Students examine dead otter

ASU students had the unusual experience of examining the cause of death of a sea otter that died of a strange infection caused by the morbillivirus microogranism. The male Washington sea otter was found May 21, 2007, at Rialto Beach in the Olympic National Park in Washington state. The animal was found still alive but died while being transported to a rehabilitation center. Sea otters, unlike other marine mammals, have very little body fat to protect them from the cold waters of the Pacific Northwest where they live. They can withstand the cold temperatures thanks to having the densest pelage among all mammals: up to 380,000 hairs per square inch. That, together with sebaceous glands under their skin that produce an oily substance that covers their hairs, allows them to have a waterproof barrier to conserve body heat. Age among sea otters can be calculated by counting the number of rings in their teeth. Just as trees, each ring represents a year in the life of these animals. What was really special about this sea otter was the presumptive cause of death: a morbillivirus infection. The first indication that this animal died of this unusual disease was the fact that when examined, its brain showed a condition known as encephalitis. Encephalitis is an inflammation of the brain caused by an infection. Lab studies confirmed that the agent causing that infection was a morbillivirus. However, this condition was not detected among marine mammals until 1988, raising the possibility of transmission from domesticated animals such as dogs into these sea creatures. This is the first documented case of a morbillivirus incident among sea otters. The real problem with this virus is that it can be transmitted to humans, with fatalities occurring in more that 50 percent of cases. Because of this, students handling the carcass of the sea otter at the ASU mammalogy laboratory had to wear protective gear. The students handling the animal directly had to wear biosafety suits. Both the skeleton and the pelt of this sea otter will be on exhibit in the Hall of Science in Laboratory Sciences Center, East Wing by January 2009. These studies of the causes of death among animals are a regular feature in some of the courses offered at ASU. In spring 2009, students of the marine mammal lab course will have the opportunity to conduct similar investigations on an elephant seal from California.