Current Summary

In review, the science behind invasive species has a good deal of evidence to support that these invaders can cause problems. However, the belief that exotic species are completely damaging to the new ecosystems they find themselves in is not entirely correct. There is evidence to suggest that some invasive species can be either helpful or at least non-harmful.

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Invasive species, when in a new environment, can cause large problems. They can upset the food chain by having qualities that no species in the current ecosystem can combat (the Cane Toads or the Lionfish). They can spread to cover incredible distances (like green algae) and shove life out of the way, and even out-compete the native animals in their niches (many types of invasive mussels) and cause extinctions.

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However, what many people do not know is that certain invasive species could have some beneficial properties. Some could perform important acts, such as cleaning water (Asian Oysters) or fixing important nutrients (green algae) better than the native species. Others could be put to good use should they be found in an ecosystem, like the creation of biofuels (green algae). They can also simply benefit an ecosystem, like the Red Sea invaders bringing the eastern Mediterranean from an ecological vacuum to a functioning ecosystem.

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But above all, what people do not know is that there are many unknowns in this science. The scientists who were in the Mediterranean and catching mostly invasive species are unsure of whether or not these species will cause mass extinctions in the sea, or whether they will simply fill the empty niches in the east and thrive. Also, Sax et al. does not know if the plants he studied will continue to live side by side, native and naturalized, in a one-to-one relationship, or if they will eventually level off and the native species will begin to decline.

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The evidence is out there for both sides, but the study of the effects of invasive species on the ecosystems they invade is not an exact science and it depends entirely upon the ecosystem involved and the nature of the species present in it and those invading.