Sea otters rebound, but their habitat shrinks

MOSS LANDING, Calif. — While threatened southern sea otters bob and sun in the gentle waves of this central California estuary, wildlife experts up and down the West Coast are struggling to figure out how to restore the crucial coastal predator to an undersea world that’s falling apart in their absence.

Southern sea otters, nearly wiped out by centuries of industrial-scale hunting for their fur pelts, have rebounded from as few as 50 survivors in the 1930s to more than 3,000 today, thanks to federal and state protection.

But there’s a problem. Southern sea otters, a top carnivore that normally helps keep other populations in check and ecosystems in balance, “are kind of stuck,” said Teri Nicholson, a senior research biologist at the nearby Monterey Bay Aquarium.

Despite decades of Southern sea otters, such as this one at the Monterey Bay Aquarium in California, have made a comeback after nearly being wiped out by the fur trade. But outside their federally protected enclave along the central California coast, much of the otters’ habitat has disappeared. government protection, southern sea otters today still occupy only about a fourth of their historic range. Federal wildlife policy calls for waiting for the otters to spread out again on their own. The otters’ habitat hasn’t really budged beyond their current central California enclave, however, over the past 20 years.

“At this point, I think for the population to increase, the range needs to expand,” said Karl Mayer, manager of the aquarium’s sea-otter program. It doesn’t really make sense, Mayer said, “to stuff more otters into a limited environment.”

Mayer spoke as his boat putt-putted among sea otters, harbor seals and pelicans crowding the salt-water estuary called Elkhorn Slough.

At the former whaling town of Moss Landing, the restored slough forms part of the southern sea otters’ modern-day range: 300 miles of coast along the middle of California.

Though small by marinemammal standards, sea otters are the largest members of the weasel family and males can grow to nearly 100 pounds. Their fur, the densest on Earth, keeps them warm.

Efforts to get the southern sea otters back into more of their old range reflect growing global recognition of the benefits of restoring top predators to their historic territory.