2024-28994. Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Marine Site Characterization Surveys Off Rhode Island and Massachusetts

Table 1—Common Dolphin Detection Events During Bay State Wind HRG Survey Activities

Total number of common dolphin detection events	Total number of groups within Level B harassment zone	Total number of dolphins within Level B harassment zone	Min pod size	Max pod size	Average group size for detections within Level B harassment zone
55	38	1,045	3	110	32.6

According to Roberts et al. (2023) monthly marine mammal density data, estimated common dolphin occurrence in the region appears to be seasonal with the highest monthly density occurring during the months of October (0.1652 animals km^{− 22} ) and September (0.1224 km^{− 2}). Density data for the months of November and December begin to decrease (0.1034 km^{− 2} and 0.1155 km^{− 2} respectively). Density for the months of January-August decreases further and remains under 0.0800 km^{− 2} . Density does not exceed 0.0800 km^{− 2} until the month of September.

The 1,045 common dolphin sightings over 20 days averages to approximately 52 sightings per day. This high number of sightings is unanticipated and has occurred during the month of October when, as previously mentioned, common dolphin density is expected to be highest. As the common dolphin density is expected to decrease in November and December (0.1034 km^{− 2} and 0.1155 km^{− 2}, respectively) and remain relatively low (below 0.0800 km^{− 2}) through the month of August. NMFS anticipates the encounter rate will likely subside after the peak density in October (0.1652 animals km^{− 2}) and September (0.1224 km^{− 2}). Given the expected decrease in common dolphin encounter rate, Bay State Wind has requested authorization of an additional 1,485 additional takes for the remaining 330 survey days. NMFS concurs and is proposing to modify the IHA to increase the total number of authorized take of common dolphin by Level B harassment from 1,485 to 2,970. The proposed updated total take represents 3.2 percent (table 2) of the best available abundance estimate for the western North Atlantic stock of common dolphin. The expiration date of the IHA would remain unchanged (October 5, 2025). Authorized takes remain unchanged for all other marine mammal species.

Table 2—Total Numbers of Authorized Takes by Level B Harassment of Common Dolphin and as a Percentage of Population

Species	Totals
	Take authorization (No.)	Stock abundance (CV, N min , most recent abundance survey) 1	Instances of take as percentage of population
Common dolphin	2,970	93,100 (0.56, 59,897, 2021)	3.20
1  NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/​national/​marine-mammal-protection/​marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.