MEPS prepress abstract - DOI: https://doi.org/10.3354/meps14780
Habitat use and trophic ecology of the world’s rarest whale population on a rapidly warming subarctic foraging ground
Dana L. Wright*, Geraldine Busquets-Vass, Andrew J. Read, Alaina Harmon, Seth D. Newsome
ABSTRACT: Historical commercial whaling drastically reduced North Pacific right whale (NPRW; Eubalaena japonica) populations, impeding our ecological understanding and highlighting the challenges of studying species impacted before scientific research began. The warming subarctic Bering Sea is the core summer feeding ground for the Critically Endangered eastern population of NPRW, yet knowledge about its foraging ecology, as well as distribution during other seasons, remains scarce. By modeling isotope values of NPRW skin, we revealed spring distribution and physiological responses of NPRW to ocean warming and sea ice retreat. Our findings confirm NPRW are secondary consumers and indicate that the remnant population primarily feeds in the coastal Gulf of Alaska and Pacific subarctic gyres in spring, aligning with historical records. Joint attribute modeling of whale amino acid isotope values demonstrate their ability to track baseline environmental shifts. Moreover, we observed evidence for changes in NPRW physiology and habitat use related to sea ice, including feeding north of the whales’ Critical Habitat. These insights inform recovery strategies for the NPRW and methodologies are translatable for other rare species as environmental conditions rapidly change.