By Nick Simonson
Twenty years ago, a collection of biologists and fisheries scientists set out to reestablish a population of lake sturgeon in the Red River basin straddling the North Dakota-Minnesota border; just this week members of the cooperative group began seeing their vision, which started with the stocking of fish two decades ago, come to fruition with the identification of spawning sturgeon in the river system.
“This week [of May 15] we found our first sexually mature, adult lake sturgeon in the Red River basin, just below the Big Pine Lake dam on the Otter Tail River east of Perham, Minn.,” said Jamison Wendel, Red River Basin Fisheries Biologist for the Minnesota DNR.
As part of the survey, Wendel and his team estimated that over 100 lake sturgeon were in the first mile downstream from the outlet of Big Pine Lake, with many of them being between 45 and 55 inches long, the physical point at which male lake sturgeon become sexually mature.
“They were primed and ready to go, they were looking for a female, and we surveyed 10 to 12 ripe males,” Wendel related, stating that male sturgeon are typically able to reproduce at 45- to 55-inches in length, but females typically have to be over 55 inches. In all, the team was able to collect and tag 16 lake sturgeon, despite many more coming to the surface during the survey. Limited by the time it takes to collect, measure and examine each fish, Wendel was confident in his estimate that at least 100 sturgeon were lining up below the dam and fairly well disbursed in the first river mile after it. While no ripe females emitting eggs were observed, it is expected that some females may be nearing spawning age.
“With 15 years of consistent stocking, I would expect there are some females, that if they aren’t mature now, will be in the near future,” Wendel commented, further relating that females in a re-established population like the one in the Red River may become reproductively mature a few years earlier than normal.
Typically, male sturgeon will make a spawning effort every other year, while females will spawn every three-to-five years, so natural reproduction in the Red River basin will be just a matter of timing in the coming springs. Lake sturgeon require fairly high-gradient stretches of river, with fast moving water and rocky substrate to keep the eggs well-oxygenated, similar to the spawning grounds that walleyes require. With mature fish now found in the Red River basin, identifying suitable spawning areas is a top goal for Wendel and the DNR.
A multi-agency program between North Dakota, South Dakota, Minnesota and Manitoba agencies known as the Red River Fisheries Steering Committee began reintroduction of lake sturgeon to the Red River basin in 1997, with 75 fish stocked into Big Detroit Lake and 303 fish placed in the Otter Tail River by the Minnesota DNR. It wasn’t long after the initial effort that lake sturgeon began to show up in the Red River, with early reports of young sturgeon coming from as far downstream as Lake Winnipeg in Manitoba. Currently, sturgeon eggs for repopulation efforts in the Red River basin come from Canada, and are hatched and raised to fingerling size at fish hatcheries near La Crosse, Wis. and Valley City, N.D., before the young sturgeon, at around eight inches in length, are transported to their destination lakes and rivers in the fall of each year.
In addition to stocking, removing barriers to fish migration was equally important in returning the species to the waters where, prior to 1900 it was once fairly common. Development and the installation of lowhead dams along the Red River and its many tributaries prevented sturgeon from reaching their historic spawning grounds and populations subsequently crashed.
“We keep chipping away, there are many dams we’re still working to modify; Drayton is the last one on the U.S. side of the main stem [of the Red River], and we’re still actively looking for solutions and working on many tributaries,” Wendel related, “that’s one of the key factors, without modification of the dams, we wouldn’t have continued, as they were a major factor in sturgeon extirpation,” he concluded, indicating hundreds of miles of flowing water have been opened up to fish travel via dam removal efforts in the past 20 years.
A number of dams along the Red River in and around Grand Forks and Fargo, N.D. have been converted to free-flowing rock rapids to allow for fish movement. Smaller dams along a number of tributaries to the river have seen the same improvements or the creation of fish passages, allowing the re-established population of lake sturgeon to reach some of their former spawning grounds. The steep grade of what used to be the beach of Lake Agassiz, with its faster flowing waters and gravelly substrate, provides ideal spawning habitat for lake sturgeon, as it did over a century ago before the population disappeared from the many tributary flows. This “beach ridge,” as it is known among fisheries biologists, is the region the restoration efforts focus on getting sturgeon access to.
Successful repopulation efforts have recently been documented on the St. Louis River in northeastern Minnesota, following the return of the fish which was nearly extirpated from the Rainy River system along the Minnesota-Canada border in the 1960s and 1970s. The latter now provides an exciting spring fishing option for anglers, as fish up to 70 inches in length have been caught in recent seasons. Minnesota closes the catch-and-release sturgeon fishing season from April 15 to June 15 each year, in order to allow the fish to spawn, which in itself can be a sight to behold along the Rainy River, where thousands of fish congregate in shallow, rocky areas to beget the next generation.
With the good news of established, mature fish populations coming from the Red River basin in the past few days, odds are that closure will be needed in the near future along the North Dakota-Minnesota border water for a species brought back from local extinction thanks to the vision of a multi-jurisdictional network, cooperative efforts by many agencies and cities to open rivers back up to fish travel, and support from a very appreciative angling public.
Simonson is the Managing Member of Dakota Edge Outdoors, a freelance outdoors journalist from Bismarck, N.D. and an avid multi-species angler.