Sharks blamed for record number of sea otter deaths in local waters

Posted: Feb 28, 2012 11:59 PM by Ariel Wesler
Updated: Feb 29, 2012 8:19 AM

A record number of sea otters died last year in California and scientists are searching for solutions. The U.S. Geological Survey says 335 dead, sick or injured otters were found and one major culprit is sharks.

One local biologist says it's an alarming trend. He is seeing the largest increase in the number of sea otters being killed by sharks right here on the Central Coast. He studies southern sea otters from Cayucos to Pismo Beach.

It's marine mystery puzzling scientists.

"We're seeing an unusual trend in the increased number of shark-bitten otters," said Sea Otter Biologist Mike Harris with the California Department of Fish and Game.

Harris has been studying sea otters for the past two decades. Now he and other scientists are trying to determine why sharks are killing them off at a rapid rate, especially on the Central Coast.

"It's perplexing to me and I've been covering this section of coast and doing this work for over 20 years now."

In the late 1990s, biologists say sharks were responsible for about 15 percent of sea otter deaths here on the central coast. In 2011, that number had jumped to 40 percent.

One popular place to spot sea otters on the Central Coast is along the kelp beds near Morro Rock. While you won't find sharks there, scientists say they're killing more and more otters, not by eating them but by biting them.

Based on the bite patterns and tooth fragments, experts believe most of the culprits are white sharks that could be mistaking them for seals or sea lions.

"It could be that there's an increase in the number of white sharks in the area. It could be that there's a component to the white shark population or a few individuals that are changing behavior. We don't know," Harris said.

To make matters worse, a growing number of the sea otter victims are female.

"If the females aren't there to reproduce and put pups into the population, it's a greater loss," Harris said.

Sea otters are already listed as threatened under the federal Endangered Species Act.

Scientists say they will continue monitoring the situation and working with shark researchers to find solutions.

Harris says in the meantime, the public should minimize its impact on otters by keeping the oceans clean.

If you'd like to know what you can do to help save the sea otters, click here.