Native Mussels

Team Members

• Principal Scientists
  • Teresa Newton (science and team lead)
  • Michelle R. Bartsch (distribution, abundance, dietary needs)
  • Jennifer S. Sauer (status and distribution)
  • Steven J. Zigler (hydrophysical models, limiting factors)
• All Team Members

Freshwater mussels are among the most fascinating, widespread, and endangered animals in fresh waters. Mussels perform important roles in river ecosystems, such as filtering large amounts of water and associated sediments which improves water clarity, alters water chemistry, and regulates the amounts and kinds of particles in the water. Mussels also increase species diversity by creating habitat for aquatic insects and fish. Algae and macroinvertebrates rely on mussels to convert food and waste products in the water column, like nutrients, into beneficial forms for animals living on the river bottom.

However, overharvesting, widespread habitat destruction, pollution, land-use change, and exotic species introductions have caused many freshwater 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 (Havlik and Sauer 2000). Native mussels serve as an indicator of water and sediment quality, much like canaries did for the coal mines, and declines signal a potential deterioration in the health of our riverine community.

Our long-term goal is to conserve and restore healthy freshwater mussel populations in the UMR basin and elsewhere. This focus is largely derived from conversations with resource managers who have expressed the following short-term needs:

• Identify factors limiting the distribution and abundance of freshwater mussels in the UMR basin to provide managers with conservation and restoration procedures and strategies. This currently includes a focus on:
  • Identifying suitable habitat for mussels
  • Identifying food sources and critical dietary needs for mussels
• Determine the status of the mussel community in the Upper Mississippi River
• Evaluate the effects of habitat rehabilitation projects on native mussel populations

Current Projects

• Development of Hydrophysical Models of Mussel Habitat Among Upper Mississippi River Reaches
• Comparison of Native Mussel Assemblages Among Three Reaches of the Upper Mississippi River
• Profiles of Biochemical Tracers in Native Mussels: Implications for Understanding Their Role in Riverine Food Webs
• Modeling the Response of Imperiled Freshwater Mussels to Anthropogenically Induced Changes in Water Temperature, Habitat, and Flow in Streams of the Southeastern and Central United States

Status of the mussel community

• Population Assessment of Native Mussels in the Upper Mississippi River
• Potential Functional Roles of Native Mussels in the Upper Mississippi River
• Development of Methods to Enhance Propagation Success of Federally Listed Native Mussels
• Development of Methods to Assess and Monitor Mussel Communities in the Upper Mississippi River

Evaluation of habitat restoration projects on native mussels

• Movement Patterns of Native Mussels in the Upper Mississippi River: Response to Water Level Management

Past Projects

• Relationships Among Flow, Water Depth, Sediment Texture, and Fingernail Clams
• Effects of Ammonia on Unionid Mussels: A Potential Threat to their Biodiversity in the St. Croix National Scenic Riverway
• Genetic Characterization of the Endangered Mussel Lampsilis higginsi
• Landscape Analysis of Freshwater Mussels in the Upper Mississippi River System