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Upper Midwest Environmental Sciences Center

UMESC Science Programs

River Ecology

History

The River Ecology program at the Upper Midwest Environmental Sciences Center (UMESC) began working with large river ecosystems in the 1970’s, due in part to the Center's close proximity to the Mississippi River. Over the years the Mississippi River and its floodplain have been greatly modified for multiple uses, including navigation, hydropower, flood control, agriculture, and urban development. Anticipated increases in human encroachment and use could further alter the ecological structure and functioning of the Upper Mississippi River (areas above the River's confluence with the Ohio River). UMESC has assisted resource managers by helping to fill information gaps on the ecology of large rivers, plant and animal communities, the effects of commercial navigation, and emerging issues of concern (e.g., environmental contaminants, excessive nutrients, invasive species).

River Productivity

The central issues in river ecosystem management are fundamentally all issues of biological productivity. Invasive species divert productivity. Threatened and endangered species occur in limited numbers due to lack of production. Eutrophication (excessive algal/bacteria/plant growth) is excessive primary production fueled by nutrient inputs. Human impacts (commercial navigation, water flow modification, even recreation) affect productivity. The overall goal of restoring an ecosystem is to alter factors that limit production.

UMESC’s River Productivity Team is working to, 1) increase the ability of State and Federal resource management agencies to better predict the effects of river management activities, 2) guide efforts to restore river ecosystems, 3) increase the ability of resource managers to understand and manage the effects of agricultural and urban nutrient runoff on the ecology and productivity of the Mississippi River, and 4) lead to improved understanding and management of invasive species, and minimize their impacts on Mississippi River fisheries and supporting foodwebs. Ultimately, the American public will benefit from these efforts through better managed river ecosystems, based upon efforts to optimize the Mississippi River's multiple commercial and recreational use needs.

Upper Trophic Level Production

Trophic level references are used to describe the position an organism occupies on the food chain. Upper trophic level organisms (e.g., fish) obtain their nutrition from other life forms, usually by eating plants (herbivores) or animals (predators). Scientists working with upper trophic level productivity are striving to; 1) correctly identify those factors that limit biodiversity and the biological productivity of key species; 2) develop a better understanding of ways to manipulate the factors that limit key species productivity, and 3) develop tools to predict the likely results of restoration and management alternatives.

Lower Trophic Level Production

Trophic level references are used to describe the position an organism occupies on the food chain. Lower trophic organisms, esp. primary producers (e.g., plants, phytoplankton), often acquire the nutrients they need from river water or sediments. Primary producers are the foundation riverine food webs are built upon. The health and abundance of a river ecosystem’s primary producers affect the health and abundance of upper trophic organisms. Scientists working with lower trophic level productivity are; 1) studying the role of nitrogen and phosphorus in controlling river productivity, 2) evaluating management techniques designed to promote nitrogen retention and removal in floodplain backwaters and riparian wetlands, 3) developing a greater understanding of riverine foodwebs and trophic transfer, and 4) studying the effects of invasive species (e.g., Asian carp, zebra mussels) on a river’s primary producers, and how these effects affect a river’s food web and upper trophic organisms.

Native Mussel

Freshwater mussels are among the most fascinating, most widespread, and most endangered animals in fresh waters. Mussels may be of considerable importance in riverine food webs because they can form locally dense populations (>100 animals/m2); their suspension feeding activity suggests they influence water chemistry, water clarity, and the amount and kinds of particles in the water; and their waste products can enhance local populations of algae and macroinvertebrates. These traits suggest that native mussels might perform important ecological services in rivers. However, overharvesting, widespread habitat destruction, pollution, land-use change, and exotic species introductions have caused many native mussel populations to decline or disappear. In the past 50 years about 20 mussel species have been lost from the Upper Mississippi River (UMR) basin. Given that native mussels are good barometers of water and sediment quality, these declines signal a potential deterioration in the health of our riverine community.

The Native Mussel Team is working to, (1) determine the status and distribution of the mussel community in the UMR, (2) determine which factors are limiting the distribution and abundance of freshwater mussels in the UMR basin, (3) evaluate the effects of habitat restoration projects on native mussel assemblages, and (4) provide scientific information on the conservation and management of freshwater mussels, so river managers can protect, conserve, and restore declining freshwater mussel populations in large river ecosystems.

Research Projects

Each research area (i.e., science team) maintains a Web page that contains links to background information on individual science projects and the individuals working on the projects.

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Page Last Modified: January 29, 2016