The Three Gorges Dam in China is thought to have already forced the world's largest freshwater fish, the Chinese paddle fish, into functional extinction. Now a new scheme in Indo-China may spell the end for other species of giant fish.
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. These include the giant stingray (the size of a double bed) the Mekong giant catfish, (as large as a small car),the dog-eating catfish (named because it has been caught using dog meat as bait) and the giant barb, (the national fish of Cambodia, and largest barb in the world).
The hydropower dam planned on the Mekong River in Sayabouly Province, northern Laos, is a threat to the survival of the wild population of Mekong giant catfish. The Sayabouly dam is the first lower Mekong River mainstream dam to enter a critical stage of assessment before member countries of the Mekong River Commission advise on whether to approve its construction.
"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 Roger Mollot, Freshwater Biologist for WWF Laos. "This would lead to the collapse of the wild population of this iconic species."
"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."
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.