DUNKIRK – The walleye around here tend to stick around, spending their whole lives on the eastern side of Lake Erie.
The walleye from Ohio?
They're roamers. They'll show up on the Buffalo side of the lake for the summer before heading back to their home waters to spawn in the spring.
"A lot of these fish are still around, even into the fall," said Don Einhouse, leader of the state's Lake Erie Fisheries Research Unit in Dunkirk, about the fish from the Toledo side of the lake.
What scientists have learned about the comings and goings of Lake Erie walleye matters because it helps their agencies manage a vibrant walleye population – important for recreational and commercial purposes.
“When you’re trying to manage a species, you have to know the reproductive stressors,” things like pollution, habitat and overfishing, said Jeff Jondle, president of the Erie County Federation of Sportsmen’s Clubs.
Overfishing, for example, wiped out the blue pike and drove down populations of lake sturgeon and lake trout.
The state Department of Environmental Conservation wants walleye to remain vibrant in Lake Erie, so the information its biologists are gathering isn’t just interesting, it’s useful.
“We don’t have to guess,” Jondle said. “We can fine-tune what we know.”
Scientists from several government agencies are tracking the fish by using acoustic transmitters that have been implanted in the walleye and receivers anchored to the bottom of Lake Erie in a grid pattern across 241 miles between Toledo and Buffalo.
Tracking their movements began about five years ago with a few fish and receivers. Since then, the scientists have tagged about 1,044 fish in Ohio’s western basin and 532 in the eastern basin including the Canadian shoreline.
Here’s what biologists have found so far:
• Most walleye tagged in the western basin spawn there and then fan out over the entire lake over the summer before returning to the Ohio side in fall to spawn there again the following spring.
• Most walleye return to spawn in the same places from one year to the next.
• Many individual walleye make similar migration patterns every year – some stay close to home, while others travel across the lake.
Biologists have also learned that not all of Lake Erie’s walleye behave the same.
While the western-basin fish roam widely, walleye born closer to Buffalo tend to live their whole lives in the eastern basin. That improves their chances for survival because it reduces their vulnerability to large fisheries in the western part of the lake, biologists said.
"We wouldn't have known that, except for this study," Einhouse said. "This really documented that walleye do come to the same spawning sites every year."
'Always walleye here'
“Walleye are thriving right now,” said Jason Robinson, a fisheries biologist at the DEC’s Lake Erie Unit in Dunkirk. “They’re doing as well as they’ve done in a generation.”
Walleye reproduce in large numbers in Lake Erie, and they survive to adulthood.
Ron Duliba, a charter captain who runs a fishing boat of Dunkirk harbor, knows all about the walleye bounty.
Duliba and a companion reeled in two dozen fish last weekend in 90 minutes.
“There’s always walleye here,” Duliba said.
What's even more remarkable is that New York's walleye harvest is tiny – representing only about 1 percent – of all walleye taken from Lake Erie.
"In 2017, there were almost 5 million walleye harvested in Lake Erie," Robinson said. "New York harvested 70,000 of those."
Search and research
The technology provides biologists a unique opportunity to study fish movements and preferred locations, and to answer questions to ensure sustainable management of walleye.
It's a golden opportunity for scientists who want to learn anything about fish movement, Einhouse said.
“Whether it be sturgeon, or muskellunge, walleye, lake trout – you name it – if you want to understand the dynamics of movement of these fish, there’s no better place than this than Lake Erie right now,” he said.
The tagged fish are surgically-implanted with telemetry devices – about the size of a AA battery – in their abdomen.
When they pass within approximately a mile of one of the more than 100 acoustic receivers anchored on the lake bottom, the receiver registers the fish by an identifying number as well as its location, and the date and time. Biologists usually retrieve each receiver once per year, download the data and install fresh batteries, Robinson said.
Using that information, biologists can track where the walleye came from, as well as its comings and goings on a computer-generated map of Lake Erie.
Collaborating on the project are the DEC, Ohio Department of Natural Resources, Ontario Ministry of Natural Resources and Forestry, U.S. Geological Survey and the Great Lakes Acoustic Telemetry Observation System.
In New York waters, tagging focused on five spawning shoals from the state’s most westerly shoal near Ripley, to its most easterly shoal near Lackawanna, Robinson said.
Robinson said biologists also tagged walleye not associated with any particular spawning shoal.
Each tagging effort – the western basin, eastern basin and the Grand River – is a separate effort by multiple agencies, and a part of a larger overarching international study into walleye populations.
“Obviously, each agency has its own questions about local spawning stocks,” Robinson said. “There is definitely cooperation going on using our combined data to address whole-lake population dynamics questions.”
There’s still plenty to learn.
“These tags have a five-year battery life so we will be collecting data on these fish for years to come,” Robinson said.
During a recent presentation in Dunkirk, Einhouse highlighted the behaviors of two walleye in Lake Erie with very different traveling habits.
The first one, 24.5 inches long, was spawning on Toussaint Reef in western Ohio when tagged with a transmitter.
For three years in a row, the fish spawned on the Ohio reef before covering more than 200 miles over 20 days to the eastern basin – where the fish spent most of the summer. Then, the fish returned to the western basin for spring spawning.
Meanwhile, scientists tracked another fish over five years, a 28-inch-long homebody that also spawns at Toussaint Reef.
This fish never travels more than 40 miles from the reef, with most of its life spent between the reef and Ohio’s Bass Islands.
“There’s a lot of individual behaviors going on, and they’re repeatable behaviors, which is something that I don’t think we previously knew,” Einhouse said.
What anglers suspected
For the last three decades or so, biologists relied on numeric metal jaw tags, but now they can follow the paths of walleye movements electronically.
The data shows that most walleye born in the shallow western basin, remain there to spawn then head east by mid-summer as water temperatures warm and possibly because forage fish become more plentiful in the lake’s cooler, deeper waters between Erie, Pa., and Buffalo.
For those walleye that are native to the eastern basin, spawning happens during the spring on shallow rocky shoals near Van Buren Point and Smokes Creek in Lackawanna.
These fish live mostly on this side of the lake, looking for food and returning to their usual spawning areas every year.
Additional data shows that a Canadian cohort out of Grand River at Port Maitland, Ont. – about 15 miles west of Port Colborne, Ont. – stays close to the Canadian shoreline.
That insight is important from a fisheries management perspective.
“Because walleye is a very popular sport and commercial fish that supports one of the largest freshwater commercial fisheries in the entire world, it’s really important to understand how we share these fish,” Einhouse said.
Anglers have been making anecdotal observations for years.
They suspected that fish found in certain streams and tributaries returned there every spring to spawn, and that there’s an influx of Ohio walleye that mix with the eastern basin’s walleye every summer, said Rich Davenport of the Erie County Fish Advisory Board.
“Simply enough, they’ve nailed it,” Davenport said. “It’s nice to be able to see it. It makes a lot of sense. It’s a good confirmation.”