By Cory Schmidt
Right now, swimming up and down the Red River of the North, 16,000 tagged channel catfish are trying to tell us something. In what has likely become the most ambitious catfish tracking study in history, light has just begun to shine on the species’ perhaps migratory proclivities.
With implications beyond but wholly related to catfish movements, the recently published 334-page master’s thesis of Henry Hansen of the University of Nebraska at Lincoln (UNL) opens another potentially essential discussion: catfish in this world-class fishery have begun to fall under the weighty gaze of Canadian commercial fishing. In essence, results of the research may eventually make a strong argument against commercial catfish harvest.
Inarguably North America’s finest trophy channel catfish stream, the Red flows approximately 550 miles from its headwaters near Breckenridge, Minnesota, north to Lake Winnipeg in Manitoba. Like many North American rivers, the Red has been altered by the construction of dams and flood-diversion canals. Attempts to diminish the impacts of nine dams on fish migration have prompted the removal or modification of all but three. Remaining dams (St. Andrews, Manitoba, and Drayton and Grand Forks, North Dakota) are not total barriers, but may prevent fish movement at lower discharge levels.
Research continues to indicate that channel cats commonly live beyond 20 years of age here, with fish up to at least age-27—among the oldest recorded for the species. Sexual maturity doesn’t occur until at least age-10, while channel cats in other populations typically mature around age-5. Since 1988, a cooperative management effort between the U.S. and Canada has helped protect the trophy population. Estimates show an annual natural mortality of 16 percent across the entire system. Harvest mortality is 22 percent on the U.S. side and 6 percent in Manitoba, the difference attributed to the more restrictive regulation prohibiting harvest of any catfish over 24 inches in Manitoba.
Tagging and Tracking
When we last wrote about the research spearheaded by UNL fish ecologist Mark Pegg, with cooperation from Manitoba Fisheries Branch and the Minnesota Department of Natural Resources and North Dakota Game and Fish Department, Stephon Siddons had just published his graduate thesis, Population Dynamics and Movement of Channel Catfish in the Red River of the North.
Siddons, Pegg, and their team had placed T-bar anchor tags near the dorsal fin of 15,849 catfish averaging 21 inches long and up to 39 inches. They had implanted another 120 catfish with radio transmitters—with results incomplete at the time. When Siddons’ study concluded in 2015, 553 anchor-tagged recaptures had been reported by anglers. Remarkably, Siddons found that 88 percent of the fish that passed the dam in Lockport were recaptured upstream in the U.S. (recall the river flows northward).
Siddons movement summary showed that the greatest distance traveled by a single catfish was 703 km (436 miles), from Selkirk, Manitoba, to the Sheyenne River near Harwood, North Dakota. He also reported a distinct trend showing catfish longer than 24 inches traveled farther than smaller individuals, possibly a function of spawning migration. Upstream migrations were more common than downstream movements.
Grand Forks, North Dakota, guide Captain Brad Durick reported catching 40 tagged catfish in 2016. “Each catfish tag is imprinted with a phone number and unique ID,” he says. “When you call in the ID number, you can find out where the fish was originally tagged.
“Just three of those 40 fish were tagged in Grand Forks and another 1 or 2 from Drayton, North Dakota. But the remaining 35 or so were all fish tagged in Canada about 350 river miles downstream around Lockport, Manitoba.” According to Durick’s research, a 36-inch catfish can swim 90 river miles between Grand Forks and Drayton, North Dakota, in one and a half days.
“In May 2016, my buddy Charlie caught one around Drayton with a tag, which I called in for him. Turns out, I’d caught the same fish 100 yards from where he’d caught it on September 28, 2015, which was the third time the tag had been reported. This was another Lockport fish originally tagged in August 2014. If this doesn’t prove catch-and-release works, nothing does.”
Additionally, several other tagged fish caught by Durick have been recaptured by other anglers up to three additional times. Siddons reported that 28 tagged catfish were recaptured twice, while at least three more fish were recaptured at least three times.
When Hansen’s thesis came to light in early 2019, a total of 1,078 recaptures of anchor-tagged catfish had been reported. Movements of individual catfish ranged from 0 to 236 river miles. Only one of the fish had moved from U.S. to Canadian waters. Most of the tag returns once again showed a tendency toward upstream movement. Catfish moved upstream past St. Andrew’s Dam versus downstream by a margin of 15 to 1, though most of the recaptured fish never crossed the dam. Harvest of tagged fish was approximately 6 percent.
Pegg observed that many of the catfish that were anchor-tagged at Selkirk eventually showed up in the stretch between Drayton and Fargo, with a handful of fish caught in the Sheyenne River south of Fargo. He suggested this may have reflected a spawning movement.
Durick reported that since the study began, he’s caught and released over 60 tagged catfish in North Dakota waters, fish that originally received tags near Selkirk, Manitoba—nearly 250 river miles downstream. According to Hansen, approximately 30 percent of anchor-tagged catfish reported from U.S. waters were initially tagged in Canada.
Centers of fishing pressure may explain some of the anchor-tag results. Catfishing effort is nearly non-existent from the Canadian border to south of Winnipeg, as well as within Lake Winnipeg itself. This, in part, may explain why anchor-tagged fish aren’t seen returning to Canada, or why relatively few anchor-tag returns come from Lake Winnipeg. There may not be enough anglers on the water to catch or report catfish from these locales.
“I suspect over time, we’ll see fish coming back to Canada,” Pegg says. “But there’s so little fishing pressure on the lower reaches of the river that tag returns may never reflect it.”
Meanwhile, as biologists compiled data from acoustic tags, a surprising contradiction began to emerge. A total of 250 listening stations were set up across the entire length of the Red River, including a dense grid of receivers from St. Andrew’s Dam to Lake Winnipeg. Receivers were also installed in several tributaries, including the Seine and Assiniboine rivers.
Among 161 adult catfish implanted with acoustic transmitters (121 in Canada and another 40 in the U.S.), approximately 40 percent moved downstream into Lake Winnipeg at least once during the 11/2-year research period. A downstream movement pattern proved to be the most common direction, at 54 percent. Only 3 percent of radio-tagged catfish moved upstream, while 38 percent displayed no movement. Again, most acoustic tags were implanted into catfish near St. Andrew’s Dam. Moreover, most of the 250 listening stations remain in Canadian waters, primarily from St. Andrew’s Dam to Lake Winnipeg, and into the Winnipeg River.
Hansen and Pegg both noted that larger catfish made the longest movements among both tagging groups, while sex of catfish had no bearing on movement patterns. Seasonal movements, unfortunately, weren’t a major component of the research, as specific tracking dates weren’t published or available at press time. Pegg noted that the greatest river movements occurred during spring and fall, as you might expect.
River Flow Factoring
“Initially, when we saw all these T-bar-tagged catfish moving north, but not coming back downstream to Canada, Manitoba fisheries understandably got a little antsy,” Pegg says. “But once the telemetry data showed the opposite trend, it eased some tension. I’m guessing we won’t truly see the big picture of Red River catfish movement for another three to five years, once we’ve processed a few more years of data.”
Durick, who’s on the river almost daily, May 1 through September 30, believes he already knows what’s happening. “My guess is, everything is going to change with the telemetry data when river flows pick back up this spring,” he says. “While I had been catching 18 to 29 tagged fish per season, last year I got just seven. This corresponds exactly with current and river flows. Last year, we experienced very low flows in the Red River. I didn’t expect to see much of a migration of fish from Canada.”
When I wrote about Siddons’ study in the 2017 Catfish In-Sider Guide, Durick made a few bold pronouncements, which he maintains today. “When we get big influxes of water, such as what we saw in June 2016, I start catching big catfish. This spring, we may begin to see a greater number of the radio-tagged fish moving upstream—a predictable migration pattern with high water and increased current.
“I feel strongly that lower river (Canadian) fish look physically different than those spawned in the southern (upstream) third. The Canadian tagged fish I’ve caught confirm it. These cats are shorter, heavier fish with thicker tails.” When Durick shows you the difference between a so-called U.S. catfish and a Canadian one, the physical variation seems subtle. But it’s also tough to argue with a guide who handles upward of 1,500 catfish each season.
I suspect that much of what Durick says is true, but I wonder about the existence of two distinct catfish populations within the Red River system. It appears that at least some segment of the population centered around St. Andrew’s Dam uses Lake Winnipeg as spawning and feeding grounds. As noted previously, at least 40 percent of the radio-tagged fish moved downstream into Lake Winnipeg during some portion of the year.
“From June to October, we saw fish bouncing all over the place across the southern portion of Lake Winnipeg,” Pegg says. “Then in October, most of the fish moved back into the Red River to perhaps overwinter. It’s likely the fish are out there following cisco, goldeye, or some other food source. I’d guess that maybe half the population is staying in Lake Winnipeg all summer, though that’s pure speculation.”
On the fishing front, while few recreational anglers target catfish in Lake Winnipeg, Red River guides such as Donovan Pearase talk about an incredible bite that develops from mid- to late September, with fish gorging on ciscoes. Right around early October, the pattern fizzles and the bite abruptly stops.
Commercial Fishing Considerations
In regard to whether the fish overwinter in Lake Winnipeg or deep river holes in the Red River itself, we now know that a large proportion of the catfish swim and feed in the big lake during certain seasons, particularly summer and fall.
Hansen’s data includes 111 maps of individual radio-tracked catfish. Of those, at least half of the fish made movements into Netley Marsh on the southern shore of Lake Winnipeg and most of those moved into Lake Winnipeg. Some of the fish traveled through the southern basin of Lake Winnipeg, all the way to the narrows north of Wanipigow, 100 miles north of Selkirk. And many more catfish were tracked as they swam around Lake Winnipeg, presumably keying on local baitfish.
Further substantiating the importance of the Lake Winnipeg fishery, Hansen’s thesis notes that the Netley-Libau marsh at the mouth of the Red River harbors the densest population of juvenile catfish in the entire system. Writes Hansen: “Anecdotal reports suggest the marsh acts as a nursery area for channel catfish and that is why the abundance of channel catfish below St. Andrew’s Lock and Dam is much higher in relation to other reaches in the system. Investigating fine-scale movement patterns for adult channel catfish to pinpoint spawning grounds would be critical information for ensuring consistent recruitment of the population.”
“No question, there’s a major source population at Netley, a prime catfish nursery area,” Pegg says. It’s just one fact pointing to a very large elephant in the room, and a theme that runs throughout Hansen’s entire thesis: the commercial harvest of catfish in Lake Winnipeg.
In May 2018, Manitoba announced that it would allow commercial fishers in Lake Winnipeg to sell channel catfish directly to consumers, while banning sales to restaurants, stores, and fish dealers for the time being. The move effectually lumps catfish into a broader quota system, classifying catfish as bycatch.
While Manitoba’s Sustainable Development Department lauded its decision as a measure to “protect the trophy channel catfish fishery on the Red River,” the move also garnered sharp criticism. University of Winnipeg ecologist Scott Forbes labeled the change a “terrible decision.” “It threatens a $15 million recreational fishery on the Red River for a few thousand dollars for commercial fishers,” he says. “Bad economics. Bad biology. Bad political decision.”
Hansen’s own research found a significant gap between economic value of the Red River recreational fishery and potential value of a fully functioning commercial catfishery. Assuming a projected commercial catfish exploitation rate of 20 percent, Canada’s commercial catfishery could be valued at up to $9 million. Meanwhile, the value of the Canadian recreational catfishery in the Red River is projected at over $13 million—a figure that exceeds $20 million when the recreational value of the U.S. side of the fishery is included.
Additional problematic issues enter the commercial catfishing discussion. For one, commercial harvest of Lake Winnipeg has already affected the walleye population. In‑Fisherman Field Editor Gord Pyzer has written about the decline since 2017, when he suggested the culprit for drastic declines in fishing for trophy walleyes. “The problem is a commercial fishery that is mismanaged by an absurd set of medieval rules,” he says. “While the commercial quota for the lake’s sauger, walleye, and whitefish is 6.8 million kilograms (nearly 15 million pounds), highly prized walleye account for most of that number. In recent years, the walleye catch has dropped by more than half that number, despite increased efforts and technology by commercial fishers.”
Historically—and apparently on Lake Winnipeg—when a target species declines in abundance, commercial operations turn to the next species down the ladder, and so on. Despite the claims of commercial fishers who say they don’t like to catch catfish because of their tendency to make a mess of gillnets, statistics from Canadian dealer licenses indicate the sale of commercial catfish has tripled since 2015. Moreover, scientists contend that when a new commercial fishery opens, the first specimens to vanish from a population are the largest, most fecund individuals. With the decline of the Lake Winnipeg walleye fishery, catfish suddenly seem vulnerable to commercial harvest. Time will tell.
Given that catfish in the Red River don’t sexually mature until at least age-10, removing even relatively small numbers of old, spawning catfish from the population could have a devastating, lasting impact. Although Pegg, Hansen, and others speculate that catfish populations farther upstream and into the U.S. may be augmented by localized reproduction, tracking data suggest the fishery’s nursery and epicenter revolves around the Selkirk/Netley Marsh/Lake Winnipeg region.
Hansen: “The implications of these potential (commercial) regulation changes could have cascading effects on the international usage of this species as a commercial and recreational fish if the potential implications of fish movement are not included in consideration of management plans.”
Pegg says the results of Hansen’s study make a strong statement against expanded commercial fishing. “Henry’s data show that commercial fishing would dramatically and rapidly change the size structure of the catfish population. The bottom line is, we just don’t yet know enough about where the bulk of the population is being produced. But my worry is that the population is very sensitive to mortality. Because it takes so long for fish to mature, we’re best served to protect the bulk of the mature (10-year-old-plus) catfish.”
Donovan Pearase, longtime catfish guide on the Red River in Manitoba, voiced another related concern. “Over the last three years, my boat has landed dozens of catfish between 38 and 40 inches—all around 30 pounds,” he says. “Prior to three years ago, we’d only see a small handful of these fish. It’s clear we have a very old and maximum size year-class that needs to be protected.
“Our channel catfish travel extreme distances over short periods of time, between the river and the lake and many swimming upstream to U.S. waters and back. To allow any amount of commercial catfish harvest runs the risk of threatening our world-class fishery, not to mention the economic benefits of anglers traveling here from all over North America as well as from abroad.”
The reality is that with low recreational harvest levels since the late 1980s, we don’t know the sort of havoc any increase in commercial harvest may unleash on those big old Red River catfish.
*In-Fisherman Field Editor Cory Schmidt is an astute multispecies angler who writes for all In-Fisherman publications, often on issues of fishery conservation.