E. Coli levels in Lake Michigan have declined since 2000, according to a new study out of Michigan State University.
The study found that E Coli concentrations in the lake fell by 10 percent, between 2000 and 2014. In that same time, beach advisories fell by 14 percent.
Chelsea Weiskerger is the study author. She said the reduction is a combination of e. coli management plans and invasive quagga mussels.
“This is in no way sort of a conclusion that says oh maybe mussels aren’t so bad. This is one small benefit of an otherwise very invasive.”
Weiskerger said the mussels are making the water clearer - which allows the sun to kill e. coli .
“And then the sunlight that comes in basically does the same thing to the e. coli as it does to our skin: it alters the DNA a little bit and inactivates the e. coli.”
She says the study does not mean mussels are good for the Great Lakes - simply that they have this one benefit.