A rare oasis of life has been found among geothermal vents in Wyoming's Yellowstone Lake, the first such discovery in a freshwater system, scientists say.

Montana State University researchers have found a colony of moss, worms and varieties of shrimp in inky-black, 90-degree F water in a cauldron of nutrients and gases, a university release said Monday.

The geothermal vent is almost 100 feet below the surface of Yellowstone Lake and a third of a mile offshore, where the worms and shrimp live among approximately two feet of moss that encircles the vent.

"This particular vent seemed unique relative to all other active vents thus far observed in the lake in that it is robustly colonized by plants," the researchers said.

The team explored the lake bottom with a remotely operated vehicle.

"The proliferation of complex higher organisms in close association with a Yellowstone Lake geothermal vent parallels that documented for deep marine vents, although to our knowledge this is the first such documentation for a freshwater habitat," the researchers wrote in an article published in the journal Geobiology.

The key to survival in this unusual environment is the nutrients contained in the vent water, scientists say, which feed the moss, which then feeds the shrimp and worms.