A subtle invasion
THE Worldwatch Institute of Washington, DC,has come out with some findings on the spread of exotic species from one place to another. Calling it "bioinvasion", the institute says this spread threatens biological diversity and has the potential for global disaster. The environmental watchdog group says that the increasingly global economy could bring worldwide ecological disruption.
As global trade carries non-native, "exotic" species across natural boundaries, such as deserts, mountains and ocean currents, "biological pollution" sweeps the planet, the institute warns. Invasion of species are very old processes but with trade and international releases of certain exotics invasion rates are far beyond natural levels, point out researchers.
"The integration of the global economy is spreading more and more (organisms) around - in ship ballast water, in containers, even in commodities themselves," said Chris Bright, research associate at Worldwatch andauthor the study Life Out of Bounds: Bioinvasion in a Borderless World. "Because it the intelligence of evolution to bear, bioinvasion is a kind of 'smart' pollution," Bright added. "Compared to living things, chemical spills are 'dumb'; they are inert, they cannot reproduce and they tend to dissipate over time. But when an exotic species establishes a beachead, it can proliferate over time and spread to new areas. It can also adapt. It tends to get better and better at exploiting an area's resources and at suppressing native species," Bright explained.
At a press briefing in October, Bright stressed that the public was yet to grasp the full dimensions of this threat. "In some areas, particularly islands, researchers note that that current invasion rates are possibility at one million times their natural levels. No ecosystem can stand up to that kind of pressure indefinitely," Bright noted.
Bioinvasion is becoming a new measure of the unsustainability of within the current economic order and biological pollution is becoming a social menace, Bright observed. He cited the example of the return of the cholera epidemic to the Americas in 1991 ,probably via contaminated ship ballast water released into a Peruvian harbour. "More than a million people were infected and some 10,000 died; the cost to South American countries came to more than US $200,000 in emergency drinking water and sewer repairs alone, Bright recalled.