Vientiane, Lao PDR, 19 Dec 2018
Vientiane, Lao PDR, 19 December 2018 – Available today, an updated Mekong fish species database from the Mekong River Commission (MRC) provides comprehensive information on fish species in the Mekong basin, including in the Sekong, Sesan and Srepok rivers and the Tonle Sap River.
In its newly updated system, known as the MRC Database for Mekong Fish Species, the MRC has recorded 474 fish species through its own monitoring between 2003 and 2017, with about 80% being migratory species, in the Mekong river basin. The database also includes 225 species in the “3S” system comprising the Sekong, Sesan and Srepok rivers spanning northeast Cambodia, southern Lao PDR and the Central Highlands of Viet Nam. Also recorded are 137 migratory fishes in the Cambodia’s Tonle Sap River, home to the largest commercial fishery in the Mekong river basin.
But with the review of other studies from multiple sources, it was estimated that the Mekong basin has a larger figure of 1,148 fish species.
The lower Mekong basin (LMB) inland fisheries are in fact the world’s largest fisheries, with an estimated annual yield of 4.4 million tons, or an economic value of $17 billion. More than 40 million people — two-thirds of the population of the LMB — are actively involved in the sector.
Fisheries provide between 50-80% of the animal protein for the basin’s population. They account for 18% of Cambodia’s GDP and contributes more to the country’s economy than rice production. In Lao PDR, the fisheries value is equivalent to nearly 13% of the country’s GDP. Although proportionally less significant to the national economy, the Mekong fisheries sectors in Thailand and Viet Nam add well over $5,500 million to their GDP each year.
“For the first time, our database provides a comprehensive list of Mekong fish species with their key bio-ecological characteristics collected both from our own monitoring and other studies,” MRC CEO Mr. Pham Tuan Phan said.
“The database can aid in various fish assessments, including fish species composition, abundance, stock and distribution, and bio-ecological and population dynamics studies.”
It was already used for a biological resource assessment in the MRC’s Council Study, formally titled the Study on Sustainable Management and Development of the Mekong River including Impacts of Mainstream Hydropower Projects, published late last year.
The database has documented 11 ecologically distinct groups or guilds of the total 1,148 fish species. Three among them are more vulnerable to or have a higher relative effect from changes in the river hydrological condition than other groups. The three groups make up about 25%.
One of these is the main-channel residents or long-distance white fishes, a group of species that require stamina to swim to their distant spawning grounds or take refuge in the main channel. Another guild is the main-channel spawners or short-distance white fishes, a group of species that spawn in the main channel, tributaries or margins upstream of floodplain feeding and nursery habitat often with pelagic egg or larval stages.
The third group is the floodplain spawners or grey fishes. Fishes of this guild undertake migrations from floodplain feeding and spawning habitats to take refuge in the main channel during the dry season.
But four other fish species could not be assigned to any particular group due to a lack of data.
The MRC, through its former Fisheries Program, sampled and assembled available fish species at 38 monitoring sites between northern Lao PDR and the Mekong Delta in Viet Nam. The sites were river sections or reaches of several kilometers in length. Each site had three fishermen collecting daily catch data that was then logged. Various types of fishing gear were used with gill nets being the most common.
Since the mid-1990s, the MRC and its member countries’ national line agencies have monitored fish abundance and fish diversity in the Mekong river basin. Results from this monitoring and other fisheries research and development in the region are published regularly in the Commission’s newsletter Catch and Culture.
In a report published in 2013 by the MRC and WorldFish, there were only 877 fish species in the Mekong river. Only three ecological fish groups of white, black, and grey fishes were known at the time.
“Our knowledge about fish and fisheries in the basin has advanced, but challenges remain now and in the future in how we preserve these resources in the face of rapid development and changing climate,” CEO Pham said.