Fish in the Red River-Lake Winnipeg system don’t carry passports, even though they move between Canada and the United States. And they can benefit from the river system being relatively unimpeded by dams and other barriers as they migrate and spawn.
A binational fish telemetry project supported by the International Joint Commission (IJC) is discovering how far various species travel in the system and offers insight into how removing more barriers could benefit the fishery.
The project started in 2016 and has assembled what may be one of the largest freshwater receiver networks anywhere, covering 9,000 square kilometers (about 3,500 miles) of lake habitat and more than 860 river kilometers (534 miles) in the Red, Assiniboine and Winnipeg rivers, says Eva Enders, a research scientist with Fisheries and Oceans Canada.
More than 780 fish of seven species have been tagged, including channel catfish, bigmouth buffalo, lake sturgeon and walleye. The tags include electronic transmitters to communicate with receivers installed throughout the system that track fish movements to and from Lake Winnipeg and into the Red River.
“What we definitely learned is that these fish move a lot and over large distances,” Enders says.
A bigmouth buffalo’s annual range has been tracked at up to 500 kilometers (310 miles) a year, for instance. While they come back to spawn every year in the same site, they also cruise throughout the system, using the entire habitat that’s available to them.
“It was important to show that if you allow fish to move freely in a relatively unimpeded system like the Red River where their movements are not interrupted by a chain of hydro dams, these fish really use the habitat,” Enders says.
Fish populations can survive in smaller river sections, such as in the Winnipeg River, where dams may impede river connectivity and consequently fish movement. However, allowing fish to move around as needed is better for biodiversity and gene flow in the population, along with allowing the fish to access optimal food sources and environmental conditions, Enders explains.
The findings so far
Fish can move past some barriers but not others, based on the species of fish and water levels.
On the Assiniboine River, the Portage Diversion dam is an impediment to upstream movement altogether, “a pretty solid block,” as explained by Mark Pegg, a fish ecologist at the University of Nebraska.
On the Red River, fish can move past the Drayton Dam and there’s some ability to move downstream past the St. Andrews Lock and Dam. “At the moment what happens is that fish are moving downstream to Lockport in the lower Red River, then some of them can’t get up anymore,” Enders says.
This year, more fish are due to be tagged in Lake Winnipeg, including burbot.
Why it’s being done
The IJC has provided CDN$27,500 per year for the project via its International Watersheds Initiative (IWI), which is funded by the Canadian and US governments. The fish telemetry project begins its second three-year phase in 2020, and is due to last until 2022.
The IJC’s Red River Board has an Aquatic Ecosystem Committee that’s involved in the work, which is being done by Fisheries and Oceans Canada and University of Nebraska-Lincoln. Other partners include the Minnesota Department of Natural Resources, province of Manitoba, North Dakota Game and Fish Department, University of Manitoba and Lakehead University.
“Having that long-term funding in place (from the IJC) and the binational approach of the project has really helped us leverage a lot of other funding from provincial and federal sources,” Enders says.
An improved understanding of the fish community in the Red River and movement patterns of fish between Canada and the United States is considered important for characterizing the ecological condition of the system, and differences between the Canadian and US portions of the Red River.
The Red River Board will be able to use the fish movement data to account for flows that fish need to complete their life cycle. State, provincial and federal jurisdictions also can use the data to make better decisions on fisheries management and the impacts on fish from projects to deal with flooding, for instance.
See more in a published paper by Enders, Pegg and others on the project.
Planning for the future
Pegg, the fish ecologist at the University of Nebraska, says the work is important to Minnesota, for example, because of reintroductions of lake sturgeon to the Red River.
“Are those fish moving around and if so where are they moving to? Are they going to mix in with the population already in the system? It’s a figure-out-how-connected-they-really-are kind of thing,” he says.
Pegg said there’s talk of building ramps to improve fish passage, such as on the Drayton Dam. This has been done for other dams farther upstream on the Red.
One of Pegg’s students, Henry Hansen, also recently finished a study on the ramifications of harvesting catfish. A proposal to ramp up the commercial harvest in Lake Winnipeg was one scenario explored.
“We found that certainly within the areas that they’re doing recreational or commercial harvest, sizes will decrease …” Pegg says. “Everybody goes to the Red River to catch big catfish so if we start to whittle away at the sizes that could have some dramatic economic affects.”