Rainbow run riddle: Where are the trout?
FRENCH RIVER — Ray Sickler of Knife River stood thigh-deep in Lake Superior at the mouth of the French River on Monday morning tossing a bobber-rig for Kamloops rainbow trout. The big rainbows should have been around, gathering offshore and migrating up the stream to spawn.
But after a banner year last year, the Kamloops rainbow fishing has been slow this spring. It’s also been a tough spring for anglers pursuing steelhead, Lake Superior’s other strain of rainbow trout.
“It’s been such a highly unusual year,” said Duluth’s Bruce Sederberg, who chases both the stocked Kamloops rainbows and wild steelhead.
Both strains have their devoted followers this time of year, and nobody is sure just why returns of rainbows have been lower than in recent years.
“It appears to be a poor year for both strains of rainbow trout,” said Josh Blankenheim, migratory fish specialist for the Minnesota Department of Natural Resources at French River. “We’re seeing it in both traps, as well as in our creel survey (of anglers).”
The DNR operates fish traps on the French River and the Knife River to monitor the rainbow fishery. Eggs are taken from Kamloops rainbows at the French River trap to raise next year’s young for stocking. Kamloops rainbows are entirely dependent on stocking. While steelhead reproduce naturally, the DNR supplements the population by stocking fry, tiny fish just beyond egg stage, in many North Shore streams.
Because both Kamloops and steelhead numbers appear to be down, Blankenheim thinks the problem is likely unrelated to stocking.
“That suggests to me it’s weather- or forage-related,” Blankenheim said. “If it was just the Kamloops strain, it might have something to do with the stocking program.”
Anglers and DNR fisheries officials cite a number of potential factors that could be affecting rainbow returns this spring. Those factors include stocking issues (particularly with Kamloops rainbows), a cold and partially ice-covered Lake Superior, high and cold run-off in North Shore streams, stream bed changes caused by the 2012 flooding and poor year classes of rainbows.
Kamloops issues Don Schreiner, DNR Lake Superior area fisheries supervisor at French River, is bewildered by how few Kamloops rainbows have been caught by anglers or netted by the DNR this spring.
The past two years saw high returns. Last year, the DNR caught 1,264 Kamloops rainbows at the French River trap, up a bit from the 1,242 in 2012. As of Wednesday, potentially midway through the run, just 225 Kamloops rainbows have been captured. Unless returns improve dramatically, this year will go down as one of the poorest for Kamloops rainbows in the past 20 years.
Kamloops rainbows typically return from Lake Superior at ages 2, 3, 4 and sometimes 5. A high number of 2-year-olds returned in 2012, Schreiner said, and the number of 3-year-olds returning last year was more than twice the long-term average. Four-year-olds typically make up the bulk of the return, and, based on last year’s above-average return of 3-year-olds, should be abundant this year. But so far that hasn’t been the case.
“The year classes were all here last year,” Schreiner said. “Where the heck are they this year?”
Ross Pearson of Duluth leads a group called Kamloops Advocates and is an avid Kamloops angler.
“I think all season long, there’s been one day when there were 30 fish caught,” Pearson said. “Last year, there were many days with 30 fish caught.”
Pearson contends that shifting most of the Kamloops rearing to the Spire Valley Hatchery near Remer, and away from the French River Hatchery, results in stocking the fish at a smaller size. When they’re stocked smaller, they’re more vulnerable as prey for Lake Superior’s big lake trout and salmon, he says. Fewer survive to return to the streams as adults, Pearson says.
But he can’t explain why plenty of the Kamloops rainbows that returned as 2- and 3-year-olds last year are not showing up as 3- and 4-year-olds this year.
“That’s perplexing,” Pearson said.
Last year, 736 of the Kamloops rainbows were netted as 4-year-olds by the DNR. Those fish would have been raised in the hatchery in 2009, and that was the last year that all rearing was done at French River, before the partial switch to Spire Valley. Pearson still believes that the hatchery switch could be a factor.
Steelhead situation So far this spring, the DNR has captured 242 steelhead at its Knife River trap. The trap was not in use last spring after being damaged in the 2012 flood.
Sederberg said he thinks lake and river conditions may have inhibited the steelhead spawning run.
“My best guess is, we had all that ice and colder than usual water (on Lake Superior),” he said. “I think it may have slowed down their maturity or affected their internal time clocks. Then, when we had a lot of water (in streams), the rivers were high and unfishable. And I’m sure some fish went in (to spawn) then.”
Or, he said, it could be a poor year class of steelhead and the numbers simply aren’t there.
There have been wide fluctuations in returns of steelhead and Kamloops rainbows over the years, the DNR’s Blankenheim said.
“It’s just nature,” he said. “At this point, I won’t get too excited about a year of poor rainbow trout fishing, unless we see a series of consecutive years where fishing is really poor.”