A preliminary study from the Minnesota Department of Natural Resources (DNR) is providing the state’s first scientific assessment of wetland gains and losses.
While the study finds that the state is meeting its no-net-loss of wetlands goal, there are ongoing concerns about the quantity and quality of wetlands in the state.
Despite significant state investments in wetland restoration, the report released this week estimates that Minnesota made only slight gains in overall wetland acreage. From 2006 to 2011, the study revealed a net statewide gain of 2,080 acres of wetlands, representing just a .02 percent increase in wetlands statewide.
During the same period, 1,890 acres of emergent wetlands were converted to cultivated wetlands – roughly equal to the acreage gained. While cultivated wetlands retain some wetland characteristics, they often have undergone significant drainage and lack vegetation that provides good wildlife habitat.
Moreover, a majority of the new wetlands identified by the study were pond-like, lacking wetland vegetation that provides high quality habitat for wildlife.
“While it’s encouraging that overall wetland acreage appears stable, there are still concerns about the quality of wetlands being gained and the conversion of emergent wetland to cultivated status,” said Doug Norris, DNR wetlands program coordinator.
The findings were based on nearly 5,000 randomly selected one-square-mile plots that were assessed using aerial photos for the period 2006 to 2008, then again for the period 2009 to 2011.
Norris added the slight improvements come at time of increasing pressures on wetlands. The state has lost more than 50 percent of its wetlands since pre-settlement days, and in much of the prairie region of the state, the loss exceeds 80 percent.
Norris said the report provides a first snapshot of wetland trends and that a more complete picture will be evident after future sampling. The study will be updated every three years, and a companion study of wetland quality conducted by the Minnesota Pollution Control Agency (MPCA) will be released sometime next year.
The effort is part of a comprehensive Minnesota wetlands assessment, monitoring and mapping strategy that was jointly developed by DNR, MPCA, the Board of Water and Soil Resources, the Minnesota Department of Agriculture and the U.S. Fish and Wildlife Service in 2006 to determine if state wetland policies are effective.
The report, “Status and Trends of Wetlands in Minnesota: Wetland Quantity Trends from 2006 to 2011,” is available on the DNR’s website, http://files.dnr.state.mn.us/eco/wetlands/wstmp_trend_report_2006-2011.pdf.