SciDev.Net

Water hyacinth threatens to interfere with the generation of hydroelectric power

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[BEIJING] China's rapid economic development has encouraged the spread of invasive species, says an article in the April issue of BioScience.

China, a biodiversity 'hotspot', is under threat from over 400 invasive species, and its annual economic losses from alien insects and plants are estimated at US$14.5 billion.

Invasive species are often imported and can be harmful to the environment. The China–US team say that invasive animal species increased from 1990 to 2003 by more than 30 per cent to 76 species, and invasive plant species tripled between 1995 and 2003.

Biological invasion is a worldwide problem, say the authors. Quarantine and inspection are inadequate in China, and growth of the country's industrial and transportation infrastructure has assisted the spread of unwanted species.

For example, species can be propagated through the huge Three Gorges Dam. Fifty-five invasive species have been detected in the dam's drainage area, including water hyacinth — originally introduced for cheap animal feed — which now threatens to interfere with the generation of hydroelectric power by blocking the dam's pipes.

Growing transportation networks like the Qinghai–Tibet railway help spread invasive species to remote regions, says lead author Ding Jianqing from the Wuhan Botanic Garden of the Chinese Academy of Sciences.

The 2008 Olympics are also playing a part. In 2002–04, Beijing introduced a variety of foreign plants with a view to 'greening' the games. These species, though not invasive themselves, could act as conduits for non-native parasites and insects.

"Without careful risk assessment and appropriate management, non-native species with presumed benefits could cause harm to native species," Ding told SciDev.Net.

"Despite the seriousness of invasive species in China, the attention the government and people pay is limited," he adds. "Strict laws and regulations for the restriction and control of invasive species are necessary, as well as more urgency in enhancing awareness of the risks of biological invasion."

Link to full paper in BioScience [2.84MB]