CHICAGO — Kenai the sea otter was only a pup in 1989 when the Exxon Valdez tanker leaked 11 million gallons of oil into the Prince William Sound in Alaska.
The spill killed a lot of wildlife, including almost 2,000 otters, but Kenai was rescued, rehabilitated and eventually moved to the Shedd Aquarium.
After a long life of 23 years, health problems led to the decision Tuesday to euthanize Kenai, one of only two sea otter rescued from the Valdez spill still living.
“The past 24 hours have been very difficult for the entire Shedd family who held a special place in their hearts for Kenai,” Ken Ramirez, executive vice president of animal care and training, said Wednesday in a news release. “It was a difficult, yet clearly compassionate decision as her quality of life quickly deteriorated over the last several weeks.”
Experts from around the country, including Ramirez and Jim Robinett, the aquarium’s senior vice president of external and regulatory affairs, went to Alaska to help in rehabilitation and cleaning efforts. Sea otters lack blubber and rely on their dense fur and fast metabolisms to survive frigid waters, and without help their oil-soaked fur was a death sentence.
Rescued adult otters could be rehabbed and released back into the wild, but pups lacked the survival skills they would have received from their moms so had to be hand-raised in places like the Shedd, which has an otter rescue program, officials said.
At 23, Kenai exceeded the known median life expectancy of sea otters—typically 15 to 18 years. She and another female currently living at Point Defiance Zoo and Aquarium in Tacoma, Wash. were the last two Valdez oil spill otter survivors in the U.S.
“It’s been an incredible journey to watch her thrive throughout her years at the aquarium, Robinett said.
Kenai took the role of a protective surrogate mother for several of Shedd’s other young rescue otters, and she also enjoyed the company of Kachemak, another aging otter with whom she often shared a reserve pool, Shedd officials said. In 2010, she had a root canal procedure performed on a cracked upper canine tooth but recovered well.
As the smallest marine mammal, sea otters are members of the weasel or mustelid family, according to the Shedd release. Instead of blubber to keep them warm, they have very thick hair that consists of two layers: an undercoat and longer guard hairs. The otter’s fur is important to their survival, so they spend up to four hours a day grooming. If they do not keep their coat immaculate, they risk getting cold and dying of hypothermia.
Pups stay with their mothers until they are 8 months old. Sea otters must eat at least 25 percent of their body weight each day to maintain a high metabolic rate, which keeps their internal body temperature at 100 degrees. They eat bottom-dwelling nearshore animals, such as abalone, clams, sea urchins, crabs and octopus.