[Federal Register Volume 88, Number 22 (Thursday, February 2, 2023)]
[Notices]
[Pages 7080-7084]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-02123]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC592]


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

[[Page 7081]]

of Authorization (LOA) has been issued to Chevron U.S.A. Inc. (Chevron) 
for the take of marine mammals incidental to geophysical survey 
activity in the Gulf of Mexico.

DATES: The LOA is effective from April 20, 2023, through November 30, 
2023.

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: Rachel Wachtendonk, 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

    Chevron plans to conduct a 3D borehole seismic survey using an 
airgun array as the sound source, covering portions of approximately 30 
lease blocks centered around Lease Block G16942 (Big Foot). The survey 
is a type of vertical seismic profile (VSP) survey. The array consists 
of 32 elements, with a total volume of 5,040 cubic inches (in\3\). 
Please see Chevron's application for additional detail.
    Consistent with the preamble to the final rule, the survey effort 
proposed by Chevron 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) 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 VSP 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 these survey types. 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 the 
spatial coverage of the planned survey is most similar to that 
associated with the coil survey pattern.
    The planned 3D VSP survey will involve one source vessel sailing a 
racetrack pattern along survey lines approximately 100 m apart and 23 
km in length. The coil survey pattern in the model 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 
Chevron is not proposing to perform a survey using the coil geometry, 
its planned VSP survey is expected to cover approximately 19.2 km\2\ 
per day, meaning that the coil proxy is most representative of the 
effort planned by Chevron 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. Thus, take numbers 
authorized through the LOA are considered conservative due to 
differences in both the airgun array (32 elements, 5,040 in\3\) and the 
daily survey area planned by Chevron (19.2 km\2\), as compared to those 
modeled for the rule.
    The survey is planned to occur for 23 days, with 11 days occurring 
in Zone 5 and 12 days in Zone 7. The season is defined as summer.

[[Page 7082]]

    Additionally, 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. 
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. This can result in unrealistic projections 
regarding the likelihood of encountering particularly rare species and/
or species not expected to occur outside particular habitats. 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 that are 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.
    NMFS' final rule described a ``core habitat area'' for Rice's 
whales (formerly known as GOM Bryde's whales) \3\ located in the 
northeastern GOM in waters between 100-400 m depth along the 
continental shelf break (Rosel et al., 2016). However, 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). In addition, 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 the core habitat 
area contained approximately 92 percent of the predicted abundance of 
Rice's whales. See discussion provided at, e.g., 83 FR 29228, 83 FR 
29280 (June 22, 2018); 86 FR 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 Rice's whales may occur outside of the core habitat area, 
we expect that any such occurrence would be limited to the narrow band 
of suitable habitat described above (i.e., 100-400 m) and that, based 
on the few available records, these occurrences would be rare. 
Chevron's planned activities will occur in water depths of 
approximately 1,000-3,000 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 the 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). 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 
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 three 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 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. This 
survey would take place in deep waters that would overlap with the 
depths that the GOM killer whales typically occur. However, due to the 
short duration of the survey (23 days) and the relatively small 
geographic area it will cover in relation to suitable deep water 
habitat for killer whales, it is unlikely that killer whales would be 
encountered. 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. In addition, 
as noted above in relation to the general take estimation methodology, 
the assumed proxy source (72-element, 8,000-in\3\ array) results in a 
significant overestimate of the actual

[[Page 7083]]

potential for take to occur. NMFS' determination in reflection of the 
information discussed above, which informed the final rule, is that use 
of the generic acoustic exposure modeling results for killer whales for 
this survey would result in 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 Chevron's survey, use 
of the exposure modeling produces an estimate of 12 killer whale 
exposures. Given the foregoing discussion, it is unlikely that even one 
killer whale would be encountered during this 23 day survey, and 
accordingly, no take of killer whales is authorized through the LOA.
    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 for 
the affected species or stocks of marine mammals. 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, 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 adjusted total take estimates that 
are the basis for NMFS' small numbers determinations, as depicted in 
Table 1.
    This product is used by NMFS in making the necessary small numbers 
determinations 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             n/a              51             n/a
Sperm whale.....................................             347           146.6           2,207             6.6
Kogia spp.......................................         \3\ 136            40.8           4,373             1.1
Beaked whales...................................           1,761           177.9           3,768             4.7
Rough-toothed dolphin...........................             302            86.8           4,853             1.8
Bottlenose dolphin..............................             980           281.4         176,108             0.2
Clymene dolphin.................................             817           234.4          11,895             2.0
Atlantic spotted dolphin........................             403           115.5          74,785             0.2
Pantropical spotted dolphin.....................           4,948         1,419.9         102,361             1.4
Spinner dolphin.................................             767           220.1          25,114             0.9
Striped dolphin.................................             349           100.1           5,229             1.9
Fraser's dolphin................................             108            30.9           1,665             1.9
Risso's dolphin.................................             210            62.1           3,764             1.6
Melon-headed whale..............................             555           163.7           7,003             2.3
Pygmy killer whale..............................             167            49.2           2,126             2.3
False killer whale..............................             231            68.2           3,204             2.1
Killer whale....................................               0             n/a             267             n/a
Short-finned pilot whale........................             128            37.8           1,981             1.9
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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 Rice's whale and killer whale, the larger estimated SAR abundance estimate is used.
\3\ Includes 9 takes by Level A harassment and 127 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 Chevron'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

[[Page 7084]]

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 Chevron authorizing the take of marine mammals 
incidental to its geophysical survey activity, as described above.

    Dated: January 27, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-02123 Filed 2-1-23; 8:45 am]
BILLING CODE 3510-22-P