North Atlantic right whales are among the most endangered marine species, with fewer than 500 individuals remaining. During the last few years, the population has shifted northward in summer. There has also recently been an unprecedented number of right whale deaths in Canada’s Gulf of St. Lawrence, an area where right whale sightings had previously been rare. One hypothesis for the northward movement is that the whales are following changes in the distribution of their main prey species, the planktonic copepod Calanus finmarchicus. Confirming this and explaining how and when food availability leads to right whale migration could prove invaluable for managers trying to conserve the species.
To test the hypothesis, Dr. Charles Greene of Cornell University and his research team will first analyze samples recently collected with an instrument called a continuous plankton recorder (CPR). Then they will add the resulting data to an existing mathematical model that uses prey abundance to explain variation in right whale reproductive success. This will let them test whether changes in prey abundance can explain the right whale range shift.
The team will also use the model to generate hypotheses about when right whales might abandon their traditional feeding grounds and where they might end up. For example, when prey abundances fall below thresholds that ensure reproductive success, the whales might move northward until they find adequate food. The team can then test whether this hypothesis is supported by shorter-term datasets from the Bay of Fundy, southwest Nova Scotia, and Gulf of St. Lawrence.
The project will extend through 2020. In addition to peer-reviewed papers, the researchers will produce guidance for Canadian managers on, among other things, where to conduct future surveys for right whales and plankton.
Marine Science Institute
University of California, Santa Barbara
Kimberley T.A. Davies, Ph.D.
Department of Oceanography
Laboratory Manager and Research Scientist
Head of the Continuous Plankton Recorder Survey
Marine Biological Association