Laos, Thailand, Cambodia and Vietnam established the Mekong River Commission (MRC) in 1995 to assist in the management and coordinated use of the Mekong's resources. In 1996 China and Burma became "dialogue partners" of the MRC and the six countries now work together within a cooperative framework.
The extreme seasonal variations in flow and the presence of rapids and waterfalls in this river have made navigation difficult.
In English the river is called "the Mekong River", derived from "Mae Nam Khong", a term of both Thai and Lao origin. In the Lao-Thai toponymy, all great rivers are considered "mother rivers" signalled by the prefix "mae", meaning "mother", and "nam" for water. In the Mekong's case, Mae Nam Khong means Khong, Mother of Water. "Khong" is derived from the Sanskrit "ganga", meaning the Ganges.
The Mekong basin is one of the richest areas of biodiversity in the world. Only the Amazon boasts a higher level of biodiversity. Biota estimates for the Greater Mekong Subregion (GMS) include 20,000 plant species, 430 mammals, 1,200 birds, 800 reptiles and amphibians and an estimated 850 fish species. In 2009, 145 new species were described from the Mekong Region, comprising 29 fish species previously unknown to science, two new bird species, ten reptiles, five mammals, 96 plants and six new amphibians. The Mekong Region contains 16 WWF Global 200 ecoregions, the greatest concentration of ecoregions in mainland Asia.
No other river is home to so many species of very large fish. The biggest include the giant river carp (Probarbus jullieni), which can grow up to 1.5 metres (4 ft 11 in) and weigh 70 kilograms (150 lb), the Mekong Freshwater Stingray (Himantura chaophraya), which can have a wingspan of up to 4.3 metres (14 ft), the giant pangasius (Pangasius sanitwongsei), Siamese giant carp (Catlocarpio siamensis) and the endemic Mekong giant catfish (Pangasianodon gigas), all three of which can grow up to about 3 metres (9 ft 10 in) in length and weigh 300 kilograms (660 lb). All of these are in serious decline, both because of dams and flood control and overfishing
Balls of light are observable from time to time rising from the water's surface in the stretch of the river near Vientiane or Nong Khai. These are sometimes referred to as Naga fireballs.