Streptococcus Syndrome Main Cause of Sea Otter Deaths

Dec 28, 2015

A dead sea otter on the beach at the Homer Spit on December 22, 2015.
Credit Photo by Daysha Eaton/KBBI

Tests results are back on dead sea otters from Kachemak Bay. About 82% of them had streptococcus syndrome, according to biologists with the U.S. Fish and Wildlife Service. Leslie Slater is a Wildlife Biologist with the U.S. Fish and Wildlife Service at the Alaska Maritime National Wildlife Refuge, in Homer.


Tests results are back on dead sea otters from Kachemak Bay. About 82% of them had streptococcus syndrome, according to biologists with the U.S. Fish and Wildlife Service. Leslie Slater is a Wildlife Biologist with the U.S. Fish and Wildlife Service at the Alaska Maritime National Wildlife Refuge, in Homer.

“So also in this stretch of beach, which has been under 200 yards or so that we’ve walked, we’ve come across now, looks like a yearling sea otter that’s died and a sub-adult male that’s died too,” said Slater.

Along the black pebbled beach at the homer spit, we step closer to a frozen otter just down from the Lands End Hotel and condominiums.

U.S.F.W Wildlife Biologist, Leslie Slater puts on latex gloves to handle the dead sea otter at the Homer Spit on Decmeber 22, 2015.
Credit Photo by Daysha Eaton/KBBI

“So you can tell that it’s a sub-adult because of its size and the tooth wear is pretty minimal, it’s got very white teeth. And this one happened to freeze in shape so you can see that the skin is sort of draping against the rib cage and it looks to me like it probably did die of starvation. We’ll have to thaw it out and do a necropsy on it to see what really happened with this one,” said Slater.

Since summer, more than 300 otters have died around Kachemak Bay. Joel Garlich-Miller, a biologist with the U.S. Fish and Wildlife Service Marine Mammals Management office in Anchorage, says they're still finding them.

“Things have dropped off quite a bit but we’re still getting reports of three or four animals a week, primarily from Homer area beaches,” said Garlich-Miller.

He says test results recently confirmed that it was the streptococcus syndrome that killed the otters in most cases.

“This is a syndrome caused by bacterial infection, streptococcal infection and it manifests itself in a variety of ways such as valvular endocarditis or septicemia or encephalitis. It looks like a pretty high percentage of the animals that we recovered this year, about 82%, appear to test positive for this syndrome,” said Garlich-Miller.

Garlich-Miller says most of the otters appeared to have deteriorated rapidly and succumbed to encephalitis. 

The Fish and Wildlife Service has been tracking a streptococcus illness in Kachemak Bay area otters for some time and otters with the illness usually appear sickly and emaciated. But many of the otters that have died since August appear healthier.  

Garlich-Miller says although strep syndrome appears to be the main cause of the deaths there are hints that some could have had a virus as well. Garlich-Miller says biologists are now collecting more dead otters, in order to test for viruses.

Back at the beach, biologist Leslie Slater, explains what you should do if you come across a dead otter.

“It’s best to call the sightings into the marine mammal stranding hotline, whether they’re alive or dead, and then there is another group of folks in town who will come and evaluate the carcass to see if it will be forwarded on for further pathology studies,” said Slater. 

Biologists hope those studies will shed more light on whether viruses had anything to do with the huge number of sea otter deaths this year.

Dead or dying sea otters and other marine mammals should be reported to the Alaska SeaLife Center’s Marine Mammal Stranding Network hotline at 888-774-SEAL (7325).