|INTERVIEW with Roger Knight, Lake Erie Fisheries Program Administrator, Division of Wildlife
What do you do to protect and improve Ohio’s coastal region?
I oversee fisheries research and management efforts on Ohio’s 2.24 million acres of Lake Erie that are outlined on the bathymetric map below. We share Lake Erie waters with Michigan, Pennsylvania, New York and Ontario. Our research helps to determine the health of important fish populations and to estimate how many fish can be safely removed by fishers each year.
Our biologists also investigate habitat loss, invasive species and restoration of native fishes. Basically, we want to know what habitats fish are using at different life stages and at different times of the year.
We also seek to know if habitat is sufficient for healthy fish populations and how fish habitat may change with a changing environment, such as changes caused by global warming or land management practices that effect watershed hydrology.
How do you assess fish population health?
Our biologists sample fish by either catching them in nets or by examining the catches of recreational and commercial fishers. Research enables us to estimate the abundance of various fish species, their survival rates, how fast they grow, how well they reproduce and how they interact with each other. The resulting data allows us to make decisions about how many fish of particular types can be caught each year without putting the fish stocks at risk. In April of 2007, for example, the Governor changed the bag limit for yellow perch based on our research.
You can see that collecting all types of data is very important to us. The biologists in the photo above are processing fish samples, measuring each fish for its length, weight and removing scales for age determination. Like trees, scales have rings that can be counted to determine the age of the fish. For larger fish, we remove the otoliths or “ear stones” to determine their ages because the rings in a cross-sectioned otolith of a larger fish are more easily discernible than those on their scales.
How about the other types of research you mentioned?
We have projects on nearshore fish habitat and native species, such as the endangered lake sturgeon. Lake sturgeon populations, although very small, have shown signs of increasing in the past decade and we are building an inventory database from public sightings to learn more about the relic populations.
In our projects about native species, we often have opportunities to collect data about invasive species such as white perch and round gobies. We also monitor invasive plankton species that could be altering the Lake Erie forage base in major ways.
We have walleye research underway to learn more about the health of spawning stocks, how they differentially contribute to our fisheries throughout Ohio waters and how we can improve the health of each stock. The photos above show us inserting a radio transmitter into the abdomen of an adult walleye, so that we can track her movements during the spawning run in the Sandusky Bay area.
What is most challenging about your job?
Lake Erie is a very dynamic system, full of changes. It is also a major tourism and fishing area, so there is a high level of human interest in what we do because it affects people in many different ways. You never know what issue might pop-up and occupy your time over the next day, week, month, or even longer.