(AP) -- A 21-year-old northern sea otter who survived the 1989 Exxon Valdez oil spill in Alaska died Thursday at the Seattle Aquarium.
Nuka had lived at the aquarium since 2001 after spending the earlier part of her life at a Chicago aquarium.
Aquarium officials say Nuka was considered geriatric and her health had been declining over the past several months. Aquarium staff and mammal biologists and her veterinarian decided the time had come to euthanize her.
Nuka was the oldest of the aquarium's sea otters.
Explore further: Insect mating behavior has lessons for drones