Full Article (IPR News Features)
Author Peter Payette
For decades, exotic species have been invading the Great Lakes and mixing up the ecosystem. A few years ago the constant changes led to the collapse of the food web in Lake Huron. That event has spurred on interest in restoring native fish, with the hope that they’ll provide more stability. But not everyone wants the food web in the Great Lakes to look exactly like it did a century ago.
Once upon a time, every Great lake was stuffed with lake herring. Trout would feast on them, and so would people all over the Midwest. Commercial fishing nets would haul tens of millions of pounds of herring out of the lakes every year.
Fisheries biologist Mark Ebener says herring, or cisco, would lay so many eggs in the fall it was a food source for other fish. Ebener says it still is in Superior.
“You go into parts of Lake Superior in December and the whitefish are just gorged on cisco eggs,” he says.
But herring largely disappeared from the lakes in the middle of the last century for a variety of reasons, including overfishing and invasive species. Biologists like Mark Ebener think restoring the fish should be a top priority. He’s with Chippewa Ottawa Resource Authority, a tribal fishing agency based in Sault Ste. Marie.
Some tribes have commercial fishing rights on the lakes that date back to treaties signed in the 19th century. They’d like the state to be more aggressive about restoring native species.
Ebener says if we want a stable ecosystem in the lakes, herring are crucial.
“It was the prey species,” he says. “So if you want to restore the connectivity of the lakes and the historic predator-prey dynamics, why would you ignore herring?”
So What Happened?
While nobody would admit to ignoring the fish, figuring out exactly what happened to lake herring has not been a priority of scientists. But that’s changing.
Grand Traverse Bay is the only place herring are still known to breed in Lake Michigan, and state fisheries biologists have been coming to a breeding ground near Elk Rapids for three years. The Department of Natural Resources and Environment wants to know why this remnant population doesn’t expand.
The team picks up an invasive fish in the net. Team leader Randy Claramont says this is the primary suspect, and they try to figure out why the herring has done so poorly in recent years. This exotic fish eats newborn herring.
“There’s our predator,” he says. “There’s a rainbow smelt. Right in where the cisco are, we also got an adult rainbow smelt. Again we haven’t seen these all year. At the same time that these white fish and herring moved into the nursery area, smelt showed up.”
Lake herring look and taste a lot like whitefish. In fact, these fish are too young to tell apart without a microscope. And Claramont and his staff may have just caught a hundred or more in their net. So this is going to be a lot of lab work.
May Not Be Great For Salmon
It would also be a lot of work to convince everyone that restoring herring as the main prey fish in Lake Michigan is a good idea.
That’s because the state is responsible for managing the lake’s popular salmon fishery. Salmon are not native to the Great Lakes, but are generally considered to be the most exciting fish to catch. Lot of anglers come up north to do so.
So, politically speaking, the salmon has clout.
Jim Dexter, the Lake Michigan basin coordinator for the Michigan DNRE, doesn’t think salmon like to eat herring.
“One thing that’s important to remember is that if you have a huge herring population, I don’t think you’ll be able to maintain the type of salmon sport fishery that we currently have,” he says.
But it’s a different story in Lake Huron, where the salmon disappeared in 2004 after the food web crashed because it was dominated by exotic fish. The upheaval has sparked interest in a more stable ecosystem, and that’s why the Michigan Steelhead and Salmon Fishermen’s Association actively supports efforts to reestablish the herring there. 40,000 herring were planted last year in Lake Huron.
Managers of the project think they’ll need to plant a million fish a year for a number of years to reestablish the species in the lake.