Giant Mekong catfish threatened by dam plans

This video says about itself:

Mekong giant catfish caught in the Mekong River at Chang Rai, northern Thailand, in 2008. The Lao and Thai governments have now declared a ban on fishing this critically endangered wild population of catfish that can weigh up to 350kgs and 3metres in length.

From Wildlife Extra:

Giant Mekong catfish survival threatened by new dams

14/04/2011 11:25:08

Substandard dam assessment opens way for fisheries destruction on Mekong

April 2011. Disruptions to fish migration and food supplies for millions in the Mekong basin are likely if the first mainstream dam on the lower Mekong is allowed to go ahead, according to analysis released by WWF. WWF claim that the dam feasibility study and environmental impact assessment failed to address key environmental risks.

The WWF commissioned review – coordinated by the WorldFish Centre with participation from the United Nations Food and Agriculture Organisation (FAO) found that the Environmental Impact Assessment (EIA) for the proposed Xayaburi dam in Laos and assessment were woefully inadequate and fell well below international standards for such studies. Xayaburi is the first of 11 dams proposed for the lower Mekong mainstem.

Lower Mekong countries are scheduled to decide on whether the dam project can move ahead on April 22.

Key studies ignored

The review found that the EIA ignored published studies and relied heavily on “a very light field sampling” that captured “less than a third” of the biodiversity in the impact area.

Just five migratory species from a list compiled in 1994 were mentioned and just three of more than 28 studies of Mekong fish migration were referenced. In contrast, current studies show that 229 fish species exploit habitats upstream of the dam site for spawning or dry season refuges, with 70 classified as migratory. The review finds the proposed fish passes for the dam ignore design guidelines, lack critical detail including any specification of target species and have a slope and steps which would be challenging even for salmon – not a Mekong species.

Giant catfish

Among the species threatened is the Mekong’s famed giant catfish with only known spawning areas in the upper Mekong between Chiang Rai province (Thailand) and Bokeo (Laos). While the Mekong Giant Catfish is symbolic and culturally important, smaller fish like the Pa Soi are important food sources for villagers in the Mekong River.

“How can you devise mitigation measures for fish passage without addressing the biology and the needs of target species, which in this case range from a small Siamese Mud Carp or Pa Soi to a 3 metre long giant catfish,” said Dr Jian-hua Meng, WWF International Sustainable Hydropower Specialist.

“Fish ladders of the design proposed have had some success in Europe and North America, but this is where only a handful of species are migratory, and many of those are of the salmon family, that are much stronger swimmers and jumpers than most Mekong migratory species.”

The review noted other studies that concluded that fish passes are not a realistic mitigation option for Mekong mainstream dams, and “that the Mekong should never be used as a test case” for proving or improving fish passages technologies.

April 2011. A new study by WWF on aquatic ecosystem connectivity reveals that the Mekong region could have equivalent power but dramatically less damage to river functioning by opting for tributary rather than main channel dams: here.

June 2013. Damming the mainstream of the lower Mekong River would represent a significant new threat to the survival of the Mekong giant catfish, one of the world’s largest and rarest freshwater fish, according to a new study commissioned by WWF: here.

Vietnamese scientists worried that the controversial Xayabury hydro-power project in Laos will make harmful impacts on Vietnam’s Mekong Delta: here.

Giant Catfish Caught in Thailand Sets New Record: here.

Bendable teeth seen for first time in suckermouth catfish: here.

Study finds 40 [Mediterranean] fish species could vanish: here. And here.

Frankenfish foiled? A setback for genetically modified salmon approval: here.

Related articles

• Lao Dam May Kill Off Mekong Giant Catfish (cambodiadaily.com)
• Dams could signal death knell for Mekong giant catfish (wwf.panda.org)
• Mekong Dams Threaten Burmese Fishing, Rice Farming: Activists (irrawaddy.org)
• Mekong Mystery: Dwindling Fish (scientistatwork.blogs.nytimes.com)
• Plague of deforestation sweeps across south-east Asia (guardian.co.uk)
• Dams Threaten Mekong Basin Food Supply (ipsnews.net)
• Scientist at Work Blog: Hope Amid the Dams and Dangers (scientistatwork.blogs.nytimes.com)
• Fisherman lands incredible catch (huffingtonpost.com)