(Photo: D. Weller)
Gray whales in the North Pacific have a large eastern population and a small western population. The eastern gray whales undertake one of the longest migrations of any mammal, back and forth between their wintering grounds along Mexico's Baja peninsula and their summering grounds in the Bering, Chukchi and Beaufort Seas off Alaska and western Canada. The eastern population has recovered to near pre-exploitation size, and supports a sizable whale-watching industry along the west coast of the US. In contrast, the western population remains highly depleted and its continued survival is questionable (Weller et al. 1999, 2002). Current mark-recapture assessments estimate this population to be less than or equal to 100 individuals (Wade et al., 2003) and the recent onset of large-scale oil and gas development programs on the primary feeding ground off Sakhalin Island, Russia, pose new threats to the population (Weller et al. 2002). This is clearly one of the most critically endangered whale populations in the world. Initial genetic research documented the genetic distinctness of the eastern and western populations (LeDuc et al. 2002). Ongoing research focuses on the western population. With over 80% of the population biopsy sampled and simultaneously photo-identified, it is a unique opportunity to study the relatedness and demographics of nearly an entire baleen whale population.
LeDuc, R.G., Weller, D.W., Hyde, J., Burdin, A.M., Rosel, P.E., Brownell, R.L., Jr., Würsig, B. and Dizon, A.E. 2002. Genetic differences between western and eastern gray whales (Eschrichtius robustus). Journal of Cetacean Research and Management 4(1):1-6.
Wade, P.R., Burdin, A.M., Bradford, A.L., Brownell, R.L., Jr. and Weller, D.W. 2003. Abundance estimates of western gray whales (Eschrichtius robustus) off northeastern Sakhalin Island, Russia. Paper SC/55/BRG18, International Whaling Commission Scientific Committee.
Weller, D.W., Burdin, A.M., Würsig, B., Taylor, B.L., and Brownell, R.L., Jr. 2002. The western gray whale: a review of past exploitation, current status and Potential threats. Journal of Cetacean Research and Management 4(1):7-12.
Weller, D.W., Würsig, B., Bradford, A.L., Burdin, A.M., Blokhin, S.A., Minakuchi, H. and Brownell, R. L. Jr. 1999. Gray whales (Eschrichtius robustus) off Sakhalin Island, Russia: seasonal and annual patterns of occurrence. Marine Mammal Science, 15:1208-1227.