Aquatic biodiversity in the Mekong river system is the second highest in the world after the Amazon.[11][12] The Mekong boasts the most concentrated biodiversity per hectare of any river.[13]
The commercially valuable fish species in the Mekong are generally divided between ‘black fish’, which inhabit low oxygen, slow moving, shallow waters, and ‘white fish’, which inhabit well oxygenated, fast moving, deeper waters.[14] People living within the Mekong river system generate many other sources of food and income from what are often termed ‘other aquatic animals’ (OAAs) such as freshwater crabs, shrimp, snakes, turtles, and frogs.