By Anna Barnes
A pilot project to remove large mats of algae build-up from three locations on Lake St. Clair is set to begin this fall.
The $800,000 field trial will allow two contracting groups to remove the mats with researchers studying what happens after.
Candice Miller, the Macomb County Public Works commissioner, said she has no doubt the mats will return, but the project will provide immediate relief to these three shorelines.
“Initially, you have to get rid of this stuff,” she said, “at least in some of these locales, and then see if we can figure out some sort of mitigation efforts to keep it clean once it’s gone.”
She said while the removal is important, researching long-term solutions through the project is the main goal.
The Army Corps of Engineers and Macomb County, even though it has no jurisdiction over Lake St. Clair, have been working on the project for years and pushed for the funding from the state.
State Rep. Alicia St. Germaine, R-Harrison Township, and State Sen. Kevin Hertel, D-St. Clair Shores, sponsored the project.
The mats of algae can become multiple feet deep and render the affected areas unusable. Michigan’s Department of Natural Resources had to re-locate a boat launch site due to the build-up, Miller said.
One of the sites is the Veterans Memorial Park in St. Clair Shores.
“That beach has been closed for years because all this muck just rolls in and continues to mat up,” she said. “They’ve been doing the best they can to deal with it, but they finally just gave up.”
This type of algae is called Microseira wollei and can grow up to 1.5 miles offshore. Through wind and waves, the algae becomes dislodged and ultimately deposits itself into the shoreline. The mats are formed as the algae builds-up over time.
“We are going to start with three sites,” she said. “We could have picked dozens, but we don’t have the funding to do that.”
She said the muck has not always been there and this is a new problem. Researchers say they believe there are several contributing factors to its takeover, but a new theory suggests it may have something to do with invasive mussels, whose introduction coincides with the beginning of the problem.
Erica Anculle is an Extension educator for Michigan Sea Grant and said the mats have become more common since 1990.
“That point is when we start to see more impact from the zebra and quagga mussels in the lake,” she said. “So, we also think they may be making it easier for that Microseira to be there because the mussels filter out a lot of the small plankton and other organisms. They cause the water to be clearer.”
The algae grows only in places where the sun can reach it. As the water becomes more transparent, the sun can reach further into the lake.
Research has shown mussels may encourage other types of algae growth.
“They’re causing there to be more areas where it’s able to grow,” she said.
While the algal mats are definitely an eyesore, they are also dangerous.
Preliminary tests done on the mats show they can produce toxins. More testing during the project will gauge the amount of toxins produced by them but the potential is there.
“Even the mats, when they’re on the shoreline, still potentially contain toxins, so that means people and animals should stay away from those mats,” she said.
Anculle said that kind of matting algae is not common in Michigan. However, the matting started getting bad only in the 1990s, so it cannot be ruled out as impossible in other Michigan lakes.
Especially as the climate warms, mussels make the water clear, and heavier precipitation makes for abundant nutrient runoff, all contributing factors to algae growth.
The project will last three years and the findings will inform management for Lake St. Clair but may also be useful on a broader scale.
Anna Barnes is an environmental reporting intern at Michigan Public through a collaboration with MSU’s Knight Center for Environmental Journalism and the Mott Foundation. This story was written for Michigan Public.