Gray whale research off northeastern Sakhalin Island and eastern Kamchatka, Russia, in 2017
Alexander M. Burdin, Olga Sychenko, Matvey Mamaev
International Whaling Commission
The western gray whale population is presently listed by the IUCN a critically endangered but it’s status is presently being reassessed. On the assumption that Sakhalin whales constituted a separate population, Cooke et al. (2016), using photo-id and biopsy data from the Russian Gray Whale Project (Burdin et al. 2015) funded by IFAW, estimated that the feeding aggregation off Sakhalin contained about 175 non-calf individuals by 2016 (although not all of these would be present every year), and had been growing at 2-4% per year. Between 1994 and 2017, 267 western gray whales have been identified during 477 boat-based surveys off northeastern Sakhalin Island. This paper reviews findings from 2017 research activities and combines such with data from previous years, in some cases ranging back to an opportunistic survey in 1994. Photo-identification research conducted off Sakhalin Island in 2017 resulted in the identification of 46 whales, including four calves. Five previously unidentified non-calf were observed. Four mother-calf pairs were observed, all of which had previous sighting histories. Three of these four were observed with calves in previous years while one was observed with its first known calf. In total, a minimum of 34 reproductive females have been observed since 1995. In addition to a number of biological difficulties that western gray whales are facing, the large-scale offshore oil and gas development programs near their summer feeding ground, as well as rope entanglements off Sakhalin during the feeding season and fatal net entrapments off Japan during migration, pose significant threats to the survival of the population.