Mekong Dams Threaten Extinction of Giant Catfish

The elusive Mekong giant catfish, which the U.S.-based World Wildlife Fund (WWF) called “one of the world’s largest and rarest freshwater fish,” can reach up to three meters (10 feet) and weigh up to 300 kilograms (660 pounds). The Xayaburi dam would prove an “impassable barrier” for the migratory catfish, which is believed to only exist in numbers of up to a couple hundred, a WWF said in a statement based on the findings of a new study. “A fish the size of a Mekong giant catfish simply will not be able to swim across a large barrier like a dam to reach its spawning grounds upstream,” said Zeb Hogan, the study’s author and associate research professor at the University of Nevada. … The giant catfish is already in “steep decline” due to overfishing, habitat destruction and dams along the Mekong’s tributaries, the WWF said, adding that the Xayaburi dam could “disrupt and even block spawning, and increase mortality if the fish pass through dam turbines.” … Construction on the controversial U.S. $3.5 billion dam, which will be the first across the main stem of Southeast Asia’s key waterway, resumed last year following delays amid objections from Laos’s neighbors. The dam’s construction is still in its early stages, with officials saying in March that about 8 percent had been completed. The dam has come under criticism for what some groups have said are significant gaps in data about its potential socio-economic and environmental impact, particularly in terms of how it will affect fish populations in the Mekong. Finnish consulting firm Poyry Group, which had published a glowing assessment of the dam’s impact, had said that “fish passages” can be built into the Xayaburi to allow fish to get past the dam’s turbines while swimming up and down the Mekong, but WWF said that the claim has never been successfully put into practice. … Thailand, Laos and Cambodia regulate fishing for the giant catfish, with bans in place in Thailand and Cambodia, but the species is still fished illegally and accidentally in fisheries targeting other species. …

http://www.rfa.org/english/news/laos/dams-06192013184629.html