Takes of Marine Mammals Incidental to Specified Activities; Takes of Marine Mammals Incidental to Marine Site Characterization Surveys Off Rhode Island and Massachusetts

SUPPLEMENTARY INFORMATION:

Background

The MMPA prohibits the “take” of marine mammals, with certain exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce (as delegated to NMFS) 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 proposed or, if the taking is limited to harassment, a notice of a proposed IHA is provided to the public for review.

Authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for taking for subsistence uses (where relevant). Further, NMFS must prescribe the permissible methods of taking and other “means of effecting the least practicable adverse impact” on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stocks for taking for certain subsistence uses (referred to in shorthand as “mitigation”); and requirements pertaining to the monitoring and reporting of the takings. The definitions of all applicable MMPA statutory terms cited above are included in the relevant sections below.

National Environmental Policy Act

To comply with the National Environmental Policy Act of 1969 (NEPA; 42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, NMFS must review our proposed action ( i.e., the issuance of an IHA) with respect to potential impacts on the human environment.

This action is consistent with categories of activities identified in Categorical Exclusion B4 (IHAs with no anticipated serious injury or mortality) of the Companion Manual for NAO 216-6A, which do not individually or cumulatively have the potential for significant impacts on the quality of the human environment and for which we have not identified any extraordinary circumstances that would preclude this categorical exclusion. Accordingly, NMFS has preliminarily determined that the issuance of the proposed IHA qualifies to be categorically excluded from further NEPA review.

We will review all comments submitted in response to this notice prior to concluding our NEPA process or making a final decision on the IHA request.

Summary of Request

On October 6, 2022, NMFS issued an IHA (87 FR 61575; October 12, 2022) to Ørsted (parent company of Bay State Wind) to take marine mammals incidental to marine site characterization surveys in Lease Areas OCS-A 0486, 0487, 0500 off the coasts from New York to Massachusetts and along potential ECRs to landfall locations between Raritan Bay (part of the New York Bight) and Falmouth, Massachusetts. On May 26, 2023, NMFS received a request for a renewal of that initial IHA because Ørsted's marine site characterization surveys under the initial IHA had not yet been completed and more time was required. The Renewal IHA was issued on September 29, 2023, (88 FR 62337; October 5, 2023). Ørsted has complied with all the requirements ( e.g., mitigation, monitoring, and reporting) of the previous IHAs in Lease Areas OCS-A 0486, 0487, and 0500 (84 FR 52464, October 2, 2019; 85 FR 63508, October 8, 2020; 87 FR 13975, March 11, 2022).

On March 27, 2024, NMFS received a request from Bay State Wind for an IHA to take marine mammals incidental to conducting marine site characterization surveys off the coast of Rhode Island and Massachusetts only in OCS-A 0500 and the associated ECR area. Following NMFS' review of the application, Bay State Wind submitted a revised version on June 10, 2024. Following NMFS' additional review of the application, Bay State Wind submitted another revised version on July 29, 2024. The application was deemed adequate and complete on August 1, 2024. Bay State Wind's request is for take of 17 species of marine mammals by Level B harassment only. Neither Bay State Wind nor NMFS expect serious injury or mortality to result from this activity and, therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

Bay State Wind proposes to conduct marine site characterization surveys, including high-resolution geophysical (HRG) surveys and geotechnical surveys, in BOEM Lease Area OCS-A 0500, and the associated ECR. The purpose of the marine site characterization surveys is to collect data concerning seabed (geophysical, geotechnical, and geohazard), ecological, and archeological conditions within the footprint of the offshore wind facility development. Surveys are also conducted to support engineering design and to map unexploded ordnance (UXO). Underwater sound resulting from Bay State Wind's proposed activities, specifically HRG surveys, has the potential to result in incidental take of 17 species, in the form of Level B harassment only.

Dates and Duration

While the exact dates have not yet been established, the proposed activities are planned to begin as soon as possible upon issuance of an IHA, if appropriate. The proposed activity is expected to require up to 350 survey days across a maximum of four vessels operating concurrently over the course of a single year (“survey day” defined as a 24-hour activity period in which the assumed number of line kilometers (km) are surveyed). Vessel days are defined as the number of days any single vessel is in operation regardless of any other vessel operations ( i.e., if two vessels are working concurrently within the same 24-hour period, each vessel would be counted as having a vessel day for a total of 2 vessel days even though the activity occurs within a single 24-hour period). The number of anticipated survey days was calculated as the number of days needed to reach the overall level of effort required to meet survey objectives assuming any single vessel covers, on average 70 line km per 24-hour operations.

Specific Geographic Region

The proposed survey activities will occur within the Lease Area and potential ECRs off the coasts of Rhode Island and Massachusetts (figure 1). Water depths in the Lease Area and potential ECRs extend out from shoreline to approximately 90 meters (m).

Detailed Description of the Specified Activity

Bay State Wind proposes to conduct HRG survey operations, including multibeam depth sounding, seafloor imaging, and shallow and medium penetration sub-bottom profiling (SBP). The HRG surveys will include the use of seafloor mapping equipment with operating frequencies above 180 kilohertz (kHz) ( e.g., side-scan sonar (SSS), multibeam echosounders (MBES)); magnetometers and gradiometers that have no acoustic output; and shallow- to medium-penetration SBP equipment ( e.g., parametric sonars, compressed high-intensity radiated pulses (CHIRPs), boomers, sparkers) with operating frequencies below 180 kHz. No deep-penetration SBP surveys ( e.g., airgun or bubble gun surveys) will be conducted. HRG equipment will be deployed from multiple vessels or remotely operated vehicles (ROVs) during the HRG surveys conducted within the Lease Area and potential ECRs. Typically, a survey ROV used for the proposed activities is a tethered platform that carries additional HRG equipment to increase the swath of the survey or the depth at which the equipment can be operated. The equipment deployed from an ROV is identical to the sources deployed from the survey vessel; however, sparker systems are not normally deployed from an ROV due to the power supply required. The extent of ROV usage in this project is unknown at this time, however NMFS expects the use of ROVs to have de minimis impacts relative to the use of vessels given the smaller sources and inherent nature of utilizing an ROV ( e.g., much smaller size of an ROV relative to a vessel and less acoustic exposure given location of their use in the water column). For these reasons, our analysis focuses on the acoustic sources themselves and the use of vessels to deploy such sources, rather than the specific use of ROVs to deploy the survey equipment. Therefore, ROVs are not further analyzed in this notice.

Acoustic sources planned for use during HRG survey activities proposed by Bay State Wind for which sound levels have the potential to result in Level B harassment of marine mammals include the following:

• Medium penetration SBPs (boomers) are used to map deeper subsurface stratigraphy as needed. A boomer is a broad-band sound source operating in the 3.5 Hz to 10 kHz frequency range. This system is commonly mounted on a sled and towed behind the vessel. Boomers are impulsive and mobile sources; and,
• Medium penetration SBPs (sparkers) are used to map deeper subsurface stratigraphy as needed. Sparkers create acoustic pulses from 50 Hz to 4 kHz omnidirectionally from the source, and are considered to be impulsive and mobile sources. Sparkers are typically towed behind the vessel with adjacent hydrophone arrays to receive the return signals.

Operation of the following survey equipment types is not reasonably expected to result in take of marine mammals and will not be discussed further beyond the brief summaries provided below:

• Parametric SBPs, also commonly referred to as sediment echosounders, are used to provide high data density in sub-bottom profiles that are typically required for cable routes, very shallow water, and archaeological surveys. Parametric SPBs are typically mounted on a pole, either over the side of the vessel or through a moon pool in the bottom of the hull. Crocker and Fratantonio (2016) does not provide relevant measurements or source data for parametric SBPs, however, some source information is provided by the manufacturer. For the proposed project, the SBP used would generate short, very narrow-beam (1 to 3.5°) sound pulses at relatively high frequencies (generally around 85 to 100 kHz). The narrow beam width significantly reduces the potential for exposure while the high frequencies of the source are rapidly attenuated in seawater. Given the narrow beam width and relatively high frequency. NMFS does not reasonably expect there to be potential for marine mammals to be exposed to the signal;
• Ultra-short baseline (USBL) positioning systems are used to provide high accuracy ranges by measuring the time between the acoustic pulses transmitted by vessel transceiver and a transponder (or beacon) necessary to produce the acoustic profile. It is a two-component system with a moon-pool- or side-pole-mounted transceiver and one or several transponders mounted on other survey equipment. USBLs are expected to produce extremely small acoustic propagation distances in their typical operating configuration;
• MBES are used to determine water depths and general bottom topography. MBES sonar systems project sonar pulses in several angled beams from a transducer mounted to a ship's hull. The beams radiate out from the transducer in a fan-shaped pattern orthogonally to the ship's direction. All of the proposed MBESs have operating frequencies >180 kHz and, therefore, are outside the general hearing range of marine mammals; and,
• SSSs are used for seabed sediment classification purposes and to identify natural and man-made acoustic targets on the seafloor. The sonar device emits conical or fan-shaped pulses down toward the seafloor in multiple beams at a wide angle, perpendicular to the path of the sensor through the water column. All of the proposed SSSs have operating frequencies >180 kHZ and, therefore, are outside the general hearing range of marine mammals.

Table 1 identifies representative survey equipment with the expected potential to result in exposure of marine mammals and thus potentially result in take. The make and model of the listed geophysical equipment may vary depending on availability and the final equipment choices will vary depending upon the final survey design, vessel availability, and survey contractor selection.