Technical Reports

Annual technical progress report on pinniped haul-out counts and photo-ID analyses.

During 2025 fieldwork supporting the Atlantic Behavioral Response Study (BRS Southall et al. 2026) and other related research, the study team collected more than 12,900 digital images within the Cape Hatteras study area. The team used these images to confirm species, identify individual animals, compile sighting histories, and conduct follow-up monitoring of satellite-tagged animals. The team obtained photographs of six species, but most were from goose-beaked whales (Ziphius cavirostris), the focal species of the Atlantic BRS.

Over 25 species of cetaceans utilize the shelf break regions of the US eastern seaboard, including several endangered species. Understanding patterns in species distribution, and the anthropogenic and environmental drivers that may impact their distribution, are critical for appropriate management of marine habitats. To better understand patterns in species distribution and vocal activity, NOAA’s Northeast Fisheries Science Center (NEFSC) and Scripps Institution of Oceanography (SIO) collaboratively deployed long-term high-frequency acoustic recording packages (HARPs) at eight sites along the western North Atlantic shelf break. This work was conducted from 2015-2021, with financial support from the Bureau of Ocean Energy Management (BOEM). Likewise, the U.S. Navy has been monitoring the shelf break region at 3 to 4 sites since 2007. Together these combined efforts bring the total to 11 recording sites spanning the U.S. eastern seaboard, from New England to Florida. This project focuses on analyses of the datasets collected from 2015-2021, with the inclusion of older (pre-2015) datasets where relevant. The focus of our efforts in 2025 have been to make substantial progress in the review of various detector classifications.

This annual progress report covers the 2025 field season and subsequent analyses. It provides a synthesis of experimental methods; field efforts; tagging results; and exposure-response results for two CEEs, including the second operational CAS CEE conducted with the United States Ship (USS) Donald Cook and the first-ever high-power experimental source CEE simulating CAS operations. It also includes a detailed analysis of the Kinéis satellite data receiving system relative to legacy ARGOS systems. Finally, it includes a synthesis of peer-reviewed papers that have been or are in the process of being published.

In order to locate any undocumented seal haul-out sites in Virginia, as well as provide additional data collection at the two known haul-out sites, aerial surveys were implemented and flown along the entire Virginia coast during the winter 2025 field season.