Sickness

Disease is often a killer of sea otters. Forty percent of the Californian Sea Otters die because of diseases.  Those 40% that were examined died from parasites, bacteria , or fungal infections.

Peritonitis was the most frequent disease that was found and identified in the dead sea otters. This peritonitis occurs when acanthocephalan parasite moves through the intestine walls and allows bacteria to enter the abdominal cavity.

Coccidiodomycosis also known as San Joaquin Valley Fever had been in a couple of sea otters.  This disease does best in arid soil. Inhaling the fungus soil my produce respiratory disease.  The cases of the sea otter’s San Joaquin Valley Fever is  similar to the human epidemic fever that began in California in 1991, by unusal weather and environmental conditions.

Storms

Winter storms have been linked to sea otter deaths.  When big storms occur they produce high waves which can cause sea otters to lose sight of one another, and for the mothers and their young pups to become separated. The very intense winter storms during the El Nino of 1997-1998, and another in 1982-1983, caused an unusually high number of pups to become lost from their mothers, and many died.

All three sea otters now living at the Monterey Bay Aquarium were abandoned or lost after stormy weather. Study the sea otters to find more information on the diseases that effect them.

Sharks

In Alaska, the Alaskan Sea Otters have been found killed by Killer Whales. The Great White Sharks have been eating 10-20% of the California Sea Otters. The biologists who examine the dead sea otters find shark teeth in the flesh and in the fur of the dead bodies.

One Sea Otter, Skipper, has a big scar on his lip from a Great White Shark attack, which gave him the nickname, “Scarlip”. Skipper is one of the lucky ones that survived a shark attack. Most otters die from one.  Large rocks probably attract the white shark, and when they see a California Sea Otter, it might be mistaken for a Sea Lion.

High Pup Deaths

As many as 40% of the California Sea Otter pups die before reaching the  weaning age of 4 months.  The Alaskan sea otter does not have as a high loss of pups, but the California Sea Otter population has leveled slowly, compared to the nothern population.  A reason for the high loss of pups in the Southern Sea Otter population might be that the Alaskan sea otter has thicker hair and is heavier. Scientists think that California female sea otters might of gotten a disease or a parasite that causes the pups to be very weak.