Otter Population Up 10.9%, Tally Finds

The annual spring count of California sea otters found the population up 10.9% over last year, but scientists cautioned Monday that more surveys are needed to determine whether the threatened species is recovering.

The U.S. Geological Survey’s count along 375 miles of the central coast, from Santa Barbara north to Half Moon Bay, found 2,317 of the furry animals compared with 2,090 in spring 1999. It also found the first increase across age groups in five years.

“It’s certainly better news than if we had a lower count,” said James A. Estes, a Santa Cruz-based U.S. Geological Survey scientist with the otter recovery program. “But until we have a couple more years of data, it’s very premature to embrace this as a trend.”

Brian Hatfield, a U.S. Geological Survey wildlife biologist at a station near San Simeon, concurred that several years of similar findings would be needed to be confident about the direction of the otter population.

“We think we see a very high percentage of the number of animals out there,” he said. “We don’t pretend to see them all, and they do vary from year to year. So we’re uncomfortable to say too much about a single count.”

The greatest number of otters tallied since the current method was adopted in 1982 was 2,377 in 1995.

The new survey showed a 13.8% increase in pups over spring 1999, and a 10.5% increase in adults and subadults.

There have been greater numbers of pups tallied previously, but the new count reflected the greatest number of adults and subadults since 1995, Hatfield said.

The survey was conducted by the U.S. Geological Survey, the California Department of Fish and Game, Monterey Bay Aquarium and experienced volunteers. The count is conducted by spotters on shore and aboard airplanes.

The typical adult male otter weighs 60 to 75 pounds; a female adult averages about 45 pounds. Offspring are pups for about six months.

Estes said one reason for concern about the increased count is that it is inconsistent with mortality data. There has been no great decline in the number of dead otters found, he said.

A count also is done each fall and the population number is always lower than in spring because seasonal growth of kelp with bulbous gas floats makes it difficult to spot otters floating on the surface.

The California sea otters are descendants of a group that survived along the Big Sur coast after 19th century fur traders hunted sea otters to the brink of extinction.

Sea otters once ranged in an arc around the North Pacific from northern Japan to the Pacific coast of Baja California, Mexico.