Minnesota's new ballast regulations are getting support from a Federal Appeals Court ruling.
The 6th U.S. Circuit Court of Appeals has affirmed the right of Michigan, and other states, to regulate ballast water.
A shipper's group had sued to block Michigan's regulations. Ballast water is blamed for transporting dozens of non-native plants and animals to the Great Lakes.
Minnesota Attorney General Lori Swanson said the ruling is important for Lake Superior.
"Lake Superior is really important for our state, not just for our natural resources, but also for our economy. And these invasive species can be very damaging to our lakes and can have an impact on both our environment as well as economic development here in Minnesota," Swanson said.
Michigan was the first state to impose regulations on ships which drain ballast water into state waters.
Minnesota adopted a permit system for ship ballast which took effect October 1.