By ALEX de MARBAN
Anchorage Daily News
December 09, 2006
Scientists puzzling over Steller sea lion numbers that plummeted about 75 percent in parts of Alaska in the last three decades have considered such theories as over fishing, changing climate, diet and killer-whale attacks.
But the consequences of fishermen blasting sea lions to protect fish or gear, and hunters harvesting thousands of pups for pelts, haven't been significantly studied, said researcher Henry Huntington. Yet sea lion shootings took place for decades until 1990, sometimes in large numbers, and might have played a key role in the collapse, he said.
Fishermen slaughtered sea lions for revenge - often aiming for adult females - because they punctured buoys, snatched fish and destroyed nets, said Clem Tillion, a former state lawmaker and commercial fisherman.
Tillion participated in those killings and in state-authorized hunts in the 1960s.
"We shot them because we didn't like them," he said. "They'd get on your gear and take your halibut off. They were underwater and you couldn't hit them then, so everyone would get real mad and go to a haul-out or rookery and just butcher sea lions for what they'd done to your gear."
"Everybody shot sea lions. They were a pest, like ranchers consider coyotes."
The shootings didn't really hurt Steller sea lion numbers when the population was healthy, Tillion said. But they had a severe impact as soon as their numbers began dropping sharply.
The barking, barrel-chested creatures, some weighing more than a ton, lounge on rocks or beaches from Japan to California, occupying many of the same areas where boats haul in fish.
They are divided into two stocks, at a line just east of Prince William Sound. The estimated size of the western stock in Alaska, extending out to Attu Island, peaked at 195,000 in the mid-to-late 1970s.
This stock is now considered in danger of extinction. It began plummeting in the Aleutian Islands. The decline spread eastward, and the stock nose-dived at a 15 percent annual clip in the late 1980s.
The losses continued after 1990 but slowed substantially. That year, shooting became illegal except for Native subsistence hunts because Steller sea lions were listed as threatened, a step short of endangered.
As the population kept dropping, the western stock in Alaska was declared endangered in 1997. The stock made small comebacks in recent years and was estimated at 45,000 sea lions in 2004, including about 20,500 adults.
The new study involves only the western stock in Alaska.
Shootings are rare today, said Ken Hansen, a longtime federal enforcement officer in Kodiak. Officers there investigate a couple such cases a year, with typically one to three sea lions shot and killed, he said.
The researchers began their study by conducting anonymous interviews this fall. Two teams representing the University of Alaska Fairbanks and the state Department of Fish and Game have interviewed about 50 people so far. They were in Kodiak last week.
The researchers hope to use the interviews to estimate how many sea lions were shot, Huntington said.
Why are they declining?
Estimated Steller sea lion numbers in Western and Southcentral Alaska fell from as high as 195,000 in the late 1970s to about 45,000 today.
Hypotheses about why the animals took a dive include:
- Competition for fish with the commercial fishing industry
- Climate change altered the abundance or distribution of fish that sea lions eat
- Pollutants reduced the birth rate or killed sea lions
- Predators such as killer whales
- Entanglement in commercial fishing nets
Scripps Howard News Service, http://www.shns.com
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