2024-24889. Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to SouthCoast Wind Energy Marine Site Characterization Surveys Off the Coast of Massachusetts and Rhode Island

Table 1—Geophysical Surveys Completed in 2023-2024 and Tracklines Remaining

[In Km]

Location	IHA trackline planned 2023-2024	Total trackline completed 2023-2024	Planned trackline 2024-2025
ECC—Potential HDD	750	0	a  200
Lease Area—Inter-array Cable	1,950	718	a  500
a  The length of the planned trackline is reduced from the original scope described for 2023 IHA.

The potential impacts of SouthCoast Wind's planned activities on marine mammals involve potential acoustic stressors and are unchanged from the impacts described in the Federal Register notices for the 2021 IHA (86 FR 27393, May 20, 2021; 86 FR 38033, July 19, 2021). Underwater sound, resulting from particular components of SouthCoast Wind's HRG survey activities, has the potential to result in incidental take of marine mammals, in the form of Level B harassment only, in the specified geographic region. This renewal IHA is for a subset of the work that was not completed by the expiration date of the initial IHA. The renewal IHA authorizes incidental take, by Level B harassment only, of 15 species (comprising 15 stocks) of marine mammals for a subset of marine site characterization survey activities to be completed in less than 1 year ( i.e., by May 11, 2025), in the same general area, using survey methods identical to those conducted under the initial IHA. Neither SouthCoast Wind nor NMFS expects serious injury or mortality to result from this activity and, therefore, an IHA is appropriate. Take by Level A harassment (injury) is unlikely, even absent mitigation, based on the characteristics of the signals produced by the acoustic sources planned for use. Therefore, the anticipated effects on marine mammals and the affected stocks also remain the same. All mitigation, monitoring, and reporting measures would remain exactly as required by the initial IHA (88 FR 31678, May 18, 2023).

Detailed Description of the Activity

A detailed description of the marine site characterization survey activities for which incidental take is authorized here may be found in the Federal Register notices for the 2021 IHA (86 FR 27393, May 20, 2021; 86 FR 38033, July 19, 2021). The specific geographic region, survey location, specified activities, including the types of survey equipment and number of survey vessels planned for use, are identical to those described in these previous notices, with the exception that the scale of work is reduced. Only a subset of the planned HRG work was completed under the 2023 IHA (88 FR 14335, March 8, 2023; 88 FR 31678, May 18, 2023). Between May 18 and July 10, 2023, a total of 55 survey days and 718 km (446 mi) of tracklines were completed. SouthCoast Wind proposes to conduct a subset (700 km (435 mi)) of the tracklines that were not completed prior to the expiration of the 2023 IHA (table 1).

Description of Marine Mammals

A description of the marine mammals in the area of the activities for which authorization of take is proposed here, including information on abundance, status, distribution, and hearing, may be found in the Federal Register notices of the proposed IHAs for the previous authorizations (86 FR 27393, May 20, 2021; 88 FR 14335, March 8, 2023). Since the publication of the final Federal Register notice (88 FR 31678, May 18, 2023), NMFS has reviewed the monitoring data from the prior IHA, the draft 2023 Stock Assessment Report (SAR), which included updates to certain stock abundances since the 2023 IHA was issued, information on relevant Unusual Mortality Events (UME), and other scientific literature.

The draft 2023 SAR updated the population estimate (Nbest) of North Atlantic right whales (NARW) from 338 to 340 and annual mortality and serious injury from 31.2 to 27.2. The updated population estimate in the draft 2023 SAR is based upon sighting history through December 2021 (89 FR 5495, January 29, 2024). Total annual average observed NARW mortality during the period 2017-2021 was 7.1 animals and annual average observed fishery mortality was 4.6 animals, however, ( print page 85159) estimates of 27.2 total mortality and 17.6 fishery mortality account for undetected mortality and serious injury (89 FR 5495, January 29, 2024). In October 2023, NMFS released a technical report identifying that the NARW population size based on sighting history through 2022 was 356 whales, with a 95 percent credible interval ranging from 346 to 363 (Linden, 2023).

The draft 2023 SARs include updates for additional marine mammal species and stocks ( i.e., NARW, fin whale, sei whale, minke whale, sperm whale, Atlantic spotted dolphin, Atlantic white-sided dolphin, bottlenose dolphin (Western North Atlantic—Offshore stock), common dolphin, long-finned pilot whales, Risso's dolphin, harbor porpoise, and gray seal), which are described in table 2 of the Federal Register notice proposing this renewal IHA (89 FR 76796, September 19, 2024). For species for which there has been no change between the finalization of the final 2022 SARs to the release of the draft 2023 SARs, NMFS has noted that below.

Potential Effects on Marine Mammals and Their Habitat

A description of the potential effects of the specified activity on marine mammals and their habitat for the activities for which take is authorized may be found in the Federal Register notices for the 2021 IHA (86 FR 11930, March 1, 2021; 86 FR 27393, May 20, 2021; 86 FR 38033, July 19, 2021) and are incorporated by reference in the 2023 IHA (88 FR 14335, March 8, 2023; 88 FR 31678, May 18, 2023). NMFS has reviewed the monitoring data from the initial 2023 IHA, recent draft SARs, information on relevant UMEs, other scientific literature, and public comments, and determined that there is no new information that affects our initial analysis of impacts on marine mammals and their habitat.

Estimated Take

A detailed description of the methods and inputs used to estimate take for the specified activity is found in the Federal Register notices for the 2021 IHA (86 FR 11930, March 1, 2021; 86 FR 27393, May 20, 2021; 86 FR 38033, July 19, 2021), and is incorporated by reference in both the proposed 2023 IHA (the initial authorization) (88 FR 14335, March 8, 2023), and the proposed renewal IHA (89 FR 76796, September 19, 2024). The applicable source levels and marine mammal density/occurrence data used to estimate take remain unchanged from those used in support of the initial IHA. Similarly, the stocks taken, methods of take, and types of take remain unchanged from the initial IHA. The number of takes authorized in this renewal IHA are a subset of the initial authorized takes that better represent the amount of activity that SouthCoast Wind has left to complete. These estimated takes, which reflect the remaining survey days, are indicated below in table 2.

Table 2—Number of Authorized Takes, by Level B Harassment, and Percentages of Each Stock Abundance for the 2024-2025 Survey Period

Species	NMFS stock abundance	Combined density based calculated takes	Authorized takes	Percentage of stock abundance
NARW	340	1.2	a  2	0.59
Fin whale	6,802	0.5	c  3	0.04
Sei whale	6,292	0.3	a  2	0.03
Minke whale	21,968	2.7	3	0.02
Humpback whale	1,396	0.5	b  11	0.86
Sperm whale	5,895	0.1	a  2	0.03
Atlantic white-sided dolphin	93,233	5.8	a  28	0.03
Atlantic spotted dolphin	31,506	1.0	a  29	0.09
Common bottlenose dolphin	64,587	3.0	b  31	0.05
Long finned pilot whale	39,215	0.4	a  8	0.02
Risso's dolphin	44,067	0.5	a  5	0.02
Common dolphin	93,100	49.3	b  429	0.46
Harbor porpoise	85,765	19	19	0.02
Gray seal	27,911	32.4	32	0.12
Harbor seal	61,366	14.4	14	0.24
a  Take increased to the species assumed mean group size (86 FR 38033, July 19, 2021; 88 FR 31678, May 18, 2023).
b  Take increased to equal the estimate of potential take based on previous Protected Species Observer (PSO) data (86 FR 38033, July 19, 2021; 88 FR 31678, May 18, 2023).
c  Average group size for fin whales is assumed here as two. However, we increase the authorized take number to three to equal the number of whales reported observed within the estimated harassment zone by SouthCoast during 2023-2024 survey effort.