DMR Whale Reseach Survey Program Update

By Sarah Leiter

The Department of Marine Resources (DMR) Division of Marine Mammal Research Survey Program is designed to increase our understanding of when and where North Atlantic right whales occur in the Gulf of Maine by conducting monthly visual surveys from vessels and planes. A better understanding of right whale habitat use will improve the ability of federal regulators to assess entanglement risk. These surveys have been conducted monthly since July of 2024. In discussions with the Lobster Advisory Council and the Maine Lobstermen’s Association, DMR offered to provide regular whale research updates to the fishing community. It was decided that quarterly reports were preferable, and these will be provided for publication in Landings, quarterly, going forward.

Two right whales in Cape Cod Bay. AP Photo.

The results presented here are preliminary findings from aerial and vessel surveys for North Atlantic right whales and other marine species conducted January-March (2025). Only large and medium whale sightings are reported, including North Atlantic right, blue, fin, sei, humpback, sperm, and minke whales. During surveys, standardized observation effort is conducted along pre-determined track lines throughout the Gulf of Maine. Standardized survey effort during vessel surveys employs two trained marine mammal observers on either side of the top deck observation platform and a third observer recording data while the vessel travels along track lines at a speed of 10 knots. Standardized survey effort during aerial surveys employs two observers positioned on either side of the aircraft while the plane travels along track lines at a ground speed of 100 knots and an altitude of 1000 feet.

Total effort in nautical miles from both survey platforms is summarized in tables by month. Data is also collected for other marine species including dolphins, porpoises, sea turtles, seals, and large fishes.

In addition to the survey efforts reported here, DMR conducted three response vessel surveys of Jeffery’s Ledge / Jeffery’s Basin on 19 January, 25 January, and 02 February to monitor the large aggregation of North Atlantic right whales initially detected by aerial surveys conducted by the New England Aquarium aerial survey team in January. These expeditions confirmed the presence of right whales on 19 and 25 January and detected no right whales on 02 February.

More information on the DMR survey program, including monthly and annual reports, can be found at www.maine.gov/dmr/science/right-whale/monitoring. Sightings of North Atlantic right whales and effort track lines from the Survey Program are posted on the day following each aerial or vessel survey to www.whalemap.org.