Upper Midwest Environmental Sciences Center
Introduction
Aquatic vegetation in the Upper Mississippi River System (UMRS) provides food and habitat to fish and wildlife and is a vital component of this nationally significant ecosystem (Public Law 99-662, Upper Mississippi River Management Act of 1986). The UMRS is also a nationally significant navigation system. The development of the Upper Mississippi and Illinois Rivers in the 1930s for commercial navigation greatly expanded the rivers' backwater areas in which submersed aquatic vegetation flourished for a few years following the development. Triggered by a severe drought in the basin, aquatic vegetation in the UMRS experienced a drastic decline between 1989 and 1994 (Fischer and Claflin 1995; Rogers et al. 1995; Wiener et al. 1998; Tyser et al. 2001). As of 2002, the amount of submersed aquatic vegetation is still substantially lower than the historical high levels recorded in the 1970s.
Through the Upper Mississippi River Management Act of 1986, Congress established the Environmental Management Program of the UMRS in 1986 to ensure the coordinated development and enhancement of the Upper Mississippi River System. The Environmental Management Program consists of five elements, including Habitat Rehabilitation and Enhancement Projects (HREP), Long Term Resources Monitoring Program (LTRMP), Recreation Projects, Economic Impacts of Recreation Study, and Navigation Monitoring. Aquatic vegetation in the UMRS is monitored as a component of the LTRMP, along with the fish, water quality, and macroinvertebrate components. The LTRMP is administered by the U.S. Army Corps of Engineers and implemented by the Upper Midwest Environmental Sciences Center (UMESC) of the U.S. Geological Survey in partnerships with the Illinois Department of Natural Resources, Iowa Department of Natural Resources, Minnesota Department of Natural Resources, Missouri Department of Conservation, and Wisconsin Department of Natural Resources.
The objective of stratified random sampling was to accumulate data on aquatic vegetation over a long term (>50 years) using a standardized protocol across the system. The data provide information on the distribution and abundance of vegetation within pools for the protection and enhancement of the Upper Mississippi River System. Although data on emergent macrophytes, filamentous alga, and duckweeds were included in the investigation, they are not reported here because our focus was on submersed and rooted floating-leaf vegetation. The full suite of data (inclusive of submersed, rooted floating–leaf, emergents, algae, and duckweeds) are archived in the UMESC database and are openly available online at http://www.umesc.usgs.gov/data_library/vegetation/vegetation_page.html.
Content manager: Danelle Larson
Page Last Modified: April 17, 2018