MPR’s Stephanie Hemphill reports that critics of Minnesota's new ballast water permit system will argue in court that the system doesn't do enough to protect Lake Superior from invasive species. They say with a deadly fish virus infesting every Great Lake except Lake Superior, the state needs to act more quickly and more effectively.

Every year, ocean-going ships and lakers dump millions of gallons of ballast water in the Duluth-Superior port. The ballast is used to stabilize the ships as they move from port to port, and take on cargo.