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Wild Rice Studies in Minnesota Rachel Walker  Barr Engineering & Edward Swain  Minnesota Pollution Control Agency 2013 Minnesota Wetlands Conference.

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Presentation on theme: "Wild Rice Studies in Minnesota Rachel Walker  Barr Engineering & Edward Swain  Minnesota Pollution Control Agency 2013 Minnesota Wetlands Conference."— Presentation transcript:

1 Wild Rice Studies in Minnesota Rachel Walker  Barr Engineering & Edward Swain  Minnesota Pollution Control Agency 2013 Minnesota Wetlands Conference January 30, 2013

2 Wild rice – natural history Two species in Minnesota – Zizania palustris and Zizania aquatica Annual plant, germinates after spring thaw and matures in late August Floating leaf stage in June – uses photosynthesis to make carbohydrates needed for stalk/root development – vulnerable to fluctuations in water level Seeds ripen in late August/ early September, rice shatters and scatters in water body or may be dispersed by wind/ herbivory/ humans 4-6 year boom/bust cycle with slow release of nutrients from decaying straw

3 Potential effects on wild rice populations in Minnesota Land use changes – late 1800s to present -Very little peer – reviewed literature over multiple years -Many gaps in understanding of factors that influence natural stand populations Major state-wide changes (agriculture, development, demographic changes) - Changes to many key factors(annual and inter-annual): water levels, wetlands (composition and distribution), sediments, herbivory, climate

4 Wild Rice Sulfate Standard Adopted in 1973 to protect wild rice (natural and paddy-grown) –10 mg/L, applicable to water used for production of wild rice during periods when the rice may be susceptible to damage by high sulfate levels Three key elements: –Where, What, When

5 John Moyle (MDNR) found a correlation between wild rice waters and low sulfate Moyle (1956) J Wildlife Management

6 Sulfate pattern in lakes across Minnesota (Moyle 1956) Moyle (1956) J Wildlife Management

7 Moyle’s sulfate isopleths (red) superimposed on his western limit of wild rice (green) Moyle (1956) J Wildlife Management

8 General distribution of wild rice in Minnesota

9 Wild rice surveys requested by MPCA – conducted by Barr Engineering Total number of clients for whom surveys have been conducted – 10 surveys (1-4 years) Wild rice locations, bed size, density (qualitative and quantitative measures), plant biomass (in situ and ex situ), water quality, other habitat characteristics Total shoreline surveyed for wild rice in northern MN 1600 miles over 4 years (~ 8 rivers, ~ 23 lakes, ~15 smaller creeks) General observations Begun in 2009 – some carried out 4 years Wild rice stands grow under many sediment, water quality, habitat conditions Sulfate levels range from a few ppm to hundreds of ppm in natural stands

10 Wild Rice Legislation (2011) Wild Rice Rulemaking and Research (Laws of MN 2011, 1 st Spec. Sess., Ch. 2, Art. 4, Sect. 32(c)) $1.5 million for wild rice standards study MPCA must create an advisory group and develop a study protocol

11 Wild Rice Standards Study Goal: obtain information that will be useful in evaluating Minnesota’s current standard Any modification of the standard would be based on multiple data sources, including: –Experimental/study results –Field data –Historical information –Relevant scientific literature

12 Standard is for sulfate, but: any effect on wild rice is probably indirect Sulfate is a relatively benign chemical But in wetland sediments, bacteria can convert sulfate to hydrogen sulfide, which is reactive. Hydrogen sulfide might be directly toxic to plant roots, or wild rice might be affected by other effects of sulfide production.

13 Possible sulfate interactions in wetland sediments that might affect wild rice growth

14 Study protocol identified the following areas of potential study: –Hydroponic growth experiments, comparing sulfate to sulfide –Sulfate additions to mesocosms (pots) with lake sediment –Intensive field study of natural wild rice stands –Additional field surveys Study Components

15 Study Process Finalize study protocol RFP based on protocol –Closed January 12, 2012 –Received 3 proposals (2 U of MN) –Contracted with U of MN Work underway in spring 2012: –Field survey by Amy Myrbo (Mpls) –Hydroponic dose-response experiments by John Pastor (Duluth) –Mesocosm experiments by Nate Johnson (Duluth) Protocol--May 2011 (preliminary survey 2011) RFP (Jan 2012) Studies (2012-2013) Standard Re- Evaluation/Rulemaking (start early 2014)

16 Study Process, cont. Periodic review of study results; adjust approach as needed –Mid-project review: 2/28-3/1, 2013 Studies completed: Dec. 2013 Rulemaking, as warranted

17 Stakeholder Meetings and Communication Efforts  Protocol development  Tribal Consultation (March 2011)  Individual Meetings with Minnesota Environmental Partnership Minnesota Cultivated Wild Rice Council Minnesota Chamber of Commerce  May 9, 2011, Meeting of Technical Experts  Wild Rice Standards Study Advisory Committee  Rulemaking input  Web page and e-mail