Manoomin (wild rice) and environmental change at a significant river system of the Lac du Flambeau Band of Lake Superior Chippewa

Abstract

Wild rice, an annual aquatic grass that grows across the Great Lakes region, has dietary, cultural, medicinal, and spiritual significance to the sovereign Tribes of the region, but its abundance has been declining despite its legal protection under treaties. While certain factors (both environmental and societal) have been demonstrated to impact wild rice health and growth, there is no single answer to explain this broad regional loss. Ongoing work between researchers at the University of Minnesota and tribal partners - including natural resource stewards, Tribal leaders, elders, rice chiefs, and community members - has yielded a multidimensional approach that seeks to capture the various forces influencing wild rice. The collaborative emphasis has been an integral part of the methods, and a significant result in its own right. In this study, hydrologic, geochemical, nutrient, sediment, and vegetation parameters are assessed to examine their impact on the growth of wild rice at two riverine subsites on the Lac du Flambeau reservation in northern Wisconsin: one subsite with abundant wild rice and a second subsite with sparse wild rice. To broaden the inferences that could be made from this localized, intensive study, a large statewide dataset from a previous study by Myrbo et al. (2017a) was reanalyzed to develop multiple lines of evidence for the influence of these factors. Based on this multidimensional approach, the emerging data and observations suggest highly flocculent sediments and related nutrient deficiencies may be driving forces behind the loss of wild rice in this study system and have implications for wild rice health in the wider region.