The animal, a 1,454-pound adult male being held temporarily at the Point Defiance Zoo and Aquarium, failed to resume breathing after being anesthetized for the examination.

A team that included an Oregon veterinarian, a state marine mammal biologist and a federal animal-care expert had concluded the health exam and were attempting to bring the animal out of anesthesia when the death occurred.

A necropsy is being performed to determine the exact cause of death.

The sea lion is one of seven captured during the past week for relocation to designated zoos and aquariums.

The captures are part of an effort by Washington and Oregon wildlife managers to reduce the number of California sea lions preying on protected salmon and steelhead below Bonneville Dam.

The animals are being held in temporary quarantine at the zoo for disease testing in preparation for permanent placement at designated zoological facilities around the country. Zoo staff were not involved in the health examination.