http://www.postchronicle.com/news/science/article_212861.shtmlA predatory non-native species of fish known as the Northern Snakehead, discovered 3 years ago in waters east of the Chesapeake Bay, were caught in large quantities on a small feeder creek of the Potomac River earlier in the week. The numbers were significant enough to convince some biologists that the species is not going any where, and to echo concerns over what the voracious fish will inevitably do to the natural balance of the water's ecosystem.