NOAA News Online posted this story about NOBOB (NO Ballast On Board) ships, i.e. ships that are completely loaded with cargo and have no ballast water. A survey of international ships that visit the Great Lakes region revealed that even they are at risk of introducing non-native organisms into the environment. It can happen after the cargo is unloaded, at which time a ship must take on Great Lakes water as ballast. If that ship then visits another port in the Great Lakes to load cargo, the ballast must be dumped...and along with it, all the nasty "residual foreign water and sediment and the organisms therein" that normally is not pumped out. The article links to the full report at the bottom of the page.