[Federal Register Volume 88, Number 163 (Thursday, August 24, 2023)]
[Notices]
[Pages 57943-57945]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-18220]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD270]


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 ExxonMobil 
Corporation (ExxonMobil) for the take of marine mammals incidental to 
geophysical survey activity in the Gulf of Mexico.

DATES: The LOA is effective from August 18, 2023, through April 1, 
2026.

ADDRESSES: The LOA, LOA request, and supporting documentation are 
available online at: https://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: Ben Laws, 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 U.S. waters of the 
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

    ExxonMobil plans to conduct well appraisal and high-resolution 
engineering geophysical surveys associated with its federal lease 
blocks within the High Island and Galveston areas. See Figure 1 of the 
LOA application for a map of the area.
    ExxonMobil anticipates using a daily contingent of from one to 
three source

[[Page 57944]]

vessels, depending on the survey stage and ongoing survey requirements. 
Surveys may be conducted 24 hours per day, but in some instances in 
shallow water areas will only be conducted for 12 hours per day. 
Depending on the survey objective, source vessels will tow a Sercel G-
Source II dual airgun array of 80 to 150 cubic inches (in\3\), or may 
be outfitted with sources such as a multibeam echosounder, side scan 
sonar, and sparker system (e.g., Geo-Source 200-400). During survey 
effort using non-airgun sources, only the sparker source has the 
potential to cause incidental take of marine mammals. Please see 
ExxonMobil's application for additional detail.
    Consistent with the preamble to the final rule, the survey effort 
proposed by ExxonMobil 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 5398, January 19, 2021). In order to 
generate the appropriate take numbers 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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    Summary descriptions of modeled survey geometries (i.e., 2D, 3D 
NAZ, 3D WAZ, Coil) are available in the preamble to the proposed rule 
(83 FR 29220, June 22, 2018). In addition, surveys using single airguns 
and high-resolution geophysical sources were also modeled. The single 
airgun was selected as the best available proxy survey type in this 
case, as ExxonMobil plans to conduct survey effort using two single 
airguns or, alternatively, a sparker system. Although no sparkers were 
modeled, use of the single airgun as a proxy source is conservative.
    The survey will take place over approximately 338 days, within Zone 
3 and adjacent state waters. The seasonal distribution of survey days 
is not known in advance. Therefore, the take estimates for each species 
are based on the season that produces the greater value.
    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. Thus, although the modeling conducted for 
the rule is a natural starting point for estimating take, the rule 
acknowledged that other information could be considered (e.g., 86 FR 
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.
    In this case, use of the exposure modeling produces results that 
are smaller than average GOM group sizes for two species (Maze-Foley 
and Mullin, 2006). NMFS' typical practice in such a situation is to 
increase exposure estimates to the assumed average group size for a 
species in order to ensure that, if the species is encountered, 
exposures will not exceed the authorized take number. However, other 
relevant considerations here lead to a determination that increasing 
the estimated exposures to average group sizes would likely lead to an 
overestimate of actual potential take. In this circumstance, the 
generally shallow depths (5-50 feet (1.5-15.2 meters)) associated with 
the survey and relatively small Level B harassment isopleths produced 
through use of the single airguns or sparker systems mean that it is 
unlikely that certain species would be encountered at all, much less 
that the encounter would result in exposure of a greater number of 
individuals than is estimated through use of the exposure modeling 
results. As a result, in this case NMFS has not increased the estimated 
exposure values to assumed average group sizes in authorizing take.
    Based on the results of our analysis, NMFS has determined that the 
level of taking expected for this survey and 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 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 1 day (see 86 
FR 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 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; https://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

[[Page 57945]]

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.....................................               0             n/a           2,207             n/a
Kogia spp.......................................               0             n/a           4,373             n/a
Beaked whales...................................               0             n/a           3,768             n/a
Rough-toothed dolphin...........................             137            39.2           4,853             0.8
Bottlenose dolphin..............................           4,756         1,364.9         176,108             0.8
Clymene dolphin.................................               0             n/a          11,895             n/a
Atlantic spotted dolphin........................           1,685             n/a          74,785             n/a
Pantropical spotted dolphin.....................               0             n/a         102,361             n/a
Spinner dolphin.................................               0             n/a          25,114             n/a
Striped dolphin.................................               0             n/a           5,229             n/a
Fraser's dolphin................................           \3\ 1             0.2           1,665             0.0
Risso's dolphin.................................               0             n/a           3,764             n/a
Melon-headed whale..............................               0             n/a           7,003             n/a
Pygmy killer whale..............................               0             n/a           2,126             n/a
False killer whale..............................           \3\ 5             1.3           3,204             0.0
Killer whale....................................               0             n/a             267             n/a
Short-finned pilot whale........................               0             n/a           1,981             n/a
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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
  Rice's whale and the killer whale, the larger estimated SAR abundance estimate is used.
\3\ Modeled exposure estimate less than assumed average group size (Maze-Foley and Mullin, 2006).

    Based on the analysis contained herein of ExxonMobil'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 (i.e., 
less than one-third of the best available abundance estimate) and 
therefore the taking 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 ExxonMobil authorizing the take of marine 
mammals incidental to its geophysical survey activity, as described 
above.

    Dated: August 21, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-18220 Filed 8-23-23; 8:45 am]
BILLING CODE 3510-22-P