Scientists track rare western Pacific gray whale’s migratory path to the Gulf of Alaska

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ANCHORAGE -- A highly endangered whale that spends summers in Russian waters has crossed from the Bering Sea into the Gulf of Alaska.

American and Russian researchers have tracked the 13-year-old male western Pacific gray whale, dubbed “Flex,” from Russia across the Bering Sea, through the Aleutian Islands into the Gulf of Alaska about 400 miles south of the Alaskan fishing community of Cordova.

Bruce Mate, head of Oregon State University’s Marine Mammal Institute, called the whale’s location “pretty darn amazing.” No one has documented winter habits of western gray whales, he said. Others of the species may spend winters elsewhere, but a route over deep water in the Bering Sea and the Gulf of Alaska is “something of a paradigm shift” given that eastern gray whales are considered near-shore animals.

“Flex is writing a new chapter for western gray whales, but there may be several chapters to be written yet,” he said.


Western Pacific gray whales are the second-most threatened species of large whale after North Pacific right whales. Just 130 of the animals remain. They spend summers near Sahkalin Island at the south end of the Sea of Okhotsk.

In contrast, eastern Pacific gray whales number about 18,000 animals. They breed and give birth in warm water, mostly along Baja California, and migrate north to spend summers in feeding grounds in Alaska’s Bering, Chukchi and Beaufort seas.

Scientists have been monitoring the tagged whale since he showed up as a calf with his mother in 1997. It’s unknown if the whale has company on its journey, but baleen whales generally do not travel together.

Researchers last year from Oregon State and the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences had hoped to tag 12 western Pacific gray whales but were limited to one, on the last day of field work, by typhoons and gales.

Flex was tagged Oct. 4. He spent just more than two months feeding near Sakhalin Island and moved across the Sea of Okhotsk to the west coast of the Kamchatka Peninsula.

Within a few weeks, the whale rounded the southern tip of the peninsula and left the east coast of Kamchatka across the Bering Sea, averaging about 4.5 mph. The whale reached the continental slope in the central Bering Sea without encountering a significant concentration of ice, researchers said.

Flex on Jan. 13 was about 80 miles north of Alaska’s Pribilof islands. He turned south and late last week was tracked on the south side of the Alaska Peninsula near the Shumagin Islands. Scientists speculated that he crossed the Aleutians through Unimak Pass or False Pass, two common routes for eastern grays during migration.

Most eastern gray whales have already left Gulf of Alaska waters, with their peak numbers in December.

In the 112 days since the tag was applied, Flex has traveled more than 4,127 miles.

Satellite-monitored radio tags have lasted as long as 385 days on a gray whale but average four months, a threshold now exceeded by the tag on Flex. It transmits four hours per day to conserve battery power.

If the whale continues to head south and gets closer to shore, whale scientists in British Columbia, Washington, Oregon and California will try to visually track the animal, Mate said. At the speed he’s traveling, the whale would reach Oregon before mid-February, coinciding with the last of the southbound migrants and the start of northbound whales.

If Flex were headed to breeding grounds in Baja California, Mexico, it would take at least six weeks and would be after many single whales have already headed north.

The public can track the whale on Oregon State’s website. It’s updated every Monday.

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-- Dan Joling, Associated Press