The Minnesota Pollution Control Agency (MPCA) recently announced that it has met its 2013 goal for its Wild Rice Standards Study and has released experiment and monitoring summary reports and data.
The goal of the study is to enhance understanding of the effects sulfate has on wild rice and to help decide whether a revision of the wild rice sulfate standard is warranted.
The 2011 Clean Water Funded Study consisted of parallel research efforts conducted by scientists at the University of Minnesota campuses in Duluth and the Twin Cities under contract with the MPCA. The main hypothesis of the study is that wild rice is impacted by sulfate via the conversion of sulfate to sulfide in the rooting zone of the plants. The study components are:
Field survey of wild rice habitats to investigate physical and chemical conditions correlated with the presence or absence of wild rice stands.
Controlled laboratory hydroponic experiments to determine the effect of elevated sulfate and sulfide on early stages of wild rice growth and development.
Outdoor container experiments using natural sediments to determine the response of wild rice to a range of sulfate concentrations in the surface water, and associated sulfide in the rooting zone.
Collection and analysis of rooting zone depth profiles of dissolved chemicals at wild rice outdoor container experiments and field sites to characterize sulfate, sulfide and iron in the rooting zone.
Sediment incubation laboratory experiments to explore the difference temperature has on the rate that elevated sulfate in water enters underlying sediment, converts to sulfide, and to what degree sulfate is later released back into the water.
Data collection was completed in December 2013 and is documented in individual reports from the contractors.
During January and February 2014, MPCA staff will integrate the reports, analyze the data as a whole, and review existing monitoring data, other relevant scientific studies and information, and the original basis for the sulfate standard to determine whether a change to the standard is warranted. The MPCA will release preliminary recommendations about the wild rice sulfate standard by the end of February.
To see the reports, go to the Minnesota Pollution Control Agency website.
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