A Hawaiian monk seal that became a fixture at Kailua Beach this year has been found dead of apparent natural causes on Rabbit Island, officials said yesterday.

The body of the seal known as RK15 to scientists, but named Chester by his admirers, was retrieved Wednesday night by National Marine Fisheries Service marine mammal experts.

Chester turned up at Kailua Beach on New Year's Day and stayed for nearly the entire month of January while he shed his skin.

"We're very disappointed and sad by the loss of this animal," Marine Mammal Response Coordinator David Schofield said.

"It's a huge loss," said Donna Festa, who was one of the volunteers who protected Chester from beachgoers and dogs during January. "I just wish he was here a little longer. It's very difficult for me to think I'm not going to ever see him again."

Schofield said there are 80 more seals in the main Hawaiian Islands that need to be cared for.

Only about 1,100 Hawaiian monk seals remain in the wild.

Chester was discovered in 2002 on Kaua'i, and was later spotted at several O'ahu beaches.