Western gray whale makes unexpected journey

17 February 2011 | News story

In October 2010, a team of scientists from Russia and the United States satellite tagged a western gray whale off Sakhalin Island, Russia. This is the first individual from the Critically Endangered western gray whale population to be tagged and tracked using telemetry. This whale, nicknamed Flex by researchers, has now been successfully tracked for over four months, revealing its long and unexpected migration route.

There are only about 130 western gray whales left. The species is listed as Critically Endangered on the IUCN Red List of Threatened Species™, with perhaps only about 33 mature and reproductively active females. Their feeding grounds in the Russian Far East are known but details of their migration routes and breeding grounds are not. It is believed that western gray whales migrate south in the winter, towards Japan, Korea or China.

Flex stayed at Northeast Sakhalin until around mid-December, but instead of moving south as expected, he moved across the Okhotsk Sea to the west coast of Kamchatka, then followed the coast around the southern tip of Kamchatka and up along the east coast to the Commander Islands, across the Bering Sea towards Alaska, through the Aleutian Island chain and across the Gulf of Alaska. At the beginning of February 2011, Flex arrived at the US west coast off Washington State. Since leaving the Kamchatka Peninsula, Flex travelled more than 8500 kilometers over 124 days with an average speed of 6.6 km per hour during his migration.

Flex was first photo-identified off Sakhalin Island as a calf in 1997 and has subsequently been observed in multiple years off Sakhalin during the summer feeding season. To better understand his movements, photo-identification images of Flex were compared with a photo catalog of over 1000 eastern gray whales, which revealed a match. Flex had been photographed in April 2008 off the west side of Vancouver Island and then during the summer of 2008 off Sakhalin Island. This photographic match, in combination with the telemetry data, provides the first evidence that links the Sakhalin feeding ground of western gray whales to locations in the eastern North Pacific.

Telemetry data, along with photo-identification and genetic data, is presently being analyzed by scientists to better understand the movements of western gray whales. For more information on the ongoing studies and recent findings, please see: Movements of western gray whales from the Okhotsk Sea to the eastern North Pacific: evidence from satellite tagging, photo-identification and genetic studies.

This tagging project represents a major international collaboration between the International Whaling Commission, IUCN, the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, the Oregon State University and the University of Washington. Funding was provided by Exxon Neftegas Ltd. (ENL) and Sakhalin Energy Investment Company (Sakhalin Energy).