Cooperative Fish and Wildlife Research Units Program: Massachusetts
Education, Research and Technical Assistance for Managing Our Natural Resources

Massachusetts Project

Dwarf Wedgemussel Propagation and Restoration in the Mid-Atlantic and Northeastern US

August 2018 - May 2022


Participating Agencies

  • U.S. Geological Survey

The dwarf wedgemussel (DWM), Alasmidonta heterodon, is a small, freshwater mussel historically known from at least 15 Atlantic slope drainages from New Brunswick, Canada to North Carolina; however, population declines throughout its range resulted in Federal listing of the species in 1990. The decline of DWM in areas previously thought to have the most viable and largest populations leads to significant concerns about the long-term viability of the species.

The overall goal of this project is to conduct research to inform and guide recovery of DWM through propagation and reintroduction. This project builds upon recent US Fish & Wildlife Service efforts to evaluate DWM habitat and establish a propagation facility for imperiled mussel populations. There are 3 objectives:
1) Develop propagation and culture techniques that optimize survival, growth, and production of mussels at the Cronin Aquatic Resource Center
2) Assess potential locations for restoring DWM populations based on mussel densities, population genetics, host fish densities, and mussel habitat and water quality requirements
3) Evaluate genetic structure of DWM populations and management actions for restoring DWM to preserve genetic diversity
These data will be used to identify management units, develop broodstock genetic guidelines, develop criteria and a decision tree to select ideal locations for reintroduction and augmentation, and ultimately inform recovery and management decisions of this species.

Research Publications Publication Date
Ryan, J.E., A.H. Roy, P.D. Hazelton, D.L. Perkins, T. Warren, C. Walsh, and R. Wick. 2022 Assessing methods for mitigating fungal contamination in freshwater mussel in vitro propagation. Hydrobiologia 849:2487-2501. DOI: 10.1007/s10750-022-04865-1 | Download April 2022
Presentations Presentation Date
Ryan, J.E., A.H. Roy, P.D. Hazelton, and D. Perkins. 2020. Fish assessments to inform recovery of dwarf wedgemussel. Northeast Aquatic Biologists Conference, 4-6 March 2020, Newport, RI. March 2020
Theses and Dissertations Publication Date
Ryan, J.E. 2020. In vitro propagation and fish assessments to inform restoration of dwarf wedgemussel (Alasmidonta heterodon). MS Thesis, University of Massachusetts, Amherst, MA September 2020