World’s biggest freshwater fish threatened by dams on Mekong28/07/2010 14:39:25 Mekong dams threaten rare giant fish
July 2010. Wild populations of the iconic Mekong giant catfish will be driven to extinction if hydropower dams planned for the Mekong River go ahead, says a new report by WWF.
The report, River of Giants: Giant Fish of the Mekong, profiles four giant fish living in the Mekong that rank within the top 10 largest freshwater fish on the planet. At half the length of a bus and weighing up to 600kgs, the Mekong River's Giant freshwater stingray is the world's largest freshwater fish. The critically endangered and culturally fabled Mekong giant catfish ranks third at up to 3 metres in length and 350kgs.
Full Mekong dam report
The River of Giants: Giant Fish of the Mekong report can be downloaded here.
Current scientific information suggests the Mekong giant catfish migrate from the Tonle Sap Lake in Cambodia up the Mekong River to spawn in northern Thailand and Laos. Any dam built on the lower Mekong River mainstream will block this migration route.
The Sayabouly Dam
"More giant fish live in the Mekong than any other river on Earth," said Ms Dang Thuy Trang, Mekong River Ecoregion Coordinator for the WWF Greater Mekong Programme. "Currently, the Lower Mekong remains free-flowing, which presents a rare opportunity for the conservation of these species. But the clock is ticking."
Dog-eating catfish & Giant Barb
However, the impacts of lower Mekong River mainstream dams are not restricted to these Mekong giants, they would also exacerbate the impacts of climate change on the Mekong River Delta, one of the world's most productive regions for fisheries and agriculture.
Building the Sayabouly dam would reduce sediment flowing downstream to the Mekong River Delta, increasing the vulnerability of this area to the impacts of climate change like sea level rise.
WWF supports a delay in the approval of the mainstream dams, including the Sayabouly dam, to ensure a comprehensive understanding of all the positive and negative impacts of their construction and operation. To meet immediate energy demands, WWF promotes sustainable hydropower projects on tributaries of the Mekong River, prioritising those that already have hydropower dams developed on them.