Lake Superior State University
Lake Superior State University


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Freshwater mussels in wadeable streams of the Paint and Sturgeon River watersheds (Menominee River Basin, MI)
Distribution of freshwater mussels within the Little Quinnesec Hydroelectric impoundment and tailrace (Menominee River, MI)






Distribution and habitat requirements of freshwater mussels in wadeable streams of the Upper Menominee River Basin

Principal Investigators: Ashley Moerke, Ph.D. (Lake Superior State University), Andrew Selle (Interfluve, Inc.), Peter Badra (Michigan Natural Features Inventory), and Jessica Mistak (Michigan Department of Natural Resources

Research Assistants: Kathryn Harriger, Jennifer Johnson
Funding source:  WE Energies Mitigation and Enhancement Fund

Project Goals

Determine historical and current distributions of freshwater mussels in the Upper Menominee River Basin and assess habitat available to mussels in order to determine effective management for mussel conservation. Specific objectives include:

  • Review historical information to form a map of current mussel distributions
  • Charactere age-structure and density of mussel populations present
  • Quantify habitat preferences of freshwater mussels present
  • Circulating findings with stakeholders and government and non-government organizations

Project Description

In Michigan over one third of the native freshwater mussel species are listed as imperiled, but attempts to save the remaining populations will not be effective until the gap in knowledge of their distribution and habitat preferences is bridged.  The objective of this study is to identify mussel populations in the Upper Menominee River Basin (UMRB) and assess habitat preferences by the mussels.  Wadeable streams in the UMRB (Paint River and Sturgeon River watersheds) will be surveyed for freshwater mussels and sampling will assess the age structure and habitat characteristics of the mussel populations.

What are Freshwater Mussels?

Role in Aquatic and Terrestrial Ecosystems

Freshwater mussels are invertebrates found on the bottom of lakes and streams, commonly known as “clams”.  The small organisms go largely unnoticed by most people, but they play an important role in aquatic ecosystems.  Mussels are a favorite food item of several mammalian species including muskrat (Tyrell & Hornbach 1998), which leave evidence of their dinner in the form of middens (piles of mussel shells) on the side of streams (Sietman et al. 2003).  Many species of aquatic insects use mussels as an anchoring point, shelter and feed on algae that grow on mussel shells (Spooner & Vaughn).  Freshwater mussels are filter feeders feeding on suspended nutrients in the water column.  At high densities, mussels have the ability to greatly increase water clarity (Welker and Walz 1998).




Typical freshwater mussel life cycle (diagram from Photo from


Freshwater mussels have a unique life history (Coker et al. 1921).  The reproductive cycle of many mussel species begins when a male upstream of a female releases sperm and the female takes it in through her siphon.  After a female’s eggs are fertilized she holds them in marsupial gills until the eggs grow into glochidia (larvae).  The female mussel must create a lure from her mantle to attract the appropriate host fish.  Lures often look like specific fish species or aquatic insects.  When a fish tries to bite the lure, the female ejects her glochidia, and with luck, the glochidia will be able to attach to the gills of a preferred host fish (Coker et al. 1921).  The glochidia then go though a critical parasitic phase and metamorphose into juveniles.  If glochidia do not attach to a host, they will be unable to continue the life cycle and metamorphose into juveniles.  The juveniles eventually fall off the host fish and settle in the sediment.  This reproductive process varies between mussel species.  Some species rely on one specific host fish, others can use multiple hosts and other species do not appear to require a host (Coker et al. 1921). 


North America is home to 279 species of freshwater mussel species, the greatest diversity on Earth.  Unfortunately, approximately 72 % of those species are threatened, endangered or are a species of concern (Williams et al. 1993).  In Michigan alone, Williams and Neves (1995) estimate that 36% of mussel species are listed as imperiled.

Some factors contributing to the decline of mussel populations is anthropogenic activities (Williams et al. 1993).  Watters (2000) suggests that human activities including mining, logging and the installation of dams could degrade freshwater habitat, and therefore, mussel population numbers.  Some researchers suggest that quantifying preferred habitat will increase mussel population numbers (Salmon & Green 1983).  There is much information lacking on the status and habitat preferences of freshwater mussels, and management of their populations will not be fully effective until the gap is filled.  This project aims to help fill that knowledge gap. 

Project Location

The study will be conducted in the UMRB in the Upper Peninsula of Michigan with streams within the Paint River (2008) and Sturgeon River (2009) watersheds being surveyed for freshwater mussels.  The Paint River lies mostly within Iron County whereas the Sturgeon River lies mostly within Dickinson County. (Map coming soon)

Project Completion

A final report available to the public is accessible here.  This information can be used by managers to: (1) guide restoration and mitigation plans, (2) identify river areas in need of protection, (3) predict effects of future development on benthic communities, (4) inform the public and promote public policy changes, and (5) understand trends and predict impacts of changing watersheds on freshwater mussel populations.


Photo Gallery


Literature Cited

Coker, R.E., A.F. Shira, H.W. Clark & A.D. Howard. 1921. Natural History and   Propagation of Freshwater Mussels. Bulletin of the Bureau of Fisheries, Vol. XXXVII. Government Printing Office, Washington.

Cummings, K.S. and C.A. Mayer. 1992. Field guide to the freshwater mussels of the Midwest. Illinois Natural History Survey Manual 5. 194 pp.

Holland-Bartles, L.E. 1990. Physical factors and their influence on the mussel fauna of a main channel border habitat of the upper Mississippi River. Journal of the North American Benthological Society 9(4): 327-335.

Salmon, A. and R.H. Green. 1982. Environmental determinants of unionid clam distribution in the Middle Thames River, Ontario. Canadian Journal of Zoology 61: 832-838.

Spooner D.E. and C.C. Vaughn. 2006. Context-dependent effects of freshwater mussels on stream benthic communities.   Freshwater Biology 51: 1016-1024.

Sietman, B.E., H.L. Dunn, J.K. Tucker and D.E. Kelner. 2003. Muskrat (Ondatra zibethicus) Predation on Zebra Mussels (Dreissena polymorpha) Attached to Unionid Bivalves. Journal of Freshwater Ecology 18(1):  25-32.

Strayer, D.L. and D.R. Smith. 2003. A Guide to sampling freshwater mussel populations. American Fisheries Society Monograph No. 8, Bethesda, MD.

Tyrell, M. and D.J. Hornbach. 1998. Selective predation by muskrats on freshwater mussels in two Minnesota rivers. Journal of the North American Benthological Society 17(3): 301-310.

Watters, G.T. 2000. Freshwater mussels and water quality: A review of the effects of hydrologic and instream habitat alterations. Ohio Biological Survey and Aquatic Ecology Laboratory pp. 261-274.

Welker, M. and Walz, N. 1998. Can mussels control the plankton in rivers? A phytological approach to Lagrangian sampling strategy. American Society of Limnology and Oceanography 43(5): 753-762.

Williams, J.D. and R.J. Neves. 1995. Freshwater mussels: a neglected and declining aquatic resource. Pages 19-21 in E.T. LaRoe, G.S. Farris, C.E. Puckett, P.D. Doran , and M.J. Mac (editors). Our living resources: a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems. US Department of the Interior, National Biological Service, Washington, DC.

Williams, J.D., M.L. Warren, Jr., K.S. Cummings, J.L. Harris, and R.J. Neves. 1993. Conservation status of freshwater mussels of the United States and Canada. Fisheries 18(9): 9-22.





Distribution of freshwater mussels in the Little Quinnesec impoundment and tailrace (Menominee River, MI)

Principal Investigators: Ashley Moerke, Ph.D. (Lake Superior State University), Jessica Mistak (Michigan Department of Natural Resources, Randall Piette (Wisconsin Department of Natural Resources, and Andrew Selle (Interfluve, Inc.)

Research Assistants: Chris Beyette and Amanda Chambers
Funding Source:  Little Quinnesec Fisheries Settlement
Project Time Period: August 2009-January 2010

The project goal was to determine the population structure and current status of freshwater mussels throughout the Little Quinnesec Falls Hydroelectric Project (FERC No. 2536) and its adjoining waters.  Specific research objectives were to: (1) characterize the distribution, diversity, density, and age-structure of freshwater mussel populations, and (2) characterize habitat of freshwater mussels during late summer.

The entire final report is available for download by clicking here.




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