Thompsonville, Mich. — It’s no secret that Great Lakes ecosystems are changing. Invasive species have turned the food chain on its head, starting at the bottom with the zebra and quagga mussels that filter plankton out of the water, which forms the bottom of that food web. Round gobies, sea lamprey, bloody red shrimp, and many others invasives also have taken a toll and impacted the delicate ecosystems that native and non-native game fish (salmon) depend on. Changes have been most evident in Lake Huron, where the alewife and salmon populations have crashed.
With a rapidly changing environment in Lake Michigan, DNR fisheries managers find themselves in a continual state of change when it comes to managing the resources.
“We have to expect the unexpected,” DNR fisheries biologist Randy Claramunt told members of the Michigan Outdoor Writers Association on Jan. 30 at a meeting at the Crystal Mountain Resort. “The near-shore fishery (in Lake Michigan) is expanding – brown trout, yellow perch, rock bass, walleye, bass, and pike. Lake Michigan is rapidly changing. Look at the fluctuations in water levels in the past few years. It all has an impact on fisheries.
DNR management actions are in response to these changes. We care about the Great Lakes and will respond to changes as they occur.”
One of those reactions is the drastic reduction of salmon stocking in Lake Michigan in recent years in response to a declining prey (alewife) base.
“In the past, our focus has been on the open-water fishery – salmon, alewives, etc.,” Claramunt said. “Our focus now has to be near shore in response to changes in the lake.
“We’re not ignoring or minimizing the open-water fishery. That’s still very important to us. We’re just adapting to the changes near shore.”
Claramunt said these changes aren’t all necessarily bad. Round gobies, for example, now provide an important food source for just about every game fish species in the lake except salmon. Yellow perch, he said, seem to be adapting rather well to the changing dynamics, and he believes perch numbers will start to improve somewhat over the next five years.
“Probably not to the 1970s levels, but I think we will start to see improvements,” he said.
Smallmouth bass is another species that seems to have adapted well to the changing dynamics of the lake. Smallie fishing has improved so much that national professional tournaments recently have been held on Lake Michigan.
“That’s also a positive thing, and I expect that to continue,” Claramunt said.
Some of the management changes the DNR is now focusing on include restoration and enhancement of critical near-shore coastal habitat as well as taking a look at perch-, bass-, and walleye-fishing regulations and stocking strategies.
“We don’t have any concrete changes in mind yet, but we’re looking at everything,” Claramunt said. “How do we maximize fishing opportunities in response to the changes?
“Right now, we are most interested in improving our ability to identify these changes so we’ll know how to respond to them,” he said.