Sea lion deaths still a mystery

PORTLAND – An examination of the heads of six sea lions that died in traps at Bonneville Dam on the Columbia River hasn’t given federal investigators reason to pursue toxicology tests to see whether the animals were poisoned, an official of the National Marine Fisheries Service said Thursday.

Beyond that, however, federal officials revealed little about the mystery surrounding the deaths of the six animals trapped in cages as part of an effort to keep them from feeding on endangered salmon.

Fisheries officials have ruled out their initial assumption the six sea lions were shot to death and say they are still puzzled about how the animals came to be trapped in the cages. The trap doors had been left open, so the sea lions would grow accustomed to them until it was time to send them to aquariums.

Specialists at a U.S. Fish and Wildlife Service forensic lab in Ashland examined the sea lion heads and sent findings on to the fisheries agency, which is investigating the deaths. Their report wasn’t made public.