China suffers from invasive species
China is one of the countries which suffer the most from the
invasion of alien species, with a record number of at least
283 species.

The Int'l Union for Conservation of Nature (IUCN) has
identified the world's 100 worst invasive alien species.
Of those, 50 can be found in China, acc. to Wang Jie,
director of the Office of Bio-safety Management in the
Dept of Nature & Ecology Conservation.

[[File photo shows the eichhornia crassipes (also called
'water hyacinth') covering the water.]]

Wang also notes that these invasive species have been causing
a great economic loss of about 120 billion yuan (US$29.3 bil)
every year. What's worse, 46.3% of them have invaded China's
natural reserves.

As alien species have continued to invade over the years,
the number of local species has been greatly reduced & some
have even become extinct. Alien species not only affect the
ecosystem, but also impact China's agricultural & forestry
production.

Acc. to a survey on invasive alien species by the former
State Enviro Protection Admin in 2003, the direct economic
loss caused by invasive species that year totaled 19.9 bil
yuan (US$2.9 bil); the indirect economic loss on the ecosystem,
species & genetic resources amounted to 100 billion yuan
(US$14.6 billion). Combined together, the two occupied
1.36% of China's GDP that year.

"The worst thing is an outbreak of the invasive species. Due
to great difficulty in controlling their growth, they cause
severe biological pollution & some irreversibly damage
the ecosystem," Wang Jie says.

Eichhornia crassipes (also called "water hyacinth"), originally
from South America, was introduced to Taiwan from Japan for
its beautiful flowers. During the 50s, the plant was grown
in bulk, as it was used to feed pigs. Today, the damaging
effects of the plant are well-known. Infestations of this
weed block waterways, which in turn limits boat traffic,
irrigation, drainage & aquatic breeding. Covering the water,
it damages aquatic ecosystems & threatens the local
biological diversity.

Water hyacinth has to be artificially cleared in Guangdong,
Yunnan, Jiangsu, Zhejiang, Fujian & Shanghai every year. In
Wenzhou City, Zhejiang, alone, the yearly expenditure to
clear it is 10 million yuan (US$1.46 million).

"China spends as much as 500 million yuan (US$73.2 million)
to 1 billion yuan (US$146.4 million) clearing water hyacinth
every year," says Yang Hongjun, director of the Yunnan Inst
for Ecological Agriculture. "Its direct economic losses even
amount to 10 billion yuan (US$1.5 billion)."

"Objectively speaking, some species are intentionally intro-
duced for good purpose; however, they're out of control due
to poor management," says Zhang Runzhi, a researcher at the
Institute of Zoology in the Chinese Academy of Sciences.

The red-eared slider is a turtle that was first introduced
as a pet & is still quite popular in China's pet market.
It's been listed among the world's 100 worst invasive alien
species, as identified by IUCN. The species proved to be a
medium to spread disease & has caused great destruction in
turtle populations in Taiwan.

[[File photo: Red-eared slider]]

Another similar case is the smooth cord grass, introduced
from America to improve the environment in 1979. It was
grown in Fujian Province in 1980, & later introduced into
Jiangsu, Guangdong, Zhejiang & Shandong in 1982.

"The initial intro aims to protect beaches, improve the
soil, make beaches green & hence improve the ecological
environment; however…this species not only influences the
local fishery production, but also poses a great threat to
mangroves," Zhang says.

In addition to the intentional intro of species, acc. to
Zhang, some alien species can also be unintentionally
intro'ed thru imported goods.

In July 1999, Chinese Customs ID'ed the pine wood nematode
59 times on the wood packaging of mechanical & electrical
products imported from Japan & America. This species can
cause a disease known as "pine wood cancer."

"The public should prevent the unintentional intro of these
alien species," Wang Jie indicates. "Take the notorious
German cockroach as an example. People's packages, luggage
or even goods on consignment can bring it on the journey.
Even foreign fruit can pose great ecological risks."

http://www.china.org.cn/environment/features_analyses/2009-06/03/content_17880215.htm