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Monday, January 31, 2011

"Flex": Redefining Our Understanding of the Western Gray Whale

There are so many interesting things going on in the marine science world that, in continuing with the theme of my last post, I thought I would dedicate a series of posts to some of these fascinating topics. Today: the interesting results from the recent tagging of a Western Pacific gray whale.

The Eastern Pacific gray whale that migrates from the Bering Sea in Alaska to Baja Mexico was hunted nearly to extinction, but since the whaling ban the population has recovered quite well to an estimated 20,000 animals. The Western Pacific gray whale, however, which spends the summer months feeding off of Kamchatka, remains one of the most highly endangered whale populations with only about 150 animals and seems genetically distinct from their Eastern Pacific counterparts. The population was actually considered extinct until it was re-discovered off of Russia’s Sakhalin Island in the 1970s.

It is unknown what path these Western Pacific animals take to migrate or where they go to breed, but it was assumed that they traveled south to somewhere off of China. It was essential to determine this for certain to aid in their protection, so last fall a team of Russian and American scientists set out to tag several of these animals to see where they actually go. Due to a variety of factors including bad weather they were only able to successfully deploy a single tag on October 4th, the last day of the expedition. The tagged whale is a thirteen year-old male nicknamed Flex. The data Flex’s tag has collected so far has been a shocker.

This gray whale, instead of going south, headed east. He crossed the Bering Sea in the north Pacific, made it to the Aleutian Islands of Alaska, then crossed the Gulf of Alaska, and now has started making his way south towards the west coast of North America. In today's update, they indicate that on his current trajectory he is likely to bypass Vancouver Island of BC and, if he continues, reach the west coast of North America somewhere around central Oregon. The tag hasn't broadcast for a couple of days, but they're hoping that's just due to weather (there was another data gap a bit earlier due to high seas) and not that the tag has fallen off.

“It’s got everyone scratching their heads,” said John Calambokidis at the Ways of Whales workshop last weekend.

Oregon State University, the home base for Bruce Mate who led the tagging operations, releases new maps of the whale’s travels every Monday. Keep tabs via press releases on Flex's progress here. This week's map can be seen here. Bruce Mate estimated that if Flex continued traveling south, he would reach Oregon by mid-February. If he's going all the way to Baja he wouldn’t arrive until many of the single animals have already started their northbound migration.

Tagging whales can lead to profound discoveries, such as seems to be the case with this gray whale. Another example that occurred last year was shared by Brad Hanson at the Ways of Whales workshop where he shared the track of an Alaskan resident killer whale. The data points colletced from a single tagged whale completely redefined the range of Alaskan residents, as this one male went all the way over to Kodiak.

It’s amazing to me how little we still know about whales. I understand that some people are resistant to tagging for its invasiveness, but the data gathered as a result of satellite tagging not only has the potential to be astounding, re-shaping our understanding of entire populations of whales, but also can be a key component in determining their ranges, defining their critical habitats, and hence protecting them and ensuring their long-term survival.


Lancashire and Lakeland Outback Adventure Wildlife Safaris said...

Not much can be deduced from one whale but what is the possiblility of a male travelling that distance for breeding purposes? Could it be that the eastern and western populations are not mutually exclusive - any thoughts Monika



Monika said...

Hey Dave -

It's certainly possible he's going that far to breed - seems a bit odd, since genetic evidence points to the eastern/western gray whale being different stocks, but who knows? There are a lot of humpback whale stocks in the Pacific that are isolated during the summer feeding season and meet up at the same winter breeding grounds and thus aren't really the exclusive populations they seem to be for much of the year.

Of course now the question will be are all the whales are doing this, or if Flex is just an odd ball...but either way I really hope the tag keeps transmitting at least a few more weeks!

Mark - Sea Quest Kayak Tours said...

There have been recent discoveries of both an Antarctic Minke Whale and a hybrid North Atlantic x Antarctic Minke in Norwegian whaling kills via DNA analysis. As with many bird populations previously believed to be genetically isolated, I think we will be discovering that gene flow within closely related clades of marine mammals that are highly mobile and migratory is more common than currently thought. The ocean temperature barriers along the equator that separate many northern and southern hemisphere whales today frequently disappear and reappear with climatic change. Barriers separating West Pacific and East Pacific Gray Whales are even less significant and probably reflect choices based on the energetics of reaching distant wintering grounds. Now that so few West Pacific Grays exist, some may be seeking larger aggregations on the eastern side for better breeding success.