Invasive species costly to ecology
Imported plants and animals that have proliferated in China cost the country nearly 120 billion yuan (US$14.5 billion) every year.
Called alien invasive species, they are brought in from abroad only to end up harming local ecosystems, threaten native species and lead to the loss of local biodiversity.
The problem has caught the eye of the State Environmental Protection Administration and the Ministry of Science and Technology. Together, they are drafting a law on biological security to address the problem.
One example is the water hyacinth, introduced from South America in the 1950s as pig feedstuff, said Xu Haigen, director of the Division of Nature Conservation and Biodiversity of the Nanjing Institute of Environmental Sciences.
Later, as people started using other feedstuff they stopped feeding pigs with water hyacinth.
However, the species reproduced rapidly and spread in provinces such as South China's Guangdong and East China's Jiangsu and Fujian.
The plant covers water surface, it fights off other water plants and organisms and damages local ecosystems.
Local governments have invested large sums of money to get rid of water hyacinth but all their efforts failed, Xu said.
A national survey conducted in 2001 and last year found 283 alien invasive species in the country, ranging from terricolous plants to reptiles and microorganisms.
Nearly 40 per cent of them were considered useful and deliberately introduced, only to prove disastrous for local ecosystems and species.
About 49 per cent entered the country accidentally, travelling on products traded internationally. They then developed wildly.
According to the survey, headed by Xu and experts from ministries such as the State Environmental Protection Administration, the Ministry of Agriculture and the State Forestry Administration, alien invasive species cause direct economic losses of nearly 20 billion yuan (US$2.4 billion) every year.
Direct economic loss are losses in sectors such as agriculture, forestry and fishery.
Meanwhile, indirect losses, including damage to ecosystems and species resources in the country, totals 100 billion (US$12 billion) yuan every year, he said.
"Many people in the country lack sufficient knowledge about the impact of alien species on ecosystems and the environment and therefore pay no attention to the problem," said Xu, who Friday in Beijing attended an experts' forum on biodiversity.
Some even believe blindly that alien plants are better than native ones. Xu said almost all the grass seeds for lawns are imported from abroad.
No risk assessment is in place before introducing alien species. At the same time, management of new species is not effective and may contribute to the problem, he said.
Xu proposed a number of steps, including a law on biological safety, strengthening risk assessment capacity, more research on the control of alien invasive species, and raising public awareness.
Cai Lei of the State Environmental Protection Administration's biodiversity and biosafety office said in addition to drafting a law on biological safety, research on a risk assessment system for introducing alien species is underway.