In the article Danbo posted:
It states that the Gobies force out native species like the Sculpin and Darter and removes them an important species) from the food chain. It doesn't mention that the Gobie replaces them in the food chain (which they do).
The aforementioned article also states the nuisance of the Zebra Mussel. It doesn't mention the new jobs created for removing the mussel, nor that the Zebra Mussel has cleaned up a tremendous amount of pollution in the Great Lakes, the Great Lakes are cleaner than they have been in years!
... but here's a really interesting twist to the whole thing!
Zebra Mussels can comprise up to 82% of the Gobies diet!!!
I found that tid bit of info in this interesting article:
http://www.glwi.uwm.edu/people/jjanssen/pa.../mandypaper.pdf
I don't condone the introduction or spread of invasive species... but Mother Nature has a way of taking care of herself, and it might be interesting to see how this unfolds in the years to come.
