A dolphin species has been EXTERMINATED by a dam
In the past sixty years or so, we've dammed most of the world's major rivers, resulting in huge hydrological changes, and major disruptions to the web of life once supported by free-flowing waters. Gone are the famed river dolphins of the Yangtze, thanks to Three Gorges Dam - the first human-caused extinction of a dolphin species. Most of the damned species are less charismatic than the Baiji dolphin, but no less important in the big web of life.
Tragically, many governments are planning big, destructive dams in biodiversity hotspots. Brazil's President Lula wants to build the world's third biggest dam in the Amazon. He says the Belo Monte Dam won't proceed without an $800 million "mitigation fund" to compensate indigenous people living in the dam's way, and to address the project's environmental impacts. But species on the edge can't use money, they need habitat. The Kihansi Spray Toad can tell you all about that; the millions spent have not brought back its watery world.
Southeast Asia's Mekong is another species-rich ecosystem that is threatened by a wave of big dams (the species at risk include another dolphin, and many, many fish that provide the bulk of protein for the region's people). The most remarkable animal that could fall to the walls of concrete now being built or planned by China, Laos, Burma and Vietnam is the giant Mekong Catfish, a grizzly-bear-sized creature that breaks all records for freshwater fish. More than a thousand fish species live in the Mekong River system, a biodiversity second only to the Amazon. The river's fisheries support some 40 million people, and bring in $2 billion a year.