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 feed, 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 feed 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 the 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 have failed, according to
Xu.
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 percent of them were considered useful and
deliberately introduced, only to prove disastrous for local
ecosystems and species.
About 49 percent entered the country accidentally, traveling 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 losses are losses in sectors such as
agriculture, forestry and fishery. Indirect losses, including
damage to ecosystems and species resources in the country, total
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 on Friday
in Beijing attended an experts' forum on biodiversity.
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.
(China Daily May 22, 2004)