Deep down in three ocean abysses in the Bahamas, some cave divers have discovered some hot spots of microbial life. These ocean abysses, commonly known as blue holes, are yielding scientific findings which are assisting scientists to discover and learn about life beyond Earth. Questions have rise to whether these are clues to life in alien oceans, and teams of scientists have been exploring the depths to find out how these minute ecosystems survive.
Blue holes were once sinkholes that formed on land and later filled with ocean water. The deepest blue hole known on earth is Dean’s Blue Hole in the Bahamas which reaches some 663 feet and is known to divers as a world class freediving destination where competitions are held annually.
Originally sinkholes were formed during the ice age when ocean water was locked up as ice, and freshwater rain caused erosion through the coastal limestone rock causing deep caverns. As Earth warmed up and the oceans rose many of these caverns collapsed and filled with saltwater.
The bacteria found down in these depths which are yet unreachable by divers except on SCUBA or by submarine, are living in sulfur-based ecosystems. Scientists have become interested in these life-forms as similar conditions could exist in pitch-black oceans millions of miles away— “perhaps under the icy crusts of Jupiter’s moon Europa and Saturn’s moon Enceladus”, Kevin Hand reports in National Geographic. Kevin Hand is an astrobiologist and NASA’s deputy chief scientist for solar system exploration.
Rich ecosystems thrive in the inhospitable depths of these blue holes, including species of shrimp, aquatic mites, copepods, and other crustaceans and survive on microbial nutrition.
“It’s through our study of life’s extremes on Earth that we can extend our understanding of habitable environments off Earth,” he said.
You can read more about this on the National Geographic website.