Baleen whale distribution, behaviour and overlap with anthropogenic activity in coastal regions of the New York Bight

ABSTRACT

The New York Bight (NYB) is one of the busiest waterways along the US East Coast, and has recently seen an apparent increase in baleen whale presence. With growing anthropogenic pressures, a better understanding of their distribution and behaviour is needed. Encounter rates (sightings km⁻¹) and behaviour of humpback (Megaptera novaeangliae), fin (Balaenoptera physalus) and minke (Balaenoptera acutorostrata) whales were obtained from dedicated non-systematic small vessel surveys conducted from May–November 2017–2019 in previously under-surveyed coastal areas of the NYB. Humpback whales were the most frequently sighted species, and their distribution in the NYB varied significantly by region and season. Within the mid-shelf region (10–60 km from shore), sightings of all species were generally concentrated spatially and temporally in mixed-species aggregations where feeding on sand lance (Ammodytes spp.) was observed. In the nearshore region (<10 km from shore), sightings of all species were more dispersed and typically occurred in close proximity to Atlantic menhaden (Brevoortia tyrannus). Humpback whales were commonly observed lunge feeding on these prey patches. The prevalence of foraging behaviour throughout the study area supports the hypothesis that the NYB may be an important supplementary feeding area for some species. Encounter rates were generally higher in areas overlapping with anthropogenic activity, suggesting that whales may be particularly vulnerable to anthropogenic impacts in the NYB. The observed species distribution patterns and importance of the NYB as a foraging habitat for baleen whales provides valuable information for the development of new baselines and best management practices within this heavily urbanized region.

KEYWORDS:

• New York Bight
• baleen whales
• foraging behaviour
• distribution
• anthropogenic impacts

Acknowledgements

We are grateful to John McMurray, Jim Miller and Joe DePalma for chartering their vessels and providing valuable local knowledge of fish species and distribution. We also thank three anonymous reviewers and editor Rus Hoelzel for helping us greatly improve this manuscript. We appreciate the dedication given by all members of the research team, interns and volunteers, with particular thanks to Anita Murray, Leigh Terres West, Julia Zeh and Stephanie Adamczak. We would also like to thank Eliza Phillips and Dana Tricarico for logistical support. Thanks to Samantha Strindberg and Gautam Surya for feedback on the statistical analyses. We thank Duke University, particularly Doug Nowacek, as well as Teri Rowles, Stephen Manley and the National Marine Fisheries Service (NMFS) Marine Mammal Health and Stranding Response Program. All research was conducted pursuant to NMFS Federal Research Permits Nos. 14809, 18786- 03 and 18786-04.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was funded by multiple grants to the Wildlife Conservation Society.