Study: Ships move non-native species in the Great Lakes

MADISON, Wis. (AP) -- A new study on ballast water discharge has found Great Lakes ships are moving non-native species from the lower lakes to western Lake Superior.
Wisconsin Public Radio reports that the study was conducted by the Great Waters Research Collaborative, which is a project of University of Wisconsin-Superior's Lake Superior Research Institute.
Principal investigator Allegra Cangelosi says they sampled 15 ballast water discharges from U.S. and Canadian lake vessels last year. Researchers found 13 had non-native species.
The report recommends researching ballast water treatment systems for ships.
Tom Rayburn is director of environmental and regulatory affairs with the Lake Carriers Association. He says more research should be done to determine if the organisms were alive or dead at the time of discharge and if they could survive in the lake.