Only on Mid-Ocean Ridges and... (Ping Athelind!)

As underwater environments go the two couldn't be much more different, and yet...

Let me start over. You have hydrothermal vents on mid-ocean ridges, spewing water heated to hundreds of degrees. And then you have...

Oh hades. Just read the article.

http://greatlakesecho.org/2009/07/14/lake-huron-sinkholes-hold-exotic-life-scientific-clues/