North Shore steelhead anglers have long wondered how much interbreeding goes on between wild Lake Superior rainbow trout — steelhead — and their hatchery-reared counterparts, Kamloops rainbow trout.
Now, steelhead anglers are invited to help Minnesota Department of Natural Resources fisheries biologists try to answer that question with a soon-to-launch steelhead genetics study. Precisely where anglers’ services are required is on the stream, once a steelhead has been landed.
Participating anglers who have registered with the DNR and possess the proper permit will be asked to scrape a few scales from the fish, slip them in an envelope and return it to the DNR.
“We’re trying to figure out if hybridization occurs in the wild and if hybrid offspring have survived to be caught as adults,” said Nick Peterson, DNR migratory fish specialist at French River.
Previous genetic studies have indicated that some interbreeding of the two varieties of rainbow trout does occur on the North Shore. Very few young fish from that hybridization survive, Peterson said. But advances in genetic research techniques in the past few years make a new research project both appealing and relatively low in cost, he said.
“It’s about $5 to $8 a sample — much cheaper than it used to be,” Peterson said. “That’s a drop in the bucket to learn as much as we could learn.”
The Lake Superior Steelhead Association, Minnesota Steelheader and Trout Unlimited all have agreed to participate in the study. Minnesota Steelheader, a Twin Cities-based group, has created packets to distribute to anglers and has produced a video that shows anglers how to remove scales.
Peterson stresses that anglers must first contact his office at French River, preferably in person, to obtain a DNR permit allowing their participation in the study. Anglers must have those permits with them on the rivers this spring in order to take scale samples from fish they catch.
A tale of two rainbows
Steelhead, first introduced to Minnesota waters from the West Coast in 1895, are prized for their fight and their ability to leap North Shore falls. To protect the steelhead fishery, anglers must release all steelhead they catch.
Kamloops rainbows are raised from eggs taken from adult Kamloops rainbows captured at the French River and reared at the DNR’s Spire Valley hatchery near Remer and the French River Cold Water Hatchery on the shore of Lake Superior. They are stocked in a limited area from Duluth to the French River. They typically return to spawn after a few years in Lake Superior, but biologists assume that little successful spawning occurs in streams. Anglers may keep three, with a minimum size of 16 inches.
Although Kamloops rainbows are stocked in the limited area near Duluth, they have strayed to other streams as far as the Devil Track River northeast of Grand Marais, Peterson said. Steelhead spawn in many streams along the Minnesota and Ontario North Shore, as well as in Wisconsin and Michigan rivers. Many steelhead anglers are concerned that if steelhead try to spawn with Kamloops rainbows, the progeny will not survive.
Limited studies by the DNR on the Lester River in 1999 and on Amity Creek and the Sucker River in 2004 favored survival of fish from a steelhead-steelhead cross, Peterson said.
“Others (such as steelhead-Kamloops hybrids) were few and far between,” he said.
Davin Brandt, president of Minnesota Steelheader, is eager to see what the study turns up about the interbreeding success of steelhead and Kamloops rainbows.
“We’re seeing them mingling,” Brandt said. “We’d like to know if these fish are surviving. We strongly support the natural reproduction of steelhead.”
Carl Haensel of Duluth Township is the northern Minnesota vice-chair of Trout Unlimited, a group that has done habitat work on North Shore streams.
“One of our concerns has been steelhead interbreeding with Kamloops,” Haensel said. “We think it’s important to do this type of genetic analysis so we can preserve and enhance our wild steelhead run.”
Craig Wilson, president of the Duluth-based Lake Superior Steelhead Association, said he doesn’t think a steelhead-Kamloops or even a Kamloops-Kamloops cross produces viable offspring.
“I don’t think it exists,” he said. “They just aren’t strong enough to survive.”
Once the DNR obtains steelhead scale samples from anglers, the DNA will be analyzed. No DNA will be taken from Kamloops rainbows. The study will be done over several years, Peterson said.
The idea came up during recent stakeholder meetings about updating the DNR’s Lake Superior Fishery Management Plan, which is due out in early April. The plan is updated every 10 years, and Peterson said this DNA study of steelhead is aimed at providing information that will help guide the next update a decade from now.
If you want to participate
- First, contact the Minnesota Department of Natural Resources area fisheries office on Scenic Highway 61 at the French River, preferably in person. Sign up to take part in the genetics study. Pick up a permit allowing you to take part in collecting scale samples and a packet of necessary materials. For more information, contact Nick Peterson at (218) 302-3272 or firstname.lastname@example.org.
- Watch the video showing how to remove scales from a steelhead. Watch it with this story at duluthnewstribune.com.
- Instructions in your scale-sampling kit will tell you how to return scale samples to the DNR’s French River fisheries office.