Biologists asking angler help to collect SL chinook fin clips

Anglers who catch a chinook salmon in Spirit Lake are asked to provide a fin clip for biologists to use as part of a statewide chinook salmon study.

State fishery biologist Rob Ryan, of Coeur d’Alene, said the lake has been stocked with chinook salmon since 2016 and a portion of the two-year fish population should be nearing the 20-inch threshold. Anglers aren’t allowed to keep chinook that are under that size, but if they catch a chinook — with a telltale black mouth and gum line — a small fin clipping can be removed with scissors and a knife before returning the fish to the water.

The fin clip can be dropped off at Idaho Department of Fish and Game kiosks on shore where they will be used in a statewide survey to see how well triploid or sterile chinook, and diploid chinook, fish that can reproduce, are surviving in the state’s landlocked lake systems.

“They are looking at triploid chinook, how well they perform, relative to a diploid,” Ryan said.

Biologists will use the fin clippings to gather genetic information.

The state stocks land-locked chinook in lakes and reservoirs at Anderson Ranch, Lucky Peak and Deadwood reservoirs in southwest Idaho; and Spirit Lake in North Idaho.

Signs and drop boxes, or kiosks, have been installed at those locations where anglers who catch a chinook can leave the tissue samples for research.

“To evaluate the performance of these fish, we are asking for anglers to provide fin clips,” research biologist Phil Branigan said. “We’re currently stocking two types of chinook in reservoirs, sterile and fertile, and we’re trying to learn which ones are more likely to get caught by anglers.”

Researchers are also doing work to determine how the two types of chinook differ in growth rates, said Roger Phillips of Fish and Game. The study is expected to last four to five years. In order to evaluate which fish do better in landlocked systems, biologists need anglers’ help.

“We can’t do this evaluation without their cooperation,” Branigan said.

Spirit Lake got its first batch of both fertile and non-fertile chinook, about 5,000 fish in 2016, Ryan said. A year later, about 6,000 were stocked comprised again of both triploid and diploid fish.

The fish can be used to curb the kokanee population, providing for larger kokanee, or blue back (also called silvers) salmon, and they can be a popular sport fishery, Ryan said.

The Spirit Lake fish, just like the Lake Coeur d’Alene chinook, spawn in the fall.

Anglers are asked to clip a portion about the size of a hole punch from any fin on any size chinook, place it in a plastic envelope provided at the box stations and deposit the envelope in the drop box at the Fish and Game kiosks at the Spirit Lake boat launch.

“We’re hopeful that by stocking the best type of chinook, we can ultimately make fishing better, so we’re optimistic anglers will help us with this project,” Branigan said.