In 2022, NOAA researchers conducting sonar surveys in Lake Michigan's Wisconsin Shipwreck Coast National Marine Sanctuary, initially searching for shipwrecks, discovered something unexpected—large craters spanning miles, located 450 feet underwater. These depressions remained largely unexplored until August 2024, when scientists used a subaquatic vehicle for a closer investigation. They found various forms of aquatic life inhabiting the craters, including freshwater shrimp, deepwater sculpin fish, bacteria, and invasive quagga mussels. However, answers to questions about how the craters formed, how long they’ve been there, and exactly what they are remain open to debate. These mysteries in Lake Michigan have area researchers excited.

“It’s an extreme environment,” said Greg Dick. “We typically have to go to Antarctica or Yellowstone National Park or some exotic location to get these extreme ecosystems, but this is in our backyard in the Great Lakes.”

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