Wetlands in Minnesota's northeast and north-central regions are in mostly great shape, but it's a much different story in southern Minnesota, where farm runoff and invasive species post a significant to wetland biology.
Those are the conclusions of two reports published Thursday by the Minnesota Pollution Control Agency.
Overall, researchers found 33 percent of the state's 10 million-plus acres of wetlands in fair or poor condition. These are places where vegetation is degraded and native plants are being replaced by cattails and other non-native invasive plants, the agency said.
"Excess phosphorus and nitrogen levels from runoff pose a significant threat to the biological integrity of these wetlands," Michael Bourdaghs, MPCA research scientist and author of the report on overall vegetation quality, said in a statement.
The agency released its findings ahead of Saturday's 2015 waterfowl hunting opener, noting that the health of a wetland's vegetation can affect its quality as a habitat for ducks, geese, insects, and other animals.