Study keeps track of just how far walleye wanders to spawn
MATT MARKEY BLADE OUTDOORS EDITOR03/27/2016, 12:09am EDT
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Biologist Chris Vandergoot inserts a tracking tag in this walleye along the Maumee at Orleans Park in Perrysburg. THE BLADE/LORI KING
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A pioneering study of the movements of walleyes is giving biologists terabytes of valuable data on these prized gamefish and revealing that Sander vitreus often travels great distances to reach the Maumee River spawning grounds each spring.
Fish that were netted and outfitted with acoustic transmitters along the Maumee in recent years left the river after spawning and ventured as far as Lake Huron to the north, and to the Welland Canal near Buffalo, in the extreme eastern end of Lake Erie.
Toledo native and professional walleye angler Ross Robertson, who has made it his life’s work to catch these fish in both size and numbers, is somewhat puzzled about the walleyes’ penchant for long distance journeys around the lower Great Lakes, but he is not surprised by their seemingly endless excursions.
“There’s a lot about these fish that we don’t understand, but I’ve come to the conclusion a long time ago that walleyes are just like people — and people do things we don’t understand,” he said. “But nothing about walleyes surprises me anymore.”
Developing a better understanding of these fish was a major driver behind this research, which biologists believe will lead to more effective management of this precious resource. Lake Erie is acclaimed as the “Walleye Capital of the World” and sportfishing contributes a major share of the $11.5 billion economic impact Ohio receives from tourism in its eight counties that border the lake. Walleyes are overwhelmingly the top target of anglers on the lake.
The multiyear walleye research project is part of the Great Lakes Acoustic Telemetry Observation System, which calls on a consortium of researchers from the states around the lakes and the Canadian province of Ontario.
By tracking the movements of these fish, then combing through the mass of fish detection data, the fisheries biologists hope to get a better handle on the number of walleyes from river and reef-spawning stocks that migrate into the Detroit River, Lake Huron, and Lake Erie’s central and eastern regions after spawning, determine how much site fidelity the various spawning stocks display by returning to the same location to spawn each year, and look at the mortality rates for the various spawning stocks.
About 800 fish so far have carried the transmitters, which are about the size of an AA battery and last 4 to 5 years. On a frigid early April night in 2012, biologist Chris Vandergoot of the Ohio Division of Wildlife was on the shore of the Maumee River at Orleans Park, surgically implanting the transmitters in large female walleyes that had been collected from the waterway by electroshocking.
As the anesthetizing agent wore off and the fish swam off into the dark waters of the Maumee, Mr. Vandergoot was eager to learn where their travels might take them. He is getting his answer to the tune of millions of “pings” or detections that match individual fish to specific locations throughout the GLATOS network. The walleyes of Lake Erie and those that spawn in the Maumee River are on the move, and distance appears to be no limiting factor.
“To this point, the study has been an overwhelming success,” said Mr. Vandergoot, a PhD who is the supervisor of the Sandusky Fisheries Research Unit and the project's lead biologist. “We are getting what we were hoping to get, and that is a better understanding of the travel corridors these fish use and the movement patterns they follow.”
Individual walleyes implanted with transmitters have left the Maumee River and roamed around the Lake Erie Islands before moving into the central and eastern portions of the lake. Some have ventured as far east at the Welland Canal, which connects Lake Erie and Lake Ontario, a distance of roughly 300 miles. Other fish have been tracked leaving the Maumee and heading up the Detroit River, with some moving on to Lake St. Clair, then the St. Clair River, and on into lower Lake Huron.
“I was somewhat familiar with the general movements of walleyes,” said Bob Barnhart, who owns Maumee-based tackle supplier Netcraft and has been fishing for walleyes for 35 years, including in tournaments. “But the information from this study is stunning. The actual distances these fish travel continues to amaze me.”
The transmitters implanted in the fish are programmed to send out a signal every two minutes, and when that fish passes within roughly a kilometer of the tracking receivers, that device records the time and date and the specific code assigned to that individual fish. A bright orange external tag alerts anglers to the presence of the transmitter in the fish and lets the fisherman know there is a $100 reward for returning the transmitter to the researchers.
All of the transmitters are outfitted with a thermal button that records the water temperature at certain intervals. When a transmitter is returned, Mr. Vandergoot said the temperature data is downloaded, giving the biologists a better idea of the water temperature preferences of these fish and unveiling another treasure trove of information. He said about 20 percent of the transmitters that were implanted in fish during the course of the study have been returned and their thermal data collected.
The walleyes’ movements are being tracked by an array of more than 100 receivers stretched across Lake Erie, and a similar number covering the Detroit River, Lake St. Clair and St. Clair River corridors, Lake Huron and its Saginaw and Georgian bays, the Welland Canal, Niagara River, and sites on the north shore of Lake Ontario. These devices, which are small data-logging computers, are anchored on the bottom of the lakes and rivers, but they can be remotely released and will float to the surface so they can be retrieved and their information downloaded. Other GLATOS projects around the Great Lakes are studying sturgeon, lamprey, and lake trout.
The Ohio Department of Natural Resources, New York State Department of Environmental Conservation, and the Ontario Ministry of Natural Resources and Forestry have all placed transmitters for use in the study. The ODNR, Michigan DNR, the New York and Ontario entities, and the Lake Erie Biological Station of the United States Geological Survey all assist in maintaining the receivers in and around Lake Erie. Other GLATOS partners assist in maintaining receivers else where in the Great Lakes.
The Ohio fisheries biologists have put transmitters in fish from the Maumee and Sandusky rivers and those from the Western Basin reef complexes, which are also prime spawning grounds for Lake Erie walleyes. The receivers in the waterways are generally retrieved, and their information downloaded once or twice a year, depending on the location, Mr. Vandergoot said, so there is a bit of a lag in getting the data.
“The fish swims by, and the time and date are logged, very much like the E-ZPass system on the turnpike,” Mr. Vandergoot said. “If the fish is there for a week, we know that. We can take the collected data and relate it to the demographics of that fish — length, sex, age — and maybe begin to make inferences, such as, are all of the big females doing the same thing.”
The study is funded primarily by the Great Lakes Research Initiative, and early data show that about 80 percent of the walleyes that spawn in the Maumee River will return to that waterway the next year. But because the study is expected to run through 2020, a final report is well in the future, and the first preliminary report is not expected until 2017.
“There might be some fish that are spawning someplace else, or possibly the females skip spawning for a year,” Mr. Vandergoot said. “It is fairly evident that we have fish that spawn in the river or the Western Basin, and then spend a considerable amount of time in the central and eastern parts of the lake.”
For the professional walleye fisherman, any and all information that provides a peek into the habits and patterns of that fish is valuable currency.
“Anything and everything you can learn is beneficial, because we spend every waking hour trying to figure out these fish, think like these fish, and be like these fish, but where we are often wrong is with our preconceived notions about these fish,” Mr. Robertson said. “The movement and temperature information are interesting, but I tend to think a lot of this is also baitfish-related movement. These fish are predators, and the old line says that predators don’t go far from the grocery store.”
While he finds the tracking data intriguing, Mr. Barnhart said the study also has opened up a font of new questions.
“I’m an X and O kind of guy, so when I learn something like this I just want to know more. There are so many layers to this, and each time we turn one over, a bunch more pop up,” he said. “My bottom line is that I think we are getting closer and closer to understanding more about these fish, but I don’t know that we will ever get the exact science of this down. In a unique way, Mother Nature takes care of her own by not giving up all of the secrets.”
Contact Blade outdoors editor Matt Markey at: This email address is being protected from spambots. You need JavaScript enabled to view it. or 419-724-6068.
