Feb 14, 2007 — U.S. ports receive more than imported cargo. They often receive fish and other aquatic organisms from foreign ports. They stow away in the ballast water of cargo ships. Once in U.S. waters, some of the foreign species become invaders, damaging the ecosystem. The federal government has done little to stop these invasive species. Rick Pluta reports now some states have decided to take things into their own hands.