Fin, Humpback, and Minke Whale Foraging Events in the New York Bight as Observed from Aerial Surveys, 2017-2020

Abstract

The fin whale (Balaenoptera physalus), humpback whale (Megaptera novaeangliae), and minke whale (Balaenoptera acutorostrata) are known to occur in the New York Bight (NYB). The primary North Atlantic feeding grounds for these large whale species are commonly recognized to be further north in waters of the Gulf of Maine, eastern Canada, West Greenland, and the eastern North Atlantic (e.g., Iceland, Norway, Ireland, Scotland). Although much is known about their feeding activities in the North Atlantic, relatively little is known about their occurrence and foraging behaviors in mid-Atlantic regions such as the NYB. Understanding how large whales utilize NYB waters is important to evaluate potential impacts from direct (e.g., offshore development, vessel strikes, entanglements) and indirect (e.g., rising ocean temperatures) anthropogenic sources. The New York State Department of Environmental Conservation funded a 3-year baseline monitoring program (2017-2020) which conducted monthly line-transect aerial surveys focused on large whales. Over 3 years, 36 surveys comprised of 263 flights and totaling 688.3 hours of observation time along 140,370 km of over-water flight path were completed. Aerial survey observers documented foraging events for the fin, humpback, and minke whales, including mixed-species aggregations, and analyzed other parameters such as distance from shore, distribution zones, and presence of fish schools. Foraging behavior was observed for 27% of the recorded fin whale sightings, 40% of the recorded humpback whale sightings, and 18% of the recorded minke whale sightings. Sighting rates of foraging whales were highest for humpback whales (4.4 whales/1,000 km of effort), followed by fin whales (0.6 whales/1,000 km effort) and minke whales (0.1 whales/1,000 km of effort), and varied by season, year, and distribution zone. In addition, nearly 5,700 fish schools were recorded with fish presence highest during summer and fall.