Each summer, more lake beaches in Michigan are shut down as toxic algae blooms spread across the water. While climate change is often blamed, new research has revealed a deeper culprit: humans.
Researchers from Michigan State University used open data to study climate change in 24,000 U.S. lakes. They found climate-driven patterns in algae levels across freshwater lakes.
Michigan State University ecologist Patricia Soranno, who co-led the study, has spent nearly 30 years researching what affects water quality. While climate change plays a role, she says human activity is the true driving force behind the growing problem.
“We know what causes lakes to be greener, and it’s agricultural runoff, urban runoff, extra nutrients that come from lawns,” Soranno said. “All of those things we’ve known for decades, that’s what causes lakes to be green.”
Soranno and her team found climate affected algae in a third of the lakes, but not as expected. Only 4% had lasting algae growth, while 71% saw short-term spikes.
Soranno stresses the need for strong policies and regulations to protect waterways. Her team has a goal to study every U.S. lake using satellite imagery. However, she’s concerned that federal cuts could threaten their research.
