Sea Lion Survival
INTRO: Scientists have for years been trying to unravel the causes of the decline in the number of Steller sea lions roaming Alaska's coast. Thus far they've been largely unsuccessful. As Doug Schneider reports in this week's Arctic Science Journeys Radio, scientists say capturing and studying juvenile sea lions may be the species' best hope for survival.
STORY: Ever since the 1960s, the number of Steller sea lions
living along the remote and rocky coast of Alaska has been in a kind
of free-fall. By some estimates the total population—believed to
have once numbered in the hundreds of thousands—has plummeted some
80 percent. In most of Alaska, the species is now considered in danger
of extinction. Scientists themselves are frustrated that after so much
research, they're still no closer to understanding the causes of
the decline, or how to help the species recover.
Like most scientists, Shannon Atkinson thinks sea lions—especially young, juvenile sea lions—are simply not getting enough to eat in order to survive. Atkinson is the science director for the Alaska SeaLife Center, a marine research and animal rehabilitation facility in Seward. She says juvenile sea lions are the single largest segment of the overall decline.
ATKINSON: "There's an estimated 10-, 20-percent decrease in the survival rate of juveniles. There are several factors that are probably weighing into the decline of this species. The leading hypothesis is that it is nutritional stress. That in itself will probably lead to some sort of reduced foraging efficiency and that could lead to decreased survival. But we really don't know this, and until we start looking at the animals in question, it's going to be hard to answer these questions."
At a recent meeting of scientists in Anchorage, Alaska, Atkinson put forth what is likely to become a controversial proposal—to capture and hold wild juvenile Steller sea lions for study.
Atkinson says captive juvenile Steller sea lions are needed to learn how this at-risk group forages as well as to develop a medical profile of their health. Following juveniles throughout the year in the wild is just too expensive, she says. Instead, she proposes that juvenile sea lions be captured several times during the year and brought to the SeaLife Center for evaluation and study.
ATKINSON: "What we decided was probably to capture small groups of juveniles, up to four animals, at a time, and maintain them up to four months. Because we'd be getting different animals periodically and through different seasons, we'd start to build up a database of what these animals look like at different times of the year."
The proposal has received a favorable response from environmental groups. Jack Sterne, staff attorney with Trustees for Alaska, a law firm representing Greenpeace and other environmental organizations, believes the research may hold promise for learning more about sea lion declines.
STERN: "Our clients have always been supportive of legitimate research projects that attempt to determine the cause of the decline of Steller sea lions. It looks to us like they are attempting to gather useful information on some of the life history of juvenile Steller sea lions, which is an important age group that's experienced a pretty significant loss in the last few years."
While supportive of the research, that support comes with a note of caution from Paul Joslin. He's the executive director of the Alaska Wildlife Alliance in Anchorage, and former assistant director of the Brookfield Zoo in Chicago, where he looked after several thousand captive animals. He's also former head of research for Wolf Haven International, where he helped reintroduce wolves into the wild. He cautions that experiments on wild animals in captivity won't necessarily give scientists clues to how animals behave in the wild.
JOSLIN: "At the outset I would be somewhat cautious about how one would interpret the results. When we take an animal from the wild into captivity, that can be an enormous shock. It's not the same as when the animal is born in captivity. Stress hormone levels you can expect to be elevated in animals that are not born in captivity but taken from the wild as juveniles. You're asking an awful lot for a higher-level animal to behave as if it were perfectly normal."
Joslin also questions whether juvenile sea lions will be able to survive once they're returned to the wild after months of captivity.
JOSLIN: "Are there major learning experiences that animal needed to acquire but were left out in terms of wild experience because they were held in captivity. The animal, for its own survival, has to fit back into the wild and catch its food. We think of the juvenile period as a learning curve and if I take a part of that away, are they going to adapt as well?"
The Alaska SeaLife Center still needs a permit from the National Marine Fisheries Service Office of Protected Resources to capture and hold endangered juvenile sea lions. It's a permit that even Atkinson admits will be hard to get.
ATKINSON: "It's probably going to be a nightmare for them. On the other hand I think for the future of the species and for the research we're conducting, I think it is the way research should go."
A decision on the permit is still months away. Meanwhile, Atkinson says the center has already begun preparing facilities to house and care for the sea lions, and hopes to be able to capture the first round of juvenile Stellers as soon as next fall.
OUTRO: This is Arctic Science Journeys Radio, a production of the Alaska Sea Grant Program and the University of Alaska Fairbanks. I'm Doug Schneider.
Audio version and related Web sites (sidebar at top right)
Thanks to the following individuals for help preparing this script:
Paul Joslin, Executive Director
Jack Sterne, Attorney
Arctic Science Journeys is a radio service highlighting science, culture, and the environment of the circumpolar north. Produced by the Alaska Sea Grant College Program and the University of Alaska Fairbanks. The shortcut to our ASJ news home page is www.asjnews.org.
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Related Web sites
Is It Food? (book about sea lion declines)
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