The northern snakehead is a fish that is traditionally indigenous to China, Russia, North Korea and South Korea. The earliest detection of a nontraditional niche was when the snakehead was found in a freshwater lake in Crofton, Maryland. This occured in 2002. The pond was drained, and two breeding adults and over one hundred smaller fish were found and destroyed. The fear was that the snakehead would invade the freshwater ways surrounding the greater Chesapeake Bay area. In 2004, nineteen snakehead were captured in the Potomac river. These fish were established, meaning they were living and breeding within the confines of the Potomac river. The snakehead is specifically a freshwater fish, it can not endure more than ten parts of salinity per thousand. The snakehead has been found as far south as Florida, where it was found in three freshwater lakes there. Establishment has not been ascertained at this point.