When it comes to fish movement around Lake Erie, biologists are finding that there are specific patterns and habits that some fish tend to follow.
Thanks to several acoustic telemetry studies that have been ongoing for several years, fish management agencies are starting to get a better understanding of fish migration and movement in this Great Lake. The studies involve surgically implanting acoustic tags inside the abdomen of a variety of fish species such as walleye, lake trout, lake sturgeon and muskellunge.
“Fish seem to be showing repeated behavior,” said Dr. Jason Robinson with the Department of Environmental Conversation's Lake Erie Unit. “It doesn’t appear to be influenced by water temperatures or bait movement. We’re still working on getting more data to try and figure this lake out.”
“We’re trying to understand which spawning stocks are a shared resource around the lake. The Western Basin of the lake is where most of spawning takes place – Maumee River, Niagara Reef, Toussaint Reef, Detroit River and Sandusky River. Certain stocks move more than others, especially from the Western Basin. They spread out across the entire lake. Some stay close to home, some move to the Central Basin and some move all the way to the Eastern Basin. However, Eastern Basin fish tend to move around the basin but will go no further.”
Some of the examples he used during a DEC public angler outreach session last week were for specific fish that they have followed for at least three years. One male walleye from the Western Basin performed its spawning ritual and then traveled more than 200 miles to a spot in the Eastern Basin in less than three weeks. It stayed there most of the time until it returned to spawn. The fish performed the exact same travel pattern for three consecutive years.
Another spawning 28-inch female from the west never moved more than 40 miles from “home” and then back again for spawning – for five consecutive years. A tagged Grand River 23-inch female from the north shore of the lake traveled to the Toussaint Reef and to Buffalo.
The biologists would like to retrieve more data, all through this amazing acoustic telemetry technology that places receivers on the bottom of the lake. The process is becoming much more refined. U.S. Geological Survey (USGS) has implemented a grid network of receivers that now covers the entire lake rather than rows of receivers from one side of the lake to the other in different locations.
“Using a grid system in the lake, biologists can be much more flexible with implementing other studies,” Robinson said. “This is a great example of cooperation between the various agencies – all of the states surrounding this lake, the Province of Ontario, U.S. Fish and Wildlife, USGS, Great Lakes Fishery Commission and Michigan State University. The grid is a big step forward for continuing the acoustic telemetry work into the future.”
Hundreds of walleyes have been tagged so far in the lake and these agencies will continue to tag fish and monitor movement all through the Great Lakes Acoustic Telemetry Observation System (GLATOS), a network of researchers all collaborating to determine fish behavior. “GLATOS is an essential central collection point of information that is invaluable to our work,” Robinson said. “Our work is becoming more refined and we are becoming more efficient in our data collecting.”
Once a year, researchers will collect the receivers off the bottom of the lake and download the data into GLATOS, replacing it with a new receiver. There is a one-year lag time for information. As far as the internal tag, battery life is good for about five years in the walleye. Each walleye with an internal tag is marked with an orange external floy tag in the dorsal fin area.
To make sure that the acoustic tag is returned, a $100 reward is offered to the lucky fish catcher. Since 2015, they have paid out 92 tags. There are still plenty of other tagged walleye swimming around, too. This year, the DEC is adding tagged females from Cattaraugus Creek into the mix.
“We’ve answered the initial question of whether or not this is walleye movement from west to east,” Robinson said. “Different populations exhibit different degrees of movement. This underscores the need for continued cooperation with other agencies.”
It’s safe to say that approximately 10 percent of the Western Basin fish will make an “appearance” in the Eastern Basin of the lake. How long they stay and why, though, is anyone’s guess.
“We’re also working on other species such as lake trout, part of a federal restoration effort," Robinson said. "We tagged 75 lake trout in 2016 and 75 in 2018. They are also identified with an orange floy tag and are worth $100 when the person catching the fish returns the internal acoustic tag. We are still trying to figure out why we’ve seen no natural reproduction in the past 35 years of studies.”
“Hopefully this research will show us where these fish want to be when it comes to spawning in the fall.”
It appears the char prefer to be along the south shore of the lake between Buffalo and Presque Isle, but the prime shoals and reefs are covered so severely with zebra and quagga mussels (the latter replacing the former as time goes on), there are no crevices for the eggs to fall into. DEC’s James Markham with the Lake Erie Unit is charged with conducting that research for cold water fish.
“We have to try and think of ways to provide and improve spawning habitat for lake trout,” Robinson said.