Michigan researchers tested carbon dioxide treated benthic mats at Loon Lake in Sleeping Bear Dunes National Lakeshore to control invasive zebra mussels. In a 2024 study led by the U.S. Geological Survey, treatment plots with CO2 infused mats killed over 80% of caged zebra mussels within five days. Ordinary mats killed only 20.6%, and untreated areas saw 12.7% mortality. CO2 levels under the mats reached nearly 200 mg/L and stayed high for the treatment period. The approach matters because zebra mussels are more sensitive to CO2 than many native unionid mussels. However, the treatment also reduced benthic macroinvertebrates, so the method needs refinement to limit collateral impact. One practical advantage is speed. Conventional mats require longer deployment, while CO2 treated mats may clear sites in days, allowing crews to treat more areas in a season. The study is preliminary, but it offers a possible alternative to broad-spectrum chemical controls.
