Just When You Thought ...

...it was safe to go back in the water.

Sea otters face a growing threat: shark attacks

California's sea otters have struggled for years with diseases, parasites and even the occasional collision with boats. But now the fuzzy coastal mascots are increasingly facing another threat: shark attacks.

For reasons still a mystery to scientists, the number of sea otters killed by sharks has soared in recent years, with great whites as the leading suspects.
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In the mid-1990s, about 10 percent of the dead sea otters found along the California coast had shark bites. Today, it's about 30 percent -- and growing -- to the point where shark attacks now represent the largest hurdle to the otters' recovery from the endangered species list.

Sea otters may be cute and fuzzy little acrobats in the water, but something out there is doing a number on the population. And scientists aren't sure why the sharks are going after them. Perhaps the sharks need glasses. Or maybe they are just opportunists.

One major change: the abundance of elephant seals. Until 1990, the large mammals were rare along the coast in San Luis Obispo and Santa Barbara counties. But that year, two dozen came ashore at Piedras Blancas, near Hearst Castle. Now there are more than 15,000.

A small number of white sharks, perhaps juveniles, could be coming into the area to feed on young elephant seals and ending up killing otters, as well, Tinker said. Had the rate of shark attacks remained where it was a decade ago, there would be about 500 more California sea otters now -- around 3,250, according to his computer models. That would be enough to reach the 3,090 population target to remove the otter from the federal endangered species list.

In any case, the sharks have discovered something the killer whales up north have known for a couple of decades: Sea otters taste good.

In the 1990s, Tinker and other biologists published studies showing that orca whales in southern Alaska were beginning to feed on otters there. Since then, the otter population there has fallen from 80,000 to about 5,000.

The question then arises:

Can anything be done?

No, he said. Even if people wanted to try to identify the sharks responsible and somehow kill them, others could easily take their place.

"It's a hard thing to explain to people," he said. "But there's nothing we can do about changes in shark distribution or shark behavior. It's natural."