Scientists Stumped on Mass Sea Lion Strandings

More than 1,000 have washed up on California's shores

Scientists still don't know why nearly 1,300 sickly sea lions have beached themselves on the shores of southern California since the beginning of the year. However, they think some weird oceanic phenomenon may be blocking off the sea lion pups' source of food, scientists reported today (April 17).

The stranded sea lions -- mostly pups born last summer -- are typically turning up alive, but severely emaciated, some weighing less than 20 pounds (9 kg) when they should be well over 50 pounds (22 kg), marine officials say.