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PUBLISHED: 1:38 PM on Wednesday, September 24, 2008
Minkes: enigmas wrapped in blubber
JUNEAU - Minke whales are frequent targets for Japanese and Icelandic whalers, and they are at the heart of international controversy about commercial whaling. But in Southeast Alaskan waters, where there is no history of commercial and subsistence hunting of the whales, minkes mostly remain a mystery.

"They're definitely the most underrated whale in Southeast," said John Moran, a whale researcher at the National Oceanic and Atmospheric Association's Auke Bay lab. "I think they're around (but) they're hard to see. They're sneaky."


courtesy photo
  Minke whales are a rare sight in Southeast Alaska. Researchers are unsure about their population size but estimate there are fewer than 100 in all of Southeast. Like humpbacks, Minkes feed on small fish like herring. Minkes typically surface only briefly to breathe and do not show their tails when they dive. Nobody knows where Northeast Pacific Minkes breed.
The minke whale, also known as the Lesser Rorqual, is the smallest member of the rorqual family which includes humpback, fin and blue whales. Minkes grow to a maximum length of around 30 feet and weight of 10 tons.

For early Norwegian whalers, minkes were too small. They were named (mockingly) for a whaler who accidentally harpooned one thinking it was a blue whale.

Minkes have been observed this year near Haines and Juneau, but the bulk of the Minke seen in Southeast Alaska have been in Glacier Bay and Icy Strait, according to Christine Gabriele, a wildlife biologist who monitors humpbacks for Glacier Bay National Park. Minke sightings are rare even in that area, although Park biologists are out looking for whales about five days a week in the summer.

"(Minkes are) elusive," Gabriele said. "(It's) hard to predict where they're going to surface. They're fast. They're very unlikely to approach boats. They don't seem to have any affinity at all for boats. They're the kind of whale that you see out of the corner of your eye and don't really see them again."

Minkes do not have a noticeable blow like the humpback. The first sign of a minke is usually a "bow wave" from the rostrum, or snout, followed by a sickle-shaped dorsal fin. They rarely show their tail flukes, so dorsal fin photographs are used to identify individuals. Unlike killer whales, which can be easily identified by black and white markings below their dorsal fin, individual minkes are difficult to distinguish. Although Gabriele has collected 36 photographs of Minke dorsal fins in the past decade, it is difficult to say how many individuals are represented by those photos.


"You're pretty much relying on the shape of their dorsal fin," Gabriele said. "There are a couple that are really distinctive because they have a notch in the dorsal fin. (But usually) it can be really hard to tell if you're looking at the same or different animal."

Dr. Jon Stern, a researcher with the Northwest Pacific Minke Whale Project in California, is also unsure about the Southeast Alaskan population. He has seen a decline in the Northeast Pacific minke stock, which he believes includes the Southeast Alaskan minkes.

"I suspect that the population that's in Southeast Alaska is part of the California-Oregon-Washington stock, which also includes British Columbia and the Gulf of Alaska," Stern said. "I wouldn't be surprised if there are [fewer than] 100 in Southeast Alaska."

On the Web

To learn more about Minke whales, visit www.northeastpacificminke.org.

Minke vocalizations: http://omp.gso.uri.edu/dosits/gallery/marinemm/18.htm

Stern has seen a decline in minkes in recent years and estimates there may be only 600 minkes off the coasts of California, Oregon and Washington altogether, and at most a couple thousand in the entire Northeast Pacific. By contrast, there are about 150,000 minkes in the North Atlantic.

"It's an interesting phenomenon. Why aren't there more?" Stern said.

One explanation Stern offers is that the competition for resources is too fierce for the area to support minkes. Northeast Pacific minkes, which eat primarily small fish like herring, must compete with seals, sea lions, birds and humpbacks for their food.


Whale biologist Jan Straley, who has researched whales in Southeast for decades, also believes minkes in the region have thinned out over the years. She pointed out that predation by killer whales might also account for the small numbers of Minkes in Southeast.

"There was a killer whale that chased one into a cove in Sitka a few years ago, and one just got eaten in Juneau," Straley said. "If a killer whale is going to kill a large (whale), it's (most likely) going to be a minke."

Countless minke mysteries remain. Nobody knows where they breed, for example. Only recently a strange "boing" sound picked up by hydrophones in Hawaii was determined to be a minke vocalization.

For the novice minke-watcher unsure if they've seen one or not, the answer may be as elusive as the whale itself.

"My rule of thumb is if I just see it once... and then never see it again, I'm pretty sure it's a minke," Straley said.


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