ECOLOGY:
Sea Otter Declines Blamed on Hungry Killers
Jocelyn Kaiser
Sea otters off the Alaskan coast play a pivotal role in marine ecosystems: By dining on sea urchins, the animals help preserve kelp forests that feed a range of species, from barnacles to bald eagles. Now, on page 473, a team of ecologists has documented a 90% crash in sea otter populations in western Alaska's Aleutian Islands since 1990, with devastating effects on kelp forests. The reason for the crash, the researchers believe, is that killer whales, never before known to eat sea otters, appear to be snacking on the creatures, apparently because their usual food source--seals and sea lions--is declining.