Aquatic Invasive Species

Recent studies have discovered a higher alien richness in the Curonian lagoon than in the benthic zones of the Baltic Sea.  Through their research, scientists have postulated what allows an ecosystem to be invaded, and for that matter, why is the invader invading?

There are two general hypotheses concerning species diversity and the “invisibility” of a habitat. Stachowicz et al.(1999) argues that the diversity of an ecosystem  increases is resistance, amd protects it from foreign invasion Stohlgren et al.(2003), on the other hand, believes that invasive species are “invisible” and undetectable under such a huge lens of a marine ecosystem.

Research concluded that systems have already been modified by man, through dams or embankments, or have already been invaded by a species, such as the zebra mussel, are high susceptible to further invasion. For instance, when a concrete construction is made in the Klaipeda strait, it provides the zebra mussel a hard substrate to bind to. The mussels then provide foreign invaders with nutrients and thus create a positive feedback system that may never be stopped.  The correlation between debth range and inasice species richness is explained by the decline in oxygen and thus yielding more vigorous conditions (Leppakoski and Olenin 2000). Species tend to approach less diverse ecosystems that have less competition and more of their particular nutrients of interest. It’s important for biological control to focus on these hot spots of lagoons and swamps, even if they aren’t directly related to the fishing trade; an abundance of invasive species can clog or poison entire water channels that deposit  into our water reserves.

http://www.glerl.noaa.gov/pubs/fulltext/2006/20060037.pdf

Biol Invasions- DOI 10.1007

An analysis conducted by David L Strayer of Cary Institute for Ecosystem Studies shows that in the 20 years that Zebra Mussels (Dreissena Polymorpha) have been present in the United States, they have become one of the most dominant freshwater species. This comes at a huge expense to both native species as well as to humans. Even though the Zebra Mussel has had such a spectacular impact on the habitats in which it establishes itself, there are important questions that are still being ignored.

            The economic expenses alone caused by the Zebra Mussel infestation are estimated at over $100 million. While this is a staggering amount, key policies have still not been passed or even proposed in order to keep the spreading of the Mussel at bay.

            Public alarm associated with the expansion of the Mussel has driven technological and some policy advances, but much change is necessary to halt the spreading of the Zebra Mussel.

Front Ecol Environ 2009; 7(3): 135-141, doi:10.1890/080020(published online 25 Sept 2008)