USGS - science for a changing world

Upper Midwest Environmental Sciences Center

Landscape Analysis of Freshwater Mussels in the Upper Mississippi River Basin

Fact Sheet: Development of Landscape Models for Conservation of Freshwater Mussels in the Upper Mississippi River Basin

butterfly musselFreshwater mussels are the largest group of federally listed endangered or threatened invertebrates, and their declines may signal declining riverine health. They are a renewable resource, providing significant ecological and economic benefits to the Nation. Mussels are a food resource for many animals; they improve water quality by filtering contaminants, sediments, and nutrients; and the shells of some species are used in the production of cultured pearls. Because of their complex life history, which includes a larval stage that requires a fish, traditional management approaches are not effective in conserving freshwater mussels. Although numerous threats have been suggested as contributing to their decline, past efforts have not been sufficient to identify which threats are responsible for the decline. Such information is needed to identify management approaches to sustain this resource.

fragile papershell musselBecause freshwater mussels are declining nationwide, it is important to understand the factors contributing to their distribution and abundance. Attempts to predict their distribution from readily available habitat descriptors, such as sediment grain size or flow, have largely failed when tested critically. This suggests that traditional measures of riverine habitats appear to be poor descriptors of community structure. Consequently, additional variables not often used in biological studies should be considered at a variety of spatial scales, from small to much larger areas. Our goal is to provide for an integrated, ecological, and proactive approach to management of freshwater mussels by placing them in the context of other landscape, biological, and sociological components. Much of the prior work on mussels has been conducted by teams of mussel specialists on small streams and by measuring variables typically associated with biological studies (i.e., flow, temperature, sediment features). The assembled team of scientists working on our project includes biologists, mussel specialists, hydrologists, modelers, acoustic ecologists, and landscape ecologists. Future work on freshwater mussels needs to take a larger-scale approach to allow managers and scientists to use a variety of approaches across a broad geographic area.

watershed (photo)Our study uses a landscape-level approach to assess whether the distribution of mussels can be predicted from a variety of features in the surrounding landscape. These features will likely differ depending on the scale of the analyses, but may include the following: distribution of host fishes, hydrologic measurements in the river bed, land-use and land-cover in the surrounding area, and proximity to the main navigation channel. The objectives of our study are as follows:

  1. backwater (photo)Develop a Geographic Information System framework to explore the relation between the distribution of mussels in the Upper Mississippi River Basin and a series of physical and biological variables, measured across a broad geographic area.
  2. Evaluate the effectiveness of acoustic technology to identify existing mussel populations over a large geographic area.
  3. Evaluate the importance of simple and complex hydrologic variables in structuring mussel communities.

Pool 8 - Reach 1 - Upper Mississippi River (map)This study is conducted in the Upper Mississippi River Basin. This project is initiated at the river reach scale and focus on Navigation Pool 8, a 30-mile stretch of the Upper Mississippi River. This allows us to develop appropriate methods and modeling approaches and to use additional data that are readily available at this scale. For example, the Long Term Resource Monitoring Program has data on invertebrates, fishes, and water quality that can be used in this project.

Upper Mississippi River (map)

Analyses at other scales (watersheds and tributaries) may be needed because certain features of the landscape may only be important in structuring mussel communities at a given scale. Thus, we will initiate analyses at other scales in later years.

Higgins Eye musselThe conservation of freshwater mussels is a management priority of the U.S. Fish and Wildlife Service and the National Park Service. Region 3 of the Fish and Wildlife Service, for example, is relying on relocation of the endangered Higgins Eye Pearly Mussel in the Upper Mississippi River to help recover this species as a result of the invasion of the zebra mussel. Relocation of freshwater mussels is a risky conservation strategy, yet the Service has few other options. The approach used in our study may provide the Service and other management agencies with additional tools to help conserve imperiled species. In addition, this research supports the goals of the joint Federal and State "National Strategy for the Conservation of Native Freshwater Mussels" drafted by biologists in the U.S. Geological Survey, the U.S. Fish and Wildlife Service, and many states in the eastern United States, including Minnesota and Wisconsin.

The study completion is scheduled for 2005.

Principal Investigator: Teresa Newton

Research Team: Michelle Bartsch, Steve Gutreuter, Robert Kennedy, Melinda Knutson, Ken Lubinski, Jennifer Sauer, Jeff Steuer, and Steve Zigler

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contacting the Upper Midwest Environmental Sciences Center
Page Last Modified: March 13, 2014