Wednesday, March 28

Noon-1:00 p.m.
NEFSC Seminar Series
Tracking the Migration Patterns and Habitat Use of North Atlantic Right Whales with Stable Isotopes
Nadine Stewart Lysiak, Boston University
Sponsored by: National Marine Fisheries Service - Stephen H. Clark Aquarium Conf. Rm.

Abstract:

Several lines of evidence including sighting records, genetic, and historic data suggest that right whale distribution extends far outside of seasonally protected habitats along the eastern US and Canadian coasts. Since right whales experience a high rate of anthropogenic mortality throughout their range, it is an urgent management priority to describe the location of unknown habitats. Stable isotope analysis of animal tissue is a non-invasive method to track the migration patterns of megafauna, and here I present the isotope data collected from right whale baleen plates and zooplankton prey from major right whale feeding habitats. Zooplankton tows were conducted over several years in six important regions within the Gulf of Maine to determine if a detectable chemical gradient exists among right whale feeding areas that could explain the annual oscillating isotope patterns observed in right whale baleen plates. Tows were also collected in the Great South Channel at several times during one year to examine the temporal stability of isotope signatures within a region. Results indicate that the feeding habitats sampled provide biogeochemically distinct signals to foraging right whales, and therefore the oscillations of baleen carbon and nitrogen isotope signatures reflect a right whale’s movement through the various habitats during their annual migration cycles. My results demonstrate the high resolution that stable isotope data afford when used to track right whales through space and time. Further analysis of zooplankton and right whale baleen could allow us to determine right whale occurrence outside of currently recognized habitat areas, and thereby inform us of additional regions which should be considered for management and conservation.