By Tony Briscoe
Despite their minuscule size, microorganisms — including, bacteria, viruses and algae — are among the most prolific environmental regulators on the planet. These tiny, single-celled species wield the ability to alter the Earth’s climate, spread human disease, regulate the metabolism of animals and some serve as the building block of the aquatic food chain. In the Great Lakes — which provide drinking water for 48 million people and support a $7 billion recreational fishery — researchers know next to nothing about some of the most abundant microbes.
As Great Lakes climate trends make harmful algae blooms more likely and raise questions about how other microorganisms may behave, this research has taken on a sense of urgency.
In 2012, Maureen Coleman, an assistant professor of earth sciences at U. of C., started the first long-term study of microorganisms across the five Great Lakes to better understand what microbes are present in the region and what role they play in the environment.
So far, after analyzing four years’ worth of samples, the team has discovered around 160 new species. With funding from the National Science Foundation, U. of C. scientists embarked on a six-day sampling expedition from Milwaukee to Duluth, Minnesota. The research vessel steamed to lake trout spawning reefs colonized by invasive mussels, along the Straits of Mackinac, up the misty St. Marys River, through the Soo Locks and onto a cold and foggy Lake Superior.
“We don’t often appreciate the microbes around us, but the Great Lakes are full of them,” Coleman said. “Every drop of water you swallow when you are swimming in Lake Michigan has about 1 million bacterial cells and 10 million viruses. Our goal is to understand who’s there and what are they doing, and then eventually to understand how they’re changing over time.”