WHAT MAKES SOME INVASIVE SPECIES SO BAD?

by Whit Gibbons

July 8, 2002

Peter Paul van Dijk's business card sports a panda , the logo used by the World Wide Fund for Nature (WWF). A primary goal of WWF is to "stop the degradation of the planet's natural environment," and Peter Paul works with a program called TRAFFIC, which monitors international trade in wild plants and animals.

Living in Malaysia, being Dutch, and speaking fluent English, Peter Paul is well equipped to deal with the melee of cultural politics and agendas related to international trade in plants and animals. The job presumably ranges from one of frustration in dealing with international bureaucracies and a few greedy people to one of extreme satisfaction when progress is made on a conservation front. As the Senior Programme Officer for TRAFFIC Southeast Asia, Peter Paul has been involved in many conservation issues, one being the problems resulting from introduced species that are viewed as invasive. Standard examples in the United States are fire ants, kudzu, and ragweed.

Invasive species are generally unpopular in their foster homes, where they are viewed as interlopers that need to be eradicated. Although many invasive species require legitimate eradication efforts, the issue is not entirely black-and-white. Peter Paul offered some intriguing thoughts about whether certain problems associated with some proclaimed invasive species are as serious as people in the region make them out to be. The common denominator in this scenario is that a plant or animal species touted as an invasive nuisance may provide a source of funding, validation, or other justification for an agency or organization. If there's no nuisance there's no rationale for the agency or organization.

What are the reasons for an introduced species to be declared an invasive problem? One valid reason, of course, is that the introduced species is responsible for eliminating a native species such as happened with the chestnut blight. But an agency with a program directed toward eliminating an introduced alien species does not want the nuisance value of the species downplayed. If a species can be given a bad rap, an agency is more likely to receive public and government support, support that translates into funding for eradicating the species or preventing it from becoming established. No nuisance means no funding. I'm sure we can all think of a situation that has been made to seem worse than it is so someone can gain power, control, or money.

Peter Paul has seen some introduced species declared as invasive perils because of cultural reasons. If the introduced species is from a country that is an enemy of or unpopular in the host country, the newcomer is less likely to be accepted. For example, red-eared slider turtles are native to the United States but survive successfully in most temperature zone areas in the world where they have been introduced. They may be a problem in some countries because they compete with native species of turtles. But even when they are not a problem, their U.S. origin prevents their getting any special understanding or sympathy in many regions of the world.

A final reason for declaring a species a problem is to use it as a scapegoat for environmental degradation that has already occurred. The red-eared slider is again a good example. In regions of Southeast Asia where red-ears have been accidentally introduced, they are often the only turtle species to be found. Blaming a North American species for the loss of native turtles may make a good story politically, but in much of Southeast Asia, most native turtles had already disappeared long before the red-ears arrived. Removal of Asian wild turtles for the restaurant trade has reached such proportions that many are now gone from entire counties, and some will soon be extinct throughout their geographic range, red-eared sliders or not. Blaming a home-caused environmental problem on an introduced species from another continent can cover a multitude of sins.

None of these examples detract from the fact that some introduced species are legitimate nuisances that we would do well to be rid of. But the reason they are defined as problems may be of our own making. Can you think of any examples in your region that fit one of the models given above?



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