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Environmental group warns foreign species to stay home

HA NOI — The World Conservation Union (IUCN) has published a booklet which lists 100 of the World’s Worst Invasive Alien Species to warn against the perils of introducing species into unfamiliar habitats.

The IUCN hopes to illustrate the incredible variety of species that have the ability to travel in ingenious ways, establish themselves and come to thrive and dominate their new environments. Today, alien invasion is second only to habitat destruction as a cause of species endangerment and extinction.

"The species involved in the study were selected for their serious impact on biological diversity and or human activities, and for how they highlight the important issues involved in the alien invasion," says Dr. Mick Clout, who heads IUCN’s Invasive Species Specialist Group.

"There are some particularly notorious cases , but that does not mean that a species absent from the list is any less dangerous. Our purpose in publishing the booklet is to draw attention to the scale and complexity of the rapidly growing invasive species problem," Clout said. " But it is really only the tip of the iceberg. Invading alien species are driving untold numbers of native plant and animal species to extinction world-wide."

Historically, most intentional introductions have had disastrous outcomes such as that of the Nile perch, which resulted in the extinction of more than 200 other fish species.

In Viet Nam, the yellow snail (Pila sinensis) was imported 10 years ago and has rapidly caused widespread destruction to rice fields in the Cuu Long (Mekong) River Delta and spread to the north and central parts of the country. The first yellow snail epidemic struck in 1994, destroying thousands of ha of rice and other cash crops throughout the country. This resulted in reducing rice production despite government efforts and outlay of hundreds of millions of dong to eliminate it.

The genes, species and ecosystems that make up the earth’s biological diversity are all important because their loss and degradation diminishes nature. Species other than our own have a right to exist and to retain their place in the world. We do not know how to estimate which species are essential to the ecosystem , which are redundant, and which will be the next to flourish as the due to environmental changes.

When a new species is introduced into an eco-system, the full impact is often not immediately apparent. Invasion by plant life (such as Miconia calvescens) can change entire habitats, making them uninhabitable for the original native community.

Safeguarding the earth’s diversity is the best way to maintain our life support system. There is evidence to suggest that the biosphere acts as a self-regulating whole, and that diverse systems may be more resilient. Island ecosystems, which have evolved in isolation, often have relatively fewer plants, herbivores, and carnivores. These systems are more vulnerable to invasion.

On islands around the world species extinction is increasing at an unprecedented rate.

Useful initiatives, which contribute to better management practices and a reduced incidence of biological invasion, are being taken by communities all over the world. Invasive alien species are now a major focus of international conservation concern and the subject of co-operative international efforts, such as the Global Invasive Species Programme (GISP). As awareness grows, individuals and nations are able to make informed choices that will have lasting effects on their descendants.

The list of "100 of the World’s Worst Invasive Alien Species" aims to enhance awareness of the fascinating complexity, and also the terrible consequences, of invasive alien species." There are many invasive alien species, in addition to those included in the list. There are many more than 100 species proving a significant threat in the world..

Experts hope that, by raising general awareness, the risks of further harmful invasions will be reduced in future. — IUCN/VNS

www.ecologyasia.com

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