Perch Thrive in Great Lakes Despite Changing EcosystemsAgency: Natural Resources
July 29, 2010
Long before salmon were introduced to the Great Lakes, well before invasive species began finding their way in, yellow perch were a popular quarry for Great Lakes anglers. But as the ecosystem became more complicated with species such as zebra mussels and gobies inserting themselves into the food chain - some people began to wonder whether perch would continue to thrive in a changing environment.
"One of the things we were concerned about is whether the invasive species would shift the regime to the point that we'd never have perch fishing like we used to," explained Dave Clapp, a fisheries research biologist who works out Charlevoix.
Indeed, several years of poor recruitment in the early 21st century seemed to confirm that worry. And then?
"In 2005, we had the best reproduction on record," Clapp continued. "Recreational catch rates of perch are the highest they've been since 1995 right now. And that's mirrored in our assessments. So we have had some reasonable reproduction even with all the invasive species coming into the lakes."
And it's not just Lake Michigan where the future for perch has been a question mark. Fact is, perch fishing is pretty good right now in a number of Michigan's Great Lakes waters. But in others? Maybe not so much.
"Yellow perch began to decline in both Lake Michigan and Lake Huron at the same time and our instinct was to look for a common explanation," said Dave Fielder, a fisheries research biologist out of Alpena. "But there are some differences in what has been going on in Lake Michigan and Lake Huron.
"In Lake Michigan, it was a problem largely of recruitment. There was some evidence that it was alewife predation on the young perch as well as zebra and quagga mussels influencing the food supply for young perch."
But the more Fielder looked into Lake Huron perch populations, the more he found differences within Lake Huron itself.
"In Saginaw Bay we saw similar declines and we thought it was a lot of the same reasons as Lake Michigan, but up in the Les Cheneaux Islands we saw a lot of young perch coming into the system, but they were disappearing at a later age," Fielder said. "And up in the St. Marys River, perch were doing great."
Fielder said investigation into the Lake Cheneaux Islands area showed that it was cormorants that were cropping off the perch population and subsequent population controls on the birds have led to improved perch populations.
Meanwhile, Saginaw Bay had different issues all together.
"Today alewives are largely gone from Lake Huron and perch reproduction has exploded in Saginaw Bay," Fielder said. "There are lots of young-of-the-year perch. But we're not seeing them beyond that first year - they're not recruiting into the population.
"What we know is all the predators - walleye, pike, bass - are eating the perch."
In the Upper Peninsula, fisheries research biologist Troy Zorn says perch fishing in the northern waters of Lake Michigan is currently pretty strong.
"Creel estimates in Little Bay de Noc in 2006 and 2007 were some of the best years in a decade or so," Zorn said. "There's decent fishing in Big Bay de Noc, better than it was, but angling effort is about 10 percent of what it is in Little Bay."
Mike Thomas, a fisheries research biologist at Lake St. Clair, says there are a lot of young perch in Michigan's waters of the border lake.
"Our trawl surveys indicate we've had several very good year classes produced," Thomas said. "Over the last couple of years the fishing has been slow - by some reports it's been terrible - especially during the winter. But this year, all of a sudden, the reports say the fishing has been really good. The fishing is hot and the fishermen are much happier, nice-sized perch and good numbers of them."
So overall the perch fishery in Lake St. Clair remains in pretty good shape and it continues to be very popular, Thomas said.
Lake Erie, on the other hand, has produced pretty good and pretty consistent perch fishing over the last five years, Thomas said.
"In general it's a late summer and fall fishery," Thomas explained. "The population is considerably lower than it was back in the late 1990s - something in the neighborhood of 50 percent of what it was back then - so there's a little concern about that.
"For the last several years, algae blooms in the Western Basin have been more frequent," he continued. "There are a lot of unanswered questions about exactly what is causing that - some evidence suggests that it has to do with exotic species - zebra mussels and quagga mussels and how they cycle nutrients in the lake.
"So things are good in Lake Erie but there is kind of cloud on the horizon; there are things going on that may prove to be problematic in the future."
In summation? The perch fishery continues to be cyclical in all of the Great Lakes' waters where they have long existed. Fishing is good in some, not so good in others. But the fish seem to have adapted to sharing the lakes with the invasive species and there's no reason to assume Michigan anglers are going to lose perch fishing in the Great Lakes, as was once feared.