Associate professor of biology at Temple University Erik Cordes has been studying this "lake" at the bottom of the Gulf of Mexico. The water in this "lake within the sea" is about five times as salty as the sea water and contains highly toxic methane and hydrogen sulfide. It cannot mix with the sea water forming a "lake".

Only bacteria, tube worms and shrimp can survive.

Scientists can also use this area as a possible example of environments on other planets. Watch the video of scientists exploring the area in a submarine below.