Benthic Mat Slideshow

Scientists estimate the Great Lakes have been invaded by more than 180 species. Invasive species have an impact on every system here and cost more than $200 million annually in lost revenue and prevention strategies.

While aquatic invasive species have irrevocably changed the Great Lakes, we are taking steps to stem new introductions, contain new arrivals from becoming established and minimize the impact of those aquatic invasive species that are here to stay. A stronger, more resilient Great Lakes ecosystem is one of the most powerful weapons we have against aquatic invasive species.

Last year, a small crew of boaters and scuba divers captured the attention of property owners on Barton Lake in southwest Michigan, as they rolled out large burlap mats from a pontoon boat and dropped sandbags into the water. But as odd as it may have looked, the crew was working to improve the health of the lake.

Invasive aquatic plants often grow in dense stands that can reach the water’s surface. These invasive weeds get caught in boat propellers and can make it incredibly difficult for swimmers in the lake.

While plants are important for fish and other aquatic life in lakes, large stands of Carolina fanwort (sometimes known by its Latin name, Cabomba) and Eurasian watermilfoil, two of the most common invasive species in Barton Lake, can make it harder for fish to feed and reproduce. The research team is running studies to determine if biodegradable benthic mats could be an effective tool for controlling these weeds.

A team from The Nature Conservancy, Central Michigan University, Grand Valley State University, Montana State University and Progressive AE have received funding from the Michigan Invasive Species Grant Program to install biodegradable benthic mats on the lake floor to test the control method on invasive plant species.

The crew will investigate whether the mats can prevent the growth of invasive plant species and facilitate improvements in water quality and native plant and fish diversity. 

The mats work by blocking out sunlight to infested areas, stopping plant growth. Research in some European lakes has shown that burlap mats can control some invasive weeds and promote regrowth of native plants, without the use of chemicals.

Leading scientist on the project, Lindsay Chadderton, gears up to instruct the crew where to place the mats.

Benthic mats roll out over the water from a pontoon boat and are anchored on the lake bottom with sand bags deployed from a support boat.

The crew chose burlap material for the mats because it is biodegradable and less costly than many other fabrics and synthetic materials.

To ensure a controlled and accurate placement of the mats, scuba divers gently lower the mats into place.

Sandbags rest on the lake floor until the next visit to observe the mats and collect data.

Thank you to all of our partners and to the engaged citizens and volunteers that support our research and enable us to conserve lands and waters with innovative, science-based solutions.

You can help in the fight against invasive species and keep our Great Lakes great! A gift from you will help us protect drinking water for 40 million people and the home of thousands of native wildlife species. Thank you for supporting our conservation work in the Great Lakes.


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