Development and Testing of Environmental DNA (eDNA) Protocols for the Endangered James Spinymussel (Pleurobema collina)

About the report:

Molecular genetic techniques provide tools that may be used to locate, monitor, and survey cryptic aquatic species. This study developed genetic markers useful in determining if the James Spinymussel (Pleurobema collina), an endangered species, can be detected solely by sampling stream water.

Genetic markers developed for this species were tested in locales where P. collina exists with known relative density. Detection probability of target species was 50%. Three sites with a historical, though not contemporary, record of the Spinymussel did not return positive identification, one of which because of inhibition of marker reactions. Among locales with positive findings, the researchers were able to rank relative biomass to census size successfully.

The results of the study suggest that subsequent work should focus on overcoming abiotic inhibitory compounds in the water column and examining biomass across a set of locales with few individuals to determine the lower limits of detectability for this protocol. These findings suggest continued development of this approach, as it is broadly applicable to activities of the Virginia Department of Transportation beyond this sole cryptic and endangered species. The study recommends that a second phase of research be conducted to refine the eDNA methods developed in this study in order to increase their implementation potential as a survey tool.

Authors