Scientists: $200M loss from Great Lakes invasives

In this Jan. 5, 2006 file photo, a group of round gobies swim in an exhibit of the kinds of invasive species threatening the Great Lakes ecosystem at Chicago's Shedd Aquarium. A scientific report released Wednesday, July 16, 2008 says invasive species that reached the Great Lakes in ballast tanks of oceangoing ships may cost the regional economy about $200 million a year. (AP Photo/M. Spencer Green)