Article courtesy of Annette Manwell | September 19, 2012 | Holland Sentinel | Shared as educational material
The point of a water-quality tour at Holland is somewhat simple: The Lake Macatawa Watershed affects Lake Michigan.
The run-off from lawns, farms and streets flows into creeks and storm drains. Creeks and storm drains empty into Lake Macatawa. Lake Macatawa is connected to Lake Michigan.
And the Great Lakes are 20 percent of the fresh surface water in the world.
Grand Valley State University’s Robert B. Annis Water Resources Institute in Muskegon and the Macatawa Area Coordinating Council offered a series of water-quality tours on Lake Macatawa and Lake Michigan last week. And while those who attended the tours did some procedures with the water, the GVSU scientists and MACC’s Watershed Coordinator Kelly Goward wanted people to take home a better understanding of the lakes’ health.
The tours were provided through an Environmental Protection Agency Great Lakes Restoration Initiative grant, said Janet Vail, associate research scientist at GVSU’s Annis Water Research Institute. The EPA wants people to know about the Lake Michigan Lakewide Action and Management Plan, she said. That plan looks at whether fish can be eaten, if the water is safe to drink, healthy habitats and much more.
“It’s one of the resources we need to preserve and protect,” Vail said. “Everything we do affects Lake Michigan.”
Compare the lakes
The same experiments were done in both lakes so people could understand how the two lakes differ.
What they found was a drastic difference in the Secchi reading, which measures the depth of the waters transparency. In Lake Macatawa, the Secchi disk disappeared from view 0.75 meters. In Lake Michigan, it could be seen 8.5 meters. Lake Macatawa the water was brown because of sediment and green because of green algae. In Lake Michigan, it was a clear turquoise.
The main difference is Lake Macatawa collects the organic material that flows from streets, the creeks and farms. Leaves that flow down storm sewers and creeks decompose in Lake Macatawa, giving it the mucky bottom. Lake Michigan has a sandy bottom.
The lakes are classified differently and have different fish and food chains also.
In Lake Macatawa the blood worm, the larvae of the midge fly, is prevalent and an important member of the food chain. In Lake Michigan many different kinds of plankton could be scooped up and observed via a microscope.
The plankton are important part of the food chain in Lake Michigan, Annis science instructor Paula Capizzi said. But the invasive quagga mussels are filter feeders and clearing the lake of plankton. The mussels are slowly becoming part of the food chain as well, she said, “But they are still a problem.”
“I live on Lake Macatawa and have watched the green slime get worse and worse,” said Holland resident Tim Hemingway on the Friday tour. “This year has been the worst.”
Hemingway is the chairman of the of Holland Board of Public Works Board of Directors. He has a keen interest in the watershed from that perspective and as a homeowner along the lake.
The algae has been pretty persistent since the water warmed up and the sun started shining, Capizzi said.
The green algae is “a double-edged sword,” Goward said. “It’s ugly and stinks, but it’s a sign of improvement; the phosphorous is getting used up.”
The lake was clear enough to allow sunlight to penetrate to the bottom because of the lengthy drought.
The lack of rain stopped run-off from washing into the lake. The sunlight allowed the algae to grow and with the help of phosphorous, which is washed into the lake from excessive fertilizer on lawns and farms, the algae managed to get as thick as it has this year.
Phosphorous helps plants grow. But if too much is used and the plants don’t absorb it, it will bind with the sediment that gets washed away.
“Our goal is to reduce the phosphorous,” Goward said.
If heavy fall storms don’t come through and churn the lake to get what Capizzi calls “a turn over,” there could possibly be a large fish kill as the green algae begins to decompose.
“That’s something you have to look forward to if you live on the lake,” Goward said.
As the algae dies off, it could choke the oxygen out of the water. The lack of oxygen could kill the fish.
And while there are some toxins in the algae — enough that people could get sick if they get it on their skin or ingest it — those toxins aren’t the biggest problem.
“The bigger problem is the decay process,” Goward said.
The MACC works directly with farmers to eliminate run off, Goward said. “But it’s easier said than done.”
For farmers, it means expensive changes in equipment and different practices, she said, adding there are grant programs to ease some of that burden.
Phosphorous binds to sediment, so the idea is to keep the sediment in place.