Dams one reason for biodiversity loss

BIODIVERSITY: Earth's Life Support Systems Failing by Stephen Leahy

The world has failed to slow the accelerating extinction crisis despite 17 years of national and international efforts since the great hopes raised at the 1992 Earth Summit in Rio de Janeiro.

Experts convening an international meeting in South Africa this week agree that target will not be met next year, which is also the International Year of Biodiversity.

"It is hard to imagine a more important priority than protecting the ecosystem services underpinned by biodiversity. We will certainly miss the target for reducing the rate of biodiversity loss by 2010." ...

Freshwater ecosystems may be the first collapse of one of Earth's life support systems in 13,000 years. Species that live in lakes and rivers are vanishing four to six times faster than anywhere else on the planet, said Klement Tockner of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Germany.

"There is clear and growing scientific evidence that we are on the verge of a major freshwater biodiversity crisis," Tockner told IPS.

Some experts predict that by 2025, not a single Chinese river will reach the sea, except during floods, with tremendous effects on coastal fisheries in China. Worldwide, all 25 species of sturgeon and all species of the river dolphins are either extinct or facing extinction. The species remaining in the world's great rivers like the Danube, Rhine, Hudson and Mekong are mostly non-native species, Tockner said.

"This is a complete change, and few are aware of the threat," he added.

Freshwater ecosystems cover only 0.8 percent of the planet's surface, but they contain roughly 10 percent of all animals, including more than 35 percent of all vertebrates. The pace of extinctions is quickening, Tockner warns - especially in hot spot areas around the Mediterranean, in Central America, China and throughout Southeast Asia.

"Our priority must be to conserve the last free flowing river systems...there are very few left," he said.

And many have new dams proposed to generate carbon-free electricity. Ironically, freshwater ecosystems do a better job at keeping carbon out of the atmosphere as they absorb and bury about seven percent of the carbon humans add annually to the atmosphere.

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