September 12, 2006

The Working Group on Marine Mammal Unusual Mortality Events has determined that a significant increase in sea otter deaths in Kachemak Bay in recent years constitutes an Unusual Mortality Event (UME). This determination comes in response to a request for such a finding by the U.S. Fish and Wildlife Service's Alaska Region Marine Mammals Management Office. This declaration will provide the Service with access to expertise and funds that will help us conduct an in-depth analysis on the overall health and population size of Kachemak Bay sea otters. It is also hoped the UME will raise public awareness of the situation so that more sea otter carcasses can be recovered.

Since 2002, Service biologists have reported an increase in sea otter mortality in the Bay. The predominant cause of death among the animals necropsied has been damage to the heart resulting from Streptococcus bovis/equinus, a bacterial infection. It is not known whether some other factor might be increasing the susceptibility of otters in this population to such an infection.

As a consequence of the UME, a team of internationally recognized marine mammal disease experts will travel to Alaska in November to work with the Service in determining a plan of action to address this mortality. In the interim, the Service will continue to collect and analyze samples from the dead otters. Plans for 2007 include capturing live sea otters in Lower Cook Inlet to screen them for infectious diseases, and conducting aerial surveys to look at sea otter population trends in the area. The last aerial survey of sea otters in Kachemak bay was conducted in 2002, about the time the current mortality event apparently began. An updated aerial survey of Kachemak Bay and adjoining Lower Cook Inlet would allow biologists to estimate the impacts this mortality event has had to date, and provide baseline numbers should the event continue or worsen.

Sea otters in the Kachemak Bay area belong to the southcentral Alaska population. A few cases of Streptococcus infection have also been observed in the southwest Alaska population of sea otters now listed as threatened under the Endangered Species Act, and one case has been reported in the southeast population. There are no obvious human health concerns, though Service biologists wish to remind the public to not handle any live or dead sea otters that they may find on the beach. If you do find a dead or sick sea otter any where in Alaska, please call the Fish and Wildlife Service immediately at 1-800-362-5148. The Service will arrange for shipment and treatment or necropsy of the animal. Guidelines for notifying authorities can also be found at: http://alaska.fws.gov/fisheries/mmm/strandings.htm.