In addition to everything else, the Great Lakes are also home to some of the most interesting little critters on the planet.
You may have heard of extremophiles. They’re the microscopic organisms living in places that, by rights, should be off-limits to any living thing: volcanic vents, super-cold environments, whacked-out reaches in the upper atmosphere where O2 is at a premium, but you can get crazy-deadly cosmic rays by the wholesale.
Turns out, the Great Lakes has ’em by the bucketload. 60 feet down, in these FRESHWATER LAKES, researchers have discovered sinkholes – over 300 feet across – filled with BRINY WATER. This, you might think, is slightly odd. Turns out, groundwater is rising through the bedrock into the lake, dissolving minerals in the bedrock. The bedrock is actually an ancient seabed more than 400 million years old. And in these briny holes, microscopic bacterial colonies are thriving.
These bacterial colonies – brilliant purple cyanobacteria – are close relatives to other colonies found living among the “black smokers” in the deep ocean, as well as bacterial colonies found in submerged Antarctic glacial lakes.