Smaller Squawfish Control Their Numbers, Study Says

Small squawfish are beneficial to trout and kokanee anglers, according to preliminary results of research on Lake Pend Oreille predator fish.

The finding that northern squawfish under 12 inches long primarily eat their own kind is one of the few surprises after the first year of a three-year study.

Dmitri Vidergar, who coordinates the research for the University of Idaho and the state Fish and Game Department, analyzed the stomach contents of 278 squawfish under 12 inches that were caught last year.

“They were hardly eating any kokanee at all,” he said. “Mostly, they ate other squawfish, indicating they help keep their own numbers in check.”

Squawfish longer than 12 inches, however, appear to be more likely to consume kokanee and trout, he said.

The researchers are working with the Lake Pend Oreille Idaho Club to get all the stomachs from the squawfish derby, which started May 23 and runs through Aug. 23.

“I hired a summer helper to clean every squawfish and keep the innards for study,” Vidergar said. “We’ve already had more than 600 pounds of fish to work with.”

Squawfish are not the only target of the Lake Pend Oreille study. Vidergar hopes to determine the population sizes of Kamloops, mackinaw and bull trout by having anglers report the numbers of fish that have been tagged by researchers and trained fishing guides. The study also should determine the food preferences of these predator fish.

However, the study also is dispelling some myths about the habits of these trout.

“We tended to think that the big Kamloops tended to hang out in favorite fishing holes within the lake,” Vidergar said. “But our tagging reports show that these fish move great distances from one end of the lake to the other.”

Anglers are the main source of information for the study, he said.

Tagged fish can be released. If an angler chooses to kill any trout or squawfish, Vidergar would like to have the intact stomachs saved in a zipper-type plastic bag.

Anglers who contribute to the study receive certificates detailing the history of the tagged fish.

Info: (208) 683-6083.