THE MYSTERY OF FISH MOVEMENT ON LAKE WINNIPEG
EDITOR’S NOTE- THIS IS THE SECOND ARTICLE IN A THREE PART SERIES ON THE RISE AND FALL OF FISH STOCKS IN LAKE WINNIPEG AND IT’S TRIBUTARIES. IN THE FIRST PART I RECOUNTED MY OWN EXPERIENCES WITH THE BIG LAKE AND ITS TRIBUARTIES. IN THE SECOND PART WE EXAMINE FISH MOVEMENT THROUGHOUT THE SYSTEM. IN THE THIRD PART WE WILL DISCUSS WHAT THE FUTURE HOLDS.
Lake Winnipeg has undergone a number of environmental stresses over the last two decades. These include massive algae blooms, overharvest by commercial fishers, a die off of smelt in the north basin and the introduction of zebra mussels.
I had a chance recently to interview Doug Watkinson, a biologist with Fisheries and Oceans Canada. For the last five years he has been involved in program detailing fish movement in Lake Winnipeg.
UNDERWATER RECEIVERS TRACK FISH
The project involves a network of underwater acoustic receivers in the Lake Winnipeg basin, allowing researchers to track movement, behavior, and interactions of tagged fish. The one that holds the most interest by far is the world-famous greenback. These Lake Winnipeg fish are highly sought by both commercial fishers and anglers. Recent economic studies have placed the value of this fishery through the roof, making it essential to protect the stocks.
In 2016, Fisheries and Oceans Canada in partnership with the Universities of Manitoba, Nebraska–Lincoln, and Lakehead as well as the Province of Manitoba began the Lake Winnipeg Basin Fish Movement Project. The project involves a network of underwater acoustic receivers in the Lake Winnipeg basin, allowing researchers to track movement, behavior, and interactions of tagged fish. Beside the walleye they include bigmouth buffalo, burbot, channel catfish, Common Carp, Freshwater Drum, Lake Sturgeon, and Lake Whitefish.
CRUCIAL DATA FOR FISHERIES MANAGEMENT
The work that Doug and his team are doing, provides crucial information to managers to make informed and scientific evidence-based decisions around species protection, habitat restoration, and instream flow needs.
Doug was introduced at a young age to fishing and hunting and developed a passion for the outdoors. He obtained a BSc and a MSc degree from the University of Manitoba and was fortunate to find his dream job as a biologist with Fisheries and Oceans Canada. He is also the co-author of “The Freshwater Fishes of Manitoba” as well as numerous scientific articles and reports.
In fact, I first met Doug at the launch of the book many years ago and I still have an autographed copy in my bookshelf in my office.
In our recent conversation he outlined several fascinating facts about species movement and interaction within the lake and its tributaries. These include the Red and Assiniboine rivers as well as the Winnipeg River.
WALLEYE AND LAKE WINNIPEG
Doug and his crew have tagged close to 130 walleyes with over half of those done in the Red River in the springtime north of Selkirk. He says over all the years he has been electro shocking fish, he has never seen such a density of large walleye that come into the river to spawn.
WHY THE RED RIVER?
Doug says there are several reasons for that. First, the Red River flows south to north bringing warm water with it. Those temperatures are a month ahead of those in the lake itself, which is still frozen when those fish spawn in the river. It gives the walleye a head start, providing great habitat with extensive rock rip rap on to which they drop their eggs. There is also plenty of food in the system for the fish to recover and for the fry to hatch and thrive.
Once the lake thaws, it doesn’t take long for the majority of the walleye to start to head north. The tracking studies show most of the walleye head up the west side of the lake, reaching Hecla Island by early June.
From there the data shows that about 40 percent of the fish then head even further north, passing Matheson Island into the north basin.
RAINBOW SMELT MAKING A COMEBACK
Doug says it seems that the rainbow smelt in the north basin are also making a bit of a comeback. This is a result of the trawling studies done by the Namao on the north basin.
SURPRISING RESULTS
What surprised Doug was that only five percent of the tagged walleye returned to the Red River as part of the fall run. He says that gives you an idea of just how many mature females come into the Red River in the spring time!
One of the most interesting points Doug Watkinson made was about the walleye feeding window. He says the optimum water clarity for walleye to feed efficiently is in the four-to-six-foot range. With the proliferation of zebra mussels, the water quality in the big lake has now changed to this optimum window. As an individual that has tried to catch walleye in Lake Winnipeg itself for the last 40 years, it only makes sense that now we can catch fish in the lake year-round.
It all has to do with the ability of the walleye to feed more successfully with the increased water quality.
WALLEYE STAY NORTH OF THE BORDER
Also of interest was that the walleye had no interest in going further south than Lockport for the most part. Not like channel catfish and bigmouth buffalo that love to travel the river down as far south as Fargo and back again. The study also indicated that these two species prefer the river habitat over the lake itself. That also includes the lake sturgeon.
STURGEON PREFER CURRENT
The majority of the fish tagged came from the Winnipeg River below the Pine Falls Generating Station. While Watkinson says they managed to tag two sturgeon in the Red River, almost all of the sturgeon spent the majority of their time in the Winnipeg River and Traverse Bay, preferring moving water that the river supplied.
Traverse Bay was also a popular spot for the common carp. Watkinson says after they finished spawning in the Netley-Libau Marsh, they would head out to Lake Winnipeg to feed, then overwinter in Traverse Bay in large aggregations.
FRESHWATER DRUM PUT ON THE MILES
Doug Watkinson says the freshwater drum was by far the most nomadic of the nine species tracked. They would travel south of the border to the U.S. then turn around and head as far north as Grand Rapids. They are truly a here today gone tomorrow kind of fish, the true explorers of the big lake
LAKE WHITEFISH
This past November Doug and his crew were out with the electroshock boat hoping to find lake whitefish. And find them they did. Doug says provincial fisheries staff had determined that there was a late fall spawning run up to Lockport. It turns out they were correct and Doug says they found a large number of whitefish spawning on the rock rubble in the fast water below the locks. They managed to put transmitters in several fish. He is hopeful by late fall next year he will be able to determine if these fish came all the way from the north basin.
IN SUMMARY
You can listen to the whole Complete Angler podcast with Doug Watkinson here or to one of your music providers and look up The Complete Angler podcast. There are many other podcasts to choose from including talks with Jeff Gustafson, Al Lindner and Wes David to just mention the few of the 27 online.
In the third installment we will talk about how the Manitoba government is working with commercial fishers for sustainability of the fishing resource. Lake Winnipeg has been one of the toughest nuts to crack but there is finally light at the end of the tunnel. It should be a wild ride. Stay tuned.