The beginning of a new year led me to thoughts about what is on the agenda list for the continual progression and management of Lake Erie by the Ohio Department of Natural Resources (ODNR) Division of Wildlife. My initial idea for a story was to interview Roger Knight, the Lake Erie Fisheries Program Manager, questioning him about a top-three or five list of things on the ODNR’s agenda list for Lake Erie management. What the interview turned out to be was a discussion about the particulars of managing walleye populations on Lake Erie, along with what is being done to stop invasive species.
At the forefront of the discussion was the ODNR’s quest for continually monitoring and studying the sport fish of Lake Erie, namely walleye and yellow perch.
“We’re working very diligently with our inter-agency partners, namely-Canada, Michigan, Pennsylvania and New York to set reasonable Total Allowable Catches (TAC) for walleye and perch,” said Knight. “We take a hard look at the science and do what we can to improve the models to make sure that those levels are set appropriately, so we have good fishing now and into the future.”
Looking into the future, there will be changes made on how the ODNR views the population of walleyes swimming in Lake Erie.
“Currently all of the models treat the lake as having two stocks of walleye, a Western Basin and Central Basin Stock, which primarily spawn in the Western Basin, and an Eastern Basin stock,” said Knight. “We know that the Western and Central Basin Stock is make up of a number of component stocks; the Maumee stock, the Sandusky stock, the Grand River, Detroit River and the Lake Erie reefs stock. Right now we don’t know if the Maumee or the Lake Erie reef stock is bigger, because the reef stock is hard to sample.”
Sampling bottom content for eggs, analyzing creel/net surveys and telemetry are all methods used to help understand life processes of the walleye in Lake Erie.
“We’re starting a new Master’s project with Ohio State that will take over the walleye telemetry study that we began on the Sandusky Bay and (Sandusky) River,” said Knight. “This is a program that we started a couple of years ago by implanting some radio transmitters in fish to learn more about specific habitat and spawning habitats in the Sandusky area to answer some of the questions on why that stock of fish isn’t doing as well as we would like it to do, and if there are things we can do to improve it.”
Tracking studies of fish are historically accomplished through the process of placing a jaw tag on a fish, and then relying on anglers or commercial fishermen to report that a fish was harvested. Information on the size and whereabouts of the fish is recorded if available.
“We’ve started to use PIT tags instead of jaw tags to eliminate any bias in our reporting and tracking of fish,” said Knight. “PIT tags are injected under the skin of the fish, but can still be detected by telemetry. This allows us to not have to depend on anglers for our information. This gives us a better estimate of differential survival rates of different stocks of fish.”
Analyzing and studying the different stocks will give the ODNR an advantage in management.
“From all of our studies we’ve learned that the Sandusky Bay and River stock likes to move east after spawning,” said Knight. “So if we want to improve fishing for people in the Central Basin then that is an important stock. The work we did on this study was a pilot program. What we’ve learned so far is that many of the fish staging off of Huron in the fall are Sandusky Bay and River spawners. Some of the questions left to answer are-Where are the fish spawning, in the bay or in the river? Another question is whether or not the areas in the bay are as good reproductive sites as the traditional areas below the dam (Sandusky River)?”
“The goal of the telemetry study is to understand different behavior, where and why walleyes move, and then overlay that with where the actual fishing takes place,” said Knight. “This gives us potential options for management in the future. For example, allowing us to protect certain stocks if they need it.”
Another element of the Ohio State project is looking at the size of fish contributing to the spawn. Are the bigger fish or smaller fish more valuable.
“The old assumption has been that the old fish don’t contribute much, but the research isn’t showing that,” said Knight. “It’s still to early (the study) to predict for sure. Another angle that is being looked at is if the older fish will produce every year possible, or will they take a year or two off?”
My next question posed to Mr. Knight was-If the inter-agency partners and state governments all work together so well to manage Lake Erie for the best fishing possible, then why hasn’t anything been done to stop foreign traveling ships from dumping their ballast waters in the Great Lakes causing and contributing to our invasive species problem.
“The management agencies do not have direct management authority over the issue,” said Knight. “If we had, we would have done something about it.”
A major problem with invasive species is how they affect the Great Lakes and disrupt the ecology of the lake. Zebra mussels, white perch and gobies all have had dramatic impacts on the Great Lakes.
The task of managing a system that is changing due to the introduction of new species is very challenging for biologists.
“It’s an extremely frustrating thing for us. It confounds our models in many ways,” said Knight. “Many of the states have grown tired of the Federal Governments lack of progress on dealing with the issue, and are now passing legislation dealing with the treatment of ballast water. Michigan already has something on the books regarding this. Right now we have a similar bill in Ohio legislation.”
Legislation at the state level will definitely help to alleviate some of the issues, but the true authoritative legislation must be on a Federal level.
“Our hopes for the last twenty years have been through the National Invasive Species Act, on the Federal level, that this issue would be taken care of,” said Knight. “Obviously, it hasn’t been enough. I will be attending two ballast water conferences coming up to learn about the latest science in dealing with ballast water.”
“In general, Great Lakes States and agencies are all over the issue. There are a lot of people pushing for this at many levels. The problem is its being stonewalled in Congress. It’s frustrating for everyone involved. I’ve been involved in it for most of my career and it’s a complicated problem that we can’t give up on.
The states and involving agencies are doing what they can, but it is a federally solved problem.”
Fish behavior and understanding why they behave that way is and will continue to be a goal for all fisheries biologists across the world. Tracking fish with new telemetry technology, along with the historical methods of surveys and nets, are all a necessity in the quest for knowledge of the species. Additional outside variables, such as the effects of zebra mussels and gobies on Lake Erie, continually pose a threat to any sustained management of Lake Erie. Until those on a Federal level decide to limit the continual release of foreign ballast waters into the Great Lakes we will continue to pay for our lack of decisive action.