It’s no secret that Idaho steelhead and salmon anglers rely on hatcheries for fish that they can take home and eat, and anglers can identify “keepers” because a small fin on their back is removed when the fish are young. The clipped adipose fin does not grow back – letting anglers identify hatchery fish for harvest. What’s less known is how the fins get clipped.
Idaho hatcheries produce about 20 million young salmon and steelhead annually that are released in the spring to migrate to the ocean. Clipping millions of tiny adipose fins is a huge undertaking that used to take thousands of hours of manual labor.
Now it’s largely automated with specialized trailers traveling to hatcheries throughout the state to safely, effectively and efficiently prepare hatchery smolts for release so they can be identified by anglers, biologists and conservation officers when the salmon and steelhead return from the ocean as adults.
Machinery housed in the trailers clips fins and also implants tiny wire tags into the fish without the need for anesthetic, removal from the water, or handling by a human. The machinery has a system that holds fish immobile so coded wire tags can be inserted. Almost simultaneously, an imaging system determines the location of the adipose fin then sends an electronic message to an automated clipping device that removes the fin.
You can see the fish getting marked during a series of events in the coming months. Visitor hours will be 8 a.m. to 4 p.m. June 2 at Clearwater Hatchery near Ahsahka and June 16 at Rapid River Hatchery near Riggins.
IDFG also has scheduled dates elsewhere. Contact Idaho Fish and Game at 334-3791.