for scheduling by the 
International Ocean Discovery Program (IODP). The total survey effort 
would consist of ~1083 kilometers (km) of transect lines (Figure 1 in 
IHA application).
    The R/V Kairei has a length of 106.0 meters (m), a beam of 16.0 m, 
and a maximum draft of 4.7 m. Its propulsion system consists of two 
diesel engines, each producing 2206 kW, which drive the two propellers 
at 600 revolutions per minute (rpm). The operation speed during seismic 
acquisition would be ~8.3 km/hour (~4.5 knots (kn)). When not towing 
seismic survey gear, the Kairei typically cruises at 30 km/hour (~16.2 
kn) and has a range of ~18,000 km.
    During the survey, the Kairei would deploy an airgun array (i.e., a 
certain number of airguns of varying sizes in a certain arrangement) as 
an energy source (Table 1). An airgun is a device used to emit acoustic 
energy pulses into the seafloor and generally consists of a steel 
cylinder that is charged with high-pressure air. Release of the 
compressed air into the water column generates a signal that reflects 
(or refracts) off the seafloor and/or subsurface layers having acoustic 
impedance contrast. When fired, a brief (~0.1 second) pulse of sound is 
emitted by all airguns nearly simultaneously. The airguns are silent 
during the intervening periods with the array typically fired on a 
fixed distance (or shot point) interval. The return signal is recorded 
by a listening device and later analyzed with computer interpretation 
and mapping systems used to depict the subsurface.
    The airgun array to be used would consist of 32 Bolt Annular Port 
airguns, with a total volume of ~7800 in\3\. The airguns would be 
configured as four identical linear arrays or ``strings'' (See Figure 2 
in the IHA application for a visual representation of the strings). 
Each string would have 8 airguns; the first and last airguns in the 
strings would be spaced 10 m apart. All 8 airguns in each string would 
be fired simultaneously. The 4 airgun strings would be towed behind the 
Kairei and would be distributed across an area ~40 m x 10 m. The shot 
interval would be ~22 seconds. The firing pressure of the array would 
be ~2000 psi. During firing, a brief (~0.1 s) pulse of sound would be 
emitted. The airguns would be silent during the intervening periods. 
The array would be towed at a depth of 10 m. It is expected that the 
aigun array would be active 24 hours per day during seismic activities. 
Specifications of the Kairei's airgun array are shown in Table 1. 
Source levels of the Kairei's airgun array are shown in Table 6.

         Table 1--Specifications of the R/V Kairei Airgun Array
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Number of airguns.........................  32.
Tow depth of energy source................  10 meters (m).
Dominant frequency components.............  2-120 Hz.
Total volume..............................  ~7800 in.\3\
Pulse duration............................  ~0.1 second.
Shot interval.............................  ~22 seconds.
------------------------------------------------------------------------

    The receiving system would consist of one 6 km long hydrophone 
streamer and ocean bottom seismometers (OBSs). As the airgun array is 
towed along the survey lines, the hydrophone streamer would receive the 
returning acoustic signals and transfer the data to the on-board 
processing system. The OBSs would record the returning acoustic signals 
internally for later analysis. Upon arrival at the survey area, two 
OBSs would be deployed. The streamer and airgun array would then be 
deployed, and seismic operations would commence. After completion of 
seismic operations, the OBSs would be recovered by UH via a separate 
vessel; the recovery cruise would be funded by the National Science 
Foundation.
    Survey protocols generally involve a predetermined set of survey, 
or track, lines. The seismic acquisition vessel (source vessel) travels 
down a linear track for some distance until a line of data is acquired, 
then turn and acquire data on a different track. In the case of the 
proposed survey, the two shorter north-south lines would each be 
surveyed once, while the longer west-east line would be surveyed twice 
(see Figure 1 in the IHA application).
    In addition to the operations of the airgun array, a SeaBeam 3012 
multibeam echosounder (MBES) would also be operated from the Kairei 
continuously throughout the survey. The MBES would operate at 12 
kilohertz (kHz) and would be hull-mounted on the Kairei. The 
transmitting beamwidth of the MBES would be 2[deg] fore-aft and 
150[deg] (max.) athwartship, or 120[deg] (in water up to 4500 m deep), 
and 100[deg] (in water up to 8000 m).
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see ``Proposed 
Mitigation'' and ``Proposed Monitoring and Reporting'').

Description of Marine Mammals in the Area of Specified Activities

    Section 4 of the application summarizes available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS' Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/), and more general information about these species (e.g., 
physical and behavioral descriptions) may be found on NMFS' Web site 
(www.nmfs.noaa.gov/pr/species/mammals/).
    Table 2 lists all species with expected potential for occurrence in 
the central Pacific Ocean and summarizes information related to the 
population or stock, including regulatory status under the MMPA and ESA 
and potential biological removal (PBR), where known. For taxonomy, we 
follow Committee on Taxonomy (2016). PBR is defined by the MMPA as the 
maximum number of animals, not including natural mortalities, that may 
be removed from a marine mammal stock while allowing that stock to 
reach or maintain its optimum sustainable population (as

[[Page 34354]]

described in NMFS' SARs). While no mortality is anticipated or 
authorized here, PBR and annual serious injury and mortality from 
anthropogenic sources are included here as gross indicators of the 
status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Pacific SARs (e.g., Carretta et al. 2017). All values 
presented in Table 2 are the most recent available at the time of 
publication and are available in the 2016 SARs (Carretta et al. 2017), 
available online at: www.nmfs.noaa.gov/pr/sars, except where noted 
otherwise.

                                              Table 2--Marine Mammals that Could Occur in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                      Stock abundance \2\
                                                                ESA/MMPA status;        (CV, Nmin, most                             Relative  occurrence
              Species                         Stock            strategic (Y/N) \1\      recent abundance           PBR \4\            in  project area
                                                                                          survey) \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Family: Balaenopteridae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale (Megaptera            Central North Pacific.  -/-; N................  10,103 (0.300; 7,890;  83...................  Seasonal; throughout
 novaeangliae) \5\.                                                                   2006).                                        known breeding
                                                                                                                                    grounds during
                                                                                                                                    winter and spring
                                                                                                                                    (most common
                                                                                                                                    November through
                                                                                                                                    April).
Blue whale (Balaenoptera musculus).  Central North Pacific.  E/D; Y................  81 (1.14; 38; 2010)..  0.1..................  Seasonal; infrequent
                                                                                                                                    winter migrant; few
                                                                                                                                    sightings, mainly
                                                                                                                                    fall and winter;
                                                                                                                                    considered rare.
Fin whale (Balaenoptera physalus)..  Hawaii................  E/D; Y................  58 (1.12; 27; 2010)..  0.1..................  Seasonal, mainly fall
                                                                                                                                    and winter;
                                                                                                                                    considered rare.
Sei whale (Balaenoptera borealis)..  Hawaii................  E/D; Y................  178 (0.90; 93; 2010).  0.2..................  Rare; limited
                                                                                                                                    sightings of
                                                                                                                                    seasonal migrants
                                                                                                                                    that feed at higher
                                                                                                                                    latitudes.
Bryde's whale (Balaenoptera brydei/  Hawaii................  -/-; N................  798 (0.28; 633; 2010)  6.3..................  Uncommon; distributed
 edeni).                                                                                                                            throughout the
                                                                                                                                    Hawaiian Exclusive
                                                                                                                                    Economic Zone.
Minke Whale (Balaenoptera            Hawaii................  -/-; N................  n/a (n/a; n/a; 2010).  Undet................  Seasonal, mainly fall
 acutorostrata).                                                                                                                    and winter;
                                                                                                                                    considered rare.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Family: Physeteridae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sperm whale (Physeter                Hawaii................  E/D; Y................  3,354 (0.34; 2,539;    10.2.................  Widely distributed
 macrocephalus).                                                                      2010).                                        year round.
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Family: Kogiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pygmy sperm whale \6\ (Kogia         Hawaii................  -/-; N................  7,139 (2.91; n/a;      Undet................  Widely distributed
 breviceps).                                                                          2006).                                        year round.
Dwarf sperm whale \6\ (Kogia sima).  Hawaii................  -/-; N................  17,519 (7.14; n/a;     Undet................  Widely distributed
                                                                                      2006).                                        year round.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Family: Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Killer whale (Orcinus orca)........  Hawaii................  -/-; N................  101 (1.00; 50; 2010).  1....................  Uncommon; infrequent
                                                                                                                                    sightings.
False killer whale (Pseudorca        Hawaii Pelagic........  -/-; N................  1,540 (0.66; 928;      9.3..................  Regular.
 crassidens).                                                                         2010).
Pygmy killer whale (Feresa           Hawaii................  -/-; N................  3,433 (0.52; 2,274;    23...................  Year-round resident.
 attenuata).                                                                          2010).
Short-finned pilot whale             Hawaii................  -/-; N................  12,422 (0.43; 8,872;   70...................  Commonly observed
 (Globicephala macrorhynchus).                                                        2010).                                        around Main Hawaiian
                                                                                                                                    Islands and
                                                                                                                                    Northwestern
                                                                                                                                    Hawaiian Islands.
Melon headed whale (Peponocephala    Hawaiian Islands......  -/-; N................  5,794 (0.20; 4,904;    4....................  Regular.
 electra).                                                                            2010).
Bottlenose dolphin (Tursiops         Hawaii pelagic........  -/-; N................  5,950 (0.59; 3,755;    38...................  Common in deep
 truncatus).                                                                          2010).                                        offshore waters.
Pantropical spotted dolphin          Hawaii pelagic........  -/-; N................  15,917 (0.40; 11,508;  115..................  Common; primary
 (Stenella attenuata).                                                                2010).                                        occurrence between
                                                                                                                                    100 and 4,000 m
                                                                                                                                    depth.
Striped dolphin (Stenella            Hawaii................  -/-; N................  20,650 (0.36; 15,391;  154..................  Occurs regularly year
 coeruleoala).                                                                        2010).                                        round but infrequent
                                                                                                                                    sighting during
                                                                                                                                    survey.
Spinner dolphin \6\ (Stenella        Hawaii pelagic........  -/-; N................  3,351 (0.74; n/a;      Undet................  Common year-round in
 longirostris).                                                                       2006).                                        offshore waters.
Rough-toothed dolphin (Steno         Hawaii................  -/-; N................  6,288 (0.39; 4,581;    46...................  Common throughout the
 bredanensis).                                                                        2010).                                        Main Hawaiian
                                                                                                                                    Islands and Hawaiian
                                                                                                                                    Islands EEZ.
Fraser's dolphin (Lagenodelphis      Hawaii................  -/-; N................  16,992 (0.66; 10,241;  102..................  Tropical species only
 hosei).                                                                              2010).                                        recently documented
                                                                                                                                    within Hawaiian
                                                                                                                                    Islands EEZ (2002
                                                                                                                                    survey).

[[Page 34355]]

 
Risso's dolphin (Grampus griseus)..  Hawaii................  -/-; N................  7,256 (0.41; 5,207;    42...................  Previously considered
                                                                                      2010).                                        rare but multiple
                                                                                                                                    sightings in
                                                                                                                                    Hawaiian Islands EEZ
                                                                                                                                    during various
                                                                                                                                    surveys conducted
                                                                                                                                    from 2002-2012.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Family: Ziphiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cuvier's beaked whale (Ziphius       Hawaii................  -/-; N................  1,941 (n/a; 1,142;     11.4.................  Year-round occurrence
 cavirostris).                                                                        2010).                                        but difficult to
                                                                                                                                    detect due to diving
                                                                                                                                    behavior.
Blainville's beaked whale            Hawaii................  -/-; N................  2,338 (1.13; 1,088;    11...................  Year-round occurrence
 (Mesoplodon densirostris).                                                           2010).                                        but difficult to
                                                                                                                                    detect due to diving
                                                                                                                                    behavior.
Longman's beaked whale (Indopacetus  Hawaii................  -/-; N................  4,571 (0.65; 2,773;    28...................  Considered rare;
 pacificus).                                                                          2010).                                        however, multiple
                                                                                                                                    sightings during
                                                                                                                                    2010 survey.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 (see footnote 3) 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\ Abundance estimates from Carretta et al. (2017) unless otherwise noted.
\3\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For certain stocks, abundance
  estimates are actual counts of animals and there is no associated CV. The most recent abundance survey that is reflected in the abundance estimate is
  presented; there may be more recent surveys that have not yet been incorporated into the estimate.
\4\ Potential biological removal (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 size (OSP).
\5\ Values for humpback whale are from the 2015 Alaska SAR (Muto et al. 2015).
\6\ Values for spinner dolphin, dwarf and pygmy sperm whale are from Barlow et al. (2006).

    All species that could potentially occur in the proposed survey 
area are included in Table 2. We have reviewed UH's species 
descriptions, including life history information, distribution, 
regional distribution, diving behavior, and acoustics and hearing, for 
accuracy and completeness. We refer the reader to Section 4 of UH's IHA 
application, rather than reprinting the information here. Below, for 
the 24 species that are likely to be taken by the activities described, 
we offer a brief introduction to the species and relevant stock as well 
as available information regarding population trends and threats, and 
describe any information regarding local occurrence.

Humpback Whale

    Humpback whales are found worldwide in all ocean basins. In winter, 
most humpback whales occur in the subtropical and tropical waters of 
the Northern and Southern Hemispheres (Muto et al., 2015). These 
wintering grounds are used for mating, giving birth, and nursing new 
calves. Humpback whales migrate nearly 3,000 mi (4,830 km) from their 
winter breeding grounds to their summer foraging grounds in Alaska.
    There are five stocks of humpback whales, one of which occurs in 
Hawaii: The Central North Pacific Stock, which consists of winter/
spring populations in the Hawaiian Islands, which migrate primarily to 
northern British Columbia/Southeast Alaska, the Gulf of Alaska, and the 
Bering Sea/Aleutian Islands (Muto et al., 2015). Humpback whales occur 
seasonally in Hawaii, with peak sightings between December and May each 
year; however, sightings have occurred in other months in very low 
numbers. Most humpback whales congregate off the island of Maui in the 
shallow protected waters but can be seen off all of the islands 
including the Northwestern Hawaiian Islands (Baird 2016).
    Humpback whales were listed as endangered under the Endangered 
Species Conservation Act (ESCA) in June 1970. In 1973, the ESA replaced 
the ESCA, and humpbacks continued to be listed as endangered. NMFS 
recently evaluated the status of the species, and on September 8, 2016, 
NMFS divided the species into 14 distinct population segments (DPS), 
removed the current species-level listing, and in its place listed four 
DPSs as endangered and one DPS as threatened (81 FR 62259; September 8, 
2016). The remaining nine DPSs were not listed. The Hawaii DPS is the 
only DPS that occurs in the survey area and is not listed under the ESA 
(81 FR 62259; September 8, 2016). The Central North Pacific stock is 
still considered a depleted and strategic stock under the MMPA.

Blue Whale

    The blue whale has a cosmopolitan distribution and tends to be 
pelagic, only coming nearshore to feed and possibly to breed (Jefferson 
et al. 2008). Blue whale migration is less well defined than for some 
other rorquals, and their movements tend to be more closely linked to 
areas of high primary productivity, and hence prey, to meet their high 
energetic demands (Branch et al. 2007). Generally, blue whales are 
seasonal migrants between high latitudes in the summer, where they 
feed, and low latitudes in the winter, where they mate and give birth 
(Lockyer and Brown 1981). Some individuals may stay in low or high 
latitudes throughout the year (Reilly and Thayer 1990; Watkins et al. 
2000). Blue whales belonging to the central Pacific stock appear to 
feed in summer southwest of Kamchatka, south of the Aleutians, and in 
the Gulf of Alaska (Stafford 2003; Watkins et al. 2000), and in winter 
migrate to lower latitudes in the western and central Pacific, 
including Hawaii (Stafford et al. 2001).
    From ship line-transect surveys, Wade and Gerrodette (1993) 
estimated 1,400 blue whales for the eastern tropical Pacific. A 2010 
shipboard line-transect survey of the entire Hawaiian Islands EEZ 
resulted in a summer/fall abundance estimate of 81 (CV = 1.14) blue 
whales (Bradford et al. 2013). This is currently the best available 
abundance estimate for this stock within the Hawaii EEZ, though the 
majority of blue whales would be expected to be at higher latitudes 
feeding grounds at this time of year. Blue whales are listed as 
endangered under the ESA, and the Central North Pacific Stock of blue 
whales is considered a depleted and strategic stock under the MMPA.

[[Page 34356]]

Fin Whale

    Fin whales are found throughout all oceans from tropical to polar 
latitudes. They have been considered rare in Hawaiian waters and are 
absent to rare in eastern tropical Pacific waters (Hamilton et al. 
2009). The fin whale most commonly occurs offshore but can also be 
found in coastal areas (Aguilar 2009). Most populations migrate 
seasonally between temperate waters where mating and calving occur in 
winter, and polar waters where feeding occurs in summer (Aguilar 2009). 
However, recent evidence suggests that some animals may remain at high 
latitudes in winter or low latitudes in summer (Edwards et al. 2015).
    During spring and summer, fin whale occurrence in Hawaii is 
considered rare (DoN 2005). There were 5 sightings of fin whales during 
summer-fall surveys in 2002, most to the northwest of the Main Hawaiian 
Islands (Barlow et al. 2004) and two sightings in the Hawaiian Islands 
EEZ during summer-fall 2010 (Bradford et al. 2013); there were no 
sightings in or near the proposed survey area (Carretta et al. 2015). 
Two additional sightings in the EEZ were made by observers on Hawaii-
based longline fishing vessels, including one near the proposed survey 
area (Carretta et al. 2015). Fin whales are listed as endangered under 
the ESA, and the Hawaii stock of fin whales is considered depleted 
under the MMPA.

Sei Whale

    The sei whale occurs in all ocean basins (Horwood 2009) but appears 
to prefer mid-latitude temperate waters (Jefferson et al. 2008). It 
undertakes seasonal migrations to feed in subpolar latitudes during 
summer and returns to lower latitudes during winter to calve (Horwood 
2009). The sei whale is pelagic and generally not found in coastal 
waters (Harwood and Wilson 2001). It occurs in deeper waters 
characteristic of the continental shelf edge region (Hain et al. 1985) 
and in other regions of steep bathymetric relief such as seamounts and 
canyons (Kenney and Winn 1987; Gregr and Trites 2001).
    Sei whales occur seasonally in Hawaii in the winter and spring 
months and feed in higher latitude feeding grounds in the summer and 
fall (Carretta et al., 2016). Sightings of this species are rare in 
Hawaii. The species stays offshore of the islands in deeper waters 
(Baird 2016). Sei whales are listed as endangered under the ESA, and 
the Hawaii stock of sei whales is considered a depleted and strategic 
stock under the MMPA.

Bryde's Whale

    The Bryde's whale occurs in all tropical and warm temperate waters 
in the Pacific, Atlantic, and Indian oceans, between 40[deg] N. and 
40[deg] S. (Kato and Perrin 2009). Although there is a pattern of 
movement toward the Equator in the winter and the poles during the 
summer, Bryde's whale does not undergo long seasonal migrations, 
remaining in warm (>16 [deg]C) water year-round (Kato and Perrin 2009).
    Bryde's whales are known to occur in both shallow coastal and 
deeper offshore waters (Jefferson et al. 2008). In Hawaii, Bryde's 
whales are typically seen offshore (e.g., Barlow et al. 2004; Barlow 
2006), but Hopkins et al. (2009) reported a Bryde's whale within 70 km 
of the Main Hawaiian Islands. During summer-fall surveys of the 
Hawaiian Islands EEZ, 13 sightings were made in 2002 (Barlow 2006) and 
32 sightings were made during 2010 (Bradford et al. 2013). Bryde's 
whales were primarily sighted in the western half of the Hawaiian 
Islands EEZ, with the majority of sightings associated with the 
Northwestern Hawaiian Islands; none was made in or near the proposed 
survey area (Barlow et al. 2004; Barlow 2006; Bradford et al. 2013; 
Carretta et al. 2015). The Bryde's whale is not listed under the ESA, 
and the Hawaii stock is not listed as depleted or strategic under the 
MMPA.

Minke Whale

    The minke whale has a cosmopolitan distribution ranging from the 
tropics and subtropics to the ice edge in both hemispheres (Jefferson 
et al. 2008) and is thought to occur seasonally in Hawaii, from 
November through March (Rankin and Barlow 2005), though their migration 
routes or destinations are unknown. While they are generally believed 
to be uncommon in Hawaiian waters, several studies using acoustic 
detections suggest that minke whales may be more common than previously 
thought (Rankin et al. 2007; Oswald et al. 2011; Martin et al. 2012). 
Acoustic detections have been recorded around the Hawaiian Islands 
during fall-spring surveys in 1997 and 2000-2006 (Rankin and Barlow 
2005; Barlow et al. 2008; Rankin et al. 2008), and from seafloor 
hydrophones positioned ~50 km from the coast of Kauai during February-
April 2006 (Martin et al. 2012). Passive acoustic detections of minke 
whales have been recorded at ALOHA station (22.75[deg] N., 158[deg] W.) 
from October to May for decades (Oswald et al. 2011). A lack of 
sightings is likely related to misidentification or low detection 
capability in poor sighting conditions (Rankin et al. 2007). The minke 
whale is not listed under the ESA, and the Hawaii stock is not listed 
as depleted under the MMPA.

Sperm Whale

    Sperm whales are widely distributed across the entire North Pacific 
and into the southern Bering Sea in summer, but the majority are 
thought to be south of 40[deg] N. in winter (Rice 1974, 1989; Gosho et 
al. 1984; Miyashita et al. 1995). The Hawaii stock includes animals 
found both within the Hawaiian Islands EEZ and in adjacent high seas 
waters; however, because data on abundance, distribution, and human-
caused impacts are largely lacking for high seas waters, the status of 
the Hawaii stock is evaluated based on data from U.S. EEZ waters of the 
Hawaiian Islands (NMFS 2005).
    Sperm whales are widely distributed in Hawaiian waters throughout 
the year (Mobley et al. 2000). During summer-fall surveys of the 
Hawaiian Islands EEZ, 43 sightings were made in 2002 (Barlow 2006) and 
41 were made in 2010 (Bradford et al. 2013). Sightings were widely 
distributed across the EEZ during both surveys; numerous sightings 
occurred in and adjacent to the proposed survey area (Barlow et al. 
2004; Barlow 2006; Bradford et al. 2013). Sperm whales are listed as 
endangered under the ESA, and the Hawaii stock is considered depleted 
and strategic under the MMPA.

Pygmy Sperm Whale

    Pygmy sperm whales are found in tropical and warm-temperate waters 
throughout the world (Ross and Leatherwood 1994) and prefer deeper 
waters with observations of this species in greater than 4,000 m depth 
(Baird et al., 2013). Sightings are rare of this species. They are 
difficult to sight at sea, because of their dive behavior and perhaps 
because of their avoidance reactions to ships and behavior changes in 
relation to survey aircraft (W[uuml]rsig et al. 1998). Both pygmy and 
dwarf sperm whales are sighted primarily along the continental shelf 
edge and slope and over deeper waters off the shelf (Hansen et al. 
1994; Davis et al. 1998; Jefferson et al. 2008). There is a single 
stock of Pygmy sperm whales in Hawaii. Current abundance estimates for 
this stock are unknown. Pygmy sperm whales are not listed as endangered 
or threatened under the ESA, and the Hawaii stock is not considered 
strategic or designated as depleted under the MMPA.

Dwarf Sperm Whale

    Dwarf sperm whales are found throughout the world in tropical to

[[Page 34357]]

warm-temperate waters (Carretta et al., 2014). They are usually found 
in waters deeper than 500 m, most often sighted in depths between 500 
and 1,000 m, but they have been documented in depths as shallow as 106 
m and as deep as 4,700 m (Baird 2016). This species is often alone or 
in small groups of up to two to four individuals (Baird 2016). When 
there are more than two animals together, they are often loosely 
associated, with up to several hundred meters between pairs of 
individuals (Baird 2016). There is one stock of dwarf sperm whales in 
Hawaii. Sighting data suggests a small resident population off Hawaii 
Island (Baird 2016). It has been suggested that this species is 
probably one of the more abundant species of cetaceans in Hawaiian 
waters (Baird 2016), though there are no current abundance estimates 
for this stock. Dwarf sperm whales are not listed as endangered or 
threatened under the ESA, and the Hawaii stock is not designated as 
depleted or strategic under the MMPA.

Killer Whale

    Killer whales have been observed in all oceans and seas of the 
world (Leatherwood and Dahlheim 1978). Although reported from tropical 
and offshore waters (Heyning and Dahlheim 1988), killer whales prefer 
the colder waters of both hemispheres, with greatest abundances found 
within 800 km of major continents (Mitchell 1975). High densities of 
the species occur in high latitudes, especially in areas where prey is 
abundant.
    Killer whales are considered rare in Hawaiian waters (Carretta et 
al. 2017). Twenty one sighting records were reported in Hawaiian waters 
between 1994 and 2004 (Baird et al. 2006). During summer-fall surveys 
of the Hawaiian Islands EEZ, two sightings were made in 2002 (Barlow et 
al. 2004; Barlow 2006) and one was made in 2010 (Bradford et al. 2013), 
none near the proposed survey area (Barlow et al. 2004; Bradford et al. 
2013; Carretta et al. 2017). Numerous additional sightings in and north 
of the EEZ have been made by observers on longliners, some in and near 
the proposed survey area (Carretta et al. 2017). Killer whales are not 
listed as endangered or threatened under the ESA (with the exception of 
the endangered Southern Resident DPS which does not occur in the survey 
area), and the Hawaii stock is not designated as depleted or strategic 
under the MMPA.

False Killer Whale

    False killer whales are found worldwide in tropical and warm-
temperate waters (Stacey et al. 1994). In the North Pacific, this 
species is well known from southern Japan, Hawaii, and the eastern 
tropical Pacific. The species generally inhabits deep, offshore waters, 
but sometimes is found over the continental shelf and occasionally 
moves into very shallow water (Jefferson et al. 2008; Baird 2009).
    Telemetry, photo-identification, and genetic studies have 
identified three independent populations of false killer whales in 
Hawaiian waters: Main (insular) Hawaiian Islands, Northwestern Hawaiian 
Islands, and surrounding pelagic stock (Chivers et al. 2010; Baird et 
al. 2010, 2013; Bradford et al. 2014). Based on the ranges of these 
stocks, only the Hawaii pelagic stock is expected to occur in the 
survey area (Carretta et al. 2017). False killer whales are not listed 
as endangered or threatened under the ESA (with the exception of the 
endangered Main Hawaiian Islands insular DPS which does not occur in 
the survey area), and the Hawaii pelagic stock is not designated as 
depleted or strategic under the MMPA.

Pygmy Killer Whale

    The pygmy killer whale has a worldwide distribution in tropical and 
subtropical waters (Donahue and Perryman 2009), generally not ranging 
south of 35[deg] S. (Jefferson et al. 2008). In warmer water, it is 
usually seen close to the coast (Wade and Gerrodette 1993), but it is 
also found in deep waters. In Hawaiian waters, the pygmy killer whale 
is found in nearshore waters but rarely offshore (Carretta et al. 
2015). During small-boat surveys around the Hawaiian Islands in 2000-
2012, sightings were made in water up to 3,000 m deep (Baird et al. 
2013).
    Though a small resident population occurs in the main Hawaiian 
Islands, pygmy killer whales are relatively rare in Hawaiian waters 
(McSweeney et al. 2009). Satellite telemetry data from four tagged 
pygmy killer whales suggest the resident group remains within 20 km of 
shore (Baird et al. 2011) so would be unlikely in the proposed survey 
area. Movements have been documented between Hawaii Island and Oahu and 
between Oahu and Lanai (Baird et al. 2011a). Pygmy killer whales are 
not listed under the ESA, and the Hawaii stock is not listed as is not 
considered a depleted or strategic stock under the MMPA.

Short-Finned Pilot Whale

    Short-finned pilot whales are found in all oceans, primarily in 
tropical and warm-temperate waters (Carretta et al., 2016). The species 
prefers deeper waters, ranging from 324 m to 4,400 m, with most 
sightings between 500 m and 3,000 m (Baird 2016). This stock forms 
stable social groups, with average group size of 18 individuals but may 
form large aggregations of close to 200 individuals (Baird 2016). Other 
research suggests a larger average group size of 40.9 individuals 
(Bradford et al., 2017), but most of these sightings were farther 
offshore in pelagic waters.
    Short-finned pilot whales are commonly observed around the main 
Hawaiian Islands and are also present around the Northwestern Hawaiian 
Islands (Shallenberger 1981, Baird et al. 2013). Photo-identification 
and telemetry studies suggest there may be inshore and pelagic 
populations of short finned pilot whales in Hawaiian waters. Resighting 
and social network analyses of individuals photographed off Hawaii 
Island suggest the occurrence of one large and several smaller social 
clusters that use those waters, with some individuals within the 
smaller social clusters commonly resighted off Hawaii Island (Mahaffy 
2012). Short-finned pilot whales are not listed as endangered or 
threatened under the ESA, and the Hawaii stock is not considered a 
depleted or strategic stock under the MMPA.

Melon-Headed Whale

    Melon-headed whales are found in tropical and warm-temperate waters 
throughout the world (Carretta et al., 2016). The distribution of 
reported sightings suggests that the oceanic habitat of this species is 
primarily equatorial waters (Perryman et al. 1994). The species forms 
large groups, with average group size of almost 250 individuals, with 
the largest group documented at close to 800 individuals (Baird 2016).
    There are two demographically-independent populations in Hawaiian 
waters, the Hawaiian Islands stock and the Kohala resident stock 
(Carretta et al., 2016). The Kohala resident stock have a small range 
restricted to the shallow waters around Hawaii Island, whereas the 
Hawaiian Islands stock are found throughout the islands and offshore in 
pelagic areas (Carretta et al., 2016). As such, only the Hawaiian 
Islands stock may be affected by the proposed activities. This stock 
prefers waters deeper than 1,000 m (Baird 2016). Satellite telemetry 
data revealed distant pelagic movements, associated with feeding, 
nearly to the edge of the Hawaiian Islands EEZ; the most distal 
telemetry locations were near the proposed survey area at ~22.3[deg] 
N., 154.0[deg] W. (Oleson et al. 2013). Melon-headed whales are not 
listed as

[[Page 34358]]

endangered or threatened under the ESA and the Hawaiian Islands stock 
is not considered a depleted or strategic stock under the MMPA.

Bottlenose Dolphin

    Bottlenose dolphins are widely distributed throughout the world in 
tropical and warm-temperate waters (Perrin et al. 2009). Generally, 
there are two distinct bottlenose dolphin ecotypes: One mainly found in 
coastal waters and one mainly found in oceanic waters (Duffield et al. 
1983; Hoelzel et al. 1998; Walker et al. 1999). As well as inhabiting 
different areas, these ecotypes differ in their diving abilities 
(Klatsky 2004) and prey types (Mead and Potter 1995).
    There are four resident insular stocks of bottlenose dolphins 
around the Main Hawaiian Islands and one pelagic stock (Carretta et 
al., 2016). Photo-identification studies have suggested that the 1,000-
m isobath serves as the boundary between resident insular stocks of the 
Main Hawaiian Islands and the Hawaii pelagic stock (Martien et al. 
2012). Only the pelagic stock may be affected by the proposed activity. 
Bottlenose dolphins are not listed as endangered or threatened under 
the ESA, and the Hawaii pelagic stock is not considered a depleted or 
strategic stock under the MMPA.

Pantropical Spotted Dolphin

    Pantropical spotted dolphins are primarily found in tropical and 
subtropical waters worldwide (Perrin et al. 2009). There are two forms 
of pantropical spotted dolphin: Coastal and offshore. Pantropical 
spotted dolphins prefer deeper waters between 1,500 m and 3,000 m and 
forms large groups with average group size of 60 individuals, with the 
largest group estimated at 400 individuals (Baird 2016).
    Pantropical spotted dolphins are common and abundant throughout the 
Hawaiian archipelago (Baird et al. 2013). It is expected that it would 
be one of the most abundant cetaceans in the proposed survey area. 
There are four resident coastal stocks in Hawaii in addition to the 
Hawaii pelagic stock. Due to their ranges, only the pelagic stock is 
likely to be encountered in the project area (Carretta et al., 2016). 
Pantropical spotted dolphins are not listed as endangered or threatened 
under the ESA, and the Hawaii pelagic stock is not considered a 
depleted or strategic stock under the MMPA.

Striped Dolphin

    Striped dolphins are found in tropical to warm-temperate waters 
throughout the world (Carretta et al., 2016). This is a deep water 
species, preferring depths greater than 3,500 m (Baird 2016). Striped 
dolphins occur primarily in pelagic waters, but have been observed 
approaching shore where there is deep water close to the coast 
(Jefferson et al. 2008). This species forms large groups, with an 
average group size of 28 individuals, and a maximum group size of 100 
individuals (Baird 2016).
    The striped dolphin is expected to be one of the most abundant 
cetaceans in the proposed survey area. It has been sighted near the 
proposed survey area during summer-fall shipboard surveys of the Hawaii 
Islands EEZ (Carretta et al. 2017). Striped dolphins are not listed as 
endangered or threatened under the ESA, and the Hawaii stock of striped 
dolphins is not considered a depleted or strategic stock under the 
MMPA.

Spinner Dolphin

    Spinner dolphins are found in tropical and warm-temperate waters 
worldwide (Carretta et al., 2016). They are pantropical in 
distribution, including oceanic tropical and sub-tropical waters 
between 40[deg] N. and 40[deg] S. (Jefferson et al., 2008). Generally 
considered a pelagic species (Perrin 2009b), spinner dolphins can also 
be found in coastal waters and around oceanic islands (Rice 1998). 
There are six separate stocks managed within the Hawaiian Islands EEZ 
(Carretta et al. 2017); only individuals of the Hawaii pelagic stock 
are expected to overlap with the proposed survey area. Spinner dolphins 
have been sighted near the proposed survey area during summer-fall 
surveys of the Hawaiian Islands EEZ (Carretta et al. 2017). The spinner 
dolphin is not listed as endangered or threatened under the ESA, and 
the Hawaii pelagic stock is not considered a depleted or strategic 
stock under the MMPA.

Rough-Toothed Dolphin

    Rough-toothed dolphins are found in tropical and warm-temperate 
waters (Carretta et al., 2016). While there is evidence for two island-
associated stocks and one pelagic stock in Hawaii, there is only one 
stock designated for Hawaii (Carretta et al., 2016). Most sightings of 
this species off Kauai are in water depths of less than 1,000 m; 
however, it is the most often sighted species in depths greater than 
3,000 m (Baird 2016). This species forms stable associations as part of 
larger groups, with average group sizes of 11 animals and maximum group 
sizes, observed off Kauai, of 140 individuals (Baird 2016).
    The rough-toothed dolphin is expected to be one of the most 
abundant cetaceans in the proposed survey area (Barlow et al. 2004; 
Barlow 2006; Bradford et al. 2013). During summer-fall surveys of the 
Hawaiian Islands EEZ in 2002 and 2010, rough-toothed dolphins were 
observed throughout the EEZ and near the proposed survey area. The 
rough-toothed dolphin is not listed as endangered or threatened under 
the ESA, and the Hawaii stock is not considered a depleted or strategic 
stock under the MMPA.

Fraser's Dolphin

    Fraser's dolphin are found in tropical waters (Carretta et al., 
2011). This is a deep water species occurring offshore of the Hawaiian 
islands, with sightings occurring in water depths between 1,515 m and 
4,600 m (Baird 2016). The species forms large groups with average group 
sizes between 75 and 110 individuals (Baird 2016). Fraser's dolphin is 
one of the most abundant cetaceans in the Hawaiian Islands EEZ (Barlow 
2006; Bradford et al. 2013). Fraser's dolphin is not listed as 
endangered or threatened under the ESA, and the Hawaii stock is not 
considered a depleted or strategic stock under the MMPA.

Risso's Dolphin

    Risso's dolphins are found in tropical to warm-temperate waters 
(Carretta et al., 2016). The species occurs from coastal to deep water 
but is most often found in depths greater than 3,000 m with the highest 
sighting rate in depths greater than 4,500 m (Baird 2016). It occurs 
between 60[deg] N. and 60[deg] S. where surface water temperatures are 
at least 10[ordm] C (Kruse et al. 1999). The species forms small groups 
with an average group size of 4 individuals, and a maximum group size 
of 25 individuals off the coast of Hawaii (Baird 2016). Risso's 
dolphins are not listed as endangered or threatened under the ESA, and 
the Hawaii stock is not considered a depleted or strategic stock under 
the MMPA.

Longman's Beaked Whale

    The Longman's beaked whale, also known as Indo-Pacific beaked 
whale, is considered one of the least known cetacean species (Carretta 
et al., 2016). Longman's beaked whales are found in tropical waters 
from the eastern Pacific westward through the Indian Ocean to the 
eastern coast of Africa (Carretta et al., 2016). The species occurs is 
most often sighted in waters with temperatures >=26[deg] C and depth 
>2,000 m, and sightings have also been reported along the continental 
slope (Anderson et al. 2006; Pitman 2009). Group sizes range from 18 to 
110

[[Page 34359]]

individuals (Baird 2016). The Longman's beaked whale is not listed as 
endangered or threatened under the ESA, and the Hawaii stock is not 
considered a depleted or strategic stock under the MMPA.

Cuvier's Beaked Whale

    Cuvier's beaked whale is the most widespread of the beaked whales 
occurring in almost all temperate, subtropical, and tropical waters and 
even some sub-polar and polar waters (MacLeod et al. 2006). It is found 
in deep water over and near the continental slope (Jefferson et al. 
2008). In the eastern tropical Pacific, the mean water depth for 
sighted Cuvier's beaked whales was ~3.4 km (Ferguson et al. 2006). 
During small-boat surveys around the Hawaiian Islands in 2000-2012, 
sightings were made in water depths of 500-4000 m (Baird et al. 2013). 
Summer/fall shipboard surveys of the waters within the U.S. EEZ of the 
Hawaiian Islands resulted in 4 sightings in 2002 and 22 in 2010, 
including markedly higher sighting rates during nearshore surveys in 
the Northwestern Hawaiian Islands. (Barlow 2006, Bradford et al. 2013). 
Resighting and movement data of individual Cuvier's beaked whales 
suggest the existence of insular and offshore populations of this 
species in Hawaiian waters. A 21-yr study off Hawaii Island suggests 
long-term site fidelity and year-round occurrence (McSweeney et al. 
2007). The Cuvier's beaked whale is not listed as endangered or 
threatened under the ESA, and the Hawaii stock is not considered a 
depleted or strategic stock under the MMPA.

Blainville's Beaked Whale

    Blainville's beaked whale is found in tropical and warm temperate 
waters of all oceans; it has the widest distribution throughout the 
world of all mesoplodont species and appears to be common (Pitman 
2009b). Recent analysis of Blainville's beaked whale resightings and 
movements near the main Hawaiian Islands suggest the existence of 
insular and pelagic populations of this species in Hawaiian waters 
(McSweeney et al. 2007, Schorr et al. 2009, Baird et al. 2013). Photo-
identification of individual Blainville's beaked whales from Hawaii 
Island since 1986 reveal repeated use of this area by individuals for 
over 17 years (Baird et al. 2011) and 75% of individuals seen off 
Hawaii Island link by association into a single social network (Baird 
et al. 2013). Those individuals seen farthest from shore and in deep 
water (>2100m) have not been resighted, suggesting they may be part of 
an offshore, pelagic population (Baird et al. 2011). The Hawaii stock 
of Blainville's beaked whales includes animals found both within the 
Hawaiian Islands EEZ and in adjacent high seas waters. The Blainville's 
beaked whale is not listed as endangered or threatened under the ESA, 
and the Hawaii stock is not considered a depleted or strategic stock 
under the MMPA.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

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

Description of Active Acoustic Sound Sources

    This section contains a brief technical background on sound, the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document.
    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. Root mean square is calculated by squaring 
all of the sound amplitudes, averaging the squares, and then taking the 
square root of the average (Urick, 1983). Root mean square accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral effects, in part because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy contained within a puls and considers both 
intensity and duration of exposure. Peak sound pressure (also referred 
to as zero-to-peak sound pressure or 0-p) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source and is represented in the same units as the rms sound pressure. 
Another common metric is peak-to-peak sound pressure (pk-pk), which is 
the algebraic difference between the peak positive and peak negative 
sound pressures. Peak-to-peak pressure is typically approximately 6 dB 
higher than peak pressure (Southall et al., 2007).
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in a 
manner similar to ripples on the surface of a pond and may be either 
directed in a beam or beams or may radiate in all directions 
(omnidirectional sources), as is the case for pulses produced by the 
airgun arrays considered here. 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

[[Page 34360]]

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 a given 
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., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or 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.
    Airgun arrays produce pulsed signals with energy in a frequency 
range from about 10-2,000 Hz, with most energy radiated at frequencies 
below 200 Hz. The amplitude of the acoustic wave emitted from the 
source is equal in all directions (i.e., omnidirectional), but airgun 
arrays do possess some directionality due to different phase delays 
between guns in different directions. Airgun arrays are typically tuned 
to maximize functionality for data acquisition purposes, meaning that 
sound transmitted in horizontal directions and at higher frequencies is 
minimized to the extent possible.
    As described above, a SeaBeam 3012 MBES would also be operated from 
the Kairei continuously throughout the survey. Due to the lower source 
level of the MBES relative to the Kairei's airgun array (241 dB re 1 
[mu]Pa [middot] m for the MBES versus 259 dB re 1 [mu]Pa [middot] m 
(rms) for the airgun array), the sounds from the MBES are expected to 
be effectively subsumed by the sounds from the airgun array. In 
addition, given the movement and speed of the vessel, the intermittent 
and narrow downward-directed nature of the sounds emitted by the MBES 
would result in no more than one or two brief ping exposures of any 
individual marine mammal, if any exposure were to occur. For these 
reasons, any marine mammal that was exposed to sounds from the MBES 
would already have been exposed to sounds from the airgun array, which 
are expected to propagate further in the water. As such, the MBES is 
not expected to result in the take of any marine mammal that has not 
already been taken by the sounds from the airgun array, and therefore 
we do not consider noise from the MBES further in this analysis.

Acoustic Effects

    Here, we first provide background information on marine mammal 
hearing before discussing the potential effects of the use of active 
acoustic sources on marine mammals.
    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

[[Page 34361]]

hearing groups based on directly measured or estimated hearing ranges 
on the basis of available behavioral response data, audiograms derived 
using auditory evoked potential techniques, anatomical modeling, and 
other data. Note that no direct measurements of hearing ability have 
been successfully completed for mysticetes (i.e., low-frequency 
cetaceans). Subsequently, NMFS (2016) described generalized hearing 
ranges for these marine mammal hearing groups. Generalized hearing 
ranges were chosen based on the approximately 65 dB threshold from the 
normalized composite audiograms, with the exception for lower limits 
for low-frequency cetaceans where the lower bound was deemed to be 
biologically implausible and the lower bound from Southall et al. 
(2007) retained. Pinniped functional hearing is not discussed here, as 
no pinnipeds are expected to be affected by the specified activity. 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): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz, with best 
hearing estimated to be from 100 Hz to 8 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz, with best hearing from 10 to 
less than 100 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.

 Table 3--Marine Functional Mammal Hearing Groups and Their Generalized
                             Hearing Ranges
------------------------------------------------------------------------
               Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low frequency (LF) cetaceans (baleen        7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,     150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true         275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus cruciger
 and L. australis).
Phocid pinnipeds (PW) (underwater) (true    50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea    60 Hz to 39 kHz.
 lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Twenty four marine mammal species (all cetaceans) have the reasonable 
potential to co-occur with the proposed survey activities. Please refer 
to Table 2. Of the cetacean species that may be present, six are 
classified as low-frequency cetaceans (i.e., all mysticete species), 16 
are classified as mid-frequency cetaceans (i.e., all delphinid and 
ziphiid species and the sperm whale), and two are classified as high-
frequency cetaceans (i.e., 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. Note that, in the following discussion, we refer 
in many cases to a recent review article concerning studies of noise-
induced hearing loss conducted from 1996-2015 (i.e., Finneran, 2015). 
For study-specific citations, please see that work. Anthropogenic 
sounds cover a broad range of frequencies and sound levels and can have 
a range of highly variable impacts on marine life, from none or minor 
to potentially severe responses, depending on received levels, duration 
of exposure, behavioral context, and various other factors. The 
potential effects of underwater sound from active acoustic sources can 
potentially result in one or more of the following: Temporary or 
permanent hearing impairment, non-auditory physical or physiological 
effects, behavioral disturbance, stress, and masking (Richardson et 
al., 1995; Gordon et al., 2004; Nowacek et al., 2007; Southall et al., 
2007; G[ouml]tz et al., 2009). The degree of effect is intrinsically 
related to the signal characteristics, received level, distance from 
the source, and duration of the sound exposure. In general, sudden, 
high level sounds can cause hearing loss, as can longer exposures to 
lower level sounds. Temporary or permanent loss of hearing will occur 
almost exclusively for noise within an animal's hearing range. We first 
describe specific manifestations of acoustic effects before providing 
discussion specific to the use of airgun arrays.
    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 certain non-auditory physical 
or physiological effects only briefly as we do not expect that use of 
airgun arrays are reasonably likely to result in such effects (see 
below for further discussion). Potential effects from impulsive sound 
sources can range in severity from effects such as behavioral 
disturbance or tactile perception to physical discomfort, slight injury 
of the internal organs and the auditory system, or mortality (Yelverton 
et al., 1973). Non-auditory physiological effects or injuries that 
theoretically might occur in

[[Page 34362]]

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; Tal et al., 2015). The survey activities 
considered here do not involve the use of devices such as explosives or 
mid-frequency tactical sonar that are associated with these types of 
effects.
    1. Threshold Shift--Marine mammals exposed to high-intensity sound, 
or to lower-intensity sound for prolonged periods, can experience 
hearing threshold shift (TS), which is the loss of hearing sensitivity 
at certain frequency ranges (Finneran, 2015). TS can be permanent 
(PTS), in which case the loss of hearing sensitivity is not fully 
recoverable, or temporary (TTS), in which case the animal's hearing 
threshold would recover over time (Southall et al., 2007). Repeated 
sound exposure that leads to TTS could cause PTS. In severe cases of 
PTS, there can be total or partial deafness, while in most cases the 
animal has an impaired ability to hear sounds in specific frequency 
ranges (Kryter, 1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans but such 
relationships are assumed to be similar to those in humans and other 
terrestrial mammals. PTS typically occurs at exposure levels at least 
several decibels above (a 40-dB threshold shift approximates PTS onset; 
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB 
threshold shift approximates TTS onset; e.g., Southall et al. 2007). 
Based on data from terrestrial mammals, a precautionary assumption is 
that the PTS thresholds for impulse sounds (such as airgun 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.
    For mid-frequency cetaceans in particular, potential protective 
mechanisms may help limit onset of TTS or prevent onset of PTS. Such 
mechanisms include dampening of hearing, auditory adaptation, or 
behavioral amelioration (e.g., Nachtigall and Supin, 2013; Miller et 
al., 2012; Finneran et al., 2015; Popov et al., 2016).
    TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter, 1985). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher level in order to be 
heard. In terrestrial and marine mammals, TTS can last from minutes or 
hours to days (in cases of strong TTS). In many cases, hearing 
sensitivity recovers rapidly after exposure to the sound ends. Few data 
on sound levels and durations necessary to elicit mild TTS have been 
obtained for marine mammals.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to 
serious. For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS in a non-critical frequency 
range that occurs during a time where ambient noise is lower and there 
are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts.
    Finneran et al. (2015) measured hearing thresholds in three captive 
bottlenose dolphins before and after exposure to ten pulses produced by 
a seismic airgun in order to study TTS induced after exposure to 
multiple pulses. Exposures began at relatively low levels and gradually 
increased over a period of several months, with the highest exposures 
at peak SPLs from 196 to 210 dB and cumulative (unweighted) SELs from 
193-195 dB. No substantial TTS was observed. In addition, behavioral 
reactions were observed that indicated that animals can learn behaviors 
that effectively mitigate noise exposures (although exposure patterns 
must be learned, which is less likely in wild animals than for the 
captive animals considered in this study). The authors note that the 
failure to induce more significant auditory effects likely due to the 
intermittent nature of exposure, the relatively low peak pressure 
produced by the acoustic source, and the low-frequency energy in airgun 
pulses as compared with the frequency range of best sensitivity for 
dolphins and other mid-frequency cetaceans.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin, beluga whale, harbor porpoise, and Yangtze finless 
porpoise) exposed to a limited number of sound sources (i.e., mostly 
tones and octave-band noise) in laboratory settings (Finneran, 2015). 
In general, harbor porpoises have a lower TTS onset than other measured 
cetacean species (Finneran, 2015). Additionally, the existing marine 
mammal TTS data come from a limited number of individuals within these 
species. There are no data available on noise-induced hearing loss for 
mysticetes.
    Critical questions remain regarding the rate of TTS growth and 
recovery after exposure to intermittent noise and the effects of single 
and multiple pulses. Data at present are also insufficient to construct 
generalized models for recovery and determine the time necessary to 
treat subsequent exposures as independent events. More information is 
needed on the relationship between auditory evoked potential and 
behavioral measures of TTS for various stimuli. For summaries of data 
on TTS in marine mammals or for further discussion of TTS onset 
thresholds, please see Southall et al. (2007), Finneran and Jenkins 
(2012), Finneran (2015), and NMFS (2016).
    2. Behavioral Effects--Behavioral disturbance may include a variety 
of effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. Behavioral responses to sound are highly 
variable and context-specific and any reactions depend on numerous 
intrinsic and extrinsic factors (e.g., species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day), as well as the interplay between factors (e.g., 
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007; 
Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not 
only among

[[Page 34363]]

individuals but also within an individual, depending on previous 
experience with a sound source, context, and numerous other factors 
(Ellison et al., 2012), and can vary depending on characteristics 
associated with the sound source (e.g., whether it is moving or 
stationary, number of sources, distance from the source). Please see 
Appendices B-C of Southall et al. (2007) for a review of studies 
involving marine mammal behavioral responses to sound.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance (Bejder et al., 2009). The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. As noted, behavioral state may affect the type of response. 
For example, animals that are resting may show greater behavioral 
change in response to disturbing sound levels than animals that are 
highly motivated to remain in an area for feeding (Richardson et al., 
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with 
captive marine mammals have showed pronounced behavioral reactions, 
including avoidance of loud sound sources (Ridgway et al., 1997). 
Observed responses of wild marine mammals to loud pulsed sound sources 
(typically seismic airguns or acoustic harassment devices) have been 
varied but often consist of avoidance behavior or other behavioral 
changes suggesting discomfort (Morton and Symonds, 2002; see also 
Richardson et al., 1995; Nowacek et al., 2007). However, many 
delphinids approach acoustic source vessels with no apparent discomfort 
or obvious behavioral change (e.g., Barkaszi et al., 2012).
    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; 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.
    Visual tracking, passive acoustic monitoring, and movement 
recording tags were used to quantify sperm whale behavior prior to, 
during, and following exposure to airgun arrays at received levels in 
the range 140-160 dB at distances of 7-13 km, following a phase-in of 
sound intensity and full array exposures at 1-13 km (Madsen et al., 
2006; Miller et al., 2009). Sperm whales did not exhibit horizontal 
avoidance behavior at the surface. However, foraging behavior may have 
been affected. The sperm whales exhibited 19 percent less vocal (buzz) 
rate during full exposure relative to post exposure, and the whale that 
was approached most closely had an extended resting period and did not 
resume foraging until the airguns had ceased firing. The remaining 
whales continued to execute foraging dives throughout exposure; 
however, swimming movements during foraging dives were 6 percent lower 
during exposure than control periods (Miller et al., 2009). These data 
raise concerns that seismic surveys may impact foraging behavior in 
sperm whales, although more data are required to understand whether the 
differences were due to exposure or natural variation in sperm whale 
behavior (Miller et al., 2009).
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et 
al., 2007; Gailey et al., 2016).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Cerchio et al. (2014) used passive acoustic monitoring to document 
the presence of singing humpback whales

[[Page 34364]]

off the coast of northern Angola and to opportunistically test for the 
effect of seismic survey activity on the number of singing whales. Two 
recording units were deployed between March and December 2008 in the 
offshore environment; numbers of singers were counted every hour. 
Generalized Additive Mixed Models were used to assess the effect of 
survey day (seasonality), hour (diel variation), moon phase, and 
received levels of noise (measured from a single pulse during each ten 
minute sampled period) on singer number. The number of singers 
significantly decreased with increasing received level of noise, 
suggesting that humpback whale breeding activity was disrupted to some 
extent by the survey activity.
    Castellote et al. (2012) reported acoustic and behavioral changes 
by fin whales in response to shipping and airgun noise. Acoustic 
features of fin whale song notes recorded in the Mediterranean Sea and 
northeast Atlantic Ocean were compared for areas with different 
shipping noise levels and traffic intensities and during a seismic 
airgun survey. During the first 72 h of the survey, a steady decrease 
in song received levels and bearings to singers indicated that whales 
moved away from the acoustic source and out of the study area. This 
displacement persisted for a time period well beyond the 10-day 
duration of seismic airgun activity, providing evidence that fin whales 
may avoid an area for an extended period in the presence of increased 
noise. The authors hypothesize that fin whale acoustic communication is 
modified to compensate for increased background noise and that a 
sensitization process may play a role in the observed temporary 
displacement.
    Seismic pulses at average received levels of 131 dB re 1 
[micro]Pa\2\-s caused blue whales to increase call production (Di Iorio 
and Clark, 2010). In contrast, McDonald et al. (1995) tracked a blue 
whale with seafloor seismometers and reported that it stopped 
vocalizing and changed its travel direction at a range of 10 km from 
the acoustic source vessel (estimated received level 143 dB pk-pk). 
Blackwell et al. (2013) found that bowhead whale call rates dropped 
significantly at onset of airgun use at sites with a median distance of 
41-45 km from the survey. Blackwell et al. (2015) expanded this 
analysis to show that whales actually increased calling rates as soon 
as airgun signals were detectable before ultimately decreasing calling 
rates at higher received levels (i.e., 10-minute SELcum of 
~127 dB). Overall, these results suggest that bowhead whales may adjust 
their vocal output in an effort to compensate for noise before ceasing 
vocalization effort and ultimately deflecting from the acoustic source 
(Blackwell et al., 2013, 2015). These studies demonstrate that even low 
levels of noise received far from the source can induce changes in 
vocalization and/or behavior for mysticetes.
    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). Humpback whales showed avoidance behavior in the presence of an 
active seismic array during observational studies and controlled 
exposure experiments in western Australia (McCauley et al., 2000). 
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., Bejder et al., 2006; Teilmann et al., 2006).
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996). The result of a flight response could range from 
brief, temporary exertion and displacement from the area where the 
signal provokes flight to, in extreme cases, marine mammal strandings 
(Evans and England, 2001). However, it should be noted that response to 
a perceived predator does not necessarily invoke flight (Ford and 
Reeves, 2008), and whether individuals are solitary or in groups may 
influence the response.
    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In 
addition, chronic disturbance can cause population declines through 
reduction of fitness (e.g., decline in body condition) and subsequent 
reduction in reproductive success, survival, or both (e.g., Harrington 
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-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.
    Stone (2015) reported data from at-sea observations during 1,196 
seismic surveys from 1994 to 2010. When large arrays of airguns 
(considered to be 500 in\3\ or more) were firing, lateral displacement, 
more localized avoidance, or other changes in behavior were evident for 
most odontocetes. However, significant responses to large arrays were 
found only for the minke whale and fin whale. Behavioral responses 
observed included changes in swimming or surfacing behavior, with 
indications that cetaceans remained near the water surface at these 
times. Cetaceans were recorded as feeding less often when large arrays 
were active. Behavioral observations of gray whales during a seismic 
survey monitored whale movements and respirations pre-, during and 
post-seismic survey

[[Page 34365]]

(Gailey et al., 2016). Behavioral state and water depth were the best 
`natural' predictors of whale movements and respiration and, after 
considering natural variation, none of the response variables were 
significantly associated with seismic survey or vessel sounds.
    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 
sufficiently to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker, 2000; 
Romano et al., 2002b) and, more rarely, studied in wild populations 
(e.g., Romano et al., 2002a). For example, Rolland et al. (2012) found 
that noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC, 2003).
    4. Auditory Masking--Sound can disrupt behavior through masking, or 
interfering with, an animal's ability to detect, recognize, or 
discriminate between acoustic signals of interest (e.g., those used for 
intraspecific communication and social interactions, prey detection, 
predator avoidance, navigation) (Richardson et al., 1995; Erbe et al., 
2016). Masking occurs when the receipt of a sound is interfered with by 
another coincident sound at similar frequencies and at similar or 
higher intensity, and may occur whether the sound is natural (e.g., 
snapping shrimp, wind, waves, precipitation) or anthropogenic (e.g., 
shipping, sonar, seismic exploration) in origin. The ability of a noise 
source to mask biologically important sounds depends on the 
characteristics of both the noise source and the signal of interest 
(e.g., signal-to-noise ratio, temporal variability, direction), in 
relation to each other and to an animal's hearing abilities (e.g., 
sensitivity, frequency range, critical ratios, frequency 
discrimination, directional discrimination, age or TTS hearing loss), 
and existing ambient noise and propagation conditions.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007; Di Iorio and Clark, 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore, 2014). Masking can be tested 
directly in captive species (e.g., Erbe, 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial 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.

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

[[Page 34366]]

vessel's propeller. 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 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) also found that the probability of death or 
serious injury increased rapidly with increasing vessel speed. 
Specifically, the predicted probability of serious injury or death 
increased from 45 to 75 percent as vessel speed increased from 10 to 14 
kn, and exceeded 90 percent at 17 kn. Higher speeds during collisions 
result in greater force of impact, but higher speeds also appear to 
increase the chance of severe injuries or death through increased 
likelihood of collision by pulling whales toward the vessel (Clyne, 
1999; Knowlton et al., 1995). In a separate study, Vanderlaan and 
Taggart (2007) analyzed the probability of lethal mortality of large 
whales at a given speed, showing that the greatest rate of change in 
the probability of a lethal injury to a large whale as a function of 
vessel speed occurs between 8.6 and 15 kn. The chances of a lethal 
injury decline from approximately 80 percent at 15 kn to approximately 
20 percent at 8.6 kn. At speeds below 11.8 kn, the chances of lethal 
injury drop below 50 percent, while the probability asymptotically 
increases toward one hundred percent above 15 kn.
    The Kairei travels at a speed of ~8.3 km/hour while towing seismic 
survey gear (LGL 2017). At this speed, both the possibility of striking 
a marine mammal and the possibility of a strike resulting in serious 
injury or mortality are discountable. At average transit speed, the 
probability of serious injury or mortality resulting from a strike is 
less than 50 percent. However, the likelihood of a strike actually 
happening is again discountable. Ship strikes, as analyzed in the 
studies cited above, generally involve commercial shipping, which is 
much more common in both space and time than is geophysical survey 
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 no such incidents were reported 
for geophysical survey vessels during that time period.
    It is possible for ship strikes to occur while traveling at slow 
speeds. For example, a hydrographic survey vessel traveling at low 
speed (5.5 kn) while conducting mapping surveys off the central 
California coast struck and killed a blue whale in 2009. The State of 
California determined that the whale had suddenly and unexpectedly 
surfaced beneath the hull, with the result that the propeller severed 
the whale's vertebrae, and that this was an unavoidable event. 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, 2013b). 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 to occur. In that case, the incident report indicated that an 
animal apparently was struck by the vessel's propeller as it was 
intentionally swimming near the vessel. While indicative of the type of 
unusual events that cannot be ruled out, neither of these instances 
represents a circumstance that would be considered reasonably 
foreseeable or that would be considered preventable.
    Although the likelihood of the vessel striking a marine mammal is 
low, we require a robust ship strike avoidance protocol (see ``Proposed 
Mitigation''), which we believe eliminates any foreseeable risk of ship 
strike. We anticipate that vessel collisions involving a seismic data 
acquisition vessel towing gear, while not impossible, represent 
unlikely, unpredictable events for which there are no preventive 
measures. Given the required mitigation measures, the relatively slow 
speed of the vessel towing gear, the presence of bridge crew watching 
for obstacles at all times (including marine mammals), the presence of 
marine mammal observers, and the short duration of the survey (5.5 
days), 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 
the specified activity will not be discussed further in the following 
analysis.
    Stranding--When a living or dead marine mammal swims or floats onto 
shore and becomes ``beached'' or incapable of returning to sea, the 
event is a ``stranding'' (Geraci et al., 1999; Perrin and Geraci, 2002; 
Geraci and Lounsbury, 2005; NMFS, 2007). The legal definition for a 
stranding under the MMPA is that ``(A) a marine mammal is dead and is 
(i) on a beach or shore of the United States; or (ii) in waters under 
the jurisdiction of the United States (including any navigable waters); 
or (B) a marine mammal is alive and is (i) on a beach or shore of the 
United States and is unable to return to the water; (ii) on a beach or 
shore of the United States and, although able to return to the water, 
is in need of apparent medical attention; or (iii) in the waters under 
the jurisdiction of the United States (including any navigable waters), 
but is unable to return to its natural habitat under its own power or 
without assistance.''
    Marine mammals 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. 
However, the cause or causes of most strandings are unknown (Geraci et 
al., 1976; Eaton, 1979; Odell et al., 1980; Best, 1982). Numerous 
studies suggest that the physiology, behavior, habitat relationships, 
age, or condition of cetaceans may cause them to strand or might pre-
dispose them to strand when exposed to another phenomenon. These 
suggestions are consistent with the conclusions of numerous other 
studies that have demonstrated that combinations of dissimilar 
stressors commonly combine to kill an animal or dramatically reduce its 
fitness, even though one exposure without the other does not produce 
the same result (Chroussos, 2000; Creel, 2005; DeVries et al., 2003; 
Fair and Becker, 2000; Foley et al., 2001; Moberg, 2000; Relyea, 2005a; 
2005b, Romero, 2004; Sih et al., 2004).
    Use of military tactical sonar has been implicated in a majority of 
investigated stranding events, although one stranding event was 
associated with the use of seismic airguns. This event occurred in the 
Gulf of California, coincident with seismic reflection profiling by the 
R/V Maurice Ewing operated by Columbia University's Lamont-Doherty 
Earth Observatory and involved two Cuvier's beaked whales (Hildebrand, 
2004). The vessel had been firing an array of 20 airguns with a total

[[Page 34367]]

volume of 8,500 in\3\ (Hildebrand, 2004; Taylor et al., 2004). Most 
known stranding events have involved beaked whales, though a small 
number have involved deep-diving delphinids or sperm whales (e.g., 
Mazzariol et al., 2010; Southall et al., 2013). In general, long 
duration (~1 second) and high-intensity sounds (>235 dB SPL) have been 
implicated in stranding events (Hildebrand, 2004). With regard to 
beaked whales, mid-frequency sound is typically implicated (when 
causation can be determined) (Hildebrand, 2004). Although seismic 
airguns create predominantly low-frequency energy, the signal does 
include a mid-frequency component. We have considered the potential for 
the proposed survey to result in marine mammal stranding and have 
concluded that, based on the best available information, stranding is 
not expected to occur.
    Other Potential Impacts--Here, we briefly address the potential 
risks due to entanglement and contaminant spills. We are not aware of 
any records of marine mammal entanglement in towed arrays such as those 
considered here. The discharge of trash and debris is prohibited (33 
CFR 151.51-77) unless it is passed through a machine that breaks up 
solids such that they can pass through a 25-mm mesh screen. All other 
trash and debris must be returned to shore for proper disposal with 
municipal and solid waste. Some personal items may be accidentally lost 
overboard. However, U.S. Coast Guard and Environmental Protection Act 
regulations require operators to become proactive in avoiding 
accidental loss of solid waste items by developing waste management 
plans, posting informational placards, manifesting trash sent to shore, 
and using special precautions such as covering outside trash bins to 
prevent accidental loss of solid waste. There are no meaningful 
entanglement risks posed by the described activity, and entanglement 
risks are not discussed further in this document.
    Marine mammals could be affected by accidentally spilled diesel 
fuel from a vessel associated with proposed survey activities. 
Quantities of diesel fuel on the sea surface may affect marine mammals 
through various pathways: surface contact of the fuel with skin and 
other mucous membranes, inhalation of concentrated petroleum vapors, or 
ingestion of the fuel (direct ingestion or by the ingestion of oiled 
prey) (e.g., Geraci and St. Aubin, 1980, 1985, 1990). However, the 
likelihood of a fuel spill during any particular geophysical survey is 
considered to be remote, and the potential for impacts to marine 
mammals would depend greatly on the size and location of a spill and 
meteorological conditions at the time of the spill. Spilled fuel would 
rapidly spread to a layer of varying thickness and break up into narrow 
bands or windrows parallel to the wind direction. The rate at which the 
fuel spreads would be determined by the prevailing conditions such as 
temperature, water currents, tidal streams, and wind speeds. Lighter, 
volatile components of the fuel would evaporate to the atmosphere 
almost completely in a few days. Evaporation rate may increase as the 
fuel spreads because of the increased surface area of the slick. 
Rougher seas, high wind speeds, and high temperatures also tend to 
increase the rate of evaporation and the proportion of fuel lost by 
this process (Scholz et al., 1999). We do not anticipate potentially 
meaningful effects to marine mammals as a result of any contaminant 
spill resulting from the proposed survey activities, and contaminant 
spills are not discussed further in this document.

Anticipated Effects on Marine Mammal Habitat

    Effects to Prey--Marine mammal prey varies by species, season, and 
location and, for some, is not well documented. Fish react to sounds 
which are especially strong and/or intermittent low-frequency sounds. 
Short duration, sharp sounds can cause overt or subtle changes in fish 
behavior and local distribution. Hastings and Popper (2005) identified 
several studies that suggest fish may relocate to avoid certain areas 
of sound energy. Additional studies have documented effects of pulsed 
sound on fish, although several are based on studies in support of 
construction projects (e.g., Scholik and Yan, 2001, 2002; Popper and 
Hastings, 2009). Sound pulses at received levels of 160 dB may cause 
subtle changes in fish behavior. SPLs of 180 dB may cause noticeable 
changes in behavior (Pearson et al., 1992; Skalski et al., 1992). SPLs 
of sufficient strength have been known to cause injury to fish and fish 
mortality. The most likely impact to fish from survey activities at the 
project area would be temporary avoidance of the area. The duration of 
fish avoidance of a given area after survey effort stops is unknown, 
but a rapid return to normal recruitment, distribution and behavior is 
anticipated.
    Information on seismic airgun impacts to zooplankton, which 
represent an important prey type for mysticetes, is limited. However, 
McCauley et al. (2017) reported that experimental exposure to a pulse 
from a 150 inch\3\ airgun decreased zooplankton abundance when compared 
with controls, as measured by sonar and net tows, and caused a two- to 
threefold increase in dead adult and larval zooplankton. Although no 
adult krill were present, the study found that all larval krill were 
killed after air gun passage. Impacts were observed out to the maximum 
1.2 km range sampled.
    In general, impacts to marine mammal prey are expected to be 
limited due to the relatively small temporal and spatial overlap 
between the proposed survey and any areas used by marine mammal prey 
species. The proposed survey would occur over a relatively short time 
period (5.5 days) and would occur over a very small area relative to 
the area available as marine mammal habitat in the central Pacific 
Ocean. We do not have any information to suggest the proposed survey 
area represents a significant feeding area for any marine mammal, and 
we believe any impacts to marine mammals due to adverse affects to 
their prey would be insignificant due to the limited spatial and 
temporal impact of the proposed survey. However, adverse impacts may 
occur to a few species of fish and to zooplankton.
    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 use of airgun arrays). 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

[[Page 34368]]

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). Although the signals emitted by 
seismic airgun arrays are generally low frequency, they would also 
likely be of short duration and transient in any given area due to the 
nature of these surveys. As described previously, exploratory surveys 
such as these cover a large area but would be transient rather than 
focused in a given location over time and therefore would not be 
considered chronic in any given location.
    In summary, activities associated with the proposed action are not 
likely to have a permanent, adverse effect on any fish habitat or 
populations of fish species or on the quality of acoustic habitat. 
Thus, any impacts to marine mammal habitat are not expected to cause 
significant or long-term consequences for individual marine mammals or 
their populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of whether the number of takes is ``small'' and the 
negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as: Any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the seismic airguns have the potential to result in disruption of 
behavioral patterns for individual marine mammals. There is also some 
potential for auditory injury (Level A harassment) to result, primarily 
for mysticetes and high frequency cetaceans (i.e., kogiidae spp.), due 
to larger predicted auditory injury zones for those functional hearing 
groups. Auditory injury is unlikely to occur for mid-frequency species 
given very small modeled zones of injury for those species. The 
proposed mitigation and monitoring measures are expected to minimize 
the severity of such taking to the extent practicable.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Described in the most basic way, we estimate take by considering: 
(1) Acoustic thresholds above which NMFS believes the best available 
science indicates marine mammals will be behaviorally harassed or incur 
some degree of permanent hearing impairment; (2) the area or volume of 
water that will be ensonified above these levels in a day; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and (4) and the number of days of activities. Below, we describe these 
components in more detail and present the exposure estimate and 
associated numbers of take proposed for authorization.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources-- Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2011). Based on the best available science and the 
practical need to use a threshold based on a factor that is both 
predictable and measurable for most activities, NMFS uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS predicts that marine mammals are likely to 
be behaviorally harassed in a manner we consider to fall under Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (rms) for continuous (e.g., 
vibratory pile-driving, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns) or intermittent 
(e.g., scientific sonar) sources. UH's proposed activity includes the 
use of impulsive seismic sources. Therefore, the 160 dB re 1 [mu]Pa 
(rms) criteria is applicable for analysis of level B harassment.
    Level A harassment for non-explosive sources-- NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (NMFS, 2016) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). The 
Technical Guidance identifies the received levels, or thresholds, above 
which individual marine mammals are predicted to experience changes in 
their hearing sensitivity for all underwater anthropogenic sound 
sources, reflects the best available science, and better predicts the 
potential for auditory injury than does NMFS' historical criteria.
    These thresholds were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers to inform the final product, and are 
provided in Table 4 below. The references, analysis, and methodology 
used in the development of the thresholds are described in NMFS 2016 
Technical Guidance, which may be accessed at: http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm. As described above, UH's proposed activity 
includes the use of intermittent and impulsive seismic sources.

[[Page 34369]]



 Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
                            in Marine Mammals
------------------------------------------------------------------------
                                           PTS onset thresholds
          Hearing group          ---------------------------------------
                                      Impulsive*         Non-impulsive
------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans....  Lpk,flat: 219 dB..  LE,LF,24h: 199 dB
                                  LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans....  Lpk,flat: 230 dB..  LE, MF,24h: 198 dB
                                  LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans...  Lpk,flat: 202 dB..  LE,HF,24h: 173 dB
                                  LE, HF,24h: 155 dB
------------------------------------------------------------------------
Note: * Dual metric acoustic thresholds for impulsive sounds: Use
  whichever results in the largest isopleth for calculating PTS onset.
  If a non-impulsive sound has the potential of exceeding the peak sound
  pressure level thresholds associated with impulsive sounds, these
  thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and
  cumulative sound exposure level (LE) has a reference value of
  1[mu]Pa2s. In this Table, thresholds are abbreviated to reflect
  American National Standards Institute standards (ANSI 2013). However,
  peak sound pressure is defined by ANSI as incorporating frequency
  weighting, which is not the intent for this Technical Guidance. Hence,
  the subscript ``flat'' is being included to indicate peak sound
  pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure
  level thresholds indicates the designated marine mammal auditory
  weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The
  cumulative sound exposure level thresholds could be exceeded in a
  multitude of ways (i.e., varying exposure levels and durations, duty
  cycle). When possible, it is valuable for action proponents to
  indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into estimating the area ensonified above the 
acoustic thresholds.
    The proposed survey would entail use of a 32-airgun array with a 
total discharge of 7,800 in\3\ at a tow depth of 10 m. The distance to 
the predicted isopleth corresponding to the threshold for Level B 
harassment (160 dB re 1 [mu]Pa) was calculated based on results of 
modeling performed by Lamont-Doherty Earth Observatory (LDEO) of 
Columbia University. Received sound levels were predicted by LDEO's 
model (Diebold et al. 2010) as a function of distance from the full 32-
airgun array as well as for a single 100 in\3\ airgun, which would be 
used during power-downs. The LDEO modeling approach uses ray tracing 
for the direct wave traveling from the array to the receiver and its 
associated source ghost (reflection at the air-water interface in the 
vicinity of the array), in a constant-velocity half-space (infinite 
homogeneous ocean layer unbounded by a seafloor). LDEO's modeling 
methodology is described in greater detail in the IHA application (LGL 
2017) and we refer to the reader to that document rather than repeating 
it here. The estimated distances to the Level B harassment isopleth for 
the Kairei's full airgun array and for the single 100-in\3\ airgun are 
shown in Table 5.

  Table 5--Predicted Radial Distances From R/V Kairei Seismic Source to
         Isopleth Corresponding to Level B Harassment Threshold
------------------------------------------------------------------------
                                               Predicted  distance to
         Source and volume (in\3\)             threshold (160  dB re 1
                                                    [mu]Pa)  (m)
------------------------------------------------------------------------
1 airgun, 100.............................  722
4 strings, 32 airguns, 7,800..............  9,289
------------------------------------------------------------------------

    Predicted distances to Level A harassment isopleths, which vary 
based on marine mammal hearing groups (Table 3), were calculated based 
on modeling performed by LDEO using the Nucleus software program and 
the NMFS User Spreadsheet, described below. The updated acoustic 
thresholds for impulsive sounds (such as airguns) contained in the 
Technical Guidance (NMFS 2016) were presented as dual metric acoustic 
thresholds using both SELcum and peak sound pressure 
metrics. As dual metrics, NMFS considers onset of PTS (Level A 
harassment) to have occurred when either one of the two metrics is 
exceeded (i.e., metric resulting in the largest isopleth). The 
SELcum metric considers both level and duration of exposure, 
as well as auditory weighting functions by marine mammal hearing group. 
In recognition of the fact that the requirement to calculate Level A 
harassment ensonified areas could be more technically challenging to 
predict due to the duration component and the use of weighting 
functions in the new SELcum thresholds, NMFS developed an 
optional User Spreadsheet that includes tools to help predict a simple 
isopleth that can be used in conjunction with marine mammal density or 
occurrence to facilitate the estimation of take numbers.
    The values for SELcum and peak SPL for the Kairei airgun 
array were derived from calculating the modified farfield signature 
(Table 6). The farfield signature is often used as a theoretical 
representation of the source level. To compute the farfield signature, 
the source level is estimated at a large distance below the array 
(e.g., 9 km), and this level is back projected mathematically to a 
notional distance of 1 m from the array's geometrical center. However, 
when the source is an array of multiple airguns separated in space, the 
source level from the theoretical farfield signature is not necessarily 
the best measurement of the source level that is physically achieved at 
the source (Tolstoy et al. 2009). Near the source (at short ranges, 
distances <1 km), the pulses of sound pressure from each individual 
airgun in the source array do not stack constructively, as they do for 
the theoretical farfield signature. The pulses from the different 
airguns spread out in time such that the source levels observed or 
modeled are the result of the summation of pulses from a few airguns, 
not the full array (Tolstoy et al. 2009). At larger distances, away 
from the source array center, sound pressure of all the airguns in the 
array stack coherently, but not within one time sample, resulting in 
smaller source levels (a few dB) than the source level derived from the 
farfield signature. Because the farfield signature does not take into 
account the large array effect near the source and is calculated as a 
point source, the modified farfield signature is a more appropriate 
measure of the sound source level for distributed

[[Page 34370]]

sound sources, such as airgun arrays. UH used the acoustic modeling 
developed by LDEO (same as used for Level B takes) with a small grid 
step of 1 m in both the inline and depth directions (for example, see 
Figure 5 in the IHA application). The propagation modeling takes into 
account all airgun interactions at short distances from the source, 
including interactions between subarrays which are modeled using the 
NUCLEUS software to estimate the notional signature and MATLAB software 
to calculate the pressure signal at each mesh point of a grid.

 Table 6--Modeled Source Levels for R/V Kairei 7,800 in \3\ Airgun Array and 100 in \3\ Airgun Based on Modified
                                               Farfield Signature
----------------------------------------------------------------------------------------------------------------
                                                   7,800 in \3\
                                                   airgun array    7,800 in \3\     100 in \3\      100 in \3\
            Functional hearing group              (Peak SPLflat)   airgun array    airgun (Peak       airgun
                                                        (db)      (SELcum)  (db)  SPLflat)  (db)  (SELcum)  (db)
 
----------------------------------------------------------------------------------------------------------------
Low frequency cetaceans.........................          256.36          235.01          229.46          208.41
(Lpk,flat: 219 dB; LE,LF,24h: 183 dB)...........
Mid frequency cetaceans.........................          245.59          235.12          229.47          208.44
(Lpk,flat: 230 dB; LE,MF,24h: 185 dB)...........
High frequency cetaceans........................          256.26          235.16          229.59          209.01
(Lpk,flat: 202 dB; LE,HF,24h: 155 dB)...........
----------------------------------------------------------------------------------------------------------------

    In order to more realistically incorporate the Technical Guidance's 
weighting functions over the seismic array's full acoustic band, 
unweighted spectrum data for the Kairei's airgun array (modeled in 1 Hz 
bands) was used to make adjustments (dB) to the unweighted spectrum 
levels, by frequency, according to the weighting functions for each 
relevant marine mammal hearing group. These adjusted/weighted spectrum 
levels were then converted to pressures (micropascals) in order to 
integrate them over the entire broadband spectrum, resulting in 
broadband weighted source levels by hearing group that could be 
directly incorporated within the User Spreadsheet (i.e., to override 
the Spreadsheet's more simple weighting factor adjustment). Using the 
User Spreadsheet's ``safe distance'' methodology for mobile sources 
(described by Sivle et al., 2014) with the hearing group-specific 
weighted source levels, and inputs assuming spherical spreading 
propagation, a source velocity of 2.315 meters/second, and shot 
interval of 21.59 seconds (LGL 2017), potential radial distances to 
auditory injury zones were then calculated for SELcum 
thresholds. To estimate Peak SPL thresholds, modeling was run for a 
single shot and then a high pass filter was applied for each hearing 
group. A high pass filter is a type of band band-pass filter, which 
pass frequencies within a defined range without reducing amplitude and 
attenuate frequencies outside that defined range (Yost 2007). Inputs to 
the User Spreadsheet are shown in Table 6; outputs from the User 
Spreadsheet in the form of estimated distances to Level A harassment 
isopleths are shown in Table 7. The User Spreadsheet used by UH is 
shown in Table 3 of the IHA application.

   Table 7--Modeled Radial Distances From R/V Kairei 7800 in\3\ Airgun Array and 100 in\3\ Airgun to Isopleths
                                 Corresponding to Level A Harassment Thresholds
----------------------------------------------------------------------------------------------------------------
                                                    7,800 in\3\
                                                   airgun array     7,800 in\3\      100 in\3\       100 in\3\
            Functional hearing group              (peak SPLflat)   airgun array    airgun (Peak       airgun
                                                        (m)        (SELcum)  (m)   SPLflat) (m)    (SELcum)  (m)
 
----------------------------------------------------------------------------------------------------------------
Low frequency cetaceans.........................            61.5           752.8             3.2            4.48
(Lpk,flat: 219 dB; LE,LF,24h: 183 dB)...........
Mid frequency cetaceans.........................             0.0             0.0             0.0             n/a
(Lpk,flat: 230 dB; LE,MF,24h: 185 dB)...........
High frequency cetaceans........................            14.5             1.7             3.7             n/a
(Lpk,flat: 202 dB; LE,HF,24h: 155 dB)...........
----------------------------------------------------------------------------------------------------------------

    Note that because of some of the assumptions included in the 
methods used, isopleths produced may be overestimates to some degree, 
which will ultimately result in some degree of overestimate of Level A 
take. However, these tools offer the best way to predict appropriate 
isopleths when more sophisticated 3D modeling methods are not 
available, and NMFS continues to develop ways to quantitatively refine 
these tools and will qualitatively address the output where 
appropriate. For mobile sources, such as the proposed seismic survey, 
the User Spreadsheet predicts the closest distance at which a 
stationary animal would not incur PTS if the sound source traveled by 
the animal in a straight line at a constant speed.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    The best available scientific information was considered in 
conducting marine mammal exposure estimates (the basis for estimating 
take). For most cetacean species, densities calculated by Bradford et 
al. (2017) from summer-fall vessel-based surveys that are part of the 
Hawaiian Island Cetacean Ecosystem Assessment Survey (HICEAS) were 
used. The surveys were conducted by NMFS' Southwest Fisheries Science 
Center (SWFSC) and Pacific Islands Fisheries Science Center (PIFSC) in 
2010 using two NOAA research vessels, one during August 13-December 1 
and the other during September 2-October 29. The densities were 
estimated using a multiple-covariate line-transect approach (Buckland 
et al. 2001; Marques and

[[Page 34371]]

Buckland 2004). Density estimates for pygmy and dwarf sperm whales and 
spinner dolphins, which were not calculated from the 2010 surveys, were 
derived from the ``Outer EEZ stratum'' of the vessel-based HICEAS 
survey conducted in summer-fall 2002 by SWFSC (Barlow 2006) using line-
transect methodology (Buckland et al. 2001). The density estimate for 
the false killer whale was based on the pelagic stock density 
calculated by Bradford et al. (2015) using line-transect methodology 
(Buckland et al. 2001).
    All densities were corrected for trackline detection probability 
bias (f(0)) and availability (g(0)) bias by the authors. Bradford et 
al. (2017) used g(0) values estimated by Barlow (2015), whose analysis 
indicated that g(0) had previously been overestimated, particularly for 
high sea states. Barlow (2006) used earlier estimates of g(0), so 
densities used here for pygmy and dwarf sperm whales and spinner 
dolphins likely are underestimates. The density for the ``Sei or 
Bryde's whale'' category identified by Bradford et al. (2017) was 
allocated between sei and Bryde's whales according to their 
proportionate densities. Density estimates for humpback and minke 
whales were not available.
    There is some uncertainty related to the estimated density data and 
the assumptions used in their calculations, as with all density data 
estimates. However, the approach used is based on the best available 
data.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate. In order to estimate 
the number of marine mammals predicted to be exposed to sound levels 
that would result in Level B harassment or Level A harassment, radial 
distances to predicted isopleths corresponding to the Level A 
harassment and Level B harassment thresholds are calculated, as 
described above. We then use those distances to calculate the area(s) 
around the airgun array predicted to be ensonified to sound levels that 
exceed the Level A and Level B harassment thresholds. The total 
ensonified area for the survey is then calculated, based on the areas 
predicted to be ensonified around the array and the trackline distance. 
The marine mammals predicted to occur within these respective areas, 
based on estimated densities, are expected to be incidentally taken by 
the proposed survey.
    To summarize, the estimated density of each marine mammal species 
within an area (animals/km\2\) is multiplied by the daily ensonified 
areas (km\2\) that correspond to the Level A and Level B harassment 
thresholds for the species. The product (rounded) is the number of 
instances of take for each species within one day. The number of 
instances of take for each species within one day is then multiplied by 
the number of survey days (plus 25 percent contingency, as described 
below). The result is an estimate of the number of instances that 
marine mammals are predicted to be exposed to airgun sounds above the 
Level B harassment threshold and the Level A harassment threshold over 
the duration of the proposed survey. Estimated takes for all marine 
mammal species are shown in Table 8.
    The proposed survey would occur both within the U.S. EEZ and 
outside the U.S. EEZ. We propose to authorize incidental take that is 
expected to occur as a result of the proposed survey both within and 
outside the U.S. EEZ.

           Table 8--Numbers of Potential Incidental Take of Marine Mammals Proposed for Authorization
----------------------------------------------------------------------------------------------------------------
                                                                                                       Total
                                                                                                  Proposed Level
                                   Estimated and     Estimated    Proposed Level  Total proposed  A  and Level B
             Species              proposed Level   Level B takes      B takes       Level A and      takes as a
                                      A takes                                      Level B takes   percentage of
                                                                                                    population
----------------------------------------------------------------------------------------------------------------
Humpback whale \1\..............               0               0               2               2            <0.1
Minke whale \1\.................               0               0               1               1             n/a
Bryde's whale...................               2              25              25              27             3.4
Sei whale.......................               0               6               6               6             3.4
Fin whale.......................               0               2               2               2             3.4
Blue whale \1\..................               0               1               3               3             3.7
Sperm whale.....................               0              51              51              51             1.5
Cuvier's beaked whale...........               0               8               8               8            <0.1
Longman's beaked whale..........               0              85              85              85             1.9
Blainville's beaked whale.......               0              76              76              76             3.3
Rough-toothed dolphin...........               0             812             812             812            12.9
Bottlenose dolphin..............               0             246             246             246             4.1
Pantropical spotted dolphin.....               0             639             639             639             4.0
Spinner dolphin \1\.............               0              23              32              32             0.9
Striped dolphin.................               0             685             685             685             3.3
Fraser's dolphin................               0             577             577             577             3.4
Risso's dolphin.................               0             130             130             130             1.8
Melon-headed whale..............               0              97              97              97             1.7
Pygmy killer whale..............               0             119             119             119             3.5
False killer whale..............               0              16              16              16             1.0
Killer whale \1\................               0               2               5               5             4.9
Short-finned pilot whale........               0             218             218             218             1.8
Pygmy sperm whale...............               0              87              87              87             1.2
Dwarf sperm whale...............               0             214             214             214             1.2
----------------------------------------------------------------------------------------------------------------
\1\ The proposed number of authorized takes (Level B harassment only) for these species has been increased from
  the calculated take to mean group size. Sources for mean group sizes are as follows: blue whale (Bradford et
  al. 2017); minke whale (Jackson et al. 2008); humpback whale (Mobley et al. 2001); spinner dolphin (Barlow
  2006); killer whale (Bradford et al. 2017).


[[Page 34372]]

    Species With Take Estimates Less Than Mean Group Size: Using the 
approach described above to estimate take, the take estimates for the 
blue whale, killer whale, and spinner dolphin (Table 8) were less than 
the average group sizes estimated for these species. However, 
information on the social structures and life histories of these 
species indicates it is common for them to be encountered in groups. As 
the results of take calculations support the likelihood that UH's 
survey would be expected to encounter and to incidentally take these 
species, and we believe it is likely that these species may be 
encountered in groups, it is reasonable to conservatively assume that 
one group of each of these species will be taken during the proposed 
survey. We therefore propose to authorize the take of the average 
(mean) group size for the blue whale, killer whale, and spinner dolphin 
to account for the possibility that UH's survey encounters a group of 
any of these species (Table 8).
    Species With No Available Density Data: No density data were 
available for humpback and minke whales. Both species would typically 
be found further north than the proposed survey area during the time of 
year that the proposed survey is planned to occur, based on sightings 
data around the Hawaiian Islands (Carretta et al. 2017). However, based 
on input from subject matter experts, we believe it is reasonable to 
assume that both species may be encountered by UH during the proposed 
survey. Humpback whales have typically not been observed in the project 
area in the fall (Carretta et al. 2017). However, there are increasing 
anecdotal reports of confirmed sightings of humpback whales from early 
September through October in areas near the planned project area (pers. 
comm. E. Lyman, NOAA Office of National Marine Sanctuaries, to J. 
Carduner, NMFS, June 20, 2017). Like humpback whales, sightings data 
does not indicate that minke whales would typically be expected to be 
present in the project area in the fall (Carretta et al. 2017). 
However, detections of minke whales are common in passive acoustic 
recordings from various locations around the main Hawaiian Islands, 
including during the fall (pers. comm. E. Oleson, NOAA PIFSC, to J. 
Carduner, NMFS, June 20, 2017). Additionally, as minke whales in the 
North Pacific do not have a visible blow, they can be easily missed by 
visual observers, suggesting a lack of sightings is likely related to 
misidentification or low detection capability in poor sighting 
conditions (Rankin et al. 2007). Though no density data are available, 
we believe it is reasonable to conservatively assume that UH's proposed 
survey may encounter and incidentally take minke and humpback whales. 
We therefore propose to authorize the take of the average (mean) group 
size (weighted by effort and rounded up) for the humpback and minke 
whale (Table 8).
    It should be noted that the proposed take numbers shown in Table 8 
are believed to be conservative for several reasons. First, in the 
calculations of estimated take, 25% has been added in the form of 
operational survey days (equivalent to adding 25% to the proposed line 
km to be surveyed) to account for the possibility of additional seismic 
operations associated with airgun testing, and repeat coverage of any 
areas where initial data quality is sub-standard. Additionally, marine 
mammals would be expected to move away from a sound source that 
represents an aversive stimulus. However, the extent to which marine 
mammals would move away from the sound source is difficult to quantify 
and is therefore not accounted for in take estimates shown in Table 8.

Proposed Mitigation

    In order to issue an IHA under Section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, ``and other means of effecting the least practicable impact 
on such species or stock and its habitat, paying particular attention 
to rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking'' for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned), and
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    UH has reviewed mitigation measures employed during seismic 
research surveys authorized by NMFS under previous incidental 
harassment authorizations, as well as recommended best practices in 
Richardson et al. (1995), Pierson et al. (1998), Weir and Dolman 
(2007), Nowacek et al. (2013), Wright (2014), and Wright and Cosentino 
(2015), and has incorporated a suite of proposed mitigation measures 
into their project description based on the above sources.
    To reduce the potential for disturbance from acoustic stimuli 
associated with the activities, UH has proposed to implement the 
following mitigation measures for marine mammals:
    (1) Vessel-based visual mitigation monitoring;
    (2) Vessel-based passive acoustic monitoring;
    (3) Establishment of an exclusion zone;
    (4) Power down procedures;
    (5) Shutdown procedures;
    (6) Ramp-up procedures; and
    (7) Ship strike avoidance measures.

Vessel-Based Visual Mitigation Monitoring

    PSO observations would take place during all daytime airgun 
operations and nighttime start ups (if applicable) of the airguns. 
Airgun operations would be suspended when marine mammals are observed 
within, or about to enter, designated Exclusion Zones (as described 
below). PSOs would also watch for marine mammals near the seismic 
vessel for at least 30 minutes prior to the planned start of airgun 
operations. Observations would also be made during daytime periods when 
the Kairei is underway without seismic operations, such as during 
transits, to allow for comparison of sighting rates and behavior with 
and without airgun operations and between acquisition periods.

[[Page 34373]]

    During seismic operations, four visual PSOs would be based aboard 
the Kairei. PSOs would be appointed by JAMSTEC with NMFS approval. 
During the majority of seismic operations, two PSOs would monitor for 
marine mammals around the seismic vessel. Use of two simultaneous 
observers would increase the effectiveness of detecting marine mammals 
around the source vessel. However, during meal times, only one PSO may 
be on duty. PSO(s) would be on duty in shifts of duration no longer 
than 4 hours. Other crew would also be instructed to assist in 
detecting marine mammals and in implementing mitigation requirements 
(if practical). Before the start of the seismic survey, the crew would 
be given additional instruction in detecting marine mammals and 
implementing mitigation requirements. The Kairei is a suitable platform 
for marine mammal observations. When stationed on the observation 
platform, the PSO would have a good view around the entire vessel. 
During daytime, the PSO(s) would scan the area around the vessel 
systematically with reticle binoculars (e.g., 7x50 Fujinon), Big-eye 
binoculars (25x150), and with the naked eye.
    The PSOs must have no tasks other than to conduct observational 
effort, record observational data, and communicate with and instruct 
relevant vessel crew with regard to the presence of marine mammals and 
mitigation requirements. PSO resumes would be provided to NMFS for 
approval. At least two PSOs must have a minimum of 90 days at-sea 
experience working as PSOs during a deep penetration seismic survey, 
with no more than eighteen months elapsed since the conclusion of the 
at-sea experience. One ``experienced'' visual PSO would be designated 
as the lead for the entire protected species observation team. The lead 
would coordinate duty schedules and roles for the PSO team and serve as 
primary point of contact for the vessel operator. The lead PSO would 
devise the duty schedule such that ``experienced'' PSOs are on duty 
with those PSOs with appropriate training but who have not yet gained 
relevant experience, to the maximum extent practicable
    The PSOs must have successfully completed relevant training, 
including completion of all required coursework and passing a written 
and/or oral examination developed for the training program, and must 
have successfully attained a bachelor's degree from an accredited 
college or university with a major in one of the natural sciences and a 
minimum of 30 semester hours or equivalent in the biological sciences 
and at least one undergraduate course in math or statistics. The 
educational requirements may be waived if the PSO has acquired the 
relevant skills through alternate training, including (1) secondary 
education and/or experience comparable to PSO duties; (2) previous work 
experience conducting academic, commercial, or government-sponsored 
marine mammal surveys; or (3) previous work experience as a PSO; the 
PSO should demonstrate good standing and consistently good performance 
of PSO duties.
    In summary, a typical daytime cruise would have scheduled two 
observers (visual) on duty from the observation platform, and an 
acoustic observer on the passive acoustic monitoring system.

Vessel-Based Passive Acoustic Mitigation Monitoring

    Passive acoustic monitoring (PAM) would take place to complement 
the visual monitoring program. Visual monitoring typically is not 
effective during periods of poor visibility or at night, and even with 
good visibility, is unable to detect marine mammals when they are below 
the surface or beyond visual range. Acoustic monitoring can be used in 
addition to visual observations to improve detection, identification, 
and localization of cetaceans. The acoustic monitoring would serve to 
alert visual observers (if on duty) when vocalizing cetaceans are 
detected. It is only useful when marine mammals vocalize, but it can be 
effective either by day or by night and does not depend on good 
visibility. It would be monitored in real time so that visual observers 
can be alerted when marine mammals are detected acoustically.
    The PAM system consists of hardware (i.e., hydrophones) and 
software. The ``wet end'' of the system consists of a towed hydrophone 
array that is connected to the vessel by a tow cable. A deck cable 
would connect the tow cable to the electronics unit on board where the 
acoustic station, signal conditioning, and processing system would be 
located. The acoustic signals received by the hydrophones are 
amplified, digitized, and then processed by the software.
    One acoustic PSO (in addition to the four visual PSOs) would be on 
board. The towed hydrophones would be monitored 24 hours per day 
(either by the acoustic PSO or by a visual PSO trained in the PAM 
system if the acoustic PSO is on break) while at the seismic survey 
area during airgun operations, and during most periods when the Kairei 
is underway while the airguns are not operating. However, PAM may not 
be possible if damage occurs to the array or back-up systems during 
operations. One PSO would monitor the acoustic detection system at any 
one time, in shifts no longer than six hours, by listening to the 
signals via headphones and/or speakers and watching the real-time 
spectrographic display for frequency ranges produced by cetaceans.
    When a vocalization is detected, while visual observations are in 
progress, the acoustic PSO would contact the visual PSOs immediately, 
to alert them to the presence of marine mammals (if they have not 
already been detected visually), in order to facilitate a power down or 
shut down, if required. The information regarding the marine mammal 
acoustic detection would be entered into a database.

Exclusion Zone and Buffer Zone

    An exclusion zone is a defined area within which occurrence of a 
marine mammal triggers mitigation action intended to reduce the 
potential for certain outcomes, e.g., auditory injury, disruption of 
critical behaviors. The PSOs would establish a minimum exclusion zone 
with a 500 m radius for the full array. The 500 m EZ would be based on 
radial distance from any element of the airgun array (rather than being 
based on the center of the array or around the vessel itself). With 
certain exceptions (described below), if a marine mammal appears 
within, enters, or appears on a course to enter this zone, the acoustic 
source would be powered down (see Power Down Procedures below). In 
addition to the 500 m EZ for the full array, a 100 m exclusion zone 
would be established for the single 100 in\3\ airgun. With certain 
exceptions (described below), if a marine mammal appears within, 
enters, or appears on a course to enter this zone the acoustic source 
would be shut down entirely (see Shutdown Procedures below).
    Potential radial distances to auditory injury zones were calculated 
on the basis of maximum peak pressure using values provided by the 
applicant (Table 7). The 500 m radial distance of the standard EZ is 
intended to be precautionary in the sense that it would be expected to 
contain sound exceeding peak pressure injury criteria for all cetacean 
hearing groups, while also providing a consistent, reasonably 
observable zone within which PSOs would typically be able to conduct 
effective observational effort. Although significantly greater 
distances may be observed from an elevated platform under good 
conditions, we believe that 500 m is likely regularly attainable for

[[Page 34374]]

PSOs using the naked eye during typical conditions.
    An appropriate EZ based on cumulative sound exposure level 
(SELcum) criteria would be dependent on the animal's applied 
hearing range and how that overlaps with the frequencies produced by 
the sound source of interest (i.e., via marine mammal auditory 
weighting functions) (NMFS, 2016), and may be larger in some cases than 
the zones calculated on the basis of the peak pressure thresholds (and 
larger than 500 m) depending on the species in question and the 
characteristics of the specific airgun array. In particular, the EZ 
radii would be larger for low-frequency cetaceans, because their most 
susceptible hearing range overlaps the low frequencies produced by 
airguns, but the zones would remain very small for mid-frequency 
cetaceans (i.e., including the ``small delphinoids'' described below), 
whose range of best hearing largely does not overlap with frequencies 
produced by airguns.
    Consideration of exclusion zone distances is inherently an 
essentially instantaneous proposition--a rule or set of rules that 
requires mitigation action upon detection of an animal. This indicates 
that consideration of peak pressure thresholds is most relevant, as 
compared with cumulative sound exposure level thresholds, as the latter 
requires that an animal accumulate some level of sound energy exposure 
over some period of time (e.g., 24 hours). A PSO aboard a mobile source 
will typically have no ability to monitor an animal's position relative 
to the acoustic source over relevant time periods for purposes of 
understanding whether auditory injury is likely to occur on the basis 
of cumulative sound exposure and, therefore, whether action should be 
taken to avoid such potential. Therefore, definition of an exclusion 
zone based on SELcum thresholds is of questionable relevance 
given relative motion of the source and receiver (i.e., the animal). 
Cumulative SEL thresholds are likely more relevant for purposes of 
modeling the potential for auditory injury than they are for informing 
real-time mitigation. We recognize the importance of the accumulation 
of sound energy to an understanding of the potential for auditory 
injury and that it is likely that, at least for low-frequency 
cetaceans, some potential auditory injury is likely impossible to 
mitigate and should be considered for authorization.
    In summary, our intent in prescribing a standard exclusion zone 
distance is to (1) encompass zones for most species within which 
auditory injury could occur on the basis of instantaneous exposure; (2) 
provide additional protection from the potential for more severe 
behavioral reactions (e.g., panic, antipredator response) for marine 
mammals at relatively close range to the acoustic source; (3) provide 
consistency for PSOs, who need to monitor and implement the exclusion 
zone; and (4) to define a distance within which detection probabilities 
are reasonably high for most species under typical conditions.
    Our use of 500 m as the EZ is a reasonable combination of factors. 
This zone would contain all potential auditory injury for all cetaceans 
(high-frequency, mid-frequency and low-frequency functional hearing 
groups) as assessed against peak pressure thresholds (NMFS, 2016) 
(Table 7), would contain all potential auditory injury for high-
frequency and mid-frequency cetaceans as assessed against 
SELcum thresholds (NMFS, 2016) (Table 7), and has been 
proven to be practicable through past implementation in seismic surveys 
conducted for the oil and gas industry in the Gulf of Mexico (as 
regulated by BOEM pursuant to the Outer Continental Shelf Lands Act 
(OCSLA) (43 U.S.C. 1331-1356)). In summary, a practicable criterion 
such as this has the advantage of simplicity while still providing in 
most cases a zone larger than relevant auditory injury zones, given 
realistic movement of source and receiver.
    The PSOs would also establish and monitor a 1,000-m buffer zone. 
During use of the acoustic source, occurrence of marine mammals within 
the buffer zone (but outside the exclusion zone) would be communicated 
to the operator to prepare for the potential power down or shutdown of 
the acoustic source. The buffer zone is discussed further under Ramp Up 
Procedures below.

Power Down Procedures

    A power down involves decreasing the number of airguns in use such 
that the radius of the mitigation zone is decreased to the extent that 
marine mammals are no longer in, or about to enter, the 500 m EZ. 
During a power down, one 100-in\3\ airgun would be operated. The 
continued operation of one 100-in\3\ airgun is intended to alert marine 
mammals to the presence of the seismic vessel in the area, and to allow 
them to leave the area of the seismic vessel if they choose. In 
contrast, a shutdown occurs when all airgun activity is suspended 
(shutdown procedures are discussed below). If a marine mammal is 
detected outside the 500 m EZ but appears likely to enter the 500 m EZ, 
the airguns would be powered down before the animal is within the 500 m 
EZ. Likewise, if a mammal is already within the 500 m EZ when first 
detected, the airguns would be powered down immediately. During a power 
down of the airgun array, the 100-in\3\ airgun would be operated.
    Following a power down, airgun activity would not resume until the 
marine mammal has cleared the 500 m EZ. The animal would be considered 
to have cleared the 500 m EZ if the following conditions have been met:
     It is visually observed to have departed the 500 m EZ, or
     it has not been seen within the 500 m EZ for 15 min in the 
case of small odontocetes, or
     it has not been seen within the 500 m EZ for 30 min in the 
case of mysticetes and large odontocetes, including sperm, pygmy sperm, 
dwarf sperm, and beaked whales.
    This power down requirement would be in place for all marine 
mammals, with the exception of small delphinoids under certain 
circumstances. As defined here, the small delphinoid group is intended 
to encompass those members of the Family Delphinidae most likely to 
voluntarily approach the source vessel for purposes of interacting with 
the vessel and/or airgun array (e.g., bow riding). This exception to 
the power down requirement would apply solely to specific genera of 
small dolphins--Steno, Tursiops, Stenella and Lagenodelphis--and would 
only apply if the animals were traveling, including approaching the 
vessel. If, for example, an animal or group of animals is stationary 
for some reason (e.g., feeding) and the source vessel approaches the 
animals, the power down requirement applies. An animal with sufficient 
incentive to remain in an area rather than avoid an otherwise aversive 
stimulus could either incur auditory injury or disruption of important 
behavior. If there is uncertainty regarding identification (i.e., 
whether the observed animal(s) belongs to the group described above) or 
whether the animals are traveling, the power down would be implemented.
    We propose this small delphinoid exception because power-down/
shutdown requirements for small delphinoids under all circumstances 
represent practicability concerns without likely commensurate benefits 
for the animals in question. Small delphinoids are generally the most 
commonly observed marine mammals in the specific geographic region and 
would typically be the only marine mammals likely to intentionally 
approach the vessel. As described

[[Page 34375]]

below, auditory injury is extremely unlikely to occur for mid-frequency 
cetaceans (e.g., delphinids), as this group is relatively insensitive 
to sound produced at the predominant frequencies in an airgun pulse 
while also having a relatively high threshold for the onset of auditory 
injury (i.e., permanent threshold shift). Please see ``Potential 
Effects of the Specified Activity on Marine Mammals'' above for further 
discussion of sound metrics and thresholds and marine mammal hearing.
    A large body of anecdotal evidence indicates that small delphinoids 
commonly approach vessels and/or towed arrays during active sound 
production for purposes of bow riding, with no apparent effect observed 
in those delphinoids (e.g., Barkaszi et al., 2012). The potential for 
increased shutdowns resulting from such a measure would require the 
Kairei to revisit the missed track line to reacquire data, resulting in 
an overall increase in the total sound energy input to the marine 
environment and an increase in the total duration over which the survey 
is active in a given area. Although other mid-frequency hearing 
specialists (e.g., large delphinoids) are no more likely to incur 
auditory injury than are small delphinoids, they are much less likely 
to approach vessels. Therefore, retaining a power-down/shutdown 
requirement for large delphinoids would not have similar impacts in 
terms of either practicability for the applicant or corollary increase 
in sound energy output and time on the water. We do anticipate some 
benefit for a power-down/shutdown requirement for large delphinoids in 
that it simplifies somewhat the total range of decision-making for PSOs 
and may preclude any potential for physiological effects other than to 
the auditory system as well as some more severe behavioral reactions 
for any such animals in close proximity to the source vessel.
    At any distance, power down of the acoustic source would also be 
required upon observation of a large whale (i.e., sperm whale or any 
baleen whale) with a calf, or upon observation of an aggregation of 
large whales of any species (i.e., sperm whale or any baleen whale) 
that does not appear to be traveling (e.g., feeding, socializing, 
etc.). These would be the only two potential situations that would 
require power down of the array for marine mammals observed beyond the 
500 m exclusion zone.

Shut Down Procedures

    The single 100-in\3\ operating airgun would be shut down if a 
marine mammal is seen within or approaching the 100 m EZ for the single 
100-in\3\ airgun. Shutdown would be implemented if (1) an animal enters 
the 100 m EZ of the single 100-in\3\ airgun after a power down has been 
initiated, or (2) an animal is initially seen within the 100 m EZ of 
the single 100-in\3\ airgun when more than one airgun (typically the 
full array) is operating. Airgun activity would not resume until the 
marine mammal has cleared the 500 m EZ. Criteria for judging that the 
animal has cleared the EZ would be as described above.
    The shutdown requirement, like the power down requirement, would be 
waived for dolphins of the following genera: Steno, Tursiops, Stenella 
and Lagenodelphis. The shutdown waiver only applies if the animals are 
traveling, including approaching the vessel. If animals are stationary 
and the source vessel approaches the animals, the shutdown requirement 
would apply. If there is uncertainty regarding identification (i.e., 
whether the observed animal(s) belongs to the group described above) or 
whether the animals are traveling, the shutdown would be implemented.

Ramp-Up Procedures

    Ramp-up of an acoustic source is intended to provide a gradual 
increase in sound levels following a power down or shutdown, enabling 
animals to move away from the source if the signal is sufficiently 
aversive prior to its reaching full intensity. The ramp-up procedure 
involves a step-wise increase in the number of airguns firing and total 
array volume until all operational airguns are activated and the full 
volume is achieved. Ramp-up would be required after the array is 
powered down or shut down for any reason.
    Ramp-up would begin by activating a single airgun of the smallest 
volume in the array and would continue in stages by doubling the number 
of active elements at the commencement of each stage, with each stage 
of approximately the same duration. This approach to ramp-up 
(increments of array elements) is proposed because it is relatively 
simple to implement for the operator and is intended to ensure a 
perceptible increase in sound output per increment while employing 
increments that produce similar degrees of increase at each step.
    If airguns have been powered down or shut down due to PSO detection 
of a marine mammal within or approaching the 500 m EZ, ramp-up would 
not be initiated until all marine mammals have cleared the EZ, during 
the day or night. Visual and acoustic PSOs would be required to monitor 
during ramp-up. If a marine mammal were detected by visual PSOs within 
or approaching the 500 m EZ during ramp-up, a power down (or shut down 
if appropriate) would be implemented as though the full array were 
operational. Criteria for clearing the EZ would be as described above.
    Thirty minutes of pre-clearance observation are required prior to 
ramp-up for any power down or shutdown of longer than 30 minutes (i.e., 
if the array were shut down during transit from one line to another). 
This 30 minute pre-clearance period may occur during any vessel 
activity (i.e., transit). If a marine mammal were observed within or 
approaching the 500 m EZ during this pre-clearance period, ramp-up 
would not be initiated until all marine mammals cleared the EZ. 
Criteria for clearing the EZ would be as described above. If the airgun 
array has been shut down for reasons other than mitigation (e.g., 
mechanical difficulty) for a period of less than 30 minutes, it may be 
activated again without ramp-up if PSOs have maintained constant visual 
and acoustic observation and no visual detections of any marine mammal 
have occurred within the buffer zone and no acoustic detections have 
occurred.
    Ramp-up would be planned to occur during periods of good visibility 
when possible. However, ramp-up would be allowed at night and during 
poor visibility if the 500 m EZ and 1,000 m buffer zone have been 
monitored by visual PSOs for 30 minutes prior to ramp-up and if 
acoustic monitoring has occurred for 30 minutes prior to ramp-up with 
no acoustic detections during that period.
    The operator would be required to notify a designated PSO of the 
planned start of ramp-up as agreed-upon with the lead PSO; the 
notification time should not be less than 60 minutes prior to the 
planned ramp-up. A designated PSO must be notified again immediately 
prior to initiating ramp-up procedures and the operator must receive 
confirmation from the PSO to proceed. The operator must provide 
information to PSOs documenting that appropriate procedures were 
followed. Following deactivation of the array for reasons other than 
mitigation, the operator would be required to communicate the near-term 
operational plan to the lead PSO with justification for any planned 
nighttime ramp-up.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular

[[Page 34376]]

attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.
    UH submitted a marine mammal monitoring and reporting plan in 
section XIII of their IHA application. Monitoring that is designed 
specifically to facilitate mitigation measures, such as monitoring of 
the EZ to inform potential power downs or shutdowns of the airgun 
array, are described above and are not repeated here.
    UH's monitoring and reporting plan includes the following measures:

Vessel-Based Visual Monitoring

    As described above, PSO observations would take place during 
daytime airgun operations and nighttime start ups (if applicable) of 
the airguns. During seismic operations, four visual PSOs would be based 
aboard the Kairei. PSOs would be appointed by JAMSTEC with NMFS 
approval. During the majority of seismic operations, two PSOs would 
monitor for marine mammals around the seismic vessel. Use of two 
simultaneous observers would increase the effectiveness of detecting 
animals around the source vessel. However, during meal times, only one 
PSO may be on duty. PSOs would be on duty in shifts of duration no 
longer than 4 hours. Other crew would also be instructed to assist in 
detecting marine mammals and in implementing mitigation requirements 
(if practical). During daytime, PSOs would scan the area around the 
vessel systematically with reticle binoculars (e.g., 7x50 Fujinon), 
Big-eye binoculars (25x150), and with the naked eye.
    PSOs would record data to estimate the numbers of marine mammals 
exposed to various received sound levels and to document apparent 
disturbance reactions or lack thereof. Data would be used to estimate 
numbers of animals potentially `taken' by harassment (as defined in the 
MMPA). They would also provide information needed to order a power down 
or shut down of the airguns when a marine mammal or sea turtle is 
within or near the EZ.
    When a sighting is made, the following information about the 
sighting would be recorded:
    1. Species, group size, age/size/sex categories (if determinable), 
behavior when first sighted and after initial sighting, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
apparent reaction to the airguns or vessel (e.g., none, avoidance, 
approach, paralleling, etc.), and behavioral pace.
    2. Time, location, heading, speed, activity of the vessel, sea 
state, visibility, and sun glare.
    All observations and power downs or shutdowns would be recorded in 
a standardized format. Data would be entered into an electronic 
database. The accuracy of the data entry would be verified by 
computerized data validity checks as the data are entered and by 
subsequent manual checking of the database. These procedures would 
allow initial summaries of data to be prepared during and shortly after 
the field program and would facilitate transfer of the data to 
statistical, graphical, and other programs for further processing and 
archiving. The time, location, heading, speed, activity of the vessel, 
sea state, visibility, and sun glare would also be recorded at the 
start and end of each observation watch, and during a watch whenever 
there is a change in one or more of the variables.
    Results from the vessel-based observations would provide:
    1. The basis for real-time mitigation (airgun power down or shut 
down).
    2. Information needed to estimate the number of marine mammals 
potentially taken by harassment, which must be reported to NMFS.
    3. Data on the occurrence, distribution, and activities of marine 
mammals and turtles in the area where the seismic study is conducted.
    4. Information to compare the distance and distribution of marine 
mammals and turtles relative to the source vessel at times with and 
without seismic activity.
    5. Data on the behavior and movement patterns of marine mammals and 
turtles seen at times with and without seismic activity.

Vessel-Based Passive Acoustic Monitoring

    PAM would take place to complement the visual monitoring program as 
described above. Please see the Proposed Mitigation section above for a 
description of the PAM system and the acoustic PSO's duties. The 
acoustic PSO would record data collected via the PAM system, including 
the following: An acoustic encounter identification number, whether it 
was linked with a visual sighting, date, time when first and last heard 
and whenever any additional information was recorded, position and 
water depth when first detected, bearing if determinable, species or 
species group (e.g., unidentified dolphin, sperm whale), types and 
nature of sounds heard (e.g., clicks, continuous, sporadic, whistles, 
creaks, burst pulses, strength of signal, etc.), and any other notable 
information. Acoustic detections would also be recorded for further 
analysis.

Reporting

    A report would be submitted to NMFS within 90 days after the end of 
the cruise. The report would describe the operations that were 
conducted and sightings of marine mammals near the operations. The 
report would provide full documentation of methods, results,

[[Page 34377]]

and interpretation pertaining to all monitoring. The 90-day report 
would summarize the dates and locations of seismic operations, and all 
marine mammal sightings (dates, times, locations, activities, 
associated seismic survey activities). The report would also include 
estimates of the number and nature of exposures that occurred above the 
harassment threshold based on PSO observations.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as ``an impact resulting from 
the specified activity that cannot be reasonably expected to, and is 
not reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival'' (50 CFR 216.103). 
A negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    To avoid repetition, our analysis applies to all the species listed 
in Table 2, given that NMFS expects the anticipated effects of the 
proposed seismic survey to be similar in nature. Where there are 
meaningful differences between species or stocks, or groups of species, 
in anticipated individual responses to activities, impact of expected 
take on the population due to differences in population status, or 
impacts on habitat, NMFS has identified species-specific factors to 
inform the analysis.
    NMFS does not anticipate that serious injury or mortality would 
occur as a result of UH's proposed seismic survey, even in the absence 
of proposed mitigation. Thus the proposed authorization does not 
authorize any mortality. As discussed in the Potential Effects section, 
non-auditory physical effects, stranding, and vessel strike are not 
expected to occur.
    We propose to authorize a limited number of instances of Level A 
harassment of one marine mammal species (Table 8). However, we believe 
that any PTS incurred in marine mammals as a result of the proposed 
activity would be in the form of only a small degree of PTS and not 
total deafness that would not be likely to affect the fitness of any 
individuals, because of the constant movement of both the Kairei and of 
the marine mammals in the project area, as well as the fact that the 
vessel is not expected to remain in any one area in which individual 
marine mammals would be expected to concentrate for an extended period 
of time (i.e., since the duration of exposure to loud sounds will be 
relatively short). Also, as described above, we expect that marine 
mammals would be likely to move away from a sound source that 
represents an aversive stimulus, especially at levels that would be 
expected to result in PTS, given sufficient notice of the Kairei's 
approach due to the vessel's relatively low speed when conducting 
seismic surveys. We expect that the majority of takes would be in the 
form of short-term Level B behavioral harassment in the form of 
temporary avoidance of the area or decreased foraging (if such activity 
were occurring), reactions that are considered to be of low severity 
and with no lasting biological consequences (e.g., Southall et al., 
2007).
    Potential impacts to marine mammal habitat were discussed 
previously in this document (see Potential Effects of the Specified 
Activity on Marine Mammals and their Habitat). Marine mammal habitat 
may be impacted by elevated sound levels, but these impacts would be 
temporary. Feeding behavior is not likely to be significantly impacted, 
as marine mammals appear to be less likely to exhibit behavioral 
reactions or avoidance responses while engaged in feeding activities 
(Richardson et al., 1995). Prey species are mobile and are broadly 
distributed throughout the project area; therefore, marine mammals that 
may be temporarily displaced during survey activities are expected to 
be able to resume foraging once they have moved away from areas with 
disturbing levels of underwater noise. Because of the temporary nature 
of the disturbance, the availability of similar habitat and resources 
in the surrounding area, and the lack of important or unique marine 
mammal habitat, the impacts to marine mammals and the food sources that 
they utilize are not expected to cause significant or long-term 
consequences for individual marine mammals or their populations. In 
addition, there are no mating or calving areas known to be biologically 
important to marine mammals within the proposed project area.
    The activity is expected to impact a very small percentage of all 
marine mammal stocks that would be affected by UH's proposed survey 
(less than 2 percent for all marine mammal stocks). Additionally, the 
acoustic ``footprint'' of the proposed survey would be very small 
relative to the ranges of all marine mammals that would potentially be 
affected. Sound levels would increase in the marine environment in a 
relatively small area surrounding the vessel compared to the range of 
the marine mammals within the proposed survey area. The seismic array 
would be active 24 hours per day throughout the duration of the 
proposed survey. However, the very brief overall duration of the 
proposed survey (5.5 days) would further limit potential impacts that 
may occur as a result of the proposed activity.
    The proposed mitigation measures are expected to reduce the number 
and/or severity of takes by allowing for detection of marine mammals in 
the vicinity of the vessel by visual and acoustic observers, and by 
minimizing the severity of any potential exposures via power downs and/
or shutdowns of the airgun array. Based on previous monitoring reports 
for substantially similar activities that have been previously 
authorized by NMFS, we expect that the proposed mitigation will be 
effective in preventing at least some extent of potential PTS in marine 
mammals that may otherwise occur in the absence of the proposed 
mitigation.
    Of the marine mammal species under our jurisdiction that are likely 
to occur in the project area, the following species are listed as 
endangered under the ESA: Blue, fin, sei, and sperm whales. There are 
currently insufficient data to determine population trends for blue, 
fin, sei, and sperm whales (Carretta et al., 2016); however, we are 
proposing to authorize very small numbers of takes for these species 
(Table 8), relative to their population sizes, therefore we do not 
expect population-level impacts to any of these species. The other 
marine mammal species that may be taken by harassment during UH's 
seismic survey

[[Page 34378]]

are not listed as threatened or endangered under the ESA. There is no 
designated critical habitat for any ESA-listed marine mammals within 
the project area; and of the non-listed marine mammals for which we 
propose to authorize take, none are considered ``depleted'' or 
``strategic'' by NMFS under the MMPA.
    NMFS concludes that exposures to marine mammal species and stocks 
due to UH's proposed seismic survey would result in only short-term 
(temporary and short in duration) effects to individuals exposed. 
Animals may temporarily avoid the immediate area, but are not expected 
to permanently abandon the area. Major shifts in habitat use, 
distribution, or foraging success are not expected. NMFS does not 
anticipate the proposed take estimates to impact annual rates of 
recruitment or survival.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the marine mammal 
species or stocks through effects on annual rates of recruitment or 
survival:
     No mortality is anticipated or authorized;
     The anticipated impacts of the proposed activity on marine 
mammals would primarily be temporary behavioral changes due to 
avoidance of the area around the survey vessel. The relatively short 
duration of the proposed survey (5.5 days) would further limit the 
potential impacts of any temporary behavioral changes that would occur;
     PTS is only anticipated to occur for one species and the 
number of instances of PTS that may occur are expected to be very small 
in number (Table 8). Instances of PTS that are incurred in marine 
mammals would be of a low level, due to constant movement of the vessel 
and of the marine mammals in the area, and the nature of the survey 
design (not concentrated in areas of high marine mammal concentration);
     The availability of alternate areas of similar habitat 
value for marine mammals to temporarily vacate the survey area during 
the proposed survey to avoid exposure to sounds from the activity;
     The proposed project area does not contain areas of 
significance for mating or calving;
     The potential adverse effects on fish or invertebrate 
species that serve as prey species for marine mammals from the proposed 
survey would be temporary and spatially limited;
     The proposed mitigation measures, including visual and 
acoustic monitoring, power-downs, and shutdowns, are expected to 
minimize potential impacts to marine mammals.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers; so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities. Table 8 provides numbers of take by Level A harassment 
and Level B harassment proposed for authorization. These are the 
numbers we use for purposes of the small numbers analysis.
    The numbers of marine mammals that we propose for authorization to 
be taken, for all species and stocks, would be considered small 
relative to the relevant stocks or populations (approximately 13 
percent for rough-toothed dolphin, and less than five percent for all 
other species and stocks). For the blue whale, killer whale, humpback 
whale, minke whale and spinner dolphin we propose to authorize take 
resulting from a single exposure of one group of each species or stock, 
as appropriate (using best available information on mean group size for 
these species or stocks). We believe that a single incident of take of 
one group of any of these species represents take of small numbers for 
that species
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
preliminarily 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)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the ESA Interagency 
Cooperation Division, whenever we propose to authorize take for 
endangered or threatened species.
    The NMFS Permits and Conservation Division is proposing to 
authorize the incidental take of four species of marine mammals which 
are listed under the ESA: the sei, fin, blue and sperm whale. We have 
requested initiation of Section 7 consultation with the Interagency 
Cooperation Division for the issuance of this IHA. NMFS will conclude 
the ESA section 7 consultation prior to reaching a determination 
regarding the proposed issuance of the authorization.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to UH for conducting a seismic survey in the central 
Pacific Ocean in September, 2017, provided the previously mentioned 
mitigation, monitoring, and reporting requirements are incorporated. 
This section contains a draft of the IHA itself. The wording contained 
in this section is proposed for inclusion in the IHA (if issued).
    1. This incidental harassment authorization (IHA) is valid for a 
period of one year from the date of issuance.
    2. This IHA is valid only for marine geophysical survey activity, 
as specified in the University of Hawaii's (UH) IHA application and 
using an array aboard the R/V Kairei with characteristics specified in 
the application, in the Central Pacific Ocean.
    3. General Conditions
    (a) A copy of this IHA must be in the possession of UH, the vessel 
operator and other relevant personnel, the lead

[[Page 34379]]

protected species observer (PSO), and any other relevant designees of 
UH operating under the authority of this IHA.
    (b) The species authorized for taking are listed in Table 8. The 
taking, by Level A and Level B harassment only, is limited to the 
species and numbers listed in Table 8. Any taking exceeding the 
authorized amounts listed in Table 8 is prohibited and may result in 
the modification, suspension, or revocation of this IHA.
    (c) The taking by serious injury or death of any species of marine 
mammal is prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    (d) During use of the airgun(s), if marine mammal species other 
than those listed in Table 8 are detected by PSOs, the acoustic source 
must be shut down to avoid unauthorized take.
    (e) UH shall ensure that the vessel operator and other relevant 
vessel personnel are briefed on all responsibilities, communication 
procedures, marine mammal monitoring protocol, operational procedures, 
and IHA requirements prior to the start of survey activity, and when 
relevant new personnel join the survey operations.
    4. Mitigation Requirements
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) UH must use five dedicated, trained, NMFS-approved Protected 
Species Observers (PSOs), including four visual PSOs and one acoustic 
PSO. The PSOs must have no tasks other than to conduct observational 
effort, record observational data, and communicate with and instruct 
relevant vessel crew with regard to the presence of marine mammals and 
mitigation requirements. PSO resumes shall be provided to NMFS for 
approval.
    (b) At least two PSOs must have a minimum of 90 days at-sea 
experience working as PSOs during a deep penetration seismic survey, 
with no more than eighteen months elapsed since the conclusion of the 
at-sea experience. At least one of these must have relevant experience 
as a visual PSO and at least one must have relevant experience as an 
acoustic PSO. One ``experienced'' visual PSO shall be designated as the 
lead for the entire protected species observation team. The lead shall 
coordinate duty schedules and roles for the PSO team and serve as 
primary point of contact for the vessel operator. The lead PSO shall 
devise the duty schedule such that ``experienced'' PSOs are on duty 
with those PSOs with appropriate training but who have not yet gained 
relevant experience, to the maximum extent practicable.
    (c) Visual Observation
    (i) During survey operations (e.g., any day on which use of the 
acoustic source is planned to occur; whenever the acoustic source is in 
the water, whether activated or not), two PSOs must be on duty and 
conducting visual observations at all times during daylight hours 
(i.e., from 30 minutes prior to sunrise through 30 minutes following 
sunset) with the limited exception of meal times during which one PSO 
may be on duty.
    (ii) Visual monitoring must begin not less than 30 minutes prior to 
ramp-up, including for nighttime ramp-ups of the airgun array, and must 
continue until one hour after use of the acoustic source ceases or 
until 30 minutes past sunset.
    (iii) Visual PSOs shall coordinate to ensure 360[deg] visual 
coverage around the vessel from the most appropriate observation posts 
and shall conduct visual observations using binoculars and the naked 
eye while free from distractions and in a consistent, systematic, and 
diligent manner.
    (iv) Visual PSOs shall communicate all observations to the acoustic 
PSO, including any determination by the PSO regarding species 
identification, distance, and bearing and the degree of confidence in 
the determination.
    (v) Visual PSOs may be on watch for a maximum of four consecutive 
hours followed by a break of at least one hour between watches and may 
conduct a maximum of 12 hours observation per 24 hour period.
    (vi) During good conditions (e.g., daylight hours; Beaufort sea 
state 3 or less), visual PSOs shall conduct observations when the 
acoustic source is not operating for comparison of sighting rates and 
behavior with and without use of the acoustic source and between 
acquisition periods, to the maximum extent practicable.
    (d) Acoustic Observation--The R/V Kairei must use a towed passive 
acoustic monitoring (PAM) system, which must be monitored beginning at 
least 30 minutes prior to ramp-up and at all times during use of the 
acoustic source.
    (i) One acoustic PSO (in addition to the four visual PSOs) must be 
on board to operate and oversee PAM operations. Either the acoustic PSO 
or a visual PSO with training in the PAM system must monitor the PAM 
system at all times while airguns are operating, and when possible 
during periods when the airguns are not operating, in shifts lasting no 
longer than six hours.
    (ii) Acoustic PSOs shall communicate all detections to visual PSOs, 
when visual PSOs are on duty, including any determination by the PSO 
regarding species identification, distance, and bearing and the degree 
of confidence in the determination.
    (iii) Survey activity may continue for brief periods of time if the 
PAM system malfunctions or is damaged. Activity may continue for 30 
minutes without PAM while the PAM operator diagnoses the issue. If the 
diagnosis indicates that the PAM system must be repaired to solve the 
problem, operations may continue for an additional two hours without 
acoustic monitoring under the following conditions:
    (A) Daylight hours and sea state is less than or equal to Beaufort 
sea state 4;
    (B) No marine mammals (excluding small delphinids) detected solely 
by PAM in the exclusion zone in the previous two hours;
    (C) NMFS is notified via email as soon as practicable with the time 
and location in which operations began without an active PAM system; 
and
    (D) Operations with an active acoustic source, but without an 
operating PAM system, do not exceed a cumulative total of four hours in 
any 24 hour period.
    (e) Exclusion Zone and buffer zone--PSOs shall establish and 
monitor a 500 m exclusion zone (EZ) and 1,000 m buffer zone. The zones 
shall be based upon radial distance from any element of the airgun 
array (rather than being based on the center of the array or around the 
vessel itself). During use of the acoustic source, occurrence of marine 
mammals outside the EZ but within 1,000 m from any element of the 
airgun array shall be communicated to the operator to prepare for 
potential further mitigation measures as described below. During use of 
the acoustic source, occurrence of marine mammals within the EZ, or on 
a course to enter the EZ, shall trigger further mitigation measures as 
described below.
    (i) Ramp-up--A ramp-up procedure, involving a step-wise increase in 
the number of airguns firing and total array volume until all 
operational airguns are activated and the full volume is achieved, is 
required at all times as part of the activation of the acoustic source. 
Ramp-up shall begin by activating a single airgun of the smallest 
volume in the array and shall continue in stages by doubling the number 
of active elements at the commencement of each stage, with each stage 
of approximately the same duration.
    (ii) If the airgun array has been powered down or shut down due to 
a marine mammal detection, ramp-up shall not occur until all marine 
mammals have cleared the EZ. A marine mammal is considered to have 
cleared the EZ if:

[[Page 34380]]

    (A) It has been visually observed to have left the EZ
    (B) It has not been observed within the EZ, for 15 minutes (in the 
case of small odontocetes) or for 30 minutes (in the case of mysticetes 
and large odontocetes including sperm, pygmy sperm, dwarf sperm, and 
beaked whales).
    (iii) Thirty minutes of pre-clearance observation of the 500 m EZ 
and 1,000 m buffer zone are required prior to ramp-up for any power 
down or shutdown of longer than 30 minutes. This pre-clearance period 
may occur during any vessel activity. If any marine mammal (including 
delphinids) is observed within or approaching the 500 m EZ during the 
30 minute pre-clearance period, ramp-up may not begin until the 
animal(s) has been observed exiting the buffer zone or until an 
additional time period has elapsed with no further sightings (i.e., 15 
minutes for small odontocetes and 30 minutes for all other species).
    (iv) During ramp-up, PSOs shall monitor the 500 m EZ and 1,000 m 
buffer zone. Ramp-up may not be initiated if any marine mammal 
(including delphinids) is observed within or approaching the 500 m EZ. 
If a marine mammal is observed within or approaching the 500 m EZ 
during ramp-up, a power down or shutdown shall be implemented as though 
the full array were operational. Ramp-up may not begin again until the 
animal(s) has been observed exiting the 500 m EZ or until an additional 
time period has elapsed with no further sightings (i.e., 15 minutes for 
small odontocetes and 30 minutes for all other species).
    (v) If the airgun array has been shut down for reasons other than 
mitigation (e.g., mechanical difficulty) for a period of less than 30 
minutes, it may be activated again without ramp-up if PSOs have 
maintained constant visual and acoustic observation and no visual 
detections of any marine mammal have occurred within the buffer zone 
and no acoustic detections have occurred.
    (vi) Ramp-up shall only occur at night and at times of poor 
visibility where operational planning cannot reasonably avoid such 
circumstances. Ramp-up may occur at night and during poor visibility if 
the 500 m EZ and 1,000 m buffer zone have been continually monitored by 
visual PSOs for 30 minutes prior to ramp-up with no marine mammal 
detections and if acoustic monitoring has occurred for 30 minutes prior 
to ramp-up with no acoustic detections during that period.
    (vii) The vessel operator must notify a designated PSO of the 
planned start of ramp-up as agreed-upon with the lead PSO; the 
notification time should not be less than 60 minutes prior to the 
planned ramp-up. A designated PSO must be notified again immediately 
prior to initiating ramp-up procedures and the operator must receive 
confirmation from the PSO to proceed.
    (f) Power Down Requirements--UH shall power-down the airgun array 
if a PSO detects a marine mammal within, approaching, or entering the 
500 m EZ. A power down involves a decrease in the number of operational 
airguns. During a power down, one 100-in \3\ airgun shall be 
continuously operated.
    (i) Any PSO on duty has the authority to call for power down of the 
airgun array (visual PSOs on duty should be in agreement on the need 
for power down before requiring such action). When there is certainty 
regarding the need for mitigation action on the basis of either visual 
or acoustic detection alone, the relevant PSO(s) must call for such 
action immediately.
    (ii) When both visual and acoustic PSOs are on duty, all detections 
must be immediately communicated to the remainder of the on-duty PSO 
team for potential verification of visual observations by the acoustic 
PSO or of acoustic detections by visual PSOs and initiation of dialogue 
as necessary.
    (iii) The operator must establish and maintain clear lines of 
communication directly between PSOs on duty and crew controlling the 
airgun array to ensure that power down commands are conveyed swiftly 
while allowing PSOs to maintain watch.
    (iv) When power down is called for by a PSO, the power down must 
occur and any dispute resolved only following power down.
    (v) The power down requirement is waived for dolphins of the 
following genera: Steno, Tursiops, Stenella and Lagenodelphis. The 
power down waiver only applies if animals are traveling, including 
approaching the vessel. If animals are stationary and the vessel 
approaches the animals, the power down requirement applies. If there is 
uncertainty regarding identification (i.e., whether the observed 
animal(s) belongs to the group described above) or whether the animals 
are traveling, power down must be implemented.
    (vi) Upon implementation of a power down, the source may be 
reactivated under the conditions described at 4(e)(vi). Where there is 
no relevant zone (e.g., shutdown due to observation of a calf), a 30-
minute clearance period must be observed following the last observation 
of the animal(s).
    (vii) Power down of the acoustic source is required upon 
observation of a whale (i.e., sperm whale or any baleen whale) with 
calf at any distance, with ``calf'' defined as an animal less than two-
thirds the body size of an adult observed to be in close association 
with an adult.
    (viii) Power down of the acoustic source is required upon 
observation of an aggregation (i.e., six or more animals) of large 
whales of any species (i.e., sperm whale or any baleen whale) that does 
not appear to be traveling (e.g., feeding, socializing, etc.).
    (ix) When only the acoustic PSO is on duty and a detection is made, 
if there is uncertainty regarding species identification or distance to 
the vocalizing animal(s), the airgun array must be powered down as a 
precaution.
    (g) Shutdown requirements--An exclusion zone of 100 m for the 
single 100-in\3\ airgun shall be established and monitored by PSOs. If 
a marine mammal is observed within, entering, or approaching the 100 m 
exclusion zone for the single 100-in\3\ airgun, whether during 
implementation of a power down or during operation of the full airgun 
array, all airguns including the 100-in\3\ airgun shall be shut down.
    (i) Upon implementation of a shutdown, the source may be 
reactivated under the conditions described at 4(e).
    (ii) Measures described for power downs under 4(f)(i-v) shall also 
apply in the case of a shutdown.
    (h) Vessel Strike Avoidance--Vessel operator and crew must maintain 
a vigilant watch for all marine mammals and slow down or stop the 
vessel or alter course, as appropriate, to avoid striking any marine 
mammal. A visual observer aboard the vessel must monitor a vessel 
strike avoidance zone around the vessel according to the parameters 
stated below. Visual observers monitoring the vessel strike avoidance 
zone can be either third-party observers or crew members, but crew 
members responsible for these duties must be provided sufficient 
training to distinguish marine mammals from other phenomena.
    (i) The vessel must maintain a minimum separation distance of 100 m 
from large whales. The following avoidance measures must be taken if a 
large whale is within 100 m of the vessel:
    (A) The vessel must reduce speed and shift the engine to neutral, 
and must not engage the engines until the whale has moved outside of 
the vessel's path and the minimum separation distance has been 
established.
    (B) If the vessel is stationary, the vessel must not engage engines 
until the whale(s) has moved out of the vessel's path and beyond 100 m.

[[Page 34381]]

    (ii) The vessel must maintain a minimum separation distance of 50 m 
from all other marine mammals, with an exception made for animals 
described in 4(g)(v) that approach the vessel. If an animal is 
encountered during transit, the vessel shall attempt to remain parallel 
to the animal's course, avoiding excessive speed or abrupt changes in 
course.
    (iii) Vessel speeds must be reduced to 10 knots or less when 
mother/calf pairs, pods, or large assemblages of cetaceans are observed 
near the vessel.
    (i) Miscellaneous Protocols
    (i) The airgun array must be deactivated when not acquiring data or 
preparing to acquire data, except as necessary for testing. Unnecessary 
use of the acoustic source shall be avoided. Notified operational 
capacity (not including redundant backup airguns) must not be exceeded 
during the survey, except where unavoidable for source testing and 
calibration purposes. All occasions where activated source volume 
exceeds notified operational capacity must be noticed to the PSO(s) on 
duty and fully documented. The lead PSO must be granted access to 
relevant instrumentation documenting acoustic source power and/or 
operational volume.
    (ii) Testing of the acoustic source involving all elements requires 
normal mitigation protocols (e.g., ramp-up). Testing limited to 
individual source elements or strings does not require ramp-up but does 
require pre-clearance.
    5. Monitoring Requirements
    The holder of this Authorization is required to conduct marine 
mammal monitoring during survey activity. Monitoring shall be conducted 
in accordance with the following requirements:
    (a) The operator must provide bigeye binoculars (e.g., 25x150; 2.7 
view angle; individual ocular focus; height control) of appropriate 
quality (i.e., Fujinon or equivalent) solely for PSO use. These shall 
be pedestal-mounted on the deck at the most appropriate vantage point 
that provides for optimal sea surface observation, PSO safety, and safe 
operation of the vessel. The operator must also provide a night-vision 
device suited for the marine environment for use during nighttime ramp-
up pre-clearance, at the discretion of the PSOs. At minimum, the device 
should feature automatic brightness and gain control, bright light 
protection, infrared illumination, and optics suited for low-light 
situations.
    (b) PSOs must also be equipped with reticle binoculars (e.g., 7x50) 
of appropriate quality (i.e., Fujinon or equivalent), GPS, digital 
single-lens reflex camera of appropriate quality (i.e., Canon or 
equivalent), compass, and any other tools necessary to adequately 
perform necessary tasks, including accurate determination of distance 
and bearing to observed marine mammals.
    (c) PSO Qualifications
    (i) PSOs must have successfully completed relevant training, 
including completion of all required coursework and passing a written 
and/or oral examination developed for the training program.
    (ii) PSOs must have successfully attained a bachelor's degree from 
an accredited college or university with a major in one of the natural 
sciences and a minimum of 30 semester hours or equivalent in the 
biological sciences and at least one undergraduate course in math or 
statistics. The educational requirements may be waived if the PSO has 
acquired the relevant skills through alternate experience. Requests for 
such a waiver must include written justification. Alternate experience 
that may be considered includes, but is not limited to (1) secondary 
education and/or experience comparable to PSO duties; (2) previous work 
experience conducting academic, commercial, or government-sponsored 
marine mammal surveys; or (3) previous work experience as a PSO; the 
PSO should demonstrate good standing and consistently good performance 
of PSO duties.
    (d) Data Collection--PSOs must use standardized data forms, whether 
hard copy or electronic. PSOs shall record detailed information about 
any implementation of mitigation requirements, including the distance 
of animals to the acoustic source and description of specific actions 
that ensued, the behavior of the animal(s), any observed changes in 
behavior before and after implementation of mitigation, and if shutdown 
was implemented, the length of time before any subsequent ramp-up of 
the acoustic source to resume survey. If required mitigation was not 
implemented, PSOs should submit a description of the circumstances. We 
require that, at a minimum, the following information be reported:
    (i) PSO names and affiliations
    (ii) Dates of departures and returns to port with port name
    (iii) Dates and times (Greenwich Mean Time) of survey effort and 
times corresponding with PSO effort
    (iv) Vessel location (latitude/longitude) when survey effort begins 
and ends; vessel location at beginning and end of visual PSO duty 
shifts
    (v) Vessel heading and speed at beginning and end of visual PSO 
duty shifts and upon any line change
    (vi) Environmental conditions while on visual survey (at beginning 
and end of PSO shift and whenever conditions change significantly), 
including wind speed and direction, Beaufort sea state, Beaufort wind 
force, swell height, weather conditions, cloud cover, sun glare, and 
overall visibility to the horizon
    (vii) Factors that may be contributing to impaired observations 
during each PSO shift change or as needed as environmental conditions 
change (e.g., vessel traffic, equipment malfunctions)
    (viii) Survey activity information, such as acoustic source power 
output while in operation, number and volume of airguns operating in 
the array, tow depth of the array, and any other notes of significance 
(i.e., pre-ramp-up survey, ramp-up, shutdown, testing, shooting, ramp-
up completion, end of operations, streamers, etc.)
    (ix) If a marine mammal is sighted, the following information 
should be recorded:
    (A) Watch status (sighting made by PSO on/off effort, 
opportunistic, crew, alternate vessel/platform)
    (B) PSO who sighted the animal
    (C) Time of sighting
    (D) Vessel location at time of sighting
    (E) Water depth
    (F) Direction of vessel's travel (compass direction)
    (G) Direction of animal's travel relative to the vessel
    (H) Pace of the animal
    (I) Estimated distance to the animal and its heading relative to 
vessel at initial sighting
    (J) Identification of the animal (e.g., genus/species, lowest 
possible taxonomic level, or unidentified); also note the composition 
of the group if there is a mix of species
    (K) Estimated number of animals (high/low/best)
    (L) Estimated number of animals by cohort (adults, yearlings, 
juveniles, calves, group composition, etc.)
    (M) Description (as many distinguishing features as possible of 
each individual seen, including length, shape, color, pattern, scars or 
markings, shape and size of dorsal fin, shape of head, and blow 
characteristics)
    (N) Detailed behavior observations (e.g., number of blows, number 
of surfaces, breaching, spyhopping, diving, feeding, traveling; as 
explicit and detailed as possible; note any observed changes in 
behavior)
    (O) Animal's closest point of approach (CPA) and/or closest 
distance from the center point of the acoustic source;
    (P) Platform activity at time of sighting (e.g., deploying, 
recovering,

[[Page 34382]]

testing, shooting, data acquisition, other)
    (Q) Description of any actions implemented in response to the 
sighting (e.g., delays, shutdown, ramp-up, speed or course alteration, 
etc.); time and location of the action should also be recorded
    (x) If a marine mammal is detected while using the PAM system, the 
following information should be recorded:
    (A) An acoustic encounter identification number, and whether the 
detection was linked with a visual sighting
    (B) Time when first and last heard
    (C) Types and nature of sounds heard (e.g., clicks, whistles, 
creaks, burst pulses, continuous, sporadic, strength of signal, etc.)
    (D) Any additional information recorded such as water depth of the 
hydrophone array, bearing of the animal to the vessel (if 
determinable), species or taxonomic group (if determinable), and any 
other notable information.
    6. Reporting
    (a) UH shall submit a draft comprehensive report on all activities 
and monitoring results within 90 days of the completion of the survey 
or expiration of the IHA, whichever comes sooner. The report must 
describe all activities conducted and sightings of marine mammals near 
the activities, must provide full documentation of methods, results, 
and interpretation pertaining to all monitoring, and must summarize the 
dates and locations of survey operations and all marine mammal 
sightings (dates, times, locations, activities, associated survey 
activities). Geospatial data regarding locations where the acoustic 
source was used must be provided as an ESRI shapefile with all 
necessary files and appropriate metadata. In addition to the report, 
all raw observational data shall be made available to NMFS. The report 
must summarize the data collected as required under condition 5(d) of 
this IHA. The draft report must be accompanied by a certification from 
the lead PSO as to the accuracy of the report, and the lead PSO may 
submit directly to NMFS a statement concerning implementation and 
effectiveness of the required mitigation and monitoring. A final report 
must be submitted within 30 days following resolution of any comments 
from NMFS on the draft report.
    (b) Reporting injured or dead marine mammals:
    (i) In the event that the specified activity clearly causes the 
take of a marine mammal in a manner not prohibited by this IHA (if 
issued), such as serious injury or mortality, UH shall immediately 
cease the specified activities and immediately report the incident to 
NMFS. The report must include the following information:
    (A) Time, date, and location (latitude/longitude) of the incident;
    (B) Vessel's speed during and leading up to the incident;
    (C) Description of the incident;
    (D) Status of all sound source use in the 24 hours preceding the 
incident;
    (E) Water depth;
    (F) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    (G) Description of all marine mammal observations in the 24 hours 
preceding the incident;
    (H) Species identification or description of the animal(s) 
involved;
    (I) Fate of the animal(s); and
    (J) Photographs or video footage of the animal(s).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with UH to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. UH may not resume 
their activities until notified by NMFS.
    (ii) In the event that UH discovers an injured or dead marine 
mammal, and the lead observer 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), UH shall immediately report 
the incident to NMFS. The report must include the same information 
identified in condition 6(b)(i) of this IHA. Activities may continue 
while NMFS reviews the circumstances of the incident. NMFS will work 
with UH to determine whether additional mitigation measures or 
modifications to the activities are appropriate.
    (iii) In the event that UH discovers an injured or dead marine 
mammal, and the lead observer determines that the injury or death is 
not associated with or related to the specified activities (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), UH shall report the incident to 
NMFS within 24 hours of the discovery. UH shall provide photographs or 
video footage or other documentation of the sighting to NMFS.
    7. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
NMFS determines the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

Request for Public Comments

    We request comment on our analyses, the draft authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed 
seismic survey by UH. Please include with your comments any supporting 
data or literature citations to help inform our final decision on the 
request for MMPA authorization.

    Dated: July 19, 2017.
Catherine Marzin,
Acting Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2017-15455 Filed 7-21-17; 8:45 am]
 BILLING CODE 3510-22-P