What's killing the sea otters.

Los Angeles They're cute, furry, and when they're not chasing each other around kelp forests, they're floating on their backs like miniature teddy bears. Hunted nearly to extinction for their luxuriant fur--the thickest of any mammal's--the sea otters of California were making a comeback until they started mysteriously dying off. State wildlife officials recovered a record 281 dead otters last year, and this year looks to be even worse. Five or six wash up on California's beaches and rocks each week. In August alone, 28 dead otters were cast ashore, including an alarming number of full-grown females. "When we start losing breeding females," says veterinarian Mike Murray at the Monterey Bay Aquarium, "that's not a healthy population."