“Getting into the shallowest areas and then just trying to make as little noise as possible is the way to go,” said U.S. Fish and Wildlife Service biologist Josh Rasmussen.

Rasmussen, who until changing jobs this past fall was the service’s sucker recovery program coordinator in the Klamath Basin, is following behind two divers with a net as they move smoothly upstream — a sort-of drysuit ballet.

“Then you just have to slowly get up behind them and grab them by the tail… What we call the caudal peduncle, the fleshy part [in front] of the tail,” he said.