Lake Huron sits on a layer of 400-million-year-old limestone – the remnants of an ancient seabed. Groundwater runs vertically under the lake and pushes through the limestone, making deep, underwater sinkholes, said Steve Ruberg, a researcher with the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory, which leads the research that begins this August. The project includes scientists from across Michigan and Wisconsin.
Much of the mystery involving the sinkholes relates to a unique “microbial community” that includes a type of cyanobacteria that live on sulfur and other bacteria. Cyanobacteria are one of the oldest organisms on Earth. They are notable for their ability to switch between oxygen and sulfur to produce the energy they need through photosynthesis.
The billions of years old cyanobacteria may hold the secret of how Earth went from inhabitable to habitable, sustaining plant and animal life. Read on.