Developing and testing eDNA markers for the Federally endangered dwarf wedgemussel, Alasmidonta heterodon and other key freshwater mussel species

Science Center Objects

Dwarf wedgemussel is a federally endangered freshwater mussel with a historic range spanning the Atlantic coast. However, populations have dramatically declines over the last 30 years.  Therefore, knowledge of current population distribution and abundance is critical to resource managers in order to monitor the species over time and to guide recovery actions. Manual survey efforts (snorkel or scuba) for freshwater mussels can be intense and time consuming. Use of environmental DNA (eDNA) could be one way to quickly identify areas in streams and rivers where dwarf wedgemussels are currently located, allowing for increased survey efficiency and coverage of a greater geographic area.

USGS researchers, in collaboration with colleagues at the USFWS, are developing markers to detect presence of dwarf wedgemussel eDNA throughout its range.  They are also evaluating traditional eDNA sampling methodologies and developing alternative approaches for efficiently collecting and isolating eDNA.  After eDNA markers are developed, rigorous testing will be conducted to determine the optimal conditions (e.g., season, water temperature, flow) for detecting dwarf wedgemussel using this method. 


Comparing eDNA sampling methods

USGS researcher Bane Schill is collecting water for a methodological comparison for isolating eDNA. 

(Credit: Heather Galbraith, USGS Leetown Science Center. Public domain.)

Collecting DNA from mussels

USGS researchers must first collect DNA from mussels in the wild to develop useful and effective eDNA markers. 

(Credit: Carrie Blakeslee, USGS Leetown Science Center. Public domain.)