[Federal Register Volume 86, Number 212 (Friday, November 5, 2021)]
[Notices]
[Pages 61160-61163]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-24251]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB461]


Taking and Importing Marine Mammals; Taking Marine Mammals 
Incidental to Geophysical Surveys Related to Oil and Gas Activities in 
the Gulf of Mexico

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

ACTION: Notice of issuance of Letter of Authorization.

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SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA), as 
amended, its implementing regulations, and NMFS' MMPA Regulations for 
Taking Marine Mammals Incidental to Geophysical Surveys Related to Oil 
and Gas Activities in the Gulf of Mexico, notification is hereby given 
that a Letter of Authorization (LOA) has been issued to WesternGeco for 
the take of marine mammals incidental to the Engagement 2 geophysical 
survey activity in the Gulf of Mexico.

DATES: The LOA is effective from January 1, 2022, through April 30, 
2022.

ADDRESSES: The LOA, LOA request, and supporting documentation are 
available online at: www.fisheries.noaa.gov/action/incidental-take-authorization-oil-and-gas-industry-geophysical-survey-activity-gulf-mexico. In case of problems accessing these documents, please call the 
contact listed below (see FOR FURTHER INFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT: Kim Corcoran, 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.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.
    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).
    On January 19, 2021, we issued a final rule with regulations to 
govern the unintentional taking of marine mammals incidental to 
geophysical survey activities conducted by oil and gas industry 
operators, and those persons authorized to conduct activities on their 
behalf (collectively ``industry operators''), in Federal waters of the 
U.S. Gulf of Mexico (GOM) over the course of 5 years (86 FR 5322; 
January 19, 2021). The rule was based on our findings that the total 
taking from the specified activities over the 5-year period will have a 
negligible impact on the affected species or stock(s) of marine mammals 
and will not have an unmitigable adverse impact on the availability of 
those species or stocks for subsistence uses. The rule became effective 
on April 19, 2021.
    Our regulations at 50 CFR 217.180 et seq. allow for the issuance of 
LOAs to industry operators for the incidental take of marine mammals 
during geophysical survey activities and prescribe the permissible 
methods of taking and other means of effecting the least practicable 
adverse impact on marine mammal species or stocks and their habitat 
(often referred to as mitigation), as well as requirements pertaining 
to the monitoring and reporting of such taking. Under 50 CFR 
217.186(e), issuance of an LOA shall be based on a determination that 
the level of taking will be consistent with the findings made for the 
total taking allowable under these regulations and a determination that 
the amount of take authorized under the LOA is of no more than small 
numbers.

Summary of Request and Analysis

    WesternGeco plans to conduct a long offset sparse 3D ocean bottom 
node (OBN) survey using airgun arrays as a sound source within the 
Green Canyon protraction area. Sparse OBN surveys reduce receiver 
spacing and use dense shots to provide full-azimuth/offset data with 
uniform sampling in the azimuth/offset (the distance from the source to 
the receiver) domain (Olofsson et al., 2012). WesternGeco's sound 
source consists of a 28-element, 5,200 cubic inch (in\3\) airgun array. 
The survey will use two source vessels, each towing three sources at a 
crossline distance of 100 meters (m) and firing every 8 seconds. Please 
see WesternGeco's application for additional information.
    Consistent with the preamble to the final rule, the survey effort 
proposed by WesternGeco in its LOA request was used to develop LOA-
specific take estimates based on the acoustic exposure modeling results 
described in the preamble (86 FR 5322, 5398; January 19, 2021). In 
order to generate the appropriate take number for authorization, the 
following information was considered: (1) Survey type; (2)

[[Page 61161]]

location (by modeling zone \1\); (3) number of days; and (4) season.\2\ 
The acoustic exposure modeling performed in support of the rule 
provides 24-hour exposure estimates for each species, specific to each 
modeled survey type in each zone and season.
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    \1\ For purposes of acoustic exposure modeling, the GOM was 
divided into seven zones. Zone 1 is not included in the geographic 
scope of the rule.
    \2\ For purposes of acoustic exposure modeling, seasons include 
Winter (December-March) and Summer (April-November).
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    No 3D OBN surveys were included in the modeled survey types, and 
use of existing proxies (i.e., 2D, 3D NAZ, 3D WAZ, Coil) is generally 
conservative for use in evaluation of 3D OBN survey effort, largely due 
to the greater area covered by the modeled proxies. Summary 
descriptions of these modeled survey geometries are available in the 
preamble to the proposed rule (83 FR 29212, 29220; June 22, 2018). Coil 
was selected as the best available proxy survey type because it most 
closely resembles sparse OBN, in that both methods use efficient 
acquisition methodology to acquire Full Azimuth and long offset data to 
provide better imaging of the sub-surface geological structures. 
Additionally, the Coil survey pattern was assumed to cover 
approximately 144 kilometers squared (km\2\) per day (compared with 
approximately 795 km\2\, 199 km\2\, and 845 km\2\ per day for the 2D, 
3D NAZ, and 3D WAZ survey patterns, respectively). Among the different 
parameters of the modeled survey patterns (e.g., area covered, line 
spacing, number of sources, shot interval, total simulated pulses), 
NMFS considers area covered per day to be most influential on daily 
modeled exposures exceeding Level B harassment criteria. Although 
WesternGeco is not proposing specifically to perform a survey using the 
coil geometry, its planned 3D OBN survey is expected to cover 
approximately 62.5 km\2\ per day, meaning that the coil proxy is most 
representative of the effort planned by WesternGeco in terms of 
predicted Level B harassment exposures.
    In addition, all available acoustic exposure modeling results 
assume use of a 72 element, 8,000 in\3\ array. In this case, take 
numbers authorized through this LOA are considered conservative due to 
differences in both the airgun array (28 elements, 5,200 in\3\) and the 
daily survey area planned by WesternGeco (62.5 km\2\), as compared to 
those modeled for the rule.
    The survey is planned to occur for 48 days in Zone 5. Take 
estimates for each species, except for sperm whales, are based on the 
winter season, which produces a greater value for these species. For 
sperm whales, greater values are produced in the summer season. Since 
the survey could potentially include up to 30 days in the summer 
season, sperm whale take estimates were calculated for 30 days in the 
summer season and 18 days in the winter season. Together, this produces 
the most conservative take estimate for sperm whales.
    For some species, take estimates based solely on the modeling 
yielded results that are not realistically likely to occur when 
considered in light of other relevant information available during the 
rulemaking process regarding marine mammal occurrence in the GOM. Thus, 
although the modeling conducted for the rule is a natural starting 
point for estimating take, our rule acknowledged that other information 
could be considered (see, e.g., 86 FR 5322, 5442 (January 19, 2021), 
discussing the need to provide flexibility and make efficient use of 
previous public and agency review of other information and identifying 
that additional public review is not necessary unless the model or 
inputs used differ substantively from those that were previously 
reviewed by NMFS and the public). For this survey, NMFS has other 
relevant information reviewed during the rulemaking that indicates use 
of the acoustic exposure modeling to generate a take estimate for 
certain marine mammal species produces results inconsistent with what 
is known regarding their occurrence in the GOM. Accordingly, we have 
adjusted the calculated take estimates for those species as described 
below.
    Rice's whales (formerly known as GOM Bryde's whales) \3\ are 
generally found within a small area in the northeastern GOM in waters 
between 100-400 m depth along the continental shelf break (Rosel et 
al., 2016). Whaling records suggest that Rice's whales historically had 
a broader distribution within similar habitat parameters throughout the 
GOM (Reeves et al., 2011; Rosel and Wilcox, 2014), and a NOAA survey 
reported observation of a Rice's whale in the western GOM in 2017 
(NMFS, 2018). Habitat-based density modeling identified similar habitat 
(i.e., approximately 100-400 m water depths along the continental shelf 
break) as being potential Rice's whale habitat (Roberts et al., 2016), 
although a ``core habitat area'' defined in the northeastern GOM 
(outside the scope of the rule) contained approximately 92 percent of 
the predicted abundance of Rice's whales. See discussion provided at, 
e.g., 83 FR 29212, 29228, 29280 (June 22, 2018); 86 FR 5322, 5418 
(January 19, 2021).
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    \3\ The final rule refers to the GOM Bryde's whale (Balaenoptera 
edeni). These whales were subsequently described as a new species, 
Rice's whale (Balaenoptera ricei) (Rosel et al., 2021).
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    Although it is possible that Rice's whales may occur outside of 
their core habitat, NMFS expects that any such occurrence would be 
limited to the narrow band of suitable habitat described above (i.e., 
100-400 m). WesternGeco's planned activity will occur in water depths 
of approximately 600-2,000 m in the central GOM. Thus, NMFS does not 
expect there to be the reasonable potential for take of Rice's whale in 
association with this survey and, accordingly, does not authorize take 
of Rice's whale through this LOA.
    Killer whales are the most rarely encountered species in the GOM, 
typically in deep waters of the central GOM (Roberts et al., 2015; 
Maze-Foley and Mullin, 2006). The approach used in the acoustic 
exposure modeling, in which seven modeling zones were defined over the 
U.S. GOM, necessarily averages fine-scale information about marine 
mammal distribution over the large area of each modeling zone. NMFS has 
determined that the approach results in unrealistic projections 
regarding the likelihood of encountering killer whales.
    As discussed in the final rule, the density models produced by 
Roberts et al. (2016) provide the best available scientific information 
regarding predicted density patterns of cetaceans in the U.S. GOM. The 
predictions represent the output of models derived from multi-year 
observations and associated environmental parameters that incorporate 
corrections for detection bias. However, in the case of killer whales, 
the model is informed by few data, as indicated by the coefficient of 
variation associated with the abundance predicted by the model (0.41, 
the second-highest of any GOM species model; Roberts et al., 2016). The 
model's authors noted the expected non-uniform distribution of this 
rarely-encountered species (as discussed above) and expressed that, due 
to the limited data available to inform the model, it ``should be 
viewed cautiously'' (Roberts et al., 2015).
    NOAA surveys in the GOM from 1992-2009 reported only 16 sightings 
of killer whales, with an additional 3 encounters during more recent 
survey effort from 2017-18 (Waring et al., 2013; www.boem.gov/gommapps). Two other species were also observed on less than 20 
occasions during the 1992-2009 NOAA surveys (Fraser's dolphin and

[[Page 61162]]

false killer whale \4\). However, observational data collected by 
protected species observers (PSOs) on industry geophysical survey 
vessels from 2002-2015 distinguish the killer whale in terms of rarity. 
During this period, killer whales were encountered on only 10 
occasions, whereas the next most rarely encountered species (Fraser's 
dolphin) was recorded on 69 occasions (Barkaszi and Kelly, 2019). The 
false killer whale and pygmy killer whale were the next most rarely 
encountered species, with 110 records each. The killer whale was the 
species with the lowest detection frequency during each period over 
which PSO data were synthesized (2002-2008 and 2009-2015). This 
information qualitatively informed our rulemaking process, as discussed 
at 86 FR 5322, 5334 (January 19, 2021), and similarly informs our 
analysis here.
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    \4\ However, note that these species have been observed over a 
greater range of water depths in the GOM than have killer whales.
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    The rarity of encounter during seismic surveys is not likely to be 
the product of high bias on the probability of detection. Unlike 
certain cryptic species with high detection bias, such as Kogia spp. or 
beaked whales, or deep-diving species with high availability bias, such 
as beaked whales or sperm whales, killer whales are typically available 
for detection when present and are easily observed. Roberts et al. 
(2015) stated that availability is not a major factor affecting 
detectability of killer whales from shipboard surveys, as they are not 
a particularly long-diving species. Baird et al. (2005) reported that 
mean dive durations for 41 fish-eating killer whales for dives greater 
than or equal to 1 minute in duration was 2.3-2.4 minutes, and Hooker 
et al. (2012) reported that killer whales spent 78 percent of their 
time at depths between 0-10 m. Similarly, Kvadsheim et al. (2012) 
reported data from a study of four killer whales, noting that the 
whales performed 20 times as many dives to 1-30 m depth than to deeper 
waters, with an average depth during those most common dives of 
approximately 3 m.
    In summary, killer whales are the most rarely encountered species 
in the GOM and typically occur only in particularly deep water. While 
this information is reflected through the density model informing the 
acoustic exposure modeling results, there is relatively high 
uncertainty associated with the model for this species, and the 
acoustic exposure modeling applies mean distribution data over areas 
where the species is in fact less likely to occur. NMFS' determination 
in reflection of the data discussed above, which informed the final 
rule, is that use of the generic acoustic exposure modeling results for 
killer whales would result in high estimated take numbers that are 
inconsistent with the assumptions made in the rule regarding expected 
killer whale take (86 FR 5322, 5403; January 19, 2021).
    In past authorizations, NMFS has often addressed situations 
involving the low likelihood of encountering a rare species such as 
killer whales in the GOM through authorization of take of a single 
group of average size (i.e., representing a single potential 
encounter). See 83 FR 63268, December 7, 2018. See also 86 FR 29090, 
May 28, 2021; 85 FR 55645, September 9, 2020. For the reasons expressed 
above, NMFS determined that a single encounter of killer whales is more 
likely than the model-generated estimates and has authorized take 
associated with a single killer whale group encounter (i.e., up to 7 
animals).
    Based on the results of our analysis, NMFS has determined that the 
level of taking authorized through the LOA is consistent with the 
findings made for the total taking allowable under the regulations. See 
Table 1 in this notice and Table 9 of the rule (86 FR 5322; January 19, 
2021).

Small Numbers Determination

    Under the GOM rule, NMFS may not authorize incidental take of 
marine mammals in an LOA if it will exceed ``small numbers.'' In short, 
when an acceptable estimate of the individual marine mammals taken is 
available, if the estimated number of individual animals taken is up 
to, but not greater than, one-third of the best available abundance 
estimate, NMFS will determine that the numbers of marine mammals taken 
of a species or stock are small. For more information please see NMFS' 
discussion of the MMPA's small numbers requirement provided in the 
final rule (86 FR 5322, 5438; n the January 19, 2021).
    The take numbers for authorization are determined as described 
above in the Summary of Request and Analysis section. Subsequently, the 
total incidents of harassment for each species are multiplied by scalar 
ratios to produce a derived product that better reflects the number of 
individuals likely to be taken within a survey (as compared to the 
total number of instances of take), accounting for the likelihood that 
some individual marine mammals may be taken on more than one day (see 
86 FR 5322, 5404; January 19, 2021). The output of this scaling, where 
appropriate, is incorporated into an adjusted total take estimate that 
is the basis for NMFS' small numbers determination, as depicted in 
Table 1 for WesternGeco's 48-day survey.
    This product is used by NMFS in making the necessary small numbers 
determination, through comparison with the best available abundance 
estimates (see discussion at 86 FR 5322, 5391; January 19, 2021). For 
this comparison, NMFS' approach is to use the maximum theoretical 
population, determined through review of current stock assessment 
reports (SAR; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and model-predicted abundance 
information (https://seamap.env.duke.edu/models/Duke/GOM/). For the 
latter, for taxa where a density surface model could be produced, we 
use the maximum mean seasonal (i.e., 3-month) abundance prediction for 
purposes of comparison as a precautionary smoothing of month-to-month 
fluctuations and in consideration of a corresponding lack of data in 
the literature regarding seasonal distribution of marine mammals in the 
GOM. Information supporting the small numbers determinations is 
provided in Table 1.

                                             Table 1--Take Analysis
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                                                    Authorized      Scaled take                       Percent
                     Species                           take             \1\        Abundance \2\     abundance
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Rice's whale....................................               0               0              51             0.0
Kogia sp \3\....................................             477             170           4,373             3.9
Beaked whales...................................           5,572             563           3,768            14.9
Bottlenose dolphin..............................           4,540           1,303         176,108             0.7

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Short-finned pilot whale........................             512             151           1,981             7.6
Sperm whale.....................................           1,258             532           2,207            24.1
Atlantic spotted dolphin........................           1,813             520          74,785             0.7
Clymene dolphin.................................           2,696             774          11,895             6.5
False killer whale..............................             663             196           3,204             6.1
Fraser's dolphin................................             303              87           1,665             5.2
Killer whale....................................               7             N/A             267             2.6
Melon-headed whale..............................           1,771             523           7,003             7.5
Pantropical spotted dolphin.....................          12,235            3511         102,361             3.4
Pygmy killer whale..............................             417             123           2,126             5.8
Risso's dolphin.................................             792             234           3,764             6.2
Rough-toothed dolphin...........................             958             275           4,853             5.7
Spinner dolphin.................................           3,278             941          25,114             3.7
Striped dolphin.................................           1,053             302           5,229             5.8
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\1\ Scalar ratios were applied to ``Authorized Take'' values as described at 86 FR 5322, 5404 (January 19, 2021)
  to derive scaled take numbers shown here.
\2\ Best abundance estimate. For most taxa, the best abundance estimate for purposes of comparison with take
  estimates is considered here to be the model-predicted abundance (Roberts et al., 2016). For those taxa where
  a density surface model predicting abundance by month was produced, the maximum mean seasonal abundance was
  used. For those taxa where abundance is not predicted by month, only mean annual abundance is available. For
  the killer whale, the larger estimated SAR abundance estimate is used.
\3\ Includes 25 takes by Level A harassment and 452 takes by Level B harassment. Scalar ratio is applied to
  takes by Level B harassment only; small numbers determination made on basis of scaled Level B harassment take
  plus authorized Level A harassment take.

    Based on the analysis contained herein of WesternGeco's proposed 
survey activity described in its LOA application and the anticipated 
take of marine mammals, NMFS finds that small numbers of marine mammals 
will be taken relative to the affected species or stock sizes and 
therefore is of no more than small numbers.

Authorization

    NMFS has determined that the level of taking for this LOA request 
is consistent with the findings made for the total taking allowable 
under the incidental take regulations and that the amount of take 
authorized under the LOA is of no more than small numbers. Accordingly, 
we have issued an LOA to WesternGeco authorizing the take of marine 
mammals incidental to its geophysical survey activity, as described 
above.

    Dated: November 2, 2021.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2021-24251 Filed 11-4-21; 8:45 am]
BILLING CODE 3510-22-P