GRAND FORKS – The Minnesota Department of Natural Resources and Manitoba’s ministry of Natural Resources and Northern Development will collaborate on a study this summer aimed at learning more about the age distribution and genetics of walleyes and saugers in the Red River.
They hope to shed light on whether walleyes and saugers in the Red River and Lake Winnipeg are a single large population, or a series of discrete smaller populations unique to the lake and segments of the river, said Nick Kludt, Red River fisheries specialist for the DNR in Detroit Lakes, Minnesota.
Manitoba is “curious about the interconnectivity of the Red River and the Lake Winnipeg system, and this collaboration has great benefits for our management, too,” Kludt said.
A separate acoustic telemetry study has indicated tagged walleyes in Lake Winnipeg move between the southern and northern lake basins. Tagged walleyes do not often move upstream of St. Andrews Lock and Dam on the Red River in Lockport, Manitoba, a key step to eventually entering U.S. waters, Kludt said.
If Red River walleyes and saugers indeed are part of discrete, fragmented populations, the genetics study may confirm barriers to fish movement play a role in structuring population breeding ranges, he said.
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“We already have the acoustic telemetry data set, which tells one story about fish movement,” Kludt said. “We’re also going to take a look at the genetics to see if that tells a similar story about population interconnectedness, as well as the age structures of the two components of the fishery – Lake Winnipeg and the Red River.”
Aging data will provide insights into year-class strength and production consistency for Red River walleyes and saugers, Kludt said. Along with fish length, aging allows managers to evaluate fish growth rates and potential changes over time, he said.
This three-pronged approach – movement, genetics and age/growth – hopefully will provide a complete picture of Red River walleye and sauger biology and status, Kludt said.
Minnesota will collect the walleyes and saugers during the DNR’s riverwide Red River assessment planned for June, Kludt said. An angler creel survey being conducted concurrently this summer by the North Dakota Game and Fish Department, will complete the picture, Kludt said, capturing angler catch and harvest behavior.
The DNR has conducted the riverwide survey every five years since 1990, dividing the Red into four reaches: Wahpeton-Breckenridge to Fargo, Fargo to Grand Forks, Grand Forks to the Drayton Dam and Drayton Dam to the Manitoba border. Fisheries crews from Detroit Lakes and Fergus Falls work the two upper reaches with trap nets, and a crew from the DNR area fisheries office in Baudette samples the two downstream sections with both trap nets and trotlines.
The DNR tries to conduct the survey in June, timing it to coincide with the catfish prespawn period when catfish are actively moving. The survey originally was scheduled for 2020, but was delayed for two years because of the COVID-19 pandemic.
For the upcoming study with Manitoba, the goal is to collect 50 walleyes and 50 saugers from each of the four reaches of the river, Kludt said. Crews will record length and weight measurements for each walleye and sauger, he said, giving the fish a unique ID number and then removing the otolith, an ear bone that can be used to age fish by counting rings in a cross section, similar to how foresters age trees.
The otoliths will be put into an envelope that corresponds with the fish’s ID number, Kludt said, and a fin clip “about the size of your pinky fingernail” will be taken from each fish for genetic sampling.
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The samples then will be sent to Manitoba, where a master’s degree student at the University of Winnipeg will do the genetic analysis, with funding provided by the Manitoba Fish and Wildlife Enhancement Fund.
“It’s kind of a nice collaboration, in terms of we do the fieldwork, they do the lab processing and everybody benefits,” Kludt said.
The riverwide survey also will provide additional freshwater drum – also known as sheepshead – for sampling as part of research to study the age of the underutilized species. Researchers have been collecting freshwater drum on the U.S. side of the river to see if they live as long as sheepshead in Manitoba, where even midsize fish have been found to be 50 to 60 years old.
More sturgeon work planned
The Minnesota DNR this spring also will continue its research of lake sturgeon in the Red River Basin, where crews last spring documented two more reproductively mature female sturgeon, a welcome sign in efforts to restore the species to lakes and rivers in the basin.
The DNR discovered the first reproductively mature female in 2019, a milestone in efforts to restore sturgeon to the Red River Basin.
Using stock from the Rainy River on the Minnesota-Ontario border, the DNR in 1997 began stocking juvenile lake sturgeon in the Otter Tail River and other Red River tributaries. Lake sturgeon were common in the basin until the early 1900s, when dams that blocked access to crucial spawning habitat and pollution resulting from settlement of the Red River Valley decimated their numbers.
In addition to looking for more reproductively mature females, crews this spring plan to implant additional PIT – short for Passive Integrated Transponder – tags in sturgeon to learn more about their movements and habitat use in the basin, the DNR’s Kludt said.
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This year’s sampling effort will mostly be focused on the lower Otter Tail River system downstream from Orwell Dam, Kludt said.
“In the upper system, we now have marked enough fish that we feel confident that if we go back and resample, we can get some idea about movement rates between lakes, as well as just general growth-at-large data,” he said. “Whereas, we don’t have that number of marked fish below Orwell, so it’s time to transition our focus down there.”
Changes at Drayton Dam
No doubt, anglers who enjoy fishing below the Drayton Dam north of Drayton, North Dakota, will encounter some changes when the old dam is removed and replaced with a rock-riffle structure that accommodates fish passage and is safer to humans.
The Drayton Dam is the last of eight lowhead dams on the U.S. portion of the Red River to be modified for fish passage as part of efforts to “reconnect the Red” that date back some two decades.
Without the barrier provided by the existing lowhead dam, fish may be less concentrated, but anglers willing to adjust their techniques should still encounter good fishing, Kludt said.
“It’s been my personal experience as well as our creel programs’ experience that the fishing below those dams does not diminish – it just changes in how you need to approach it,” said Kludt, an avid river fisherman.
For walleyes and saugers, “crawling” a jig or using a slip bobber “can be extremely effective in close vicinity to that structure,” Kludt said.
Catfish anglers might have to adapt a bit more, he said.
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“If you were to go to the exact location where you used to fish below the dam, you might have a little more trouble,” Kludt said. “Part of that has to do with just how channel catfish feed and the habitat they like. They tend to avoid the more turbulent flow areas and instead prefer a little more stable current.”
In most cases, he said, that stable current “seam” sets up a bit farther downstream from the structure than anglers might be used to fishing below traditional lowhead dams.
“It’s still there – you just need to go look for it and generally a hair downstream,” Kludt said.
But, he adds, “figuring out a new location and building new traditions is part of the fun.”
Prospective contractors had until Wednesday, April 14, to submit bids to the U.S. Army Corps of Engineers’ St. Paul office for the Drayton Dam project. The Corps will award the contract in mid-May, “once our contracting office checks all the things they need to check to ensure the contractor can actually do the work,” Kim Warshaw, project manager for the U.S. Army Corps of Engineers in St. Paul, said this week.
When construction actually begins will depend on river levels, but late fall or early winter would be a ballpark timetable, based on similar projects elsewhere along the Red. The new structure, which is a mitigation measure for the Fargo-Moorhead diversion, will maintain upstream water levels.
