Scientists Puzzled by Drop in Otter Population

The sea otter population between Santa Cruz and Point Conception was down 12% from the count last fall, and the otter colony on San Nicolas Island is slipping toward extinction, federal authorities said.

Scientists are puzzled.

“We’re going to have to pay close attention to what’s happening. We can’t point our finger at any one thing,” said Carl Benz, assistant field supervisor for species listing and recovery in the U.S. Fish and Wildlife Service office in Ventura.

Disease and pollution are suspected, and Fish and Wildlife scientists will seek answers, Benz said.

The fall count showed 1,937 otters, just above the 1,850 mark under which they could be listed as endangered. Several years ago, southern sea otters numbered well above 2,000 and neared 2,650, the figure at which they would be taken off the protected list.

The number of pups was up this fall, compared with spring, but scientists expected females to produce more because of the numbers lost during El Nino’s winter storms.

Members of Friends of the Sea Otter, a watchdog group, were alarmed by the latest figures.

“We need heavy-duty money for research--now,” said Jeff Calder, the group’s executive director. “They are at the top of the food chain. That tells you something is wrong with our marine environment.”

Southern sea otters, one of 13 otter species worldwide, generally are found from Santa Cruz to Point Conception. A small population, less than two dozen, lives on San Nicolas Island.

They are listed as threatened under the Endangered Species Act.