On Invasive Species Policy

Evolution-- it is an ongoing process. Groups of organisms change with the passage of time, and decendants differ both morphologically and physiologically from their ancestors. Through time different organisms become well-suited to their respective environments. Adaptations for climate, terrain, competition, and predators arise. The various defenses that arise are for predators in the area. But many species are very vulnerable to predators that have been introduced to the area.
Invasive species are typically defined as non-indigenous species introduced to an area (usually by human action) where it did not previously occur naturally. The effects, if any, are usually negative. The local flora and fauna do not know how to deal with the newcomer and local populations drop. In some extreme cases, species become extinct. In light of the problem with invasive species, many organizations have been formed to deal with the problems.
I have a bone to pick with these organizations. A problem was created through human interference, and now they feel that even more interference will make things better. This is simply not true. In many cases, the "solution" for an invasive species has turned out to be worse than the original problem.
In the 1900's, the giant African snail (Achatina fulica) was introduced to islands in the Pacific and Indian Oceans for a food source. The snail became an agricultural pest. The solution was to bring in another snail species to handle the giant African snail. So in their infinite wisdom, the ecological organizations decided to introduce a second species to the area: the rosy wolfsnail (Euglandina rosea). The rosy wolfsnail did not do what was expected. Rather than eliminating the giant African snail, it eliminated many local endemic species. Many snail populations in the Partulidae (tree snail) family are now in danger because of the rosy wolfsnail.
Another brilliant solution was the introduction of the small Indian mongoose (Herpestes javanicus auropunctatus) to Mauritius, Fiji, the West Indies, and Hawaii. The mongoose was brought to control rats, and has caused the local extinction of birds, reptiles, and amphibians. Now it threatens the population of the Japanese Amami rabbit (Petalagus furnessi). As a special added bonus, the mongoose is also a carrier of rabies.
Of course the list of examples could go on indefinitely, but I will mention just one more. The brown tree snake (Boiga irregularis) is native to Australia, Papua New Guinea, Indonesia, and the Solomon Islands. In the late 1940's it stowed away on a military aircraft and invaded Guam. Although it is a huge threat to the ecosystem in that region, the solutions being discussed sound even worse. The current plan is to develop a virus that will kill off the Boiga population in Guam. Considering the way some of the previous "solutions" have worked out, I would have to say that this sounds like one of the most bone-headed ideas to ever arise in the scientific community.
A question now arises: if introducing a second species is not the solution, what is? The answer is nothing. Leave well enough alone! Initially local populations may suffer when an invasive species comes to town, but there are usually survivors. Those that do survive probably have some slight variation that allowed them to live, even if just barely. Some of their offspring may handle the situation even better. My solution would be to stay out of it, and let the local species naturally evolve to deal with the invader. Are we so conceited that we think we know better than nature? Haven't we done enough damage already by introducing one species? Nature can come up with a better solution than any one of us. If we stay out of it and let it be, the problem will resolve itself.