Otter that survived Exxon Valdez is euthanized

She'd stopped socializing and wasn't eating, and her behavior suggested she was suffering.

Days after a Seattle Times story highlighted Nuka the sea otter's health woes, biologists at the Seattle Aquarium did what they always feared they'd have to do: euthanize her.

Nuka, a gray-whiskered otter plucked from Prince William Sound soaked in oil in 1989, was put down Thursday after a visiting veterinarian determined her condition had worsened rapidly. Biologists feared she was living in pain.

"Because wild animals try to mask their symptoms when they're ill, you really have to look closely to see a decline," said Traci Belting, marine-mammal curator for the aquarium. "We see her every day. The vet sees her every two weeks."

Nuka was old for a sea otter, at least 21, one of only three otters still alive in captivity that had survived Alaska's Exxon Valdez spill.

But it was the potential impact of that exposure to Exxon's crude that thrust Nuka into the spotlight this week.

For years, Nuka had struggled with immune-system problems, poor skin and fur, and seemed unable to groom herself properly, which meant she ate more than normal to avoid hypothermia. While no one could say what caused her problems, they were consistent with early exposure to petroleum.

Nuka came to represent the kind of risks BP's oil spill poses for marine life in the Gulf of Mexico.

Oil has been linked to heart defects in fish, reproduction problems in whales, and cancers and immune-system trouble in creatures throughout the food chain.

The Seattle Times published a story about Nuka Tuesday, and several television news stations followed with similar stories.

But Wednesday, a vet from the Woodland Park Zoo made her regular rounds at the aquarium and determined the always-sickly Nuka was in worse shape than normal.

Nuka was lethargic, had begun soiling the rocks where she rests (otters defecate in water), and she'd lost weight. Her paws shook more than normal.

Aquarium staffers had kept a roster of Nuka's health issues as an attempt to keep tabs on her quality of life. They discussed their options Wednesday and Thursday and decided to euthanize her. "The staff met and talked, and 100 percent agreed," said C.J. Casson, the aquarium's life-sciences curator. "We wanted to know in our hearts that this was the right decision."

A necropsy suggested Nuka's quick decline was age-related, but it will be weeks before scientists know for sure.

Nuka, meanwhile, will continue to educate. Researchers from Monterey Bay and elsewhere will take tissue samples to boost their understanding of otters, and her skeleton and pelt will land in the University of Washington's Burke Museum.

And Casson hopes Nuka's life will help Northwest residents understand that the effects of an oil spill stretch beyond what we see.

"It's so easy for us in Seattle to just ignore what's going on the Gulf," he said. "I hope that this animal and her story really puts a face on what's unfolding in the Gulf. For us, it really put a face on the devastation."

Craig Welch: 206-464-2093 or cwelch@seattletimes.com