Lake Pend Oreille sees highest kokanee density in two decades

Fisheries researchers estimated that over 2.5 million adult kokanee occupied Lake Pend Oreille in the fall of 2019, the highest count on record since the mid-1990’s. As summer heats up, reports are starting to roll in that anglers are reaping the benefits of a highly abundant kokanee population.

Tom Anderson at North 40 in Sandpoint has been hearing good things from his customers. “One of our guys has been fishing in Ellisport Bay and they knocked them dead the other night,” Anderson said. “I’ve also heard some good reports out of Garfield and the odd report of good fishing at the Monarchs.”

Most kokanee anglers know that when there are lots of fish, individuals tend to be smaller.

“That’s because when more kokanee compete for a limited food supply, they all get less to eat and growth slows down,” said fisheries biologist Sean Wilson.

The large population would normally have biologists predicting smaller-than-average adult sizes. However a “bonus class” of 4-year-old fish may be boosting the fishery, both in numbers and in size.

“As of last fall, some of the age-3 fish hadn’t matured yet,” Wilson said. “They were big enough to catch in fall 2019 and will only be bigger this year.”

So far, there are good signs that these four-year-olds are contributing to the quality fishing on Pend Oreille. Anglers are reporting average kokanee size is 9-10 inches. By fall, these fish will have grown another inch.

Biologists believe aggressive predator suppression for lake trout and walleye, coupled with low numbers of Mysis freshwater shrimp, are creating good conditions for abundant kokanee right now.

Kokanee are the keystone of the Lake Pend Oreille fisheries. Not only are they a popular sport fish in their own right, but they also provide the necessary forage to grow world-class rainbow trout, sustain native bull trout and feed a myriad of other predators.

Biologists have documented a boom in juvenile kokanee as well as adults. Since 2012, the number of juvenile kokanee (age 1-3 years old) has exceeded the 20-year average, totaling between six to 12 million fish each year.

Although these young fish are too small for anglers to catch, they provide the food base for big, predatory fish like rainbow trout. In fact, Pend Oreille researchers have been able to link fast rainbow trout growth rates to high juvenile kokanee abundance.

“We anticipate that trophy rainbows have been growing at rates on par with the early ‘90s,” Wilson said. To that end, a young angler caught a new state catch-and-release record Gerrard rainbow trout in Lake Pend Oreille in October 2019. The fish measured in at 36.5 inches.

With promising data, fishing reports and unbeatable scenery, summer fishing on Lake Pend Oreille is shaping up to be a productive season for kokanee anglers.