The government of the United States has listed its 26th Wetland of International Importance, the Upper Mississippi River Floodplain Wetlands (22,357 hectares, 43°03’N 091°10’W). As summarized by Ramsar’s Nadia Castro from the RIS, natural floodplain backwaters of the Upper Mississippi River in the US Upper Midwest were enlarged and enhanced by construction of locks and dams in the 1930s to improve commercial and recreational navigation. Today the site, which threads through four northern Midwestern states -- Minnesota, Wisconsin, Iowa and Illinois – consists primarily of flowing main and side channel habitats, large shallow to moderately deep backwater marshes, flooded floodplain forests and shrub-dominated communities.
It is perhaps the most important corridor of fish and wildlife habitat remaining in the central US; e.g., it supports significant populations of over 100 native fish species and the nationally endangered Higgins’ Eye Pearly Mussel (Lampsilis higginsii). In addition, the site is at the core of the Mississippi Flyway, through which 40% of North America’s waterfowl migrate, e.g. Canvasback Ducks (Aythya valisineria) and Tundra Swans (Cygnus columbianus). Several federal and state-managed areas are located within the site and recreation is one of the major economic activities in the area (ca. 3 million visits each year). The site is currently threatened by the accelerating spread of plant and invertebrate invasive species.
The Ramsar site includes the Upper Mississippi River National Wildlife and Fish Refuge, Trempealeau National Wildlife Refuge, and “selected contiguous federal and state-managed floodplain wetlands associated with mouths of tributary rivers and streams”.
The comprehensive Ramsar Information Sheet (RIS) for the new site was compiled by Arthur “Tex” Hawkins of the US Fish and Wildlife Service regional office, a former member of the Ramsar Scientific and Technical Review Panel (STRP). The USA now has 26 sites on the Ramsar List, totaling 1,439,937 hectares, with other new designations still undergoing processing in the Secretariat.
Photos: Sandra Lines
Trempealeau River mouth