Wearing a pair of orange gloves, Obama examined some of the fish that he caught at Kanakanak Beach in Dillingham. The second one he picked up began squirting at his shoes.
"Uh-oh, what's happening there?" he asked.
A woman standing by him explained that the salmon was spawning.
"Did you see that? Something got on my shoes," Obama told the media.
"He was spawning a little bit, which, generally you don't want fish spawning on your feet," CNN quoted him as saying.
Obama is currently in Alaska for a three-day tour of the vast state to raise awareness of the effects of climate change.