David VanHevel of Macomb Township fishes at Brandenburg Memorial Park in Chesterfield Township. Many say bass fishing at the park is the worst in memory, perhaps because of warming water.High lake temperatures puzzle regional scientists
The warm water makes swimming more comfortable, but can create a toxic stew.
Comment on this story
Sweltering heat has many Metro Detroiters seeking relief in Michigan's waters, where lakes already have warmed to peak summertime temperatures.
The average surface temperatures of the Great Lakes are at their highest in five years. Readings in the 60s and 70s from all but Lake Superior already are warmer than they were during last summer's most comfortable mid-August swimming days.
Tourists have headed north and boaters have hit the waterways for the busy Fourth of July weekend. Roger Funkhouser, manager of Bayshore Resort in Traverse City, has booked a growing number of downstaters looking to escape the heat.
"We get a lot of spur-of-the-moment visits when people decide they just can't take it anymore," he said.Victoria Davis, 14, of Pontiac, took advantage of Cass Lake's warm temperatures Friday.
"I thought it was going to be really cold. It's like bath water," said Davis.
She went swimming with her mother, Nancy, 37 and sister, Brooklyn, 8, at the lake at Dodge No. 4 State Park.
But experts warn that bountiful sunshine and warm water can have a downside. It can steam up a biological soup that spells trouble for living creatures in and out of the water.
Gary Towns, Lake Erie management supervisor for the state's fisheries division, expects to see accelerated weed growth in inland lakes and the possibility of more frequent toxic blue-green algae slicks.
Towns also expects an earlier and more dramatic onset of the annual midsummer fish die-off because of low oxygen levels in some lakes. Some algae, like the blue-green variety, can cause illness in animals.
"Heat is very good for making things grow, including weeds, algae and bacteria," said Rochelle Sturtevant, a systems ecologist with the Great Lakes Sea Grant network.
Sturtevant said researchers might not make sense of current temperature data for months or even years, but there is evidence this is an unusual season.Mary Kinzer said the weeds have grown so fast in the water in front of her Orchard Lake home in West Bloomfield that she has been unable to swim this season. Residents at the lake usually have the weeds cut and hauled out in July.
"It's like a carpet. I can see the fish making tunnels up through it," Kinzer said. "The algae is terrible, too. It seems worse than ever."
The warm water is having an effect on fish. Walleye headed out to deeper, colder water in Lake Erie two weeks ago, more than a month ahead of normal, said Towns.
"People are having some trouble catching legal-sized walleye in Michigan waters. Normally, you don't see that movement until August," he said. "This year, it happened in the second week of June."
Gilbert Garschagen, 40, of Shelby Township, was fishing Lake St. Clair from a pier at Brandenburg Memorial Park in Chesterfield Township. He was having little luck.
"It's probably the worst year for bass fishing ever," he said.
Steve Lichota, associate director of the environmental division of the Macomb County Health Department, is at a loss to explain why his monitors have registered high E. coli bacteria levels so often this season at Lake St. Clair beaches.
"It's usually rain that causes fertilizer runoff and introduction of fecal material along with combined sewage and storm water overflows. But for some reason we've been getting high readings without rain events that cannot be explained," Lichota said.
"No swimming" orders were issued at Metropolitan Beach Metropark on five days so far this season due to high E. coli counts. Memorial Beach and St. Clair Shores' Blossom Heath Beach remain closed over the holiday weekend, their third shutdowns of the season. A beach at the inland reservoir lake at Stony Creek Metropark also closed for a day in mid-June.
"That was a very rare thing," Lichota said. "Was it the geese and the lack of rainfall that caused a concentration of bacteria? Whether something out there is multiplying because of heat, I can't say."
A researcher at Central Michigan University has begun a study of bacteria that may multiply in beach sand, said David Schwab, director of the Great Lakes Environmental Research Laboratory in Ann Arbor.
Experts say the trend doesn't provide proof of global warming theories, but may point to the extremes of natural weather cycles.
"It seems the last four or five years, perhaps the last decade, have been a little bit warmer," Schwab said. "Whether that is something that will continue, we don't know. It may simply be part of a 10-year, or even a 100-year, cycle."
Chuck Pistis, a Michigan State University Extension agent and specialist in Great Lakes charter fishing, said big lake fishing remains unharmed by the warming trend.
"These bodies of water are so large that it's a constantly changing scenario. A storm can cause the really cold water to come up from the bottom, and everything is changed," Pistis said. "Right now, it's warm out there, and that's good. It means the kids can go swimming and not turn blue."
You can reach Doug Guthrie at (313) 222-2359 or dguthrie@ detnews.com.
Copyright © 2005
The Detroit News.
Use of this site indicates your agreement to the Terms of Service (updated 12/19/2002).