[Federal Register Volume 77, Number 84 (Tuesday, May 1, 2012)]
[Notices]
[Pages 25830-25857]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-10386]



[[Page 25829]]

Vol. 77

Tuesday,

No. 84

May 1, 2012

Part III





Department of Commerce





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National Oceanic and Atmospheric Administration





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Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to Marine Seismic Survey in the Beaufort Sea, 
Alaska; Notice

  Federal Register / Vol. 77 , No. 84 / Tuesday, May 1, 2012 / 
Notices  

[[Page 25830]]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XY11


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Marine Seismic Survey in the 
Beaufort Sea, Alaska

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

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

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SUMMARY: NMFS received an application from BP Exploration (Alaska), 
Inc. (BP) for an Incidental Harassment Authorization (IHA) to take 
marine mammals, by harassment only, incidental to a proposed 3-
dimensional (3D) ocean bottom cable (OBC) seismic survey in the Simpson 
Lagoon area of the Alaskan Beaufort Sea during the open water season of 
2012. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is 
requesting comments on its proposal to issue an IHA to BP to take, by 
Level B harassment, 11 species of marine mammals during the specified 
activity.

DATES: Comments and information must be received no later than May 31, 
2012.

ADDRESSES: Comments on the application should be addressed to Tammy 
Adams, Acting Chief, Permits and Conservation Division, Office of 
Protected Resources, National Marine Fisheries Service, 1315 East-West 
Highway, Silver Spring, MD 20910. The mailbox address for providing 
email comments is [email protected]. NMFS is not responsible for email 
comments sent to addresses other than the one provided here. Comments 
sent via email, including all attachments, must not exceed a 10-
megabyte file size.
    Instructions: All comments received are a part of the public record 
and will generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications without change. All Personal Identifying 
Information (for example, name, address, etc.) voluntarily submitted by 
the commenter may be publicly accessible. Do not submit Confidential 
Business Information or otherwise sensitive or protected information.
    A copy of the application used in this document may be obtained by 
writing to the address specified above, telephoning the contact listed 
below (see FOR FURTHER INFORMATION CONTACT), or visiting the Internet 
at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications. 
Documents cited in this notice may also be viewed, by appointment, 
during regular business hours, at the aforementioned address.

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

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 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.
    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.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for an authorization to 
incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of 
an application followed by a 30-day public notice and comment period on 
any proposed authorizations for the incidental harassment of marine 
mammals. Within 45 days of the close of the comment period, NMFS must 
either issue or deny the authorization.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as:

any act of pursuit, torment, or annoyance which (i) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild [``Level A harassment'']; or (ii) has the potential to disturb 
a marine mammal or marine mammal stock in the wild by causing 
disruption of behavioral patterns, including, but not limited to, 
migration, breathing, nursing, breeding, feeding, or sheltering 
[``Level B harassment''].

Summary of Request

    NMFS received an application on December 20, 2011, from BP for the 
taking, by harassment, of marine mammals incidental to a 3D OBC seismic 
survey in the Simpson Lagoon area of the Alaskan Beaufort Sea during 
the open water season of 2012.

Description of the Specified Activity

    The proposed seismic survey utilizes receivers (hydrophones and 
geophones) connected to a cable that would be deployed from a vessel to 
the seabed or would be inserted in the seabed in very shallow water 
areas near the shoreline. The generation of 3D seismic images requires 
the deployment of many parallel cables spaced close together over the 
area of interest. Therefore, OBC seismic surveys require the use of 
multiple vessels for cable deployment and recovery, data recording, 
airgun operation, re-supply, and support. The proposed 3D OBC seismic 
survey in Simpson Lagoon would be conducted by CGGVeritas.

Seismic Source Arrays

    A total of three seismic source vessels (two main source vessels 
and one mini source vessel) would be used during the proposed survey. 
The sources would be arrays of sleeve airguns. Each main source vessel 
would carry an array that consists of two sub-arrays. Each sub-array 
contains eight 40 in\3\ airguns, totaling 16 guns per main source 
vessel with a total discharge volume of 2 x 320 in\3\, or 640 in\3\. 
This 640 in\3\ array has an estimated source level of ~223 dB re 1 
[mu]Pa (rms). The mini source vessel would contain one array with eight 
40 in\3\ airguns for a total discharge volume of 320 in\3\. The 
estimated source level of this 320 in\3\ array is 212 dB re 1 [mu]Pa 
(rms).
    The arrays of the main source vessels would be towed at a distance 
of ~30 feet (ft, or 10 m) from the stern at 6 ft (2 m) depth, which is 
remotely adjustable if needed. The array of the mini source vessel 
would be towed at a distance of ~20 ft (7 m) from the stern at 3 ft (1 
m) depth, also remotely adjustable when needed. The source vessels will 
travel along pre-determined lines with a speed varying from ~1 to 5 
knots, mainly depending on the water depth. To limit the duration of 
the total survey, the source vessels would be operating in a flip-flop 
mode, with the operating source vessels alternating shots; this

[[Page 25831]]

means that one vessel discharges airguns when the other vessel is 
recharging. Outside the barrier islands, the two main source vessels 
would be operating with expected shot intervals of 8 to 10 seconds, 
resulting in a shot every 4 to 5 seconds due to the flip-flop mode of 
operation. Inside the barrier islands all three vessels (the two main 
source vessels and the mini vessel) may be operating at the same time 
in this manner. The exact shot intervals would depend on the compressor 
capacity, which determines the time needed for the airguns to be 
recharged. Seismic data acquisition would be conducted 24 hours per 
day.

Receivers and Recording Units

    The survey area in Simpson Lagoon has water depths of 0 to 9 ft (0 
to 3 m) between the shore and barrier islands and 3 to 45 ft (1 to 15 
m) depths north of the barrier islands. Because different types of 
receivers would be used for different habitats, the survey area is 
categorized by the terms onshore, islands, surf-zone and offshore. 
Onshore is the area from the coastline inland. Islands are the barrier 
islands. Surf zone is the 0 to 6 ft (0 to 2 m) water depths along the 
onshore coastline. Offshore is defined as depths of 3 ft (1 m) or more. 
There is a zone between 3 and 6 ft (1 and 2 m) which may be categorized 
both as surf zone and as offshore.
    The receivers that would be deployed in water consist of multiple 
hydrophones and recorder units (Field Digitizing Units or FDUs) placed 
on Sercel ULS cables. Approximately 5,000 hydrophones would be 
connected to the ULS cable at a minimum of 82.5 ft (27.5 m) intervals 
and secured to the ocean bottom cable. Surface markers and acoustic 
pingers will be attached to the cable at various intervals to ensure 
that the battery packs can be located and retrieved when needed and to 
determine exact positions for the hydrophones. This equipment would be 
deployed and retrieved with cable boats. The data received at each FDU 
would be transmitted through the cables to a recorder for further 
processing. This recorder will be installed on a boat-barge combination 
and positioned close to the area where data are being acquired. While 
recording, the boat-barge combination is stationary and expected to 
utilize a two or four point anchoring system.
    In the surf-zone, receivers (hydrophones or geophones) would be 
bored or flushed up to 12 ft (4 m) below the seabed. These receivers 
will transmit data through a cable (as described above) and have an 
attached line to facilitate retrieval after recording is completed.
    Autonomous recorders (nodes) would be used onshore and on the 
islands. The node is located on the ground and its geophone would be 
inserted into the ground by hand with the use of a planting pole. 
Deployment of the autonomous receiver units would be done by a lay-out 
crew on the ground using helicopters for personnel and equipment 
transport and/or approved summer travel vehicles (onshore) and a 
support boat (for the islands). Data from nodes can be remotely 
retrieved from a distance (up to a kilometer). Retrieval of data may be 
from a boat or a helicopter. Equipment would be picked up after 
recording is complete.

Survey Design

    The total area of the proposed seismic survey is approximately 110 
mi \2\, which includes onshore, surf-zone, barrier islands, and 
offshore (see Figure 1.2 of the BP's IHA application). For the proposed 
survey, the receiver cables with hydrophones and recording units would 
be oriented in an east-west direction. A total of approximately 44 
receiver lines would be deployed at the seafloor with 1,100-1,650 ft 
(367-550 m) line spacing. Total receiver line length would be 
approximately 500 miles (825 km). The source vessel would travel 
perpendicular over the offshore receiver cables along lines oriented in 
a north-south direction. These lines would have a length of 
approximately 3.75 miles (6.2 km) and a minimum spacing of 660 ft (220 
m). The total length of all source lines is approximately 4,000 miles 
(6,600 km), including line turns.
    The position of each receiver deployed onshore, in the surf zone 
and on the barrier islands will be determined using Global Positioning 
System (GPS) positioning units. Due to the variable bathymetry of the 
survey area, determining positions of receivers deployed in water may 
require more than one technique. A combination of Ocean Bottom Receiver 
Location (OBRL), GPS and acoustic pingers will be used. For OBRL, the 
source vessel fires a precisely positioned single energy source 
multiple times along either side of the receiver cables. Production 
data may also be used instead of dedicated OBRL acquisition. Multiple 
energy sources are used to triangulate a given receiver position. In 
addition, Sonardyne acoustical pingers would be located at 
predetermined intervals on the receiver lines. The pingers are located 
on the ULS cables and transmit a signal to a transponder mounted on a 
vessel. This allows for an interpolation of the receiver locations 
between the acoustical pingers on the ULS cable and also serves as a 
verification of the OBRL method. The Sonardyne pingers transmit at 19-
36 kHz and have a source level of 188-193 dB re [mu]Pa at 1m.

Vessels and Other Equipment

    The proposed Simpson Lagoon OBC seismic survey would involve 14 to 
16 vessels, as listed in Table 1 below. The contracting of vessels has 
not been finalized to date. However, BP states it would contract 
vessels with parameters similar to those described in this table. If 
contracted vessels differ significantly from those described, BP would 
submit an amendment to address these changes where required.

    Table 1--Summary of Number and Type of Vessels Involved in the Proposed Simpson Lagoon OBC Seismic Survey
                                    [The dimensions provided are approximate]
----------------------------------------------------------------------------------------------------------------
          Vessel type                Number          Dimensions           Main activity            Frequency
----------------------------------------------------------------------------------------------------------------
Source Vessel: Main............               2  71 x 20 ft........  Seismic data             24-hr operation.
                                                                      acquisition inside and
                                                                      outside barrier
                                                                      islands.
Source Vessel: Mini............               1  55 x 15 ft........  Seismic data             24-hr operation.
                                                                      acquisition inside
                                                                      barrier islands.
Recorder barge with tug boat...               1  116.5 x 24 ft       Seismic data recording.  24-hr operation.
                                                  (barge);.
                                                 23 x 15 ft (tug)..
Cable boats....................             5-6  42.6 x 13 ft......  Deploy and retrieve      24-hr operation.
                                                                      receiver cables (with
                                                                      hydrophones/geophones).
Crew transport vessels.........               2  44 x 14 ft........  Transport crew and       Intermittently,
                                                                      supplies to and from     minimum every 8
                                                                      the working vessels.     hours.

[[Page 25832]]

 
Shallow water crew and support              2-3  34 x 10.5 ft......  Transport 2-5 people     Intermittently.
 boats.                                                               and small amounts of
                                                                      gear for the boats
                                                                      operating in the
                                                                      shallower parts of the
                                                                      survey area.
HSSE vessel....................               1  38 x 15 ft........  Support SSV              As required.
                                                                      measurements, HSSE
                                                                      (health, safety,
                                                                      security, and
                                                                      environmental)
                                                                      compliance.
----------------------------------------------------------------------------------------------------------------

    To deploy and retrieve receivers in water depths less than those 
accessible by the cable boats (surf-zone), equipment such as airboats, 
buggies or an Arktos (amphibious craft) and/or Jon boats may be used. 
Helicopters and/or approved tundra travel vehicles would be used for 
deployment of receiver units onshore as well on the barrier islands. In 
the case of helicopters being used, the flight altitude would be at 
1,500 feet for 3 to 6 times each day during gear deployment and 
retrieval on barrier islands and on shore (i.e., for about 14 days in 
late July and early August for deployment and for about 14 days 
probably after the Cross Island hunt, which typically ends around 
September 10).
    Vessels and other equipment would be transported to the North Slope 
in late May/early June by trucks. Equipment would be staged at the 
CGGVeritas pad for preparation. Vessel preparation would include 
assembly of navigation and source equipment, cable deployment and 
retrieval systems and safety equipment. Once assembled, vessels would 
be launched at either West Dock or Milne Point. Deployment, retrieval, 
navigation and source systems will then be tested near West Dock or in 
the project area prior to commencement of operations.

Crew Housing and Transfer

    The total number of people that would be involved is about 220, 
including crew on boats, camp personnel, mechanics, and management. 
There are no accommodations available on the source vessels or cable 
boats for the crew directly involved in the seismic operations, so 
crews would be changed out every 8 to 12 hours. Two vessels would be 
used for crew transfers.
    The recorder barge/boat (M/V Alaganik and Hook Point) may 
accommodate up to 10 people. The barge portion is dedicated to 
recording and staging of cables, hydrophones and batteries and fuelling 
operations.
    Refueling of vessels would be via other vessels at sea, and from 
land based sources located at West Dock and Milne Point Unit following 
approved U.S. Coast Guard procedures. Sea states and the vessel's 
function will be the determining factors on which method is used.

Dates, Duration and Action Area

    BP seeks an incidental harassment authorization for the period July 
1 to October 15, 2012. Anticipated duration of seismic data acquisition 
is approximately 50 days, depending on weather and other circumstances. 
Transportation of vessels to West Dock would occur by road in late May/
early June. It is not anticipated that vessels would need to transit by 
sea; however, in case this does occur the transit would take place when 
ice conditions allow and in consideration of the spring beluga and 
bowhead hunt in the Chukchi Sea.
    The project area encompasses 110 mi \2\ in Simpson Lagoon, Beaufort 
Sea, Alaska. The approximate boundaries of the total surface area are 
between 70[deg]28' N and 70[deg]39' N and between 149[deg]24'W and 
149[deg]55' W (Figure 1.2 of BP's IHA application). About 46 mi \2\ 
(41.8%) of the survey area is located inside the barrier islands in 
water depths of 0 to 9 ft (0 to 3 m), and 36 mi\2\ (32.7%) outside the 
barrier islands in water depths of 3 to 45 ft (1 to 15 m). The 
remaining 28 mi \2\ (25.5%) of the survey area is located on land 
(onshore and barrier islands), which is solely being used for 
deployment of the receivers. The planned start date of seismic data 
acquisition offshore of the barrier islands is July 1, 2012, depending 
on the presence of ice. Open water seismic operations can only start 
when the project area is ice free (i.e. < 10% ice coverage), which in 
this area normally occurs around mid-July (+/- 14 days). Limited layout 
of receiver cables might be possible on land and barrier islands before 
the ice has cleared. To limit potential impacts to the bowhead whale 
migration and the subsistence hunt, no airgun operations would take 
place in the area north of the barrier islands after August 25, 2012. 
Surf zone geophone retrieval may continue for a brief period after 
airgun operations are complete.

Description of Marine Mammals in the Area of the Specified Activity

    The marine mammal species under NMFS jurisdiction most likely to 
occur in the seismic survey area include three cetacean species, beluga 
(Delphinapterus leucas), bowhead whales (Balaena mysticetus), and gray 
whales (Eschrichtius robustus), and three pinniped species, ringed 
(Phoca hispida), spotted (P. largha), and bearded seals (Erignathus 
barbatus).
    Five additional cetacean species: Harbor porpoise (Phocoena 
phocoena), narwhal (Monodon monoceros), killer whale (Orcinus orca), 
humpback whale (Megaptera novaeangliae), and minke whale (Balaenoptera 
acutorostrata) could also occur in the project area. However, these 
cetacean species are rare or extralimital to the Beaufort Sea and less 
likely to be encountered in the Simpson Lagoon area. BP did not request 
take for narwhal as it is very unlikely that this species would be 
encountered during the BP's proposed seismic survey.
    Ribbon seals (Histriophoca fasciata) occur mainly in the western 
part of the Beaufort Sea and are rare in the proposed action area in 
the Simpson Lagoon of the Beaufort Sea.
    The bowhead whale is listed as ``endangered'' under the Endangered 
Species Act (ESA) and as depleted under the MMPA. Certain stocks or 
populations of gray and beluga whales and spotted seals are listed as 
endangered or proposed for listing under the ESA; however, none of 
those stocks or populations occur in the proposed activity area. 
Additionally, the ribbon seal is considered a ``species of concern'', 
meaning that NMFS has some concerns regarding status and threats of 
this species, but for which insufficient information is available to 
indicate a need to list the species under the ESA. Bearded and ringed 
seals are ``candidate species'' under the ESA, meaning they

[[Page 25833]]

are currently being considered for listing.
    The Alaska stock of bearded seals, part of the Beringia distinct 
population segment (DPS), has been proposed by NMFS for listing as 
threatened under the ESA (75 FR 77496; December 10, 2011).
    The Alaska stock of ringed seals is not currently listed as 
endangered, and is not classified as a strategic stock by NMFS. 
However, there is increasing concern about the future of the ringed 
seal due to receding ice conditions and potential habitat loss. NMFS 
conducted a status review for the ringed seal (Kelly et al. 2010a), and 
has proposed to list the Arctic stock of ringed seals as threatened 
under the ESA due to threats from global warming (75 FR 77476; December 
10, 2011).
    The final decisions for listing are expected to be made in summer 
2012.
    BP's application contains information on the status, distribution, 
seasonal distribution, and abundance of each of the species under NMFS 
jurisdiction mentioned in this document. Please refer to the 
application for that information (see ADDRESSES). Additional 
information can also be found in the NMFS Stock Assessment Reports 
(SAR). The Alaska 2011 SAR is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2011.pdf.

Potential Effects of the Specified Activity on Marine Mammals

    Operating active acoustic sources such as airgun arrays, pinger 
systems, and vessel activities have the potential for adverse effects 
on marine mammals.

Potential Effects of Airgun Sounds on Marine Mammals

    The effects of sounds from airgun pulses might include one or more 
of the following: Tolerance, masking of natural sounds, behavioral 
disturbance, and temporary or permanent hearing impairment or non-
auditory effects (Richardson et al. 1995). As outlined in previous NMFS 
documents, the effects of noise on marine mammals are highly variable, 
and can be categorized as follows (based on Richardson et al. 1995):
(1) Behavioral Disturbance
    Marine mammals may behaviorally react to sound when exposed to 
anthropogenic noise. These behavioral reactions are often shown as: 
Changing durations of surfacing and dives, number of blows per 
surfacing, or moving direction and/or speed; reduced/increased vocal 
activities; changing/cessation of certain behavioral activities (such 
as socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where noise sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haulouts or rookeries).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, and reproduction. Some of these 
potential significant behavioral modifications include:
     Drastic change in diving/surfacing patterns (such as those 
thought to be causing beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cease feeding or social interaction.
    For example, at the Guerreo Negro Lagoon in Baja California, 
Mexico, which is one of the important breeding grounds for Pacific gray 
whales, shipping and dredging associated with a salt works may have 
induced gray whales to abandon the area through most of the 1960s 
(Bryant et al. 1984). After these activities stopped, the lagoon was 
reoccupied, first by single whales and later by cow-calf pairs.
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography) and is also difficult to predict (Southall et 
al. 2007).
    Currently NMFS uses 160 dB re 1 [mu]Pa (rms) at received level for 
impulse noises (such as airgun pulses) as the threshold for the onset 
of marine mammal behavioral harassment.
    In addition, behavioral disturbance is also expressed as the change 
in vocal activities of animals. For example, there is one recent 
summary report indicating that calling fin whales distributed in one 
part of the North Atlantic went silent for an extended period starting 
soon after the onset of a seismic survey in the area (Clark and Gagnon 
2006). It is not clear from that preliminary paper whether the whales 
ceased calling because of masking, or whether this was a behavioral 
response not directly involving masking (i.e., important biological 
signals for marine mammals being ``masked'' by anthropogenic noise; see 
below). Also, bowhead whales in the Beaufort Sea may decrease their 
call rates in response to seismic operations, although movement out of 
the area might also have contributed to the lower call detection rate 
(Blackwell et al. 2009a; 2009b). Some of the changes in marine mammal 
vocal communication are thought to be used to compensate for acoustic 
masking resulting from increased anthropogenic noise (see below). For 
example, blue whales are found to increase call rates when exposed to 
seismic survey noise in the St. Lawrence Estuary (Di Iorio and Clark 
2009). The North Atlantic right whales (Eubalaena glacialis) exposed to 
high shipping noise increase call frequency (Parks et al. 2007) and 
intensity (Parks et al. 2010), while some humpback whales respond to 
low-frequency active sonar playbacks by increasing song length (Miller 
el al. 2000). These behavioral responses could also have adverse 
effects on marine mammals.
    Mysticete: Baleen whales generally tend to avoid operating airguns, 
but avoidance radii are quite variable. Whales are often reported to 
show no overt reactions to airgun pulses at distances beyond a few 
kilometers, even though the airgun pulses remain well above ambient 
noise levels out to much longer distances (reviewed in Richardson et 
al. 1995; Gordon et al. 2004). However, studies done since the late 
1990s of migrating humpback and migrating bowhead whales show 
reactions, including avoidance, that sometimes extend to greater 
distances than documented earlier. Therefore, it appears that 
behavioral disturbance can vary greatly depending on context, and not 
just received levels alone. Avoidance distances often exceed the 
distances at which boat-based observers can see whales, so observations 
from the source vessel can be biased. Observations over broader areas 
may be needed to determine the range of potential effects of some 
large-source seismic surveys where effects on cetaceans may extend to 
considerable distances (Richardson et al. 1999; Moore and Angliss 
2006). Longer-range observations, when required, can sometimes be 
obtained via systematic aerial surveys or aircraft-based observations 
of behavior (e.g., Richardson et al. 1986, 1999; Miller et al. 1999, 
2005; Yazvenko et al. 2007a, 2007b) or by use of observers on one or 
more support vessels operating in coordination with the seismic vessel 
(e.g., Smultea et al. 2004; Johnson et al. 2007). However, the presence 
of other vessels near the source vessel can, at least at times, reduce 
sightability of cetaceans from the source vessel (Beland et al. 2009), 
thus complicating interpretation of sighting data.
    Some baleen whales show considerable tolerance of seismic

[[Page 25834]]

pulses. However, when the pulses are strong enough, avoidance or other 
behavioral changes become evident. Because the responses become less 
obvious with diminishing received sound level, it has been difficult to 
determine the maximum distance (or minimum received sound level) at 
which reactions to seismic activity become evident and, hence, how many 
whales are affected.
    Studies of gray, bowhead, and humpback whales have determined that 
received levels of pulses in the 160-170 dB re 1 [mu]Pa (rms) range 
seem to cause obvious avoidance behavior in a substantial fraction of 
the animals exposed (McCauley et al. 1998, 1999, 2000). In many areas, 
seismic pulses diminish to these levels at distances ranging from 4-15 
km from the source. A substantial proportion of the baleen whales 
within such distances may show avoidance or other strong disturbance 
reactions to the operating airgun array. Some extreme examples 
including migrating bowhead whales avoiding considerably larger 
distances (20-30 km) and lower received sound levels (120-130 dB re 1 
[mu]Pa (rms)) when exposed to airguns from seismic surveys. Also, even 
in cases where there is no conspicuous avoidance or change in activity 
upon exposure to sound pulses from distant seismic operations, there 
are sometimes subtle changes in behavior (e.g., surfacing-respiration-
dive cycles) that are only evident through detailed statistical 
analysis (e.g., Richardson et al. 1986; Gailey et al. 2007).
    Data on short-term reactions by cetaceans to impulsive noises are 
not necessarily indicative of long-term or biologically significant 
effects. It is not known whether impulsive sounds affect reproductive 
rate or distribution and habitat use in subsequent days or years. 
However, gray whales have continued to migrate annually along the west 
coast of North America despite intermittent seismic exploration (and 
much ship traffic) in that area for decades (Appendix A in Malme et al. 
1984; Richardson et al. 1995), and there has been a substantial 
increase in the population over recent decades (Allen and Angliss 
2010). The western Pacific gray whale population did not seem affected 
by a seismic survey in its feeding ground during a prior year (Johnson 
et al. 2007). Similarly, bowhead whales have continued to travel to the 
eastern Beaufort Sea each summer despite seismic exploration in their 
summer and autumn range for many years (Richardson et al. 1987), and 
their numbers have increased notably (Allen and Angliss 2010). Bowheads 
also have been observed over periods of days or weeks in areas 
ensonified repeatedly by seismic pulses (Richardson et al. 1987; Harris 
et al. 2007). However, it is generally not known whether the same 
individual bowheads were involved in these repeated observations 
(within and between years) in strongly ensonified areas.
    Odontocete: Little systematic information is available about 
reactions of toothed whales to airgun pulses. Few studies similar to 
the more extensive baleen whale/seismic pulse work summarized above 
have been reported for toothed whales. However, there are recent 
systematic data on sperm whales (e.g., Gordon et al. 2006; Madsen et 
al. 2006; Winsor and Mate 2006; Jochens et al. 2008; Miller et al. 
2009). There is also an increasing amount of information about 
responses of various odontocetes to seismic surveys based on monitoring 
studies (e.g., Stone 2003; Smultea et al. 2004; Moulton and Miller 
2005; Holst et al. 2006; Stone and Tasker 2006; Potter et al. 2007; 
Hauser et al. 2008; Holst and Smultea 2008; Weir 2008; Barkaszi et al. 
2009; Richardson et al. 2009).
    Dolphins and porpoises are often seen by observers on active 
seismic vessels, occasionally at close distances (e.g., bow riding). 
Marine mammal monitoring data during seismic surveys often show that 
animal detection rates drop during the firing of seismic airguns, 
indicating that animals may be avoiding the vicinity of the seismic 
area (Smultea et al. 2004; Holst et al. 2006; Hauser et al. 2008; Holst 
and Smultea 2008; Richardson et al. 2009). Also, belugas summering in 
the Canadian Beaufort Sea showed larger-scale avoidance, tending to 
avoid waters out to 10-20 km from operating seismic vessels. In 
contrast, recent studies show little evidence of conspicuous reactions 
by sperm whales to airgun pulses, contrary to earlier indications 
(e.g., Gordon et al. 2006; Stone and Tasker 2006; Winsor and Mate 2006; 
Jochens et al. 2008), except the lower buzz (echolocation signals) 
rates that were detected during exposure of airgun pulses (Miller et 
al. 2009).
    There are almost no specific data on responses of beaked whales to 
seismic surveys, but it is likely that most if not all species show 
strong avoidance. There is increasing evidence that some beaked whales 
may strand after exposure to strong noise from tactical military mid-
frequency sonars. Whether they ever do so in response to seismic survey 
noise is unknown. Northern bottlenose whales seem to continue to call 
when exposed to pulses from distant seismic vessels.
    For delphinids, and possibly the Dall's porpoise, the available 
data suggest that a >=170 dB re 1 [mu]Pa (rms) disturbance criterion 
(rather than >=160 dB) would be appropriate. With a medium-to-large 
airgun array, received levels typically diminish to 170 dB within 1-4 
km, whereas levels typically remain above 160 dB out to 4--15 km (e.g., 
Tolstoy et al. 2009). Reaction distances for delphinids are more 
consistent with the typical 170 dB re 1 [mu]Pa (rms) distances. Stone 
(2003) and Stone and Tasker (2006) reported that all small odontocetes 
(including killer whales) observed during seismic surveys in UK waters 
remained significantly further from the source during periods of 
shooting on surveys with large volume airgun arrays than during periods 
without airgun shooting.
    Due to their relatively higher frequency hearing ranges when 
compared to mysticetes, odontocetes may have stronger responses to mid- 
and high-frequency sources such as sub-bottom profilers, side scan 
sonar, and echo sounders than mysticetes (Richardson et al. 1995; 
Southall et al. 2007).
    Pinnipeds: Few studies of the reactions of pinnipeds to noise from 
open-water seismic exploration have been published (for review of the 
early literature, see Richardson et al. 1995). However, pinnipeds have 
been observed during a number of seismic monitoring studies. Monitoring 
in the Beaufort Sea during 1996-2002 provided a substantial amount of 
information on avoidance responses (or lack thereof) and associated 
behavior. Additional monitoring of that type has been done in the 
Beaufort and Chukchi Seas in 2006-2009. Pinnipeds exposed to seismic 
surveys have also been observed during seismic surveys along the U.S. 
west coast. Also, there are data on the reactions of pinnipeds to 
various other related types of impulsive sounds.
    Early observations provided considerable evidence that pinnipeds 
are often quite tolerant of strong pulsed sounds. During seismic 
exploration off Nova Scotia, gray seals exposed to noise from airguns 
and linear explosive charges reportedly did not react strongly (J. 
Parsons in Greene et al. 1985). An airgun caused an initial startle 
reaction among South African fur seals but was ineffective in scaring 
them away from fishing gear. Pinnipeds in both water and air sometimes 
tolerate strong noise pulses from non-explosive and explosive scaring 
devices, especially if attracted to the area for feeding or 
reproduction (Mate and Harvey 1987;

[[Page 25835]]

Reeves et al. 1996). Thus, pinnipeds are expected to be rather tolerant 
of, or to habituate to, repeated underwater sounds from distant seismic 
sources, at least when the animals are strongly attracted to the area.
    In summary, visual monitoring from seismic vessels has shown only 
slight (if any) avoidance of airguns by pinnipeds, and only slight (if 
any) changes in behavior. These studies show that many pinnipeds do not 
avoid the area within a few hundred meters of an operating airgun 
array. However, based on the studies with large sample size, or 
observations from a separate monitoring vessel, or radio telemetry, it 
is apparent that some phocid seals do show localized avoidance of 
operating airguns. The limited nature of this tendency for avoidance is 
a concern. It suggests that one cannot rely on pinnipeds to move away, 
or to move very far away, before received levels of sound from an 
approaching seismic survey vessel approach those that may cause hearing 
impairment.
(2) Masking
    Chronic exposure to excessive, though not high-intensity, noise 
could cause masking at particular frequencies for marine mammals that 
utilize sound for vital biological functions. Masking can interfere 
with detection of acoustic signals such as communication calls, 
echolocation sounds, and environmental sounds important to marine 
mammals. Since marine mammals depend on acoustic cues for vital 
biological functions, such as orientation, communication, finding prey, 
and avoiding predators, marine mammals that experience severe 
(intensity and duration) acoustic masking could potentially suffer 
reduced fitness, which could lead to adverse effects on survival and 
reproduction.
    Masking occurs when noise and signals (that animal utilizes) 
overlap at both spectral and temporal scales. For the airgun noise 
generated from the proposed marine seismic survey, these are low 
frequency (under 1 kHz) pulses with extremely short durations (in the 
scale of milliseconds). Lower frequency man-made noises are more likely 
to affect detection of communication calls and other potentially 
important natural sounds such as surf and prey noise. There is little 
concern regarding masking due to the brief duration of these pulses and 
relatively longer silence between airgun shots (9-12 seconds) near the 
noise source, however, at long distances (over tens of kilometers away) 
in deep water, due to multipath propagation and reverberation, the 
durations of airgun pulses can be ``stretched'' to seconds with long 
decays (Madsen et al. 2006; Clark and Gagnon 2006). Therefore it could 
affect communication signals used by low frequency mysticetes when they 
occur near the noise band and thus reduce the communication space of 
animals (e.g., Clark et al. 2009a, 2009b) and affect their vocal 
behavior (e.g., Foote et al. 2004; Holt et al. 2009). Further, in areas 
of shallow water, multipath propagation of airgun pulses could be more 
profound, thus affecting communication signals from marine mammals even 
at close distances. Average ambient noise in areas where received 
seismic noises are heard can be elevated. At long distances, however, 
the intensity of the noise is greatly reduced. Nevertheless, partial 
informational and energetic masking of different degrees could affect 
signal receiving in some marine mammals within the ensonified areas. 
Additional research is needed to further address these effects.
    Although masking effects of pulsed sounds on marine mammal calls 
and other natural sounds are expected to be limited, there are few 
specific studies on this. Some whales continue calling in the presence 
of seismic pulses and whale calls often can be heard between the 
seismic pulses (e.g., Richardson et al. 1986; McDonald et al. 1995; 
Greene et al. 1999a, 1999b; Nieukirk et al. 2004; Smultea et al. 2004; 
Holst et al. 2005a, 2005b, 2006; Dunn and Hernandez 2009).
    Among the odontocetes, there has been one report that sperm whales 
ceased calling when exposed to pulses from a very distant seismic ship 
(Bowles et al. 1994). However, more recent studies of sperm whales 
found that they continued calling in the presence of seismic pulses 
(Madsen et al. 2002; Tyack et al. 2003; Smultea et al. 2004; Holst et 
al. 2006; Jochens et al. 2008). Madsen et al. (2006) noted that airgun 
sounds would not be expected to mask sperm whale calls given the 
intermittent nature of airgun pulses. Dolphins and porpoises are also 
commonly heard calling while airguns are operating (Gordon et al. 2004; 
Smultea et al. 2004; Holst et al. 2005a, 2005b; Potter et al. 2007). 
Masking effects of seismic pulses are expected to be negligible in the 
case of the smaller odontocetes, given the intermittent nature of 
seismic pulses plus the fact that sounds important to them are 
predominantly at much higher frequencies than are the dominant 
components of airgun sounds.
    Pinnipeds have best hearing sensitivity and/or produce most of 
their sounds at frequencies higher than the dominant components of 
airgun sound, but there is some overlap in the frequencies of the 
airgun pulses and the calls. However, the intermittent nature of airgun 
pulses presumably reduces the potential for masking.
    Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior such as shifting call frequencies, 
and increasing call volume and vocalization rates, as discussed earlier 
(e.g., Miller et al. 2000; Parks et al. 2007; Di Iorio and Clark 2009; 
Parks et al. 2010); the biological significance of these modifications 
is still unknown.
(3) Hearing Impairment
    Marine mammals exposed to high intensity sound repeatedly or for 
prolonged periods can experience hearing threshold shift (TS), which is 
the loss of hearing sensitivity at certain frequency ranges (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be 
permanent (PTS), in which case the loss of hearing sensitivity is 
unrecoverable, or temporary (TTS), in which case the animal's hearing 
threshold will recover over time (Southall et al. 2007). Marine mammals 
that experience TTS or PTS will have reduced sensitivity at the 
frequency band of the TS, which may affect their capability of 
communication, orientation, or prey detection. The degree of TS depends 
on the intensity of the received levels the animal is exposed to, and 
the frequency at which TS occurs depends on the frequency of the 
received noise. It has been shown that in most cases, TS occurs at the 
frequencies approximately one-octave above that of the received noise. 
Repeated noise exposure that leads to TTS could cause PTS. For 
transient sounds, the sound level necessary to cause TTS is inversely 
related to the duration of the sound.

TTS

    TTS is the mildest form of hearing impairment that can occur during 
exposure to a strong sound (Kryter 1985). While experiencing TTS, the 
hearing threshold rises and a sound must be stronger in order to be 
heard. It is a temporary phenomenon, and (especially when mild) is not 
considered to represent physical damage or ``injury'' (Southall et al. 
2007). Rather, the onset of TTS is an indicator that, if the animal is 
exposed to higher levels of that sound, physical damage is ultimately a 
possibility.
    The magnitude of TTS depends on the level and duration of noise 
exposure, and to some degree on frequency, among other considerations 
(Kryter

[[Page 25836]]

1985; Richardson et al. 1995; Southall et al. 2007). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
recovers rapidly after exposure to the noise ends. In terrestrial 
mammals, TTS can last from minutes or hours to (in cases of strong TTS) 
days. Only a few data have been obtained on sound levels and durations 
necessary to elicit mild TTS in marine mammals (none in mysticetes), 
and none of the published data concern TTS elicited by exposure to 
multiple pulses of sound during operational seismic surveys (Southall 
et al. 2007).
    For toothed whales, experiments on a bottlenose dolphin (Tursiops 
truncates) and beluga whale showed that exposure to a single watergun 
impulse at a received level of 207 kPa (or 30 psi) peak-to-peak (p-p), 
which is equivalent to 228 dB re 1 [mu]Pa (p-p), resulted in a 7 and 6 
dB TTS in the beluga whale at 0.4 and 30 kHz, respectively. Thresholds 
returned to within 2 dB of the pre-exposure level within 4 minutes of 
the exposure (Finneran et al. 2002). No TTS was observed in the 
bottlenose dolphin.
    Finneran et al. (2005) further examined the effects of tone 
duration on TTS in bottlenose dolphins. Bottlenose dolphins were 
exposed to 3 kHz tones (non-impulsive) for periods of 1, 2, 4 or 8 
seconds (s), with hearing tested at 4.5 kHz. For 1-s exposures, TTS 
occurred with SELs of 197 dB, and for exposures >1 s, SEL >195 dB 
resulted in TTS (SEL is equivalent to energy flux, in dB re 1 
[mu]Pa\2\-s). At an SEL of 195 dB, the mean TTS (4 min after exposure) 
was 2.8 dB. Finneran et al. (2005) suggested that an SEL of 195 dB is 
the likely threshold for the onset of TTS in dolphins and belugas 
exposed to tones of durations 1-8 s (i.e., TTS onset occurs at a near-
constant SEL, independent of exposure duration). That implies that, at 
least for non-impulsive tones, a doubling of exposure time results in a 
3 dB lower TTS threshold.
    However, the assumption that, in marine mammals, the occurrence and 
magnitude of TTS is a function of cumulative acoustic energy (SEL) is 
probably an oversimplification. Kastak et al. (2005) reported 
preliminary evidence from pinnipeds that, for prolonged non-impulse 
noise, higher SELs were required to elicit a given TTS if exposure 
duration was short than if it was longer, i.e., the results were not 
fully consistent with an equal-energy model to predict TTS onset. 
Mooney et al. (2009a) showed this in a bottlenose dolphin exposed to 
octave-band non-impulse noise ranging from 4 to 8 kHz at SPLs of 130 to 
178 dB re 1 [mu]Pa for periods of 1.88 to 30 minutes (min). Higher SELs 
were required to induce a given TTS if exposure duration was short than 
if it was longer. Exposure of the aforementioned bottlenose dolphin to 
a sequence of brief sonar signals showed that, with those brief (but 
non-impulse) sounds, the received energy (SEL) necessary to elicit TTS 
was higher than was the case with exposure to the more prolonged 
octave-band noise (Mooney et al. 2009b). Those authors concluded that, 
when using (non-impulse) acoustic signals of duration ~0.5 s, SEL must 
be at least 210-214 dB re 1 [mu]Pa\2\-s to induce TTS in the bottlenose 
dolphin. The most recent studies conducted by Finneran et al. also 
support the notion that exposure duration has a more significant 
influence compared to SPL as the duration increases, and that TTS 
growth data are better represented as functions of SPL and duration 
rather than SEL alone (Finneran et al. 2010a, 2010b). In addition, 
Finneran et al. (2010b) conclude that when animals are exposed to 
intermittent noises, there is recovery of hearing during the quiet 
intervals between exposures through the accumulation of TTS across 
multiple exposures. Such findings suggest that when exposed to multiple 
seismic pulses, partial hearing recovery also occurs during the seismic 
pulse intervals.
    For baleen whales, there are no data, direct or indirect, on levels 
or properties of sound that are required to induce TTS. The frequencies 
to which baleen whales are most sensitive are lower than those to which 
odontocetes are most sensitive, and natural ambient noise levels at 
those low frequencies tend to be higher (Urick 1983). As a result, 
auditory thresholds of baleen whales within their frequency band of 
best hearing are believed to be higher (less sensitive) than are those 
of odontocetes at their best frequencies (Clark and Ellison 2004). From 
this, it is suspected that received levels causing TTS onset may also 
be higher in baleen whales. However, no cases of TTS are expected given 
the small size of the airguns proposed to be used and the strong 
likelihood that baleen whales (especially migrating bowheads) would 
avoid the approaching airguns (or vessel) before being exposed to 
levels high enough for there to be any possibility of TTS.
    In pinnipeds, TTS thresholds associated with exposure to brief 
pulses (single or multiple) of underwater sound have not been measured. 
Initial evidence from prolonged exposures suggested that some pinnipeds 
may incur TTS at somewhat lower received levels than do small 
odontocetes exposed for similar durations (Kastak et al. 1999; 2005). 
However, more recent indications are that TTS onset in the most 
sensitive pinniped species studied (harbor seal, which is closely 
related to the ringed seal) may occur at a similar SEL as in 
odontocetes (Kastak et al. 2004).
    Most cetaceans show some degree of avoidance of seismic vessels 
operating an airgun array (see above). It is unlikely that these 
cetaceans would be exposed to airgun pulses at a sufficiently high 
level for a sufficiently long period to cause more than mild TTS, given 
the relative movement of the vessel and the marine mammal. TTS would be 
more likely in any odontocetes that bow- or wake-ride or otherwise 
linger near the airguns. However, while bow- or wake-riding, 
odontocetes would be at the surface and thus not exposed to strong 
sound pulses given the pressure release and Lloyd Mirror effects at the 
surface. But if bow- or wake-riding animals were to dive intermittently 
near airguns, they would be exposed to strong sound pulses, possibly 
repeatedly.
    If some cetaceans did incur mild or moderate TTS through exposure 
to airgun sounds in this manner, this would very likely be a temporary 
and reversible phenomenon. However, even a temporary reduction in 
hearing sensitivity could be deleterious in the event that, during that 
period of reduced sensitivity, a marine mammal needed its full hearing 
sensitivity to detect approaching predators, or for some other reason.
    Some pinnipeds show avoidance reactions to airguns, but their 
avoidance reactions are generally not as strong or consistent as those 
of cetaceans. Pinnipeds occasionally seem to be attracted to operating 
seismic vessels. There are no specific data on TTS thresholds of 
pinnipeds exposed to single or multiple low-frequency pulses. However, 
given the indirect indications of a lower TTS threshold for the harbor 
seal than for odontocetes exposed to impulse sound (see above), it is 
possible that some pinnipeds close to a large airgun array could incur 
TTS.
    NMFS currently typically includes mitigation requirements to ensure 
that cetaceans and pinnipeds are not exposed to pulsed underwater noise 
at received levels exceeding, respectively, 180 and 190 dB re 1 
[micro]Pa (rms). The 180/190 dB acoustic criteria were taken from 
recommendations by an expert panel of the High Energy Seismic Survey 
(HESS) Team that performed an assessment on noise impacts by seismic 
airguns to marine mammals in 1997, although the HESS Team recommended a 
180-dB limit for pinnipeds in California (HESS

[[Page 25837]]

1999). The 180 and 190 dB re 1 [mu]Pa (rms) levels have not been 
considered to be the levels above which TTS might occur. Rather, they 
were the received levels above which, in the view of a panel of 
bioacoustics specialists convened by NMFS before TTS measurements for 
marine mammals started to become available, one could not be certain 
that there would be no injurious effects, auditory or otherwise, to 
marine mammals. As summarized above, data that are now available imply 
that TTS is unlikely to occur in various odontocetes (and probably 
mysticetes as well) unless they are exposed to a sequence of several 
airgun pulses stronger than 190 dB re 1 [mu]Pa (rms). On the other 
hand, for the harbor seal, harbor porpoise, and perhaps some other 
species, TTS may occur upon exposure to one or more airgun pulses whose 
received level equals the NMFS ``do not exceed'' value of 190 dB re 1 
[mu]Pa (rms). That criterion corresponds to a single-pulse SEL of 175-
180 dB re 1 [mu]Pa\2\-s in typical conditions, whereas TTS is suspected 
to be possible in harbor seals and harbor porpoises with a cumulative 
SEL of ~171 and ~164 dB re 1 [mu]Pa\2\-s, respectively.
    It has been shown that most large whales and many smaller 
odontocetes (especially the harbor porpoise) show at least localized 
avoidance of ships and/or seismic operations. Even when avoidance is 
limited to the area within a few hundred meters of an airgun array, 
that should usually be sufficient to avoid TTS based on what is 
currently known about thresholds for TTS onset in cetaceans. In 
addition, ramping up airgun arrays, which is standard operational 
protocol for many seismic operators, may allow cetaceans near the 
airguns at the time of startup (if the sounds are aversive) to move 
away from the seismic source and to avoid being exposed to the full 
acoustic output of the airgun array. Thus, most baleen whales likely 
will not be exposed to high levels of airgun sounds provided the ramp- 
up procedure is applied. Likewise, many odontocetes close to the 
trackline are likely to move away before the sounds from an approaching 
seismic vessel become sufficiently strong for there to be any potential 
for TTS or other hearing impairment. Hence, there is little potential 
for baleen whales or odontocetes that show avoidance of ships or 
airguns to be close enough to an airgun array to experience TTS. 
Nevertheless, even if marine mammals were to experience TTS, the 
magnitude of the TTS is expected to be mild and brief, only in a few 
decibels for minutes.

PTS

    When PTS occurs, there is physical damage to the sound receptors in 
the ear. In some cases, there can be total or partial deafness, whereas 
in other cases, the animal has an impaired ability to hear sounds in 
specific frequency ranges (Kryter 1985). Physical damage to a mammal's 
hearing apparatus can occur if it is exposed to sound impulses that 
have very high peak pressures, especially if they have very short rise 
times. (Rise time is the interval required for sound pressure to 
increase from the baseline pressure to peak pressure.)
    There is no specific evidence that exposure to pulses of airgun 
sound can cause PTS in any marine mammal, even with large arrays of 
airguns. However, given the likelihood that some mammals close to an 
airgun array might incur at least mild TTS (see above), there has been 
further speculation about the possibility that some individuals 
occurring very close to airguns might incur PTS (e.g., Richardson et 
al. 1995; Gedamke et al. 2008). Single or occasional occurrences of 
mild TTS are not indicative of permanent auditory damage, but repeated 
or (in some cases) single exposures to a level well above that causing 
TTS onset might elicit PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, but are assumed to be similar to those in humans and 
other terrestrial mammals (Southall et al. 2007). Based on data from 
terrestrial mammals, a precautionary assumption is that the PTS 
threshold for impulse sounds (such as airgun pulses as received close 
to the source) is at least 6 dB higher than the TTS threshold on a 
peak-pressure basis, and probably >6 dB higher (Southall et al. 2007). 
The low-to-moderate levels of TTS that have been induced in captive 
odontocetes and pinnipeds during controlled studies of TTS have been 
confirmed to be temporary, with no measurable residual PTS (Kastak et 
al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005; Nachtigall 
et al. 2003; 2004). However, very prolonged exposure to sound strong 
enough to elicit TTS, or shorter-term exposure to sound levels well 
above the TTS threshold, can cause PTS, at least in terrestrial mammals 
(Kryter 1985). In terrestrial mammals, the received sound level from a 
single non-impulsive sound exposure must be far above the TTS threshold 
for any risk of permanent hearing damage (Kryter 1994; Richardson et 
al. 1995; Southall et al. 2007). However, there is special concern 
about strong sounds whose pulses have very rapid rise times. In 
terrestrial mammals, there are situations when pulses with rapid rise 
times (e.g., from explosions) can result in PTS even though their peak 
levels are only a few dB higher than the level causing slight TTS. The 
rise time of airgun pulses is fast, but not as fast as that of an 
explosion.
    Some factors that contribute to onset of PTS, at least in 
terrestrial mammals, are as follows:
     Exposure to a single very intense sound,
     Fast rise time from baseline to peak pressure,
     Repetitive exposure to intense sounds that individually 
cause TTS but not PTS, and
     Recurrent ear infections or (in captive animals) exposure 
to certain drugs.
    Cavanagh (2000) reviewed the thresholds used to define TTS and PTS. 
Based on this review and SACLANT (1998), it is reasonable to assume 
that PTS might occur at a received sound level 20 dB or more above that 
inducing mild TTS. However, for PTS to occur at a received level only 
20 dB above the TTS threshold, the animal probably would have to be 
exposed to a strong sound for an extended period, or to a strong sound 
with a rather rapid rise time.
    More recently, Southall et al. (2007) estimated that received 
levels would need to exceed the TTS threshold by at least 15 dB, on an 
SEL basis, for there to be risk of PTS. Thus, for cetaceans exposed to 
a sequence of sound pulses, they estimate that the PTS threshold might 
be an M-weighted SEL (for the sequence of received pulses) of ~198 dB 
re 1 [mu]Pa\2\-s. Additional assumptions had to be made to derive a 
corresponding estimate for pinnipeds, as the only available data on 
TTS-thresholds in pinnipeds pertained to nonimpulse sound (see above). 
Southall et al. (2007) estimated that the PTS threshold could be a 
cumulative SEL of ~186 dB re 1 [mu]Pa\2\-s in the case of a harbor seal 
exposed to impulse sound. The PTS threshold for the California sea lion 
and northern elephant seal would probably be higher given the higher 
TTS thresholds in those species. Southall et al. (2007) also note that, 
regardless of the SEL, there is concern about the possibility of PTS if 
a cetacean or pinniped received one or more pulses with peak pressure 
exceeding 230 or 218 dB re 1 [mu]Pa, respectively. Thus, PTS might be 
expected upon exposure of cetaceans to either SEL >=198 dB re 1 
[mu]Pa\2\-s or peak pressure >=230 dB re 1 [mu]Pa. Corresponding 
proposed dual criteria for pinnipeds (at least harbor seals) are >=186 
dB SEL and >= 218 dB peak pressure (Southall et al. 2007).

[[Page 25838]]

These estimates are all first approximations, given the limited 
underlying data, assumptions, species differences, and evidence that 
the ``equal energy'' model may not be entirely correct.
    Sound impulse duration, peak amplitude, rise time, number of 
pulses, and inter-pulse interval are the main factors thought to 
determine the onset and extent of PTS. Ketten (1994) has noted that the 
criteria for differentiating the sound pressure levels that result in 
PTS (or TTS) are location and species specific. PTS effects may also be 
influenced strongly by the health of the receiver's ear.
    As described above for TTS, in estimating the amount of sound 
energy required to elicit the onset of TTS (and PTS), it is assumed 
that the auditory effect of a given cumulative SEL from a series of 
pulses is the same as if that amount of sound energy were received as a 
single strong sound. There are no data from marine mammals concerning 
the occurrence or magnitude of a potential partial recovery effect 
between pulses. In deriving the estimates of PTS (and TTS) thresholds 
quoted here, Southall et al. (2007) made the precautionary assumption 
that no recovery would occur between pulses.
    It is unlikely that an odontocete would remain close enough to a 
large airgun array for sufficiently long to incur PTS. There is some 
concern about bowriding odontocetes, but for animals at or near the 
surface, auditory effects are reduced by Lloyd's mirror and surface 
release effects. The presence of the vessel between the airgun array 
and bow-riding odontocetes could also, in some but probably not all 
cases, reduce the levels received by bow-riding animals (e.g., Gabriele 
and Kipple 2009). The TTS (and thus PTS) thresholds of baleen whales 
are unknown but, as an interim measure, assumed to be no lower than 
those of odontocetes. Also, baleen whales generally avoid the immediate 
area around operating seismic vessels, so it is unlikely that a baleen 
whale could incur PTS from exposure to airgun pulses. The TTS (and thus 
PTS) thresholds of some pinnipeds (e.g., harbor seal) as well as the 
harbor porpoise may be lower (Kastak et al. 2005; Southall et al. 2007; 
Lucke et al. 2009). If so, TTS and potentially PTS may extend to a 
somewhat greater distance for those animals. Again, Lloyd's mirror and 
surface release effects will ameliorate the effects for animals at or 
near the surface.
(4) Non-Auditory Physical Effects
    Non-auditory physical effects might occur in marine mammals exposed 
to strong underwater pulsed sound. Possible types of non-auditory 
physiological effects or injuries that theoretically might occur in 
mammals close to a strong sound source include neurological effects, 
bubble formation, and other types of organ or tissue damage. Some 
marine mammal species (i.e., beaked whales) may be especially 
susceptible to injury and/or stranding when exposed to intense sounds. 
However, there is no definitive evidence that any of these effects 
occur even for marine mammals in close proximity to large arrays of 
airguns, and beaked whales do not occur in the proposed project area. 
In addition, marine mammals that show behavioral avoidance of seismic 
vessels, including most baleen whales, some odontocetes (including 
belugas), and some pinnipeds, are especially unlikely to incur non- 
auditory impairment or other physical effects.
    Therefore, it is unlikely that such effects would occur during 
BPXA's proposed surveys given the brief duration of exposure and the 
planned monitoring and mitigation measures described later in this 
document.
    Additional non-auditory effects include elevated levels of stress 
response (Wright et al. 2007; Wright and Highfill 2007). Although not 
many studies have been done on noise-induced stress in marine mammals, 
extrapolation of information regarding stress responses in other 
species seems applicable because the responses are highly consistent 
among all species in which they have been examined to date (Wright et 
al. 2007). Therefore, it is reasonable to conclude that noise acts as a 
stressor to marine mammals. Furthermore, given that marine mammals will 
likely respond in a manner consistent with other species studied, 
repeated and prolonged exposures to stressors (including or induced by 
noise) could potentially be problematic for marine mammals of all ages. 
Wright et al. (2007) state that a range of issues may arise from an 
extended stress response including, but not limited to, suppression of 
reproduction (physiologically and behaviorally), accelerated aging and 
sickness-like symptoms. However, as mentioned above, BPXA's proposed 
activity is not expected to result in these severe effects due to the 
nature of the potential sound exposure.
(5) Stranding and Mortality
    Marine mammals close to underwater detonations can be killed or 
severely injured, and the auditory organs are especially susceptible to 
injury (Ketten et al. 1993; Ketten 1995). Airgun pulses are less 
energetic and their peak amplitudes have slower rise times, while 
stranding and mortality events would include other energy sources 
(acoustical or shock wave) far beyond just seismic airguns. To date, 
there is no evidence that serious injury, death, or stranding by marine 
mammals can occur from exposure to airgun pulses, even in the case of 
large airgun arrays.
    However, in numerous past IHA notices for seismic surveys, 
commenters have referenced two stranding events allegedly associated 
with seismic activities, one off Baja California and a second off 
Brazil. NMFS has addressed this concern several times, and, without new 
information, does not believe that this issue warrants further 
discussion. For information relevant to strandings of marine mammals, 
readers are encouraged to review NMFS' response to comments on this 
matter found in 69 FR 74906 (December 14, 2004), 71 FR 43112 (July 31, 
2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23, 
2006).
    It should be noted that strandings related to sound exposure have 
not been recorded for marine mammal species in the Beaufort Sea. NMFS 
notes that in the Beaufort Sea, aerial surveys have been conducted by 
MMS and industry during periods of industrial activity (and by MMS 
during times with no activity). No strandings or marine mammals in 
distress have been observed during these surveys and none have been 
reported by North Slope Borough inhabitants. In addition, there are 
very few instances that seismic surveys in general have been linked to 
marine mammal strandings, other than those mentioned above. As a 
result, NMFS does not expect any marine mammals will incur serious 
injury or mortality in the Arctic Ocean or strand as a result of the 
proposed seismic survey.

Potential Effects of Pinger Signals

    A pinger system (Sonardyne Acoustical Pingers) and acoustic 
releases/transponders would be used during seismic operations to 
position the receivers and locate and retrieve the batteries. Sounds 
transmitted by these pingers are characterized by very short pulses. 
The Sonardyne pinger has a source level ranging from ~188-193 dB re 1 
[mu]Pa at 1 m in a frequency range of 19-36 kHz and the transponder has 
source levels ~192 dB re 1 [mu]Pa at 1 m in a frequency range of 7-15 
kHz. Pulses are emitted on command from the operator aboard the source 
vessel.
    The pinger produces sounds within the frequency range that could be 
detected by some seals (functional

[[Page 25839]]

underwater hearing estimated at 75 Hz to 75 kHz), baleen whales 
(hearing sensitivity from few tens of Hz to ~10 kHz), and beluga whales 
(peak sensitivity at ~10-15 kHz) (Southall et al. 2007). However, 
marine mammal communications will not be masked appreciably by the 
pinger signals because of the relatively low power output, low duty 
cycle, and brief period when an individual mammal is likely to be 
within the area where they could potentially be exposed.
    Marine mammal behavioral reactions to pulsed sound sources such as 
airguns are discussed above, and responses to pinger sounds are likely 
similar if received at the same levels. However, the pulsed signals 
from the pinger are much weaker than those from the airgun and will 
propagate over shorter distances. Therefore, behavioral responses are 
not expected unless marine mammals are very close (within tens of 
meters) to the source. The maximum reaction that might be expected 
would be a startle reaction or other short-term response.
    Source levels of the pinger are much lower than those of the 
airguns, which are discussed above. It is unlikely that the pinger 
produces pulse levels strong enough to cause temporary hearing 
impairment or (especially) physical injuries even in an animal that is 
(briefly) in a position near the source.

Vessel Sounds

    In addition to the noise generated from seismic airguns, various 
types of vessels will be used in the operations, including source 
vessels, recorder/cable vessels, and various support vessels. Sounds 
from boats and vessels have been reported extensively (Greene and Moore 
1995; Blackwell and Greene 2002; 2005; 2006). Numerous measurements of 
underwater vessel sound have been performed in support of recent 
industry activity in the Chukchi and Beaufort Seas. Results of these 
measurements have been reported in various 90-day and comprehensive 
reports since 2007 (e.g., Aerts et al. 2008; Hauser et al. 2008; 
Brueggeman 2009; Ireland et al. 2009; Hartin et al. 2011). For example, 
Garner and Hannay (2009) estimated sound pressure levels of 100 dB at 
distances ranging from approximately 1.5 to 2.3 mi (2.4 to 3.7 km) from 
various types of barges. MacDonald et al. (2008) estimated higher 
underwater SPLs from the seismic vessel Gilavar of 120 dB at 
approximately 13 mi (21 km) from the source, although the sound level 
was only 150 dB at 85 ft (26 m) from the vessel. Compared to airgun 
pulses, underwater sound from vessels is generally at relatively low 
frequencies.
    The primary sources of sounds from all vessel classes are propeller 
cavitation, propeller singing, and propulsion or other machinery. 
Propeller cavitation is usually the dominant noise source for vessels 
(Ross 1976). Propeller cavitation and singing are produced outside the 
hull, whereas propulsion or other machinery noise originates inside the 
hull. There are additional sounds produced by vessel activity, such as 
pumps, generators, flow noise from water passing over the hull, and 
bubbles breaking in the wake.

Anticipated Effects on Habitat

    The primary potential impacts to marine mammals and other marine 
species are associated with elevated sound levels produced by airguns 
and vessels operating in the area. However, other potential impacts to 
the surrounding habitat from physical disturbance are also possible.

Potential Impacts on Prey Species

    With regard to fish as a prey source for cetaceans and pinnipeds, 
fish are known to hear and react to sounds and to use sound to 
communicate (Tavolga et al. 1981) and possibly avoid predators (Wilson 
and Dill 2002). Experiments have shown that fish can sense both the 
strength and direction of sound (Hawkins 1981). Primary factors 
determining whether a fish can sense a sound signal, and potentially 
react to it, are the frequency of the signal and the strength of the 
signal in relation to the natural background noise level.
    The level of sound at which a fish will react or alter its behavior 
is usually well above the detection level. Fish have been found to 
react to sounds when the sound level increased to about 20 dB above the 
detection level of 120 dB (Ona 1988); however, the response threshold 
can depend on the time of year and the fish's physiological condition 
(Engas et al. 1993). In general, fish react more strongly to pulses of 
sound rather than non-pulse signals (such as noise from vessels) 
(Blaxter et al. 1981), and a quicker alarm response is elicited when 
the sound signal intensity rises rapidly compared to sound rising more 
slowly to the same level.
    Investigations of fish behavior in relation to vessel noise (Olsen 
et al. 1983; Ona 1988; Ona and Godo 1990) have shown that fish react 
when the sound from the engines and propeller exceeds a certain level. 
Avoidance reactions have been observed in fish such as cod and herring 
when vessels approached close enough that received sound levels are 110 
dB to 130 dB (Nakken 1992; Olsen 1979; Ona and Godo 1990; Ona and 
Toresen 1988). However, other researchers have found that fish such as 
polar cod, herring, and capeline are often attracted to vessels 
(apparently by the noise) and swim toward the vessel (Rostad et al. 
2006). Typical sound source levels of vessel noise in the audible range 
for fish are 150 dB to 170 dB (Richardson et al. 1995).
    Further, during the seismic survey only a small fraction of the 
available habitat would be ensonified at any given time. Disturbance to 
fish species would be short-term and fish would return to their pre-
disturbance behavior once the seismic activity ceases (McCauley et al. 
2000a, 2000b; Santulli et al. 1999; Pearson et al. 1992). Thus, the 
proposed survey would have little, if any, impact on the abilities of 
marine mammals to feed in the area where seismic work is planned.
    Some mysticetes, including bowhead whales, feed on concentrations 
of zooplankton. Some feeding bowhead whales may occur in the Alaskan 
Beaufort Sea in July and August, and others feed intermittently during 
their westward migration in September and October (Richardson and 
Thomson [eds.] 2002; Lowry et al. 2004). A reaction by zooplankton to a 
seismic impulse would only be relevant to whales if it caused 
concentrations of zooplankton to scatter. Pressure changes of 
sufficient magnitude to cause that type of reaction would probably 
occur only very close to the source. Impacts on zooplankton behavior 
are predicted to be negligible, and that would translate into 
negligible impacts on feeding mysticetes. Thus, the proposed activity 
is not expected to have any habitat-related effects on prey species 
that could cause significant or long-term consequences for individual 
marine mammals or their populations.

Potential Impacts on Availability of Affected Species or Stock for 
Taking for Subsistence Uses

    Marine mammals are legally hunted in Alaskan waters by coastal 
Alaska Natives and represent between 60% and 80% of their total 
subsistence harvest. The species regularly harvested by subsistence 
hunters in and around the Beaufort Sea are bowhead and beluga whales, 
ringed, spotted, and bearded seals, and polar bears. The latter is not 
discussed in this section, as polar bears do not fall under the 
jurisdiction of NMFS. The importance of each of the subsistence species 
varies among the communities and is mainly based on availability and 
season.

[[Page 25840]]

    The communities closest to the project area are, from west to east, 
the villages of Barrow, Nuiqsut, and Kaktovik. Barrow is located about 
180 miles west from the survey area. It is the largest community on the 
Alaska's Beaufort Sea coast with a population of 4,351 in 2004 (DCED 
2005). Important marine subsistence resources for Barrow include 
bowhead and beluga whales, ice seals, polar bears, and walrus. Nuiqsut 
is located near the mouth of the Colville River, about 35 miles 
southwest of the project area and had a population of 430 in 2004 (DCED 
2005). The most important marine subsistence resource for Nuiqsut is 
the bowhead whale, and to a lesser extent beluga whales, polar bears 
and seals. Nuiqsut hunters use Cross Island as a base to hunt for 
bowhead whales during the fall migration and have historically hunted 
bowhead whales as far east as Flaxman Island. Kaktovik is located on 
Barter Island, about 150 miles east of the project area and had a 
population of 284 in 2004 (DCED 2005). Major marine subsistence 
resources include bowhead and beluga whales, seals, and polar bears. 
Approximately 50% of Kaktovik households participate in fall whaling 
(Fuller and George 1999).
(1) Bowhead Whales
    The bowhead whale is a critical subsistence and cultural resource 
for the North Slope communities of Barrow, Nuiqsut and Kaktovik. 
Contemporary whaling in Kaktovik dates from 1964 and in Nuiqsut from 
1973 (EDAW/AECOM 2007; Galginaitis and Koski 2002). The number of boats 
used or owned in 2011 by the subsistence whaling crew of the villages 
of Kaktovik, Nuiqsut, and Barrow was 8, 12, and 40, respectively. These 
numbers presumably change from year to year.
    Bowhead harvesting in Barrow occurs both during the spring (April-
May) and fall (September-October) when the whales migrate relatively 
close to shore (ADNR 2009). During spring bowheads migrate through open 
ice leads close to shore. The hunt takes place from the ice using 
umiaks (bearded seal skin boats). During the fall, whaling is shore-
based and boats may travel up to 30 miles a day (EDAW/AECOM 2007). 
Although in Barrow historically most whales were taken during spring 
whaling, the efficiency of the spring harvest tends to be lower than 
the autumn harvest due to ice and weather conditions as well as struck 
whales escaping under the ice (Suydam et al. 2010). In the past few 
years the bowhead fall hunt has become increasingly important. Between 
1993--2010, Barrow landed an average of 22 bowhead whales per year.
    Nuiqsut and Kaktovik hunters harvest bowhead whales only during the 
fall. The bowhead spring migration in the Beaufort Sea occurs too far 
from shore for hunting because ice leads do not open up nearshore (ADNR 
2009). In Nuiqsut, whaling takes place from early September through 
mid-to-late September as the whales migrate west (EDAW/AECOM 2007). 
Three to five whaling crews base themselves at Cross Island, a barrier 
island approximately 35 miles east of the Simpson Lagoon survey area. 
Nuiqsut whalers harvest an average of 3 bowheads each year.
    Whaling from Kaktovik also occurs in the fall, primarily from late 
August through late September or early October (EDAW/AECOM 2007). 
Kaktovik whalers hunt from the Okpilak and Hulahula rivers east to 
Tapkaurak Point (ADNR 2009). Whaling activities are staged from the 
community rather than remote camps; most whaling takes place within 12 
miles of the community (ADNR 2009). Kaktovik whalers harvest an average 
of 3 bowhead whales each year.
(2) Beluga Whales
    The harvest of beluga whales is managed cooperatively through an 
agreement between NMFS and the Alaska Beluga Whale Committee (ABWC). 
From 2002-2006, 5-43 beluga whales were harvested annually from the 
Beaufort Sea stock (Allen and Angliss 2010), with a mean annual take of 
25.4 animals. Few beluga whales are harvested by either Nuiqsut or 
Kaktovik.
(3) Ice Seals
    Seals represent an important subsistence resource for the North 
Slope communities. Harvest of bearded seals usually takes place during 
the spring and summer open water season from Barrow (EDAW/AECOM 2007) 
with only a few animals taken by hunters from Kaktovik or Nuiqsut. 
Seals are also taken during the ice-covered season, with peak hunting 
occurring in February (ADNR 2009). In 2003, Barrow-based hunters 
harvested 776 bearded seals, 413 ringed seals and 12 spotted seals 
(ADNR 2009). Nuiqsut hunters harvest seals in an area from Cape Halkett 
to Foggy Island Bay. For the period 2000-2001, Nuiqsut hunters 
harvested one bearded seal and 25 ringed seals (ADNR 2009). Kaktovik 
hunters also hunt seals year-round. In 2002-2003, hunters harvested 8 
bearded seals and 17 ringed seals.

Potential Impacts to Subsistence Uses

    NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 
as:

* * * an impact resulting from the specified activity: (1) That is 
likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.

Seismic surveys have the potential to impact marine mammals hunted by 
Native Alaskans. In the case of cetaceans, the most common reaction to 
anthropogenic sounds (as noted previously in this document) is 
avoidance of the ensonified area. In the case of bowhead whales, this 
often means that the animals could divert from their normal migratory 
path by up several kilometers. Additionally, general vessel presence in 
the vicinity of traditional hunting areas could negatively impact a 
hunt.
    In the case of subsistence hunts for bowhead whales in the Beaufort 
Sea, there could be an adverse impact on the hunt if the whales were 
deflected seaward (further from shore) in traditional hunting areas. 
The impact would be that whaling crews would have to travel greater 
distances to intercept westward migrating whales, thereby creating a 
safety hazard for whaling crews and/or limiting chances of successfully 
striking and landing bowheads.
    The proposed seismic survey would take place between July and 
September. The project area is located approximately 35 miles northeast 
from Nuiqsut, 35 miles west from Cross Island, 150 miles west from 
Kaktovik and 180 miles east from Barrow. Potential impact from the 
planned activities is expected mainly from sounds generated by the 
vessel and during active airgun deployment. Due to the timing of the 
project and the distance from the surrounding communities, it is 
anticipated to have no effects on spring harvesting and little or no 
effects on the occasional summer harvest of beluga whale, subsistence 
seal hunts (ringed and spotted seals are primarily harvested in winter 
while bearded seals are hunted during July-September in the Beaufort 
Sea), or the fall bowhead hunt. The community of Nuiqsut may begin fall 
whaling activities in late August to early September from Cross Island 
(east of the survey area), and their efforts are typically focused on 
whales approaching Cross Island so that any harvest would occur before 
whales approached the survey area. As part of

[[Page 25841]]

the planned mitigation measures (see below), BP plans to complete those 
portions of the survey area outside of the barrier islands prior to 
August 25, 2012. All seismic activities after this date would take 
place inshore of the barrier islands, thus avoiding subsistence bowhead 
hunt in the area.
    Finally, BP has signed a Conflict Avoidance Agreement (CAA) and 
will prepare a Plan of Cooperation under 50 CFR 216.104 Article 12 of 
the MMPA to address potential impacts on subsistent seal hunting 
activities. The CAA identifies what measures have been or will be taken 
to minimize adverse impacts of the planned activities on subsistence 
harvesting (see below for more details). BP will meet with the AEWC and 
communities' Whaling Captains' Associations as part of the CAA 
development, to establish avoidance guidelines and other mitigation 
measures to be followed where the proposed activities may have an 
impact on subsistence.

Proposed Mitigation

    In order to issue an incidental take authorization 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 adverse impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses.
    For the proposed BP open-water seismic survey in the Beaufort Sea, 
BP worked with NMFS and proposed the following mitigation measures to 
minimize the potential impacts to marine mammals in the project 
vicinity as a result of the marine seismic survey activities.
    The proposed mitigation measures are divided into the following 
major groups: (1) Sound source measurements, (2) Establishing exclusion 
and disturbance zones, (3) Vessel and helicopter related mitigation 
measures, and (4) Mitigation measures for airgun operations. The 
primary purpose of these mitigation measures is to detect marine 
mammals within, or about to enter designated exclusion zones and to 
initiate immediate shutdown or power down of the airgun(s), therefore 
it's very unlikely potential injury or TTS to marine mammals would 
occur, and Level B behavioral of marine mammals would be reduced to the 
lowest level practicable.
(1) Sound Source Measurements
    The acoustic monitoring program has two objectives: (1) To verify 
the modeled distances to the exclusion and disturbance zones from the 
640 in\3\ and 320 in\3\ airgun arrays and to provide corrected 
distances to the PSOs; and (2) to measure vessel sounds (i.e., received 
levels referenced to 1 m from the sound source) of each representative 
vessel of the seismic fleet, to obtain information on the sounds 
produced by these vessels.

Verification and Establishment of Exclusion and Disturbance Zones

    Acoustic measurements to calculate received sound levels as a 
function of distance from the airgun sound source will be conducted 
within 72 hours of initiation of the seismic survey. These measurements 
will be conducted according to a standard protocol for the 640 in\3\ 
array, the 320 in\3\ array and the 40 in\3\ gun, both inside and 
outside the barrier islands. The results of these acoustic measurements 
will be used to re-define, if needed, the distances to received levels 
of 190, 180, 160 and 120 dB. The distances of the received levels as a 
function of the different sound sources (varying discharge volumes) 
will be used to guide power-down and ramp-up procedures. A preliminary 
report describing the methodology and results of the verification for 
at least the 190 dB and 180 dB (rms) exclusion zones will be submitted 
to NMFS within 14 days of completion of the measurements.

Measurements of Vessel Sounds

    BP intends to measure vessel sounds of each representative vessel. 
The exact scope of the source level measurements (back-calculated as 
received levels at 1 m from the source) will follow a pre-defined 
protocol to eliminate the complex interplay of factors that underlie 
such measurements, such as bathymetry, vessel activity, location, 
season, etc. Where possible and practical the monitoring protocol will 
be developed in alignment with other existing vessel source level 
measurements.
(2) Establishing Exclusion and Disturbance Zones
    Under current NMFS guidelines, the ``exclusion zone'' for marine 
mammal exposure to impulse sources is customarily defined as the area 
within which received sound levels are >=180 dB re 1 [mu]Pa (rms) for 
cetaceans and >=190 dB re 1 [mu]Pa (rms) for pinnipeds. These safety 
criteria are based on an assumption that SPL received at levels lower 
than these will not injure these animals or impair their hearing 
abilities, but that at higher levels might have some such effects. 
Disturbance or behavioral effects to marine mammals from underwater 
sound may occur after exposure to sound at distances greater than the 
exclusion zones (Richarcdson et al. 1995).
    An acoustic propagation model, i.e., JASCO's Marine Operations 
Noise Model (MONM), was used to estimate the distances to received 
sound levels of 190, 180, 170, 160, and 120 dB re 1[mu]Pa (rms) for 
pulsed sounds from the 640 in\3\ and 320 in\3\ airgun arrays. Modeling 
methodology and results are described in detail in the appendix of the 
BP's IHA application (Warner and Hipsey 2011). Table 2 summarizes the 
distances from the source to specific received sound levels based on 
MONM modeling.

Table 2--Estimated Distances to Specified Received SPL (rms) From Airgun Arrays With a Total Discharge Volume of
                                       640 in\3\, 320 in\3\, and 40 in\3\
----------------------------------------------------------------------------------------------------------------
                                   Distance in meters  (inside barrier islands)     Distance in meters (outside
 Received levels (dB re 1 [mu]Pa ------------------------------------------------        barrier islands)
              rms)                                                               -------------------------------
                                     640 in\3\       320 in\3\       40 in\3\        640 in\3\       40 in\3\
----------------------------------------------------------------------------------------------------------------
190.............................             310             160              16             120             <50
180.............................             750             480              59             950             <50
170.............................           1,200             930             300           2,500             120
160.............................           1,800           1,500             700           5,500             810
120.............................           6,400           5,700           3,700          44,000          16,000
----------------------------------------------------------------------------------------------------------------
Note: Values are based on 2 m tow depth for the 640 in\3\ and 40 in\3\ array, and a 1 m tow depth for the 320
  in\3\ array.


[[Page 25842]]

    The distances to received sound levels of 160 dB re 1 [mu]Pa (rms) 
of the 640 in\3\ airgun array were used to calculate the numbers of 
marine mammals potentially harassed by the activities. The distances to 
received levels of 180 dB and 190 dB re 1 [mu]Pa (rms) are mainly 
relevant as exclusion radii to avoid level A harassment of marine 
mammals through implementation of shut down and power down measures 
(see details below).
(3) Vessel and Helicopter Related Mitigation Measures
    This proposed mitigation measures apply to all vessels that are 
part of the Simpson Lagoon seismic survey, including crew transfer 
vessels.

 Vessel operators shall avoid concentrations or groups of 
whales and vessels shall not be operated in a way that separates 
members of a group. In proximity of feeding whales or aggregations, 
vessel speed shall be less than 10 knots.
 When within 900 feet (300 m) of whales vessel operators shall 
take every effort and precaution to avoid harassment of these animals 
by:
    [cir] Reducing speed and steering around (groups of) whales if 
circumstances allow, but never cutting off a whale's travel path;
    [cir] Avoiding multiple changes in direction and speed.
 Vessel operators shall check the waters immediately adjacent 
to a vessel to ensure that no marine mammals will be injured when the 
vessel's propellers (or screws) are engaged.
 To minimize collision risk with marine mammals, vessels shall 
not be operated at speeds that would make collisions with whales 
likely. When weather conditions require, such as when visibility drops, 
vessels shall adjust speed accordingly to avoid the likelihood of 
injury to whales.
 Sightings of dead marine mammals would be reported immediately 
to the BP representative. BP is responsible for ensuring reporting of 
the sightings according to the guidelines provided by NMFS.
 In the event that any aircraft (such as helicopters) are used 
to support the planned survey, the mitigation measures below would 
apply:
    [cir] Under no circumstances, other than an emergency, shall 
aircraft be operated at an altitude lower than 1,000 feet above sea 
level (ASL) when within 0.3 mile (0.5 km) of groups of whales.
    [cir] Helicopters shall not hover or circle above or within 0.3 
mile (0.5 km) of groups of whales.
(4) Mitigation Measures for Airgun Operations
    The primary role for airgun mitigation during seismic survey is to 
monitor marine mammals near the seismic source vessel during all 
daylight airgun operations and during any nighttime start-up of the 
airguns. During the seismic survey PSOs will monitor the pre- 
established exclusion zones for the presence of marine mammals. When 
marine mammals are observed within, or about to enter, designated 
safety zones, PSOs have the authority to call for immediate power down 
(or shutdown) of airgun operations as required by the situation. A 
summary of the procedures associated with each mitigation measure is 
provided below.

Ramp Up Procedure

    Ramp up procedures for an airgun array involve a step-wise increase 
in the number of operating airguns until the required discharge volume 
is achieved. The purpose of a ramp up (sometimes also referred to as 
soft start) is to provide marine mammals in the vicinity of the 
activity the opportunity to leave the area and thus avoid any potential 
injury or impairment of their hearing abilities.
    The rate of ramp up shall be no more than 6 dB of source level per 
5 min period. A common procedure is to double the number of operating 
airguns at 5-min intervals, starting with the smallest gun in the 
array. BP states that it intends to double the number of airguns 
operating at 5 minute intervals during ramp up. For the 640 cu in 
airgun array of the Simpson Lagoon seismic survey this is estimated to 
take 20 minutes, and for the 320 in\3\ array 15 minutes. During ramp 
up, the safety zone for the full airgun array will be observed. The 
ramp up procedures will be applied as follows:
     A ramp up, following a cold start, can be applied if the 
exclusion zone has been free of marine mammals for a consecutive 30-
minute period. The entire exclusion zone must have been visible during 
these 30 minutes. If the entire exclusion zone is not visible, then 
ramp up from a cold start cannot begin.
     Ramp up procedures from a cold start will be delayed if a 
marine mammal is sighted within the exclusion zone during the 30-minute 
period prior to the ramp up. The delay will last until the marine 
mammal(s) has been observed to leave the exclusion zone or until the 
animal(s) is not sighted for at least 15 or 30 minutes. The 15 minutes 
applies to small toothed whales and pinnipeds, while a 30 minute 
observation period applies to baleen whales and large toothed whales.
     A ramp up, following a shutdown, can be applied if the 
marine mammal(s) for which the shutdown occurred has been observed to 
leave the exclusion zone or until the animal(s) is not sighted for at 
least 15 minutes (small toothed whales and pinnipeds) or 30 minutes 
(baleen whales and large toothed whales). This assumes there was a 
continuous observation effort prior to the shutdown and the entire 
exclusion zone is visible.
     If, for any reason, electrical power to the airgun array 
has been discontinued for a period of 10 minutes or more, ramp-up 
procedures need to be implemented. Only if the PSO watch has been 
suspended, a 30-minute clearance of the exclusion zone is required 
prior to commencing ramp-up. Discontinuation of airgun activity for 
less than 10 minutes does not require a ramp-up.
     The seismic operator and PSOs will maintain records of the 
times when ramp-ups start and when the airgun arrays reach full power.

Power-Down Procedures

    A power down is the immediate reduction in the number of operating 
airguns such that the radii of the 190 dB and 180 dB (rms) zones are 
decreased to the extent that an observed marine mammal is not in the 
applicable safety zone of the full array. During a power down, one 
airgun (or some other number of airguns less than the full airgun 
array) continues firing. The continued operation of one airgun is 
intended to (a) alert marine mammals to the presence of airgun 
activity, and (b) retain the option of initiating a ramp up to full 
operations under poor visibility conditions.
     The airgun array shall be immediately powered down 
whenever a marine mammal is sighted approaching close to or within the 
applicable exclusion zone of the full array, but is outside the 
applicable exclusion zone of the single mitigation airgun.
     If a marine mammal is already within the exclusion zone 
when first detected, the airguns will be powered down immediately.
     Following a power-down, ramp up to the full airgun array 
will not resume until the marine mammal has cleared the exclusion zone. 
The animal will be considered to have cleared the exclusion zone if it 
is visually observed to have left the exclusion zone of the full array, 
or has not been seen within the zone for 15 minutes (pinnipeds or

[[Page 25843]]

small toothed whales) or 30 minutes (baleen whales or large toothed 
whales).

Shutdown Procedures

     The operating airgun(s) will be shutdown completely if a 
marine mammal approaches or enters the 190 or 180 dB (rms) exclusion 
zone of the smallest airgun.
     Airgun activity will not resume until the marine mammal 
has cleared the exclusion zone of the full array. The animal will be 
considered to have cleared the exclusion zone as described above under 
ramp up procedures.

Poor Visibility Conditions

    BP plans to conduct 24-hour operations. PSOs will not be on duty 
during ongoing seismic operations during darkness, given the very 
limited effectiveness of visual observation at night (there will be no 
periods of darkness in the survey area until mid-August). The proposed 
provisions associated with operations at night or in periods of poor 
visibility include the following:
     If during foggy conditions, heavy snow or rain, or 
darkness (which may be encountered starting in late August), the full 
180 dB exclusion zone is not visible, the airguns cannot commence a 
ramp-up procedure from a full shut-down.
     If one or more airguns have been operational before 
nightfall or before the onset of poor visibility conditions, they can 
remain operational throughout the night or poor visibility conditions. 
In this case ramp-up procedures can be initiated, even though the 
exclusion zone may not be visible, on the assumption that marine 
mammals will be alerted by the sounds from the single airgun and have 
moved away.
    In addition, NMFS proposes the following additional protective 
mitigation and monitoring during the periods of darkness or low 
visibility. Specifically, NMFS does not recommend keeping one airgun 
(the so called ``mitigation gun'' in past IHAs) firing for long periods 
of time with no seismic operation ongoing during darkness or other 
periods of poor visibility on the previous assumption that marine 
mammals will be alerted by the sounds from the single airgun so that a 
cold start with pre-survey monitoring could be avoided, since there is 
no scientific evidence that such technique works (Tyack 2009). On the 
contrary, keeping an airgun firing unnecessarily for long periods of 
time would only introduce more noise into the water. Therefore, for 
seismic surveys that would start during night time and low visibility, 
NMFS proposes to require that PSOs use vessel lights, night vision 
devices (NVDs), and/or forward looking infrared (FLIR) to observe as 
much as possible for 30 minutes before ramping up the airgun array. 
PSOs will be called up to observe at nighttime during the 30-min 
periods prior to ramp-ups as well as during ramp-ups.

Mitigation Measures for Subsistence Activities

(1) Subsistence Mitigation Measures
    To limit potential impacts to the bowhead whale migration and the 
subsistence hunt, BP would not conduct airgun operations in the area 
north of the barrier islands after 25 August.
(2) Plan of Cooperation (POC) and Conflict Avoidance Agreement (CAA)
    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a POC or 
information that identifies what measures have been taken and/or will 
be taken to minimize adverse effects on the availability of marine 
mammals for subsistence purposes.
    BP has signed a Conflict Avoidance Agreement (CAA) with the Alaska 
Eskimo Whaling Commission (AEWC) and communities' Whaling Captains' 
Association for the proposed 2012 Simpson Lagoon OBV seismic survey. 
The main purpose of the CAA is to provide (1) equipment and procedures 
for communications between subsistence participants and industry 
participants; (2) avoidance guidelines and other mitigation measures to 
be followed by the industry participants working in or transiting the 
vicinity of active subsistence hunters, in areas where subsistence 
hunters anticipate hunting, or in areas that are in sufficient 
proximity to areas expected to be used for subsistence hunting that the 
planned activities could potentially adversely affect the subsistence 
bowhead whale hunt through effects on bowhead whales; and (3) measures 
to be taken in the event of an emergency occurring during the term of 
the CAA.
    In the CAA, BP agrees to employ a Marine Mammal Observer/Inupiat 
Communitor (MMO/IC) on board each primary sound source vessel owned or 
operated by BP in the Beaufort Sea, and that native residents of the 
eleven villages represented by the AEWC shall be given preference in 
hiring for MMO/IC positions.
    The CAA states that all vessels (operated by BP) shall report to 
the appropriate Communication Center (Com-Center) at least once every 
six hours commencing with a call at approximately 06:00 hours. The 
appropriate Com-Center shall be notified if there is any significant 
change in plans, such as an unannounced start-up of operations or 
significant deviations from announced course, and such Com-Center shall 
notify all whalers of such changes.
    The CAA further states that each Com-Center shall have an Inupiat 
operator (``Com- Center operator'') on duty 24 hours per day from 
August 15, or one week before the start of the fall bowhead whale hunt 
in each respective village, until the end of the bowhead whale 
subsistence hunt.
    The CAA also states that following the end of the fall 2012 bowhead 
whale subsistence hunt and prior to the 2013 pre-season introduction 
meetings, the industry participant that establishes the Deadhorse and 
Kaktovik Com Center will offer to the AEWC Chairman to host a joint 
meeting with all whaling captains of the villages of Nuiqsut, Kaktovik, 
and Barrow, the Marien Mammal Observer/Inupiat Communicators stationed 
on the industry participants' vessels in the Beaufort Sea, and with the 
Chairman and Exective Director of the AEWC, at a mutually agreed upon 
time and place on North Slope of Alaska, to review the results of the 
2012 Beaufort Sea open water season.
    In addition, BP is developing a ``Plan of Cooperation'' (POC) for 
the proposed 2012 seismic survey in the Simpson Lagoon of the Alaskan 
Beaufort Sea in consultation with representatives of communities along 
the Beaufort Sea coast at Barrow, Nuiqsut, and Kaktovik, on issues 
related to subsistence seal hunt. Mitigation measures similar to those 
listed in the CAA will be identified in the POC, and a final draft of 
the POC will be delivered to NMFS and other regulatory agencies.

Mitigation Conclusions

    NMFS has carefully evaluated the applicant's proposed mitigation 
measures and considered a range of other measures in the context of 
ensuring that NMFS prescribes the means of effecting the least 
practicable impact on the affected marine mammal species and stocks and 
their habitat. Our evaluation of potential measures included 
consideration of the following factors in relation to one another:
     The manner in which, and the degree to which, the 
successful implementation of the measure is expected to minimize 
adverse impacts to marine mammals; and
     The practicability of the measure for applicant 
implementation.

[[Page 25844]]

    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means of 
effecting the least practicable impact on marine mammal species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an ITA 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 ITAs 
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.
(1) Proposed Monitoring Measures
    The monitoring plan proposed by BP can be found in its IHA 
application. The plan may be modified or supplemented based on comments 
or new information received from the public during the public comment 
period. A summary of the primary components of the plan follows.
    There will be two vessel-based monitoring programs during the 
Simpson Lagoon OBC seismic survey. One program involves the presence of 
protected species observers (PSOs) on the seismic source vessels during 
the entire seismic survey period. The other vessel-based program 
involves two PSOs on a monitoring vessel outside the barrier islands 
after 25 August.

Visual Monitoring From Source Vessels

    Two PSOs will be present on each seismic source vessel. Of these 
two PSOs, one will be on watch at all times during daylight hours to 
monitor the 190 and 180 dB exclusion zones for the presence of marine 
mammals during airgun operations. During the fall bowhead whale 
migration season the 160 dB disturbance zone will also be monitored for 
the presence of groups of 12 or more baleen whales. The 120 dB 
disturbance zone for bowhead cow/calf pairs will be monitored from 
another vessel (see section ``Visual Monitoring Outside the Barrier 
Islands''). The main objectives of the vessel-based marine mammal 
monitoring program from the source vessels are as follows:
     To implement mitigation measures during seismic operations 
(e.g. course alteration, airgun power-down, shut-down and ramp-up);
     To record all marine mammal data needed to estimate the 
number of marine mammals potentially affected, which must be reported 
to NMFS within 90 days after the survey;
     To compare the distance and distribution of marine mammals 
relative to the source vessel at times with and without seismic 
activity; and
     To obtain data on the behavior and movement patterns of 
marine mammals observed and compare those at times with and without 
seismic activity.

Marine Mammal Observer Protocol

    BP intends to work with experienced PSOs that have had previous 
experience working on seismic survey vessels, which will be especially 
important for the lead PSO on the source vessels. At least one Alaska 
Native resident, who is knowledgeable about Arctic marine mammals and 
the subsistence hunt, is expected to be included as one of the team 
members aboard the vessels. Before the start of the seismic survey the 
crew of the seismic source vessels will be briefed on the function of 
the PSOs, their monitoring protocol, and mitigation measures to be 
implemented. They will also be aware of the monitoring objectives of 
the dedicated monitoring vessel, and how their observations can affect 
the operations.
    On all source vessels, at least one observer will monitor for 
marine mammals at any time during daylight hours (there will be no 
periods of total darkness until mid-August). PSOs will be on duty in 
shifts of a maximum of 4 hours at a time, although the exact shift 
schedule will be established by the lead PSO in consultation with the 
other PSOs.
    The three source vessels will offer suitable platforms for PSOs. 
Observations will be made from locations where PSOs have the best view 
around the vessel. During daytime, the PSO(s) will scan the area around 
the vessel systematically with reticle binoculars (e.g., 7 x 50 
Fujinon) and with the naked eye. Laser range-finding binoculars (Leica 
LRF 1200 laser rangefinder or equivalent) will be available to assist 
with distance estimation, using other vessels in the area as targets. 
Laser range finding binoculars are generally not useful in measuring 
distances to animals directly.

Communication Procedures

    When marine mammals in the water are detected within or about to 
enter the designated safety zones, the airgun(s) power-down or shut-
down procedures will be implemented immediately. To assure prompt 
implementation of power-downs and shut- downs, multiple channels of 
communication between the PSOs and the airgun technicians will be 
established. During the power-down and shut-down, the PSO(s) will 
continue to maintain watch to determine when the animal(s) are outside 
the safety radius. Airgun operations can be resumed with a ramp-up 
procedure (depending on the extent of the power down) if the observers 
have visually confirmed that the animal(s) moved outside the exclusion 
zone, or if the animal(s) were not observed within the safety zone for 
15 minutes (pinnipeds and small toothed whales) or for 30 minutes (for 
baleen whales and large toothed whales). Direct communication with the 
airgun operator will be maintained throughout these procedures.

Data Recording

    All marine mammal observations and any airgun power-down, shut-down 
and ramp- up will be recorded in a standardized format. Data will be 
entered into a custom database using a notebook computer. The accuracy 
of the data entry will be verified by computerized validity data checks 
as the data are entered and by subsequent manual checking of the 
database after each day. These procedures will allow initial summaries 
of data to be prepared during and shortly after the field program, and 
will facilitate transfer of the data to statistical, graphical, or 
other programs for further processing and archiving.

Visual Monitoring Outside the Barrier Islands

    The main purpose of the PSOs on the monitoring vessel that will 
operate outside the barrier islands is to monitor the 120 dB 
disturbance zone during daylight hours for the presence of four or more 
bowhead cow/calf pairs. The predicted distances to received levels of 
120 dB are 6.4 km for the 640 in\3\ array and 5.7 km for the 320 in\3\ 
array. The distance to the 160 dB disturbance zone is small enough (1.8 
km for the 640 in\3\ and 1.5 km for the 320 in\3\ array) to be covered 
by the PSOs on the source vessels. Of the two PSOs on the monitoring 
vessel, one will be on watch at all times during daylight hours to 
monitor the disturbance zones and to communicate any sightings of four 
bowhead cow/calf pairs to the PSOs on the source vessels. The shift 
schedule and observer protocol will be similar to that of the PSOs on 
the source vessels.

[[Page 25845]]

    Channels of communication between the lead PSOs on the source 
vessels and the dedicated monitoring vessel will also be established. 
If four or more bowhead cow/calf pairs are observed within or entering 
the 120 dB disturbance zone the lead PSO on monitoring vessel will 
immediately contact the lead PSO on the source vessel, who will ensure 
prompt implementation of airgun power downs or shutdowns. The lead PSO 
of the monitoring vessel will continue monitoring the 120 dB zone and 
notify the PSO on the source vessel when the cow/calf pairs have left 
the safety zone or when they haven't been observed within the safety 
zone for 30 minutes. Under these conditions ramp-up can be initiated.
    These vessel based surveys outside the barrier islands will be 
conducted up to 3 days per week, weather depending. Anticipated start 
date is August 25, 2012, and these surveys will be continuing until the 
end of the data acquisition period. During this period data acquisition 
will take place only inside the barrier islands. The vessel will follow 
transect lines within the 120 dB zone that are designed in such a way 
that the area ensonified by 120 dB or more will be covered. The exact 
start and end point will depend on the area to be covered by the source 
vessels during that particular day.

Monitoring Plan Peer Review

    The MMPA requires that monitoring plans be independently peer 
reviewed ``where the proposed activity may affect the availability of a 
species or stock for taking for subsistence uses'' (16 U.S.C. 
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing 
regulations state, ``Upon receipt of a complete monitoring plan, and at 
its discretion, [NMFS] will either submit the plan to members of a peer 
review panel for review or within 60 days of receipt of the proposed 
monitoring plan, schedule a workshop to review the plan'' (50 CFR 
216.108(d)).
    NMFS convened an independent peer review panel to review BP's 
mitigation and monitoring plan in its IHA application for taking marine 
mammals incidental to the proposed OBC seismic survey in the Simpson 
Lagoon of the Alaskan Beaufort Sea, during 2012. The panel met on 
January 5 and 6, 2012, and provided their final report to NMFS on 
February 29, 2012. The full panel report can be viewed at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#applications.
    NMFS provided the panel with BP's monitoring and mitigation plan 
and asked the panel to address the following questions and issues for 
BP's plan:
     Will the applicant's stated objectives effectively further 
the understanding of the impacts of their activities on marine mammals 
and otherwise accomplish the goals stated above? If not, how should the 
objectives be modified to better accomplish the goals above?
     Can the applicant achieve the stated objectives based on 
the methods described in the plan?
     Are there technical modifications to the proposed 
monitoring techniques and methodologies proposed by the applicant that 
should be considered to better accomplish their stated objectives?
     Are there techniques not proposed by the applicant (i.e., 
additional monitoring techniques or methodologies) that should be 
considered for inclusion in the applicant's monitoring program to 
better accomplish their stated objectives? And
     What is the best way for an applicant to present their 
data and results (formatting, metrics, graphics, etc.) in the required 
reports that are to be submitted to NMFS (i.e., 90-day report and 
comprehensive report)?
    The peer review panel report contains recommendations that the 
panel members felt were applicable to the BP's monitoring plans. 
Specifically the panel commented on issues related to: (1) Vessel-based 
marine mammal observers (MMOs), (2) MMO training, (3) Data recording, 
(4) Data analysis, and (5) Acoustical monitoring.
    NMFS has reviewed the report and evaluated all recommendations made 
by the panel. NMFS has determined that there are several measures that 
BP can incorporate into its 2012 OBC seismic survey. Additionally, 
there are other recommendations that NMFS has determined would also 
result in better data collection, and could potentially be implemented 
by oil and gas industry applicants, but which likely could not be 
implemented for the 2012 open water season due to technical issues (see 
below). While it may not be possible to implement those changes this 
year, NMFS believes that they are worthwhile and appropriate 
suggestions that may require a bit more time to implement, and BP 
should consider incorporating them into future monitoring plans should 
BP decide to apply for IHAs in the future.
    The following subsections lay out measures that NMFS recommends for 
implementation as part of the 2012 OBC seismic survey by BP and those 
that are recommended for future programs.

Recommendations for Inclusion in the 2012 Monitoring Plan

    The peer review panel's report contains several recommendations 
regarding vessel- based marine mammal observers, marine mammal monitor 
(MMO) training, data recording, data analysis and presentation of data 
in reports, and acoustic monitoring, which NMFS agrees that BP should 
incorporate:
(1) Vessel-Based Marine Mammal Observers
     Utilize crew members to assist the MMOs. Crew members 
should not be used as primary MMOs because they have other duties and 
generally do not have the same level of expertise, experience, or 
training as MMOs, but they could be stationed on the fantail of the 
vessel to observe the near field, especially the area around the airgun 
array and implement a rampdown or shutdown if a marine mammal enters 
the safety zone (or exclusion zone).
     If crew members are to be used as MMOs, they should go 
through some basic training consistent with the functions they will be 
asked to perform. The best approach would be for crew members and MMOs 
to go through the same training together.
     As BP plans to have a marine mammal survey vessel outside 
the barrier islands after 25 August, the panel recommends BP use MMOs 
on the vessel to monitor for the presence and behavior of marine 
mammals in the offshore area projected to be exposed to seismic sounds.
(2) MMO Training
     BP could improve its MMO training by implementing panel 
recommendations from previous years (on other seismic survey programs). 
These recommendations include:
    [cir] Observers should be trained using visual aids (e.g., videos, 
photos), to help them identify the species that they are likely to 
encounter in the conditions under which the animals will likely be 
seen.
    [cir] Observer teams should include Alaska Natives, and all 
observers should be trained together. Whenever possible, new observers 
should be paired with experienced observers to avoid situations where 
lack of experience impairs the quality of observations.
    [cir] Observers should understand the importance of classifying 
marine mammals as ``unknown'' or ``unidentified'' if they cannot 
identify the animals to species with confidence. In those cases, they 
should note any information that might aid in the

[[Page 25846]]

identification of the marine mammal sighted. For example, for an 
unidentified mysticete whale, the observers should record whether the 
animal had a dorsal fin.
    [cir] Observers should use the best possible positions for 
observing (e.g., outside and as high on the vessel as possible), taking 
into account weather and other working conditions.
     BP should train its MMOs to follow a scanning schedule 
that consistently distributes scanning effort according to the purpose 
and need for observations. For example, the schedule might call for 60 
percent of scanning effort to be directed toward the near field and 40 
percent at the far field. All MMOs should follow the same schedule to 
ensure consistency in their scanning efforts.
     MMOs also need training in documenting the behaviors of 
marine mammals. MMOs should simply record the primary behavioral state 
(i.e., traveling, socializing, feeding, resting, approaching or moving 
away from vessels) and relative location of the observed marine 
mammals.
(3) Data Recording
     MMOs should record observations of marine mammals hauled 
out on barrier islands. Because of the location of BP's proposed 
survey, most (if not all) of the marine mammals observed in the lagoon 
will be pinnipeds. It is feasible that the surveys may alter the 
hauling out patterns of pinnipeds, so observations of them should be 
recorded.
     BP should work with its observers to develop a means for 
recording data that does not reduce observation time significantly. 
Possible options include the use of a voice recorder during 
observations followed by later transcriptions, or well-designed 
software programs that minimize the time required to enter data. Other 
techniques also may be suitable.
(4) Data Analysis and Presentation of Data in Reports
     Estimation of potential takes or exposures should be 
improved for times with low visibility (such as during fog or darkness) 
through interpolation or possibly using a probability approach. For 
instance, for periods of fog or darkness one could use marine mammal 
observations obtained during a specified period of time before or fter 
the time when visibility was restricted. Those data could be used to 
interpolate possible takes during periods of restricted visibility.
     Simpson Lagoon is relatively shallow, and marine mammal 
distribution likely will be closely linked to water depth. To account 
for this confounding factor, depth should be continuously recorded by 
the vessel and for each marine mammal sighting. Water depth should be 
accounted for in the analysis of take estimates.
     BP should be very clear in their report about what periods 
are considered ``non-seismic'' for analyses.
     BP should examine data from BWASP and other such programs 
to assess possible impacts from their seismic survey.
     The panel states that it believes the best ways to present 
data and results are described in peer-review reports from previous 
years. These recommendations include:
    [cir] To better assess impacts to marine mammals, data analysis 
should be separated into periods when a seismic airgun array (or a 
single mitigation airgun) is operating and when it is not. Final and 
comprehensive reports to NMFS should summarize and plot:
    [ssquf] Data for periods when a seismic array is active and when it 
is not; and
    [ssquf] The respective predicted received sound conditions over 
fairly large areas (tens of km) around operations.
    [cir] To help evaluate the effectiveness of MMOs and more 
effectively estimate take, reports should include sightability curves 
(detection functions) for distance-based analyses.
    [cir] To better understand the potential effects of oil and gas 
activities on marine mammals and to facilitate integration among 
companies and other researchers, the following data should be obtained 
and provided electronically in the 90-day report:
    [ssquf] The location and time of each aerial or vessel-based 
sighting or acoustic detection;
    [ssquf] Position of the sighting or acoustic detection relative to 
ongoing operations (i.e., distance from sightings to seismic operation, 
drilling ship, support ship, etc.), if known;
    [ssquf] The nature of activities at the time (e.g., seismic on/
off);
    [ssquf] Any identifiable marine mammal behavioral response 
(sighting data should be collected in a manner that will not detract 
from the MMO's ability to detect marine mammals); and
    [ssquf] Adjustments made to operating procedures.
    [cir] BP should improve take estimates and statistical inference 
into effects of the activities by incorporating the following measures:
    [ssquf] Reported results from all hypothesis tests should include 
estimates of the associated statistical power.
    [ssquf] Estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available.
(5) Acoustical Monitoring
     BP should also use the offshore vessel to monitor 
(periodically) the propagation of airgun sounds from within the lagoon 
into offshore areas during its marine mammal survey using a dipping 
hydrophone.
     To help verify the propagation model results, the panel 
also recommends additional acoustic monitoring with bottom mounted 
recorders. Recorders should be deployed throughout the seismic survey. 
One suggestion is to deploy instruments including: one at the cut, or 
break, between Leavitt and Spy islands at about the 5 m isobath; one 
north of the center of Leavitt Island at the 10 m isobath; and one off 
the east end of Pingok Island at the 10 m isobath.

Recommendations To Be Considered for Future Monitoring Plans

    In addition, the panelists recommended that (1) BP continue to 
develop and test observational aids to assist with visibility during 
night, poor light conditions, inclement weather, etc.; and (2) BP 
conduct additional acoustic monitoring with bottom mounted recorders to 
monitor for calling marine mammals. It may be possible to evaluate 
calling rates relative to seismic operations or received levels of 
seismic sounds. Additionally, Shell will have several acoustic arrays 
in the general area. Those arrays will provide a basis for determining 
locations of calling marine mammals. NMFS should encourage BP to 
request data from Shell to help examine impacts of the seismic survey 
on the distribution of calling bowheads and other marine mammals.
    After discussion with BP, NMFS decided not to implement these two 
recommendations for BP's 2012 OBC seismic survey because most of BP's 
survey would occur during the time when there will be very short low-
light hours. As for the second recommendation, NMFS realized that given 
the complexity in marine mammal passive acoustic localization, BP will 
not have the time to implement this recommendation for its 2012 survey.
(2) Reporting Measures

Sound Source Verification Reports

    A report on the preliminary results of the sound source 
verification measurements, including the measured

[[Page 25847]]

190, 180, 160, and 120 dB (rms) radii of the airgun sources, would be 
submitted within 14 days after collection of those measurements at the 
start of the field season. This report will specify the distances of 
the exclusion zones that were adopted for the survey.

Technical Reports

    The results of BP's 2012 vessel-based monitoring, including 
estimates of ``take'' by harassment, would be presented in the ``90-
day'' and Final Technical reports, if the IHA is issued and the 
proposed OBC seismic survey is conducted. The Technical Reports should 
be submitted to NMFS within 90 days after the end of the seismic 
survey. The Technical Reports will include:
    (a) Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
    (b) Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
    (c) Species composition, occurrence, and distribution of marine 
mammal sightings, including date, water depth, numbers, age/size/gender 
categories (if determinable), group sizes, and ice cover;
    (d) To better assess impacts to marine mammals, data analysis 
should be separated into periods when a seismic airgun array (or a 
single mitigation airgun) is operating and when it is not. Final and 
comprehensive reports to NMFS should summarize and plot:
     Data for periods when a seismic array is active and when 
it is not; and
     The respective predicted received sound conditions over 
fairly large areas (tens of km) around operations;
    (e) Sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability), such as:
     Initial sighting distances versus airgun activity state;
     Closest point of approach versus airgun activity state;
     Observed behaviors and types of movements versus airgun 
activity state;
     Numbers of sightings/individuals seen versus airgun 
activity state;
     Distribution around the survey vessel versus airgun 
activity state; and
     Estimates of take by harassment;
    (f) Reported results from all hypothesis tests should include 
estimates of the associated statistical power when practicable;
    (g) Estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available;
    (h) The report should clearly compare authorized takes to the level 
of actual estimated takes; and

Notification of Injured or Dead Marine Mammals

    In addition, NMFS would require BP to notify NMFS' Office of 
Protected Resources and NMFS' Stranding Network within 48 hours of 
sighting an injured or dead marine mammal in the vicinity of marine 
survey operations. BP shall provide NMFS with the species or 
description of the animal(s), the condition of the animal(s) (including 
carcass condition if the animal is dead), location, time of first 
discovery, observed behaviors (if alive), and photo or video (if 
available).
    In the event that an injured or dead marine mammal is found by BP 
that is not in the vicinity of the proposed open-water marine survey 
program, BP would report the same information as listed above as soon 
as operationally feasible to NMFS.

Estimated Take by Incidental Harassment

    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]. Only take by Level B behavioral 
harassment is anticipated as a result of the proposed open water marine 
survey program. Anticipated impacts to marine mammals are associated 
with noise propagation from the survey airgun(s) used in the shallow 
hazards survey.
    The full suite of potential impacts to marine mammals was described 
in detail in the ``Potential Effects of the Specified Activity on 
Marine Mammals'' section found earlier in this document. The potential 
effects of sound from the proposed open water marine survey programs 
might include one or more of the following: Masking of natural sounds; 
behavioral disturbance; non-auditory physical effects; and, at least in 
theory, temporary or permanent hearing impairment (Richardson et al. 
1995). As discussed earlier in this document, the most common impact 
will likely be from behavioral disturbance, including avoidance of the 
ensonified area or changes in speed, direction, and/or diving profile 
of the animal. For reasons discussed previously in this document, 
hearing impairment (TTS and PTS) are highly unlikely to occur based on 
the proposed mitigation and monitoring measures that would preclude 
marine mammals being exposed to noise levels high enough to cause 
hearing impairment.
    For impulse sounds, such as those produced by airgun(s) used in the 
seismic survey, NMFS uses the 160 dB (rms) re 1 [mu]Pa isopleth to 
indicate the onset of Level B harassment. BP provided calculations for 
the 160- and 120-dB isopleths produced by these activities and then 
used those isopleths to estimate takes by harassment. NMFS used the 
calculations to make the necessary MMPA preliminary findings. BP 
provided a full description of the methodology used to estimate takes 
by harassment in its IHA application (see ADDRESSES), which is also 
provided in the following sections.
    BP has requested an authorization to take 11 marine mammal species 
by Level B harassment. These 11 marine mammal species are: beluga whale 
(Delphinapterus leucas), killer whale (Orcinus orca), harbor porpoise 
(Phocoena phocoena), bowhead whale (Balaena mysticetus), gray whale 
(Eschrichtius robustus), humpback whale (Megaptera novaeangliae), minke 
whale (Balaenoptera acutorostrata), bearded seal (Erignathus barbatus), 
ringed seal (Phoca hispida), spotted seal (P. largha), and ribbon seal 
(Histriophoca fasciata). BP did not request take of narwhal because the 
occurrence of this species is extremely rare in the proposed action 
area, and it is very unlikely to be encountered during the BP's 
proposed seismic surveys.

Basis for Estimating ``Take by Harassment''

    As stated previously, it is current NMFS practice to estimate take 
by Level A harassment for received levels above 180 dB re 1[mu]Pa (rms) 
for cetaceans and 190 dB re 1[mu]Pa (rms) for pinnipeds, and take by 
Level B harassment for all marine mammals under NMFS jurisdiction by 
impulse sounds at a received level above 160 dB re 1[mu]Pa (rms) and by 
non- impulse sounds at a received level above 120 dB re 1[mu]Pa (rms). 
However, not all animals are equally affected by the same received 
noise levels and, as described earlier, in most cases marine mammals 
are not

[[Page 25848]]

likely to be taken by Level A harassment (injury) when exposed to 
received levels higher than 180 dB for a brief period of time.
    For behavioral harassment, marine mammals will likely not show 
strong reactions (and in some cases any reaction) until sounds are much 
stronger than 160 or 120 dB (for impulse and continuous sounds, 
respectively). Southall et al. (2007) provide a severity scale for 
ranking observed behavioral responses of both free-ranging marine 
mammals and laboratory subjects to various types of anthropogenic sound 
(see Table 4 in Southall et al. (2007)). Tables 7, 9, and 11 in 
Southall et al. (2007) outline the numbers of low-frequency cetaceans, 
mid-frequency cetaceans, and pinnipeds in water, respectively, reported 
as having behavioral responses to multi-pulses in 10-dB received level 
increments. These tables illustrate that the more severe reactions did 
not occur until sounds were much higher than 160 dB re 1[mu]Pa (rms).
    As described earlier in the document, two main source vessels and a 
mini source vessel would be used to conduct the OBC seismic surveys in 
the Simpson Lagoon. Each of the main source vessels would be equipped 
with two subarrays containing eight 40 in\3\ airguns, with a total 
volume displacement of 640 in\3\. The mini source vessel would be 
equipped with one subarray containing eight 40 in\3\ airguns, with a 
total displacement volume of 320 in\3\. Modeling results show that the 
160 dB isopleths for the 640 in\3\, 320 in\3\, and 40 in\3\ airgun 
arrays inside the barrier islands are approximately 1,800 m, 1,500 m, 
and 700 m from the source, respectively; the 160 dB isopleths for the 
640 in\3\ and 40 in\3\ airgun arrays outside the barrier islands are 
approximately 5,500 m and 810 m from the source, respectively (Please 
see above for detailed description of the exclusion and disturbance 
zones).
    The radii associated with received sound levels of 160 dB re 1 
[mu]Pa (rms) or higher are used to calculate the number of potential 
marine mammal ``exposures'' to airgun sounds. The potential number of 
each species that might be exposed to received pulsed sound levels of 
>=160 dB re 1 [mu]Pa (rms) is calculated by multiplying the expected 
species density with the anticipated area to be ensonified to that 
level during airgun operations. Bowhead and beluga whales are migrating 
through the area, so every encounter likely involves a new individual. 
Although seal species are also known to cover large distances, they are 
expected to linger longer within a certain area, and so one individual 
might be exposed multiple times.
    The area expected to be ensonified was determined by entering the 
seismic survey lines into a MapInfo Geographic Information System 
(GIS). GIS was then used to identify the relevant areas by ``drawing'' 
the applicable 160-dB buffer of the 640 in\3\ array around each seismic 
source line and calculating the total area within the buffers. This was 
done for the survey area outside the barrier islands and inside the 
barrier islands separately. The area ensonified with pulsed sound 
levels of >=160 dB re 1 [mu]Pa (rms) from airgun operations outside the 
barrier islands is estimated as 197.5 mi\2\ (512 km\2\) and from airgun 
operations inside the barrier islands 105 mi\2\ (272 km\2\).
    Summer density (see below) estimates of marine mammals will be 
applied to all (100%) survey effort outside the barrier islands and to 
60% survey effort inside the barrier islands. Fall densities are not 
applied to the outside barrier islands survey effort, since no survey 
effort is planned after August 25. Fall densities are applied to 100% 
survey effort inside the barrier islands activity, because some of the 
source lines will be rerun in order to image the full fold area 
adequately.

Marine Mammal Density Estimates

    Because most cetacean species show a distinct seasonal 
distribution, density estimates for the central Beaufort Sea have been 
derived for the summer period (covering July and August) and the fall 
period (covering September and October). Animal densities encountered 
in the Beaufort Sea during both of these time periods will further 
depend on the presence of ice. However, if ice cover within or close to 
the seismic survey area is more than approximately 10%, seismic survey 
activities may not start or be halted. Cetacean and pinniped densities 
related to ice conditions are therefore not included in BP's IHA 
application. Pinniped species in the Beaufort Sea do not show a 
distinct seasonal distribution during the period July-early October and 
as such density estimates derived for seal species are used for both 
the summer and fall periods.
    In addition to seasonal variation in densities, spatial 
differentiation is an important factor for marine mammal densities, 
both in latitudinal and longitudinal gradient. Taking into account the 
size and location of the proposed seismic survey area and the 
associated area of influence, only the nearshore zone (defined as the 
area between the shoreline and the 50 m [164 ft] bathymetry line) of 
the Beaufort Sea was considered to be relevant for the calculation of 
densities.
    Density estimates are based on best available scientific data. In 
cases where the best available data were collected in regions, 
habitats, or seasons that differ from the proposed survey activities, 
information from monitoring results collected in similar habitats, 
regions or seasons was used. Some sources from which densities were 
used include correction factors to account for perception and 
availability bias in the reported densities. Perception bias is 
associated with diminishing probability of sighting with increasing 
lateral distance from the trackline, where an animal is present at the 
surface but could be missed. Availability bias refers to the fact that 
the animal might be present but is not available at the surface. The 
uncorrected number of marine mammals observed is therefore always lower 
than the actual numbers present. Unfortunately, for most marine mammals 
not enough information is available to calculate these two correction 
factors. The density estimates provided in the BP's IHA request are 
therefore based on uncorrected data, unless mentioned otherwise.
    Because the available density data is not always representative for 
the area of interest, and correction factors were not always known, 
there is some uncertainty in the data and assumptions used in the 
density calculations. To provide allowance for these uncertainties, 
maximum density estimates have been provided in addition to average 
density estimates. The marine mammal densities presented are believed 
to be close to, and in most cases higher than, the densities that are 
expected to be encountered during the proposed survey.
(1) Cetacean Densities
    Beluga Whale: Summer beluga density estimates for the Alaskan 
Beaufort Sea are derived from aerial survey data over the period 1982-
1986 as analyzed by Moore et al. (2000b). During the summer season, 
beluga whales were observed mostly in continental slope habitat (water 
depths of 201-2,000 m [660-6562 ft]) and infrequently in inner shelf 
habitat (< 50 m [164 ft]). Most applicable to the proposed OBC seismic 
survey are the data collected in water depths of less than 164 ft. 
Along 7,447 mi (11,985 km) of on-transect effort in July-August there 
were a total of nine beluga sightings (Moore et al. 2000). No 
correction was applied to this data for the purpose of this IHA request 
for two reasons: (1) All nine sightings were

[[Page 25849]]

observed offshore of the 164 ft (50 m) bathymetry line and the proposed 
survey, including the contour of the 160 dB sound level, occurs in 
shallower water depths, and (2) the majority of beluga sightings 
occurred farther to the east and there were no sightings at the 
longitude of Simpson Lagoon Bay. A density of 0.0008 whales/km\2\ was 
used as the average summer density for beluga whales.
    Fall densities for beluga whales were calculated using data derived 
from Bowhead Whale Aerial Survey Project (BWASP) aerial surveys 
collected in 2006-2008 (Clarke et al. 2011). Generally, beluga whales 
selected water on the outer shelf and slope with moderate to heavy ice 
during the westward migration, however, ice cover in the period 2006-
2008 was relatively low compared to historical years and beluga whales 
were often observed in ice free waters. Based on aerial survey data 
(Moore et al. 2000, Clarke et al. 2011) few beluga whales are expected 
to be encountered in the central part of the Beaufort Sea, especially 
shoreward of the barrier islands.
    The fall beluga whale density was calculated by using the total 
transect effort and number of belugas observed during fall of 2006, 
2007, and 2008 (Clarke et al. 2011). A value of 2.841 to correct for 
animals missed, and a value of 0.58 to correct for animals not 
available at the surface from Harwood et al. (1996) were applied to 
derive corrected density estimates. Transect effort in the fall of 2006 
was 12,393 km during which a total of 525 belugas observed. A corrected 
density of 0.1038 whales/km\2\ was derived from this data. In fall 
2007, a total of 117 belugas were sighted along 6,294 km of transect 
effort, from which a corrected density of 0.0455 whales/km\2\ was 
calculated. The density for 2008 was the lowest with 15 belugas along 
10,856 km of transect effort (corrected density of 0.0034 whales/
km\2\). The average value over these three years was 0.0545 whales/
km\2\. This was calculated by dividing the total number of belugas 
sighted with the total 2006-2008 transect effort and applying the 
correction factors. The 2006 fall density was used as the maximum 
value. Because most sightings were observed offshore of the 50 m 
bathymetry line and the proposed survey takes place in water depths of 
less than 15 m (of which a majority inside the barrier islands), the 
densities used for the purpose of this IHA request were assumed to be 
25% of the average density provided here.
    Bowhead Whale: Bowheads in the eastern Alaskan and Canadian 
Beaufort Sea occur in offshore habitats during the summer. Starting 
late August-early September whales are leaving their feeding grounds 
and migrate westward in shallower habitats during years with moderate 
and light ice-cover and in deeper waters in years with heavy ice-cover. 
During the summer period (July-August) relatively few bowhead whales 
are expected to be present in the nearshore zone of the central 
Beaufort Sea. Bowhead sightings become more common there when whales 
start their westward migration in August, with peak sighting rates 
occurring in September.
    The bowhead whale summer density estimates were derived from 2008 
aerial survey data in Camden Bay (Christie et al. 2010) and the 2010 
aerial survey in Harrison Bay (Brandon et al. 2011) conducted as part 
of a marine mammal monitoring program for seismic and shallow hazard 
surveys. Because these data sets cover the summer season (July-August) 
it was considered to be the most representative information available. 
The 2008 Camden Bay survey area covered water depths between 20-200 m. 
The average density over the period July 6-August 18 was estimated to 
be 0.009 whales/km\2\, and included correction factors from Thomas et 
al. (2002). This density was based on data collected on the three days 
that bowhead whales were sighted (July 7, 9, and 12), during periods 
without operational airguns. The 2010 Harrison Bay aerial survey 
covered the area just offshore of the barrier islands to 100 m water 
depth. The average density over the period July 16-August 13 was 0.004 
whales/km\2\, including correction factors from Thomas et al. (2002). 
This density was based on data collected before seismic operations 
started during which one bowhead was observed on August 3. For the 
purpose of this IHA request, the average summer density was derived 
from these two values (0.0065 whales/km\2\).
    The bowhead whale fall density estimates used in this IHA request 
are derived from the BWASP aerial surveys, which contain the best 
available and most current information of bowhead whale distribution 
and abundance in the Beaufort Sea. These surveys started in 1979 and 
have been repeated annually, resulting in a large multi-year dataset. 
Clarke and Ferguson (2010) present an update of this aerial survey 
effort, summarizing data from the period 2000-2009, and comparing those 
with results from data prior to 2000. Since the Simpson Lagoon OBC 
seismic project takes place around 148[deg] longitude in waters of less 
than 50 ft (15 m), densities of bowhead whales provided by Clarke and 
Ferguson (2010) for the eastern Beaufort Sea (defined as east of 
154[deg] longitude) in the 0-20 m depth zone were considered to be most 
representative of the proposed survey area. Clarke and Ferguson (2010) 
reported 96 animals during 9,933 km of on transect aerial survey effort 
in September and 42 animals during 6,143 km of on transect effort in 
October. Correction factors from Thomas et al. (2002) were applied to 
these numbers; this is a value of 2 to correct for animals available at 
the surface but not detected and a value of 0.07 for animals present 
but not available at the surface. This resulted in a density of 0.1381 
whales/km\2\ for September and 0.0977 whales/km\2\ for October. The 
combined September-October value (0.1226 whales/km\2\) is used as the 
average density and the September value as the maximum density.
    Other Cetacean Species: No densities have been estimated for gray 
whales and for cetacean species that are rare or extralimital to the 
Beaufort Sea (humpback whale, minke whale, killer whale, harbor 
porpoise, narwhal), because sightings of this animals have been very 
infrequent. Gray whales may be encountered in small numbers throughout 
the summer and fall, especially in the nearshore areas. Small numbers 
of harbor porpoises may be encountered as well. During an aerial survey 
offshore of Oliktok Point in 2008, just west of the proposed survey 
area, two harbor porpoises were sighted offshore of the barrier 
islands, one on August 25 and the other on September 10 (Hauser et al. 
2008). The first confirmed sighting of a humpback whale with calf was 
documented on August 1, 2007, about 54 mile (87 km) east of Point 
Barrow (Hashagen et al. 2009), so an occasional sighting could occur. 
Therefore, for the purpose of this IHA request, BP requested that 
``takes'' be authorized to cover chance encountering of these animals 
during the proposed seismic survey.
(2) Pinniped Densities
    Pinnipeds in the polar regions are mostly associated with sea ice 
and most census methods count pinnipeds when they are hauled out on the 
ice. To account for the proportion of animals present but not hauled 
out (availability bias) or seals present on the ice but missed 
(detection bias), a correction factor should be applied to the ``raw'' 
counts. This correction factor is dependent on the behavior of each 
species. To estimate what proportion of ringed seals were generally 
visible resting on the sea ice, radio tags were placed on seals during 
spring 1999-2003 (Kelly et al. 2006). The probability

[[Page 25850]]

that seals were visible, derived from the satellite data, was applied 
to seal abundance data from past aerial surveys and indicated that the 
proportion of seals visible varied from less than 0.40 to more than 
0.75 between survey years. The environmental factors that are important 
in explaining the availability of seals to be counted were found to be 
time of day, date, wind speed, air temperature, and days from snow melt 
(Kelly et al. 2006). Besides the uncertainty in the correction factor, 
using counts of basking seals from spring surveys to predict seal 
abundance in the open-water period is further complicated by the fact 
that seal movements differ substantially between these two seasons 
(Kelly et al. 2010b). Data from nine ringed seals that were tracked 
from one subnivean period (early winter through mid-May or early June) 
to the next showed that ringed seals covered large distances during the 
open water foraging period (Kelly et al. 2010b). Ringed seals tagged in 
2011 close to Barrow also show long distance travel during the open 
water season.
    To estimate densities for ringed, bearded and spotted seals, data 
were used from three surveys conducted as part of shallow water OBC 
seismic surveys in the Beaufort Sea (Harris et al. 2001, Aerts et al. 
2008, Hauser et al. 2008). Habitat and survey specifics are very 
similar to the proposed survey, therefore these data were considered to 
be the more representative than basking seal densities from spring 
aerial survey data (e.g., Moulton et al. 2002, Frost et al. 2002, 
2004).
    No distinction is made in density of pinnipeds between summer and 
autumn season. Also, no correction factors have been applied to the 
seal densities reported here. Instead, a multiplier was applied to the 
estimated densities to account for variability in seal abundance.
    Ringed seals are the most common seal species in the Beaufort Sea, 
followed by the bearded seal. Spotted seals also occur, specifically in 
the nearshore zone, but are not as frequently observed as the other two 
species. During the 1996 OBC survey, 92% of all seal species identified 
were ringed seals, 7% bearded seals and 1% spotted seals (Harris et al. 
2001). This 1996 survey occurred in two habitats, one about 19 mile 
east of Prudhoe Bay near the McClure Islands, mainly inshore of the 
barrier islands in water depths of 10 to 26 ft and the other 6 to 30 
miles northwest of Prudhoe Bay, about 0 to 8 mile offshore of the 
barrier islands in water depths of 10 to 56 ft (Harris et al. 2001). 
Because it is often difficult to identify seals to species, a large 
proportion of seal sightings were unidentified in all three surveys. 
The total seal sighting rate was therefore used to calculate densities 
for each species, using the ratio of 92%, 7%, and 1% for ringed, 
bearded and spotted seals as mentioned above.
    During the 1996 OBC survey (Harris et al. 2001) the sighting rate 
for all seals during periods when airguns were not operating was 0.63 
seals/hour. The sighting rate during non- seismic periods was 0.046 
seals/hour for the survey in Foggy Island Bay, just east of Prudhoe Bay 
(Aerts et al. 2008). The OBC survey that took place at Oliktok Point, 
adjacent to the proposed survey in Simpson Lagoon, recorded 0.0671 
seals/hour when airguns were not operating (Hauser et al. 2008). The 
survey effort in kilometers or miles is only reported for the survey at 
Oliktok Point.
    The total source line miles that will be travelled during the 
proposed OBC seismic survey is approximately 4,000 miles (6,440 km). 
The average vessel speed during the survey will be ~3 knots (or 3.4 
miles/hour), calculated based on a 40 ft distance traveled during the 
8-second shot interval. Applying the average vessel speed of 3.4 miles/
hour, it will take about 1176 hours to complete data acquisition along 
these source lines, which is equivalent to about 49 days. The total 
number of seals expected to be observed in the area is 741 (based on 
0.63 seals/hour), 54 (based on 0.046 seals/hour), and 79 (based on 
0.067 seals/hour). The average of these three values is 291 seals, and 
the maximum 741 seals.
    Ringed Seal: The average density for ringed seals is expected to be 
0.0420 seals/km\2\, based on a ratio of 92% and a total of 6,440 km 
[(291 x 0.92)/6,440)]. To account for variability in seal abundance the 
average density was multiplied by a factor 4.
    Bearded Seal: The average density for bearded seals is expected to 
be 0.0031 seals/km\2\, based on a ratio of 7% and a total of 6,440 km 
[(291 x 0.07)/6,440)]. To account for variability in seal abundance the 
average density was multiplied by a factor 4.
    Spotted Seal: The average density for ringed seals is expected to 
be 0.0005 seals/km\2\, based on a ratio of 1% and a total of 6,440 km 
[(291 x 0.01)/6,440)]. To account for variability in seal abundance the 
average density was multiplied by 4.
    Table 3 lists a summary of marine mammal densities used for 
calculating the estimated takes.

   Table 3--Expected Densities of Marine Mammals in the Simpson Lagoon
                               Survey Area
------------------------------------------------------------------------
                                                   Summer       Autumn
                                                 densities    densities
                    Species                     (/  (/
                                                   km\2\)       km\2\)
------------------------------------------------------------------------
Bowhead whale.................................       0.0065       0.1226
Beluga whale..................................       0.0008       0.0136
Ringed seal...................................       0.1680       0.1680
Bearded seal..................................       0.0124       0.0124
Spotted seal..................................       0.0020       0.0020
------------------------------------------------------------------------

Potential Number of Takes by Harassment

    Numbers of marine mammals that might be present and potentially 
taken are summarized in Table 4 based on available data about mammal 
distribution and densities at different locations and times of the year 
as described above.
    Some of the animals estimated to be exposed, particularly migrating 
bowhead whales, might show avoidance reactions before being exposed to 
>=160 dB re 1 [mu]Pa (rms). Thus, these calculations actually estimate 
the number of individuals potentially exposed to >=160 dB (rms) that 
would occur if there were no avoidance of the area ensonified to that 
level.
    For beluga whales and spotted seals that may form groups, 
additional takes were requested on top of the density-based take 
calculation in the event a large group is encountered during the 
survey. For marine mammal species that are extralimital and for which 
no density estimates are available in the vicinity of the proposed 
project area (such as gray, humpback, minke, and killer whales, harbor 
porpoise, and ribbon seal), a small number of takes have been requested 
in case they are encountered (Table 4).

[[Page 25851]]



Table 4--Estimates of the Possible Numbers of Marine Mammals Taken by Level B Harassment (Exposed to >=160 dB re
          1 [mu]Pa (rms)) During BP's Proposed Seismic Program in the Beaufort Seas, July-October 2012
----------------------------------------------------------------------------------------------------------------
                                           Outside barrier        Inside barrier islands
                                               islands     ------------------------------------  Total estimated
                 Species                 ------------------                                           takes
                                               Summer            Summer            Autumn
----------------------------------------------------------------------------------------------------------------
Bowhead whale...........................                 3                 1                33                37
Beluga whale............................                 0                 0                 4              * 50
Gray whale..............................  ................  ................  ................                 3
Humpback whale..........................  ................  ................  ................                 2
Minke whale.............................  ................  ................  ................                 2
Killer whale............................  ................  ................  ................                 3
Harbor porpoise.........................  ................  ................  ................                 3
Ringed seal.............................                60                19                32               111
Bearded seal............................                 9                 3                 5                17
Spotted seal............................                 1                 0                 1              * 20
Ribbon seal.............................  ................  ................  ................                 3
----------------------------------------------------------------------------------------------------------------
* Additional takes were requested in the event that a large group of beluga whales is encountered.

Estimated Take Conclusions

    Cetaceans--Effects on cetaceans are generally expected to be 
restricted to avoidance of an area around the seismic survey and short-
term changes in behavior, falling within the MMPA definition of ``Level 
B harassment''.
    Using the 160 dB criterion, the average estimates of the numbers of 
individual cetaceans exposed to sounds >=160 dB (rms) re 1 [mu]Pa 
represent varying proportions of the populations of each species in the 
Beaufort Sea and adjacent waters. For species listed as ``Endangered'' 
under the ESA, the estimates include approximately 37 bowheads. This 
number is approximately 0.24% of the Bering-Chukchi-Beaufort population 
of over 15,232 assuming 3.4% annual population growth from the estimate 
of over 10,545 animals (Zeh and Punt 2005). For other cetaceans that 
might occur in the vicinity of the Simpson Lagoon survey area, they 
also represent a very small proportion of their respective populations. 
The average estimates of the number of belugas (with additional takes 
to count for chance encounter of a large group) that might be exposed 
to >=160 dB re 1 [mu]Pa is 50, which represents 0.13% of the Beaufort 
Sea population (or 1.35% of the Eastern Chukchi Sea population, or a 
mix between these two populations) of the beluga whales. In addition, 
the average estimates of gray, humpback, minke, and killer whales, and 
harbor porpoise that might be exposed to >=160 dB re 1 [mu]Pa are 3, 2, 
2, 3,and 3. These numbers represent 0.02%, 0.21%, 0.20%, 0.96%, and 
0.0062% of these species of their respective populations in the 
proposed action area.
    Seals--A few seal species are likely to be encountered in the study 
area, but ringed seal is by far the most abundant in this area. The 
average estimates of the numbers of individuals exposed to sounds at 
received levels >=160 dB (rms) re 1 [mu]Pa during the proposed shallow 
hazards survey are as follows: ringed seals (111), bearded seals (17), 
spotted seals (20, with additional takes to count for chance encounter 
of a group), and ribbon seals (2). These numbers represent 0.05%, 
0.01%, 0.03%, and 0.0033% of Alaska stocks of ringed, bearded, spotted, 
and ribbon seals, respectively.

Negligible Impact and Small Numbers Analysis and Preliminary 
Determination

    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.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the takes occur.
    No injuries or mortalities are anticipated to occur as a result of 
BP's proposed 2012 OBC seismic survey in the Simpson Lagoon of the 
Alaskan Beaufort Sea, and none are proposed to be authorized. In 
addition, these surveys would use relatively small 640 in\3\ airgun 
arrays, which have much less acoustic power outputs compared to 
conventional airgun arrays with displacement volume in the range of 
thousands cubic inches. Additionally, the survey areas are in shallow 
waters, with approximately 42% of the survey area located inside the 
barrier islands (depth: 0-9 ft, or 0-3 m) and 33% located outside the 
barrier islands (depth: 3-45 ft, or 1-15 m), where horizontal sound 
propagation of low frequency airgun pulses is severely limited. For the 
seismic survey inside the barrier islands, the islands provide a 
natural barrier that would effectively reduce sound propagation out to 
the open ocean, if not completely eliminate its propagation. The 
modeled isopleths at 160 dB within the barrier islands is expected to 
be approximately 1.8 km, and 5.5 km outside barrier islands, from an 
airgun array of 640 in\3\ (see discussion earlier). Additionally, 
animals in the area are not expected to incur hearing impairment (i.e., 
TTS or PTS) or non-auditory physiological effects. Takes will be 
limited to Level B behavioral harassment. Although it is possible that 
some individuals of marine mammals may be exposed to sounds from the 
proposed seismic survey activities more than once, the expanse of these 
multi-exposures are expected to be less extensive since both the 
animals and the survey vessels will be moving constantly in and out of 
the survey areas.
    Most of the bowhead whales encountered during the summer will 
likely show overt disturbance (avoidance) only if they receive airgun 
sounds with levels >= 160 dB re 1 [mu]Pa. Odontocete reactions to 
seismic energy pulses are usually assumed to be limited to shorter 
distances from the airgun(s) than are those of mysticetes, probably in 
part because odontocete low-frequency hearing is assumed to be less 
sensitive than that of mysticetes. However, at least when in the 
Canadian Beaufort Sea in summer, belugas appear to be fairly responsive 
to seismic energy, with few being sighted within 6-12 mi (10-20 km) of 
seismic vessels during aerial surveys (Miller et al. 2005). Belugas 
will likely occur in small numbers in the

[[Page 25852]]

Beaufort Sea during the survey period and few will likely be affected 
by the survey activity. In addition, due to the constant moving of the 
survey vessel, the duration of the noise exposure by cetaceans to 
seismic impulse would be brief. For the same reason, it is unlikely 
that any individual animal would be exposed to high received levels 
multiple times.
    Taking into account the mitigation measures that are planned, 
effects on cetaceans are generally expected to be restricted to 
avoidance of a limited area around the survey operation and short-term 
changes in behavior, falling within the MMPA definition of ``Level B 
harassment''. The many reported cases of apparent tolerance by 
cetaceans of seismic exploration, vessel traffic, and some other human 
activities show that co-existence is possible. Mitigation measures such 
as controlled vessel speed, dedicated marine mammal observers, non-
pursuit, and shut downs or power downs when marine mammals are seen 
within defined ranges will further reduce short-term reactions and 
minimize any effects on hearing sensitivity. In all cases, the effects 
are expected to be short-term, with no lasting biological consequence.
    Of the eleven marine mammal species likely to occur in the proposed 
marine survey area, only the bowhead and humpback whales are listed as 
endangered under the ESA. These species are also designated as 
``depleted'' under the MMPA. Despite these designations, the Bering-
Chukchi-Beaufort stock of bowheads has been increasing at a rate of 3.4 
percent annually for nearly a decade (Allen and Angliss 2010). 
Additionally, during the 2001 census, 121 calves were counted, which 
was the highest yet recorded. The calf count provides corroborating 
evidence for a healthy and increasing population (Allen and Angliss 
2010). The occurrence of humpback whales in the proposed marine survey 
areas is considered very rare. There is no critical habitat designated 
in the U.S. Arctic for the bowhead, fin, and humpback whale. The Alaska 
stock of bearded seals, part of the Beringia distinct population 
segment (DPS), and the Arctic stock of ringed seals, have been proposed 
by NMFS for listing as threatened under the ESA (bearded seals: 75 FR 
77496; December 10, 2011; ringed seal: 75 FR 77476; December 10, 2011). 
None of the other species that may occur in the project area are listed 
as threatened or endangered under the ESA or designated as depleted 
under the MMPA.
    Potential impacts to marine mammal habitat were discussed 
previously in this document (see the ``Anticipated Effects on Habitat'' 
section). Although some disturbance is possible to food sources of 
marine mammals, the impacts are anticipated to be minor enough as to 
not affect rates of recruitment or survival of marine mammals in the 
area. Based on the vast size of the Arctic Ocean where feeding by 
marine mammals occurs versus the localized area of the marine survey 
activities, any missed feeding opportunities in the direct project area 
would be minor based on the fact that other feeding areas exist 
elsewhere.
    The estimated takes proposed to be authorized represent 0.13% of 
the Beaufort Sea population of approximately 39,258 beluga whales (or 
1.35% of the Eastern Chukchi Sea population of approximately 3,710 
beluga whales, or a mix of each population; Allen and Angliss 2010), 
1.59% of Aleutian Island and Bering Sea stock of approximately 314 
killer whales, 0.004% of Bering Sea stock of approximately 48,215 
harbor porpoises, 0.02% of the Eastern North Pacific stock of 
approximately 19,126 gray whales, 0.24% of the Bering- Chukchi-Beaufort 
population of 15,232 bowhead whales assuming 3.4 percent annual 
population growth from the estimate of 10,545 animals (Zeh and Punt, 
2005), 0.21% of the Western North Pacific stock of approximately 938 
humpback whales, and 0.20% of the Alaska stock of approximately 1,003 
minke whales. The take estimates presented for bearded, ringed, 
spotted, and ribbon seals represent 0.01, 0.05, 0.03, and 0.0033% of 
U.S. Arctic stocks of each species, respectively. These estimates 
represent the percentage of each species or stock that could be taken 
by Level B behavioral harassment if each animal is taken only once. In 
addition, the mitigation and monitoring measures (described previously 
in this document) proposed for inclusion in the IHA (if issued) are 
expected to reduce even further any potential disturbance 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 mitigation and monitoring 
measures, NMFS preliminarily finds that BP's proposed 2012 OBC seismic 
survey in the Simpson Lagoon of the Alaskan Beaufort Sea may result in 
the incidental take of small numbers of marine mammals, by Level B 
harassment only, and that the total taking from the marine surveys will 
have a negligible impact on the affected species or stocks.

Unmitigable Adverse Impact Analysis and Preliminary Determination

    NMFS has preliminarily determined that BP's proposed 2012 OBC 
seismic survey in the Beaufort Sea will not have an unmitigable adverse 
impact on the availability of species or stocks for taking for 
subsistence uses. This preliminary determination is supported by 
information contained in this document and BP's CAA and draft POC. BP 
has adopted a spatial and temporal strategy for its Simpson Lagoon 
operations that should minimize impacts to subsistence hunters. 
Specifically, the BP's proposed Simpson Lagoon OBC seismic survey would 
occur between July and October open water season, and would terminate 
its operations outside the barrier islands after August 25 before the 
fall bowhead whale hunt. Due to the timing of the project and the 
distance from the surrounding communities (approximately 35 miles 
northeast from Nuiqsut, 35 miles west from Cross Island, 150 miles west 
from Kaktovik and 180 miles east from Barrow), it is anticipated to 
have no effects on spring harvesting and little or no effects on the 
occasional summer harvest of beluga whale, subsistence seal hunts 
(ringed and spotted seals are primarily harvested in winter while 
bearded seals are hunted during July-September in the Beaufort Sea), or 
the fall bowhead hunt.
    In addition, based on the measures described in BP's Draft POC and 
CAA, the proposed mitigation and monitoring measures (described earlier 
in this document), and the project design itself, NMFS has determined 
preliminarily that there will not be an unmitigable adverse impact on 
subsistence uses from BP's OBC seismic survey in the Simpson Lagoon of 
the Beaufort Sea.

Proposed Incidental Harassment Authorization

    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 Authorization is valid from July 1, 2012, through October 
30, 2012.
    (2) This Authorization is valid only for activities associated with 
open-water OBC seismic surveys and related activities in the Beaufort 
Sea. The specific areas where BP's surveys will be conducted are within 
the Simpson Lagoon Area, Beaufort Sea, Alaska, as shown in Figure 1.2 
of BP's IHA application.
    (3)(a) The species authorized for incidental harassment takings, 
Level B harassment only, are: Beluga whales

[[Page 25853]]

(Delphinapterus leucas); harbor porpoises (Phocoena phocoena); killer 
whales (Orcinus orca); bowhead whales (Balaena mysticetus); gray whales 
(Eschrichtius robustus); humpback whales (Megaptera novaeangliae); 
minke whales (Balaenoptera acutorostrata); bearded seals (Erignathus 
barbatus); spotted seals (Phoca largha); ringed seals (P. hispida); and 
ribbon seals (P. fasciata).
    (3)(b) The authorization for taking by harassment is limited to the 
following acoustic sources and from the following activities:
    (i) 640 in\3\ airgun arrays for each of the two main source 
vessels;
    (ii) 320 in\3\ airgun array for one mini source vessels; and
    (ii) Vessel activities related to the OBC seismic surveys.
    (3)(c) The taking of any marine mammal in a manner prohibited under 
this Authorization must be reported within 24 hours of the taking to 
the Alaska Regional Administrator (907-586-7221) or his designee in 
Anchorage (907-271-3023), National Marine Fisheries Service (NMFS) and 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, at (301) 427-8401, or his designee (301-427-8418).
    (4) The holder of this Authorization must notify the Chief of the 
Permits and Conservation Division, Office of Protected Resources, at 
least 48 hours prior to the start of collecting seismic data (unless 
constrained by the date of issuance of this Authorization in which case 
notification shall be made as soon as possible).
    (5) Prohibitions
    (a) The taking, by incidental harassment only, is limited to the 
species listed under condition 3(a) above and by the numbers listed in 
Table 1 (attached). The taking by Level A harassment, injury or death 
of these species or the taking by harassment, injury or death of any 
other species of marine mammal is prohibited and may result in the 
modification, suspension, or revocation of this Authorization.
    (b) The taking of any marine mammal is prohibited whenever the 
required source vessel protected species observers (PSOs), required by 
condition 7(a)(i), are not onboard in conformance with condition 
7(a)(i) of this Authorization.
    (6) Mitigation
    (a) Seismic Operation Mitigation:
    (i) Whenever a marine mammal is detected outside the exclusion zone 
radius and based on its position and motion relative to the ship track 
is likely to enter the exclusion radius, calculate and implement an 
alternative ship speed or track or de-energize the airgun array, as 
described in condition 6(b)(iv) below.
    (ii) Exclusion Zones:
    (A) Establish and monitor with trained PSOs a preliminary exclusion 
zone for cetaceans surrounding the airgun array on the source vessel 
where the received level would be 180 dB re 1 [mu]Pa rms. For purposes 
of the field verification test, described in condition 7(b), this 
radius is estimated to be 750 m (2,460 ft) from the seismic source for 
the 640 in3 airgun arrays, 480 m (1,574 ft) for the 320 in3 airgun 
array, and 59 m (194 ft) for a single 40 in3 airgun for surveys 
conducted inside barrier islands; and 950 m (3,116 ft) for 640 in\3\ 
airgun arrays and less than 50 m (164 ft) for a single 40 in3 airgun 
for surveys conducted outside barrier islands.
    (B) Establish and monitor with trained PSOs a preliminary exclusion 
zone for pinnipeds surrounding the airgun array on the source vessel 
where the received level would be 190 dB re 1 [mu]Pa rms. For purposes 
of the field verification test described in condition 7(b), this radius 
is estimated to be 310 m (1,017 ft) from the seismic source for the 640 
in\3\ airgun arrays, 160 m (525 ft) for the 320 in\3\ airgun array, and 
16 m (53 ft) for the single 40 in\3\ airgun for surveys conducted 
inside barrier islands; and 120 m (394 ft) for 640 in\3\ airgun arrays 
and less than 50 m (164 ft) for a single 40 in\3\ airgun for surveys 
conducted outside barrier islands.
    (C) A 120-dB vessel monitoring zone for four or more bowhead cow/
calf pairs will be established and monitored after August 25, 2012, 
from a monitoring vessel outside the barrier islands during all daytime 
seismic surveys, as described in 7(a)(iv) below. For purposes of the 
field verification test described in condition 7(b), this radius is 
estimated to be 6,400 m (20,992 ft) from the seismic source for the 640 
in\3\ airgun arrays, 5,700 m (18,700 ft) for the 320 in\3\ airgun 
array, and 3,700 m (12,140 ft) for the single 40 in\3\ airgun for 
surveys conducted inside barrier islands.
    (D) Immediately upon completion of data analysis of the field 
verification measurements required under condition 7(b) below, the new 
180-dB and 190-dB marine mammal exclusion zones shall be established 
based on the sound source verification.
    (iii) Ramp-up:
    (A) A ramp up, following a cold start, can be applied if the 
exclusion zone has been free of marine mammals for a consecutive 30-
minute period. The entire exclusion zone must have been visible during 
these 30 minutes. If the entire exclusion zone is not visible, then 
ramp up from a cold start cannot begin.
    (B) Ramp up procedures from a cold start shall be delayed if a 
marine mammal is sighted within the exclusion zone during the 30-minute 
period prior to the ramp up. The delay shall last until the marine 
mammal(s) has been observed to leave the exclusion zone or until the 
animal(s) is not sighted for at least 15 or 30 minutes. The 15 minutes 
applies to small toothed whales and pinnipeds, while a 30 minute 
observation period applies to baleen whales and large toothed whales.
    (C) A ramp up, following a shutdown, can be applied if the marine 
mammal(s) for which the shutdown occurred has been observed to leave 
the exclusion zone or until the animal(s) is not sighted for at least 
15 minutes (small toothed whales and pinnipeds) or 30 minutes (baleen 
whales and large toothed whales).
    (D) If, for any reason, electrical power to the airgun array has 
been discontinued for a period of 10 minutes or more, ramp-up 
procedures shall be implemented. Only if the PSO watch has been 
suspended, a 30-minute clearance of the exclusion zone is required 
prior to commencing ramp-up. Discontinuation of airgun activity for 
less than 10 minutes does not require a ramp-up.
    (E) The seismic operator and PSOs shall maintain records of the 
times when ramp-ups start and when the airgun arrays reach full power.
    (iv) Power-down/Shutdown:
    (A) The airgun array shall be immediately powered down whenever a 
marine mammal is sighted approaching close to or within the applicable 
exclusion zone of the full array, but is outside the applicable 
exclusion zone of the single mitigation airgun.
    (B) If a marine mammal is already within the exclusion zone when 
first detected, the airguns shall be powered down immediately.
    (C) Following a power-down, ramp up to the full airgun array shall 
not resume until the marine mammal has cleared the exclusion zone. The 
animal will be considered to have cleared the exclusion zone if it is 
visually observed to have left the exclusion zone of the full array, or 
has not been seen within the zone for 15 minutes (pinnipeds or small 
toothed whales) or 30 minutes (baleen whales or large toothed whales).
    (D) If a marine mammal is sighted within or about to enter the 190 
or 180 dB (rms) applicable exclusion zone of the single mitigation 
airgun, the airgun array shall be shutdown.
    (E) Whenever more than four or more bowhead cow/calf pairs are 
observed

[[Page 25854]]

within or entering the 120 dB disturbance zone the lead PSO on the 
monitoring vessel will immediately contact the lead PSO on the source 
vessel, who will ensure prompt implementation of airgun power downs or 
shut-downs.
    (F) Airgun activity shall not resume until the marine mammal has 
cleared the exclusion zone of the full array. The animal will be 
considered to have cleared the exclusion zone as described above under 
ramp up procedures.
    (iv) Poor Visibility Conditions:
    (A) If during foggy conditions, heavy snow or rain, or darkness, 
the full 180 dB exclusion zone is not visible, the airguns cannot 
commence a ramp-up procedure from a full shut-down.
    (B) If one or more airguns have been operational before nightfall 
or before the onset of poor visibility conditions, they can remain 
operational throughout the night or poor visibility conditions. In this 
case ramp-up procedures can be initiated, even though the exclusion 
zone may not be visible, on the assumption that marine mammals will be 
alerted by the sounds from the single airgun and have moved away.
    (C) When seismic survey is not underway, BP shall not keep an 
airgun (the so called ``mitigation gun'' in past IHAs) firing for long 
periods of time during darkness or other periods of poor visibility on 
the assumption that marine mammals will be alerted by the sounds from 
the single airgun so that a cold start with pre survey monitoring could 
be avoided.
    (b) Vessel and Helicopter Movement Mitigation:
    (i) Avoid concentrations or groups of whales by all vessels under 
the direction of BP. Operators of support vessels should, at all times, 
conduct their activities at the maximum distance possible from such 
concentrations of whales.
    (ii) Transit and cable laying vessels shall be operated at speeds 
necessary to ensure no physical contact with whales occurs. If any 
barge or transit vessel approaches within 1.6 km (1 mi) of observed 
bowhead whales, except when providing emergency assistance to whalers 
or in other emergency situations, the vessel operator will take 
reasonable precautions to avoid potential interaction with the bowhead 
whales by taking one or more of the following actions, as appropriate:
    (A) Reducing vessel speed to less than 5 knots within 300 yards 
(900 feet or 274 m) of the whale(s);
    (B) Steering around the whale(s) if possible;
    (C) Operating the vessel(s) in such a way as to avoid separating 
members of a group of whales from other members of the group;
    (D) Operating the vessel(s) to avoid causing a whale to make 
multiple changes in direction; and
    (E) Checking the waters immediately adjacent to the vessel(s) to 
ensure that no whales will be injured when the propellers are engaged.
    (iii) When weather conditions require, such as when visibility 
drops, adjust vessel speed accordingly to avoid the likelihood of 
injury to whales.
    (iv) In the event that any aircraft (such as helicopters) are used 
to support the planned survey, the mitigation measures below would 
apply:
    (A) Under no circumstances, other than an emergency, shall aircraft 
be operated at an altitude lower than 1,000 feet above sea level (ASL) 
when within 0.3 mile (0.5 km) of groups of whales.
    (B) Helicopters shall not hover or circle above or within 0.3 mile 
(0.5 km) of groups of whales.
    (c) Mitigation Measures for Subsistence Activities:
    (i) No seismic surveys with airgun operations shall be conducted in 
the area north of the barrier islands after 25 August, 2012.
    (ii) Fully implement the following measures, consistent with the 
2012 Conflict Avoidance Agreement (CAA) and Plan of Cooperation (COP), 
in order to avoid having an unmitigable adverse impact on the 
availability of marine mammal species or stocks for taking for 
subsistence uses:
    (A) For the purposes of reducing or eliminating conflicts between 
subsistence whaling activities and BP's survey program, the holder of 
this Authorization will participate with other operators in the 
Communication and Call Centers (Com-Center) Program. The Com-Centers 
will be operated 24 hours/day during the 2012 fall subsistence bowhead 
whale hunt.
    (B) BP shall routinely call the Com-Center according to the 
established protocol in the CAA while in the Beaufort Sea.
    (C) The appropriate Com-Center shall be notified if there is any 
significant change in plans, such as an unannounced start-up of 
operations or significant deviations from announced course.
    (D) Upon notification by a Com-Center operator of an at-sea 
emergency, the holder of this Authorization shall provide such 
assistance as necessary to prevent the loss of life, if conditions 
allow the holder of this Authorization to safely do so.
    (E) Post-season Review: Following the end of the fall 2012 bowhead 
whale subsistence hunt and prior to the 2013 pre-season introduction 
meetings, BP shall offer to the Alaska Eskimo Whaling Commission (AEWC) 
Chairman to host a joint meeting with all whaling captains of the 
Villages of Nuiqsut, Kaktovik, and Barrow, the Marine Mammal Observer/
Inupiat Communicators stations on BP's vessels in the Beaufort Sea, and 
with the Chairman and Executive Director of the AEWC, at a mutually 
agreed upon time and place on the North Slope of Alaska, to review the 
results of the 2012 Beaufort Sea open-water season, unless it is agreed 
by all designated individuals or their representatives that such a 
meeting is not necessary.
    (7) Monitoring:
    (a) Vessel Monitoring:
    (i) The holder of this Authorization must designate biologically-
trained, on-site individuals (PSOs) to be onboard the source vessel and 
monitoring vessels outside the barrier islands, who are approved in 
advance by NMFS, to conduct the visual monitoring programs required 
under this Authorization and to record the effects of seismic surveys 
and the resulting noise on marine mammals.
    (A) PSO teams shall consist of Inupiat observers and experienced 
field biologists. An experienced field crew leader will supervise the 
PSO team onboard the survey vessel. New observers shall be paired with 
experienced observers to avoid situations where lack of experience 
impairs the quality of observations.
    (B) Crew leaders and most other biologists serving as observers in 
2012 will be individuals with experience as observers during recent 
seismic or shallow hazards monitoring projects in Alaska, the Canadian 
Beaufort, or other offshore areas in recent years.
    (C) PSOs shall complete a two or three-day training session on 
marine mammal monitoring, to be conducted shortly before the 
anticipated start of the 2012 open-water season. The training 
session(s) will be conducted by qualified marine mammalogists with 
extensive crew-leader experience during previous vessel-based 
monitoring programs. A marine mammal observers' handbook, adapted for 
the specifics of the planned survey program, will be reviewed as part 
of the training.
    (D) If there are Alaska Native PSOs, the PSO training that is 
conducted prior to the start of the survey activities shall be 
conducted with both Alaska Native PSOs and biologist PSOs being trained 
at the same time in the same room. There shall not be separate training 
courses for the different PSOs.
    (E) Crew members should not be used as primary PSOs because they 
have

[[Page 25855]]

other duties and generally do not have the same level of expertise, 
experience, or training as PSOs, but they could be stationed on the 
fantail of the vessel to observe the near field, especially the area 
around the airgun array and implement a rampdown or shutdown if a 
marine mammal enters the safety zone (or exclusion zone).
    (F) If crew members are to be used as PSOs, they shall go through 
some basic training consistent with the functions they will be asked to 
perform. The best approach would be for crew members and PSOs to go 
through the same training together.
    (G) PSOs shall be trained using visual aids (e.g., videos, photos), 
to help them identify the species that they are likely to encounter in 
the conditions under which the animals will likely be seen.
    (H) BP shall train its PSOs to follow a scanning schedule that 
consistently distributes scanning effort according to the purpose and 
need for observations. For example, the schedule might call for 60% of 
scanning effort to be directed toward the near field and 40% at the far 
field. All PSOs should follow the same schedule to ensure consistency 
in their scanning efforts.
    (I) PSOs shall be trained in documenting the behaviors of marine 
mammals. PSOs should simply record the primary behavioral state (i.e., 
traveling, socializing, feeding, resting, approaching or moving away 
from vessels) and relative location of the observed marine mammals.
    (ii) To the extent possible, PSOs should be on duty for four (4) 
consecutive hours or less, although more than one four-hour shift per 
day is acceptable.
    (iii) Monitoring is to be conducted by the PSOs onboard the active 
seismic vessel, to (A) ensure that no marine mammals enter the 
appropriate exclusion zone whenever the seismic acoustic sources are 
on, and (B) to record marine mammal activity as described in condition 
7(a)(vii) below. Two PSOs will be present on each seismic source 
vessel. At least one PSO shall monitor for marine mammals at any time 
during daylight hours.
    (iv) Monitoring vessel based surveys outside the barrier islands 
will be conducted up to 3 days per week, weather depending, after 
August 25, 2012, and continue until the end of the data acquisition 
period. One PSO will be present on the monitoring vessel. The 
monitoring effort will be aided by the skipper of the monitoring 
vessel.
    (v) At all times, the crew must be instructed to keep watch for 
marine mammals. If any are sighted, the bridge watch-stander must 
immediately notify the PSO(s) on-watch. If a marine mammal is within or 
closely approaching its designated exclusion zone, the seismic acoustic 
sources must be immediately powered down or shut down (in accordance 
with condition 6(a)(iv) above).
    (vi) Observations by the PSOs on marine mammal presence and 
activity will begin a minimum of 30 minutes prior to the estimated time 
that the seismic source is to be turned on and/or ramped up.
    (vii) All marine mammal observations and any airgun power-down, 
shut-down and ramp-up will be recorded in a standardized format. Data 
will be entered into a custom database using a notebook computer. The 
accuracy of the data entry will be verified by computerized validity 
data checks as the data are entered and by subsequent manual checking 
of the database after each day. These procedures will allow initial 
summaries of data to be prepared during and shortly after the field 
program, and will facilitate transfer of the data to statistical, 
graphical, or other programs for further processing and archiving.
    (viii) Monitoring shall consist of recording: (A) The species, 
group size, age/size/sex categories (if determinable), the general 
behavioral activity, heading (if consistent), bearing and distance from 
seismic vessel, sighting cue, behavioral pace, and apparent reaction of 
all marine mammals seen near the seismic vessel and/or its airgun array 
(e.g., none, avoidance, approach, paralleling, etc); (B) the time, 
location, heading, speed, and activity of the vessel (shooting or not), 
along with sea state, visibility, cloud cover and sun glare at (I) any 
time a marine mammal is sighted (including pinnipeds hauled out on 
barrier islands), (II) at the start and end of each watch, and (III) 
during a watch (whenever there is a change in one or more variable); 
(C) the identification of all vessels that are visible within 5 km of 
the seismic vessel whenever a marine mammal is sighted, and the time 
observed, bearing, distance, heading, speed and activity of the other 
vessel(s); (D) any identifiable marine mammal behavioral response 
(sighting data should be collected in a manner that will not detract 
from the PSO's ability to detect marine mammals); (E) any adjustments 
made to operating procedures; and (F) visibility during observation 
periods so that total estimates of take can be corrected accordingly.
    (ix) BP shall work with its observers to develop a means for 
recording data that does not reduce observation time significantly.
    (x) PSOs shall use the best possible positions for observing (e.g., 
outside and as high on the vessel as possible), taking into account 
weather and other working conditions. PSOs shall carefully document 
visibility during observation periods so that total estimates of take 
can be corrected accordingly.
    (xi) PSOs shall scan systematically with the unaided eye and 7 x 50 
reticle binoculars, supplemented with 20 x 60 image-stabilized Zeiss 
Binoculars or Fujinon 25 x 150 ``Big-eye'' binoculars and night-vision 
equipment (``Generation 3'') when needed.
    (xii) PSOs shall attempt to maximize the time spent looking at the 
water and guarding the exclusion radii. They shall avoid the tendency 
to spend too much time evaluating animal behavior or entering data on 
forms, both of which detract from their primary purpose of monitoring 
the exclusion zone.
    (xiii) Night-vision equipment (Generation 3 binocular image 
intensifiers, or equivalent units) shall be available for use during 
low light hours.
    (xiv) PSOs shall understand the importance of classifying marine 
mammals as ``unknown'' or ``unidentified'' if they cannot identify the 
animals to species with confidence. In those cases, they shall note any 
information that might aid in the identification of the marine mammal 
sighted. For example, for an unidentified mysticete whale, the 
observers should record whether the animal had a dorsal fin.
    (xv) Additional details about unidentified marine mammal sightings, 
such as ``blow only'', mysticete with (or without) a dorsal fin, ``seal 
splash'', etc., shall be recorded.
    (xvi) PSOs on monitoring vessels outside barrier islands shall also 
monitor for the presence and behavior of marine mammals in the offshore 
area projected to be exposed to seismic sounds.
    (b) Sound Source Verification: Using a hydrophone system, the 
holder of this Authorization is required to conduct sound source 
verification tests for seismic airgun array(s) and vessels that are 
involved in the OBC seismic surveys.
    (i) Sound source verification shall consist of distances where 
broadside and endfire directions at which broadband received levels 
reach 190, 180, 170, 160, and 120 dB re 1 [mu]Pa (rms) for the airgun 
array(s). The configurations of airgun arrays shall include at least 
the full array and the operation of a single source that will be used 
during power downs.

[[Page 25856]]

    (ii) The test results shall be reported to NMFS within 5 days of 
completing the test.
    (c) Acoustic Monitoring:
    (i) BP shall use the offshore monitoring vessel to monitor 
(periodically) the propagation of airgun sounds from within the lagoon 
into offshore areas during its marine mammal survey using a dipping 
hydrophone.
    (ii) BP shall use additional acoustic monitoring with bottom 
mounted recorders to verify noise propagation model results. Recorders 
shall be deployed throughout the entire duration of the seismic survey.
    (8) Data Analysis and Presentation in Reports:
    (a) Estimation of potential takes or exposures shall be improved 
for times with low visibility (such as during fog or darkness) through 
interpolation or possibly using a probability approach. Those data 
could be used to interpolate possible takes during periods of 
restricted visibility.
    (b) Water depth should be continuously recorded by the vessel and 
for each marine mammal sighting. Water depth should be accounted for in 
the analysis of take estimates.
    (c) BP shall be very clear in their report about what periods are 
considered ``non-seismic'' for analyses.
    (d) BP shall examine data from Bowhead Whale Aerial Survey Program 
and other such programs to assess possible impacts from their seismic 
survey.
    (e) To better assess impacts to marine mammals, data analysis shall 
be separated into periods when a seismic airgun array (or a single 
mitigation airgun) is operating and when it is not. Final and 
comprehensive reports to NMFS should summarize and plot:
    (i) Data for periods when a seismic array is active and when it is 
not; and
    (ii) The respective predicted received sound conditions over fairly 
large areas (tens of km) around operations.
    (f) To help evaluate the effectiveness of PSOs and more effectively 
estimate take, if appropriate data are available, BP shall perform 
analysis of sightability curves (detection functions) for distance-
based analyses.
    (g) To better understand the potential effects of oil and gas 
activities on marine mammals and to facilitate integration among 
companies and other researchers, the following data should be obtained 
and provided electronically in the 90-day report:
    (i) The location and time of each aerial or vessel-based sighting 
or acoustic detection;
    (ii) Position of the sighting or acoustic detection relative to 
ongoing operations (i.e., distance from sightings to seismic operation, 
drilling ship, support ship, etc.), if known;
    (iii) The nature of activities at the time (e.g., seismic on/off);
    (iv) Any identifiable marine mammal behavioral response (sighting 
data should be collected in a manner that will not detract from the 
PSO's ability to detect marine mammals); and
    (v) Adjustments made to operating procedures.
    (h) BP should improve take estimates and statistical inference into 
effects of the activities by incorporating the following measures:
    (i) Reported results from all hypothesis tests should include 
estimates of the associated statistical power when practicable.
    (ii) Estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available.
    (9) Reporting:
    (a) Sound Source Verification Report: A report on the preliminary 
results of the sound source verification measurements, including the 
measured 190, 180, 160, and 120 dB (rms) radii of the airgun sources, 
shall be submitted within 14 days after collection of those 
measurements at the start of the field season. This report will specify 
the distances of the exclusion zones that were adopted for the survey.
    (b) Seismic Vessel Monitoring Program: A draft report will be 
submitted to the Director, Office of Protected Resources, NMFS, within 
90 days after the end of BP's 2012 open water OBC seismic surveys in 
the Beaufort Seas. The report will describe in detail:
    (i) Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
    (ii) Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
    (iii) Species composition, occurrence, and distribution of marine 
mammal sightings, including date, water depth, numbers, age/size/gender 
categories (if determinable), group sizes, and ice cover;
    (iv) To better assess impacts to marine mammals, data analysis 
should be separated into periods when a seismic airgun array (or a 
single airgun) is operating and when it is not. Final and comprehensive 
reports to NMFS should summarize and plot: (A) Data for periods when a 
seismic array is active and when it is not; and (B) The respective 
predicted received sound conditions over fairly large areas (tens of 
km) around operations.
    (v) Sighting rates of marine mammals during periods with and 
without airgun activities (and other variables that could affect 
detectability), such as: (A) Initial sighting distances versus airgun 
activity state; (B) closest point of approach versus airgun activity 
state; (C) observed behaviors and types of movements versus airgun 
activity state; (D) numbers of sightings/individuals seen versus airgun 
activity state; (E) distribution around the survey vessel versus airgun 
activity state; and (F) estimates of take by harassment.
    (vi) Reported results from all hypothesis tests should include 
estimates of the associated statistical power when practicable.
    (vii) Estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available.
    (viii) The report should clearly compare authorized takes to the 
level of actual estimated takes.
    (c) The draft report will be subject to review and comment by NMFS. 
Any recommendations made by NMFS must be addressed in the final report 
prior to acceptance by NMFS. The draft report will be considered the 
final report for this activity under this Authorization if NMFS has not 
provided comments and recommendations within 90 days of receipt of the 
draft report.
    (10) (a) In the unanticipated event that survey operations clearly 
cause the take of a marine mammal in a manner prohibited by this 
Authorization, such as an injury (Level A harassment), serious injury 
or mortality (e.g., ship-strike, gear interaction, and/or 
entanglement), BP shall immediately cease survey operations and 
immediately report the incident to the Supervisor of Incidental Take 
Program, Permits and Conservation Division, Office of Protected 
Resources, NMFS, at 301-427-8401 and/or by email to 
[email protected] and [email protected] and the Alaska Regional 
Stranding Coordinators ([email protected] and 
[email protected]). The

[[Page 25857]]

report must include the following information:
    (i) Time, date, and location (latitude/longitude) of the incident;
    (ii) The name and type of vessel involved;
    (iii) The vessel's speed during and leading up to the incident;
    (iv) Description of the incident;
    (v) Status of all sound source use in the 24 hours preceding the 
incident;
    (vi) Water depth;
    (vii) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    (viii) Description of marine mammal observations in the 24 hours 
preceding the incident;
    (ix) Species identification or description of the animal(s) 
involved;
    (x) The fate of the animal(s); and
    (xi) Photographs or video footage of the animal (if equipment is 
available).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS shall work with BP to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. BP may not resume their 
activities until notified by NMFS via letter, email, or telephone.
    (b) In the event that BP discovers an injured or dead marine 
mammal, and the lead PSO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
BP will immediately report the incident to the Supervisor of the 
Incidental Take Program, Permits and Conservation Division, Office of 
Protected Resources, NMFS, at 301-427-8401, and/or by email to 
[email protected] and [email protected] and the NMFS Alaska 
Stranding Hotline (1-877-925-7773) and/or by email to the Alaska 
Regional Stranding Coordinators ([email protected] and 
[email protected]). The report must include the same 
information identified in Condition 10(a) above. Activities may 
continue while NMFS reviews the circumstances of the incident. NMFS 
will work with BP to determine whether modifications in the activities 
are appropriate.
    (c) In the event that BP discovers an injured or dead marine 
mammal, and the lead PSO determines that the injury or death is not 
associated with or related to the activities authorized in Condition 3 
of this Authorization (e.g., previously wounded animal, carcass with 
moderate to advanced decomposition, or scavenger damage), BP shall 
report the incident to the Supervisor of the Incidental Take Program, 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
at 301-427-8401, and/or by email to [email protected] and 
[email protected] and the NMFS Alaska Stranding Hotline (1-877-925-
7773) and/or by email to the Alaska Regional Stranding Coordinators 
([email protected] and [email protected]), within 24 hours 
of the discovery. BP shall provide photographs or video footage (if 
available) or other documentation of the stranded animal sighting to 
NMFS and the Marine Mammal Stranding Network. BP can continue its 
operations under such a case.
    (11) Activities related to the monitoring described in this 
Authorization do not require a separate scientific research permit 
issued under section 104 of the Marine Mammal Protection Act.
    (12) The Conflict Avoidance Agreement and the Plan of Cooperation 
outlining the steps that will be taken to cooperate and communicate 
with the native communities to ensure the availability of marine 
mammals for subsistence uses, must be implemented.
    (13) This Authorization may be modified, suspended, or withdrawn if 
the holder fails to abide by the conditions prescribed herein or if the 
authorized taking is having more than a negligible impact on the 
species or stock of affected marine mammals, or if there is an 
unmitigable adverse impact on the availability of such species or 
stocks for subsistence uses.
    (14) A copy of this Authorization and the Incidental Take Statement 
must be in the possession of each seismic vessel operator taking marine 
mammals under the authority of this Incidental Harassment 
Authorization.
    (15) BP is required to comply with the Terms and Conditions of the 
Incidental Take Statement corresponding to NMFS' Biological Opinion.

Endangered Species Act (ESA)

    The bowhead whale and humpback whale are the only marine mammal 
species currently listed as endangered under the ESA that could occur 
during BP's proposed OBC seismic survey during the Arctic open-water 
season. The Beringia DPS of the Alaska stock of bearded seals and the 
Arctic stock of ringed seals are proposed for listing as threatened 
under the ESA. Final decisions concerning the listing of these species 
are expected to be made in summer 2012.
    NMFS' Permits and Conservation Division has initiated consultation 
with NMFS' Protected Resources Division under section 7 of the ESA on 
the issuance of an IHA to BP under section 101(a)(5)(D) of the MMPA for 
this activity. Consultation will be concluded prior to a determination 
on the issuance of an IHA.

National Environmental Policy Act (NEPA)

    NMFS is currently preparing an Environmental Assessment, pursuant 
to NEPA, to determine whether or not this proposed activity may have a 
significant effect on the human environment. This analysis will be 
completed prior to the issuance or denial of the IHA.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
authorize the take of marine mammals incidental to BP's 2012 OBC 
seismic survey in the Simpson Lagoon of the Alaskan Beaufort Sea, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: April 25, 2012.
Helen Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2012-10386 Filed 4-30-12; 8:45 am]
BILLING CODE 3510-22-P