What is Meromictic body of water?
Meromictic means the upper and lower layers of water do not mix. This leads to the sea having anoxic water. Anoxic waters are areas of seawater that do not contain the adequate amount of oxygen, dissolved in it to sustain marine life.
Black Sea happens to be the largest meromictic body of water. The top layer of the Black Sea is exposed to oxygen in the atmosphere; the bottom layer has no dissolved oxygen. The Black Sea has two distinct layers forming the largest anoxic body of water on Earth.