The French River cold water fish hatchery, just north of Duluth, will be closed, the Department of Natural Resources said Thursday, casting doubt on the long-term future of the lake’s Kamloops rainbow trout, a favorite of anglers who prefer to fish Lake Superior from shore.

The hatchery is highly inefficient and consumes as much as 10 percent of all energy used by the DNR, said fisheries chief Don Pereira.

Pereira estimated the cost of each Kamloops rainbow produced at the hatchery and later caught by anglers to be as much as $200. Water from Lake Superior must be heated to raise fish there, Pereira said.

Between 1,000 and 1,200 anglers regularly pursue Kamloops rainbows, according to the DNR, casting from shore mostly between Duluth and Two Harbors.

Kamloops are domesticated rainbow trout that can’t reproduce in the wild. About 92,000 Kamloops yearlings are stocked in Lake Superior annually.

The French River cold water hatchery was designed to produce lake trout, a Lake Superior fishery that has recovered and is no longer dependent on stocking.

“Closing French River is a difficult decision,’’ Pereira said. “We know Kamloops anglers aren’t happy.”

Four DNR employees at the facility will be reassigned when Kamloops production shifts next year to the DNR’s Spire Valley Hatchery near Remer, Minn., Pereira said, though it’s unclear whether the move will ensure continued production of the fish.

Some Kamloops rainbows already are produced at Spire Valley, but fish reared there are stocked at a smaller size than those from French River.

Anglers worry that Kamloops produced at Spire Valley and released into Lake Superior will be caught as adults at an even lower rate than French River Kamloops, dooming the program.

“Kamloops returns will drop from around several thousand to only around 900 (at best!) with the Spire Valley Hatchery,” the North Shore group Kamloops Advocates warned Thursday on its website.

Only modernization of the French River hatchery and retention there of Kamloops production can ensure the fishery’s future, the group believes.

French River’s continued Kamloops production “is necessary to provide an effective combination of the best stocking size, stocking timing, and imprinting to create a successful return rate for the Kamloops program,’’ the group said.

But Pereira said another concern about Kamloops rainbows is their possible interbreeding with steelhead rainbow trout, a wild-producing species that is also popular with North Shore anglers. (Steelhead fry from wild stock currently are produced for planting in some Lake Superior streams at French River. That effort will continue at Spire Valley.)

Recent advances in genetic research methodologies might determine whether steelhead and Kamloops are interbreeding, a possibility that could threaten the steelhead’s viability.

Some North Shore steelhead anglers last spring collected scales from fish they caught to be studied by geneticists at a cost to the DNR of about $8.

“Steelheaders’’ often hike far upstream along North Shore rivers to cast yarn flies and other attractants into fast-­rushing waters — making the fish generally more challenging to catch than Kamloops.

Steelhead that are caught must be released, while Kamloops anglers can keep three fish longer than 16 inches. Some Kamloops weigh 5 pounds or more.

“Kamloops fishermen don’t have to spend a lot of money,’’ said Russ Francisco, owner of Marine General sports shop in Duluth.

“Looper’’ anglers cast crappie jigs or similar lures, often baited with wax worms, into Lake Superior from shore, fishing the rigs below bobbers usually in water 10 feet deep or less.

“The heyday for Looper fishing was a decade or so ago,’’ Francisco said. “A lot of people up here feel the DNR turns its back on Duluth when it comes to things like this. If we had more people and were closer to the Cities, we might be able to change it.’’

Kamloops Advocates hopes pressure on legislators can result in the French River hatchery being updated, rather than closed. Cost of modernizing the facility is estimated to be $8 million or more.

Meanwhile, the DNR hopes to expand inland trout fishing opportunities in northeast Minnesota by “cleaning out’’ certain cold, deep-water lakes of their present fish and stocking them with splake (a hybrid of brook trout and lake trout), brown trout and rainbow trout.

“My general philosophy of fisheries management is to provide a diverse array of fishing opportunities,’’ Pereira said. “But in my mind it’s irresponsible to support a program in which the harvest is so expensive.’’

 

Dennis Anderson danderson@startribune.com