Matching a snail’s pace: Successful use of environmental DNA techniques to detect early stages of invasion by the destructive New Zealand mud snail

Abstract

Early detection of invasive species allows for a more rapid and effective response. Restoration of the native ecosystem after an invasive population has established is expensive and difficult but more likely to succeed when invasions are detected early in the invasion process. Containment efforts to prevent the spread of known invasions also benefit from earlier knowledge of invaded sites. Environmental DNA (eDNA) techniques have emerged as a tool that can identify invasive species at a distinctly earlier time point than traditional methods of detection. Due to expected range expansion in eastern North America, we focus on the destructive New Zealand Mud Snail Potamopyrgus antipodarum (NZMS) invasion. We collected water samples from eight sites that prior evidence indicated were not yet invaded by the NZMS. After filtering these samples to collect eDNA, we used a species-specific probe with qPCR to identify NZMS eDNA. We found evidence for NZMS invasion at five of the eight sites, with later physical confirmation of mud snails at one of these sites. This study is the first example of successful detection of a previously unidentified invasive population of NZMS, setting the stage for further monitoring of at-risk sites to detect and control new invasions of this destructive snail. This study also shows potential opportunities for invasion monitoring offered by using low-cost efforts and methods that are adaptable for citizen science.

Mobilising molluscan models and genomes in biology

“…There is also considerable potential in using the extraction of environmental DNA to monitor and/or identify molluscs [151][152][153][154]. The 'ancient' DNA that remains in molluscan shells and other material, including subfossil and museum species, also has the potential to transform our study of the past ecological and evolutionary dynamics.…”

Environmental DNA Reveals Patterns of Biological Invasion in an Inland Sea

“…Prevention and early detection of biological invasions leads to the most successful economic and ecological outcomes (14–16). Towards this goal, the sampling of environmental DNA (eDNA) has shown promise when applied to the detection of non-native species (17). Targeted quantitative Polymerase Chain Reaction (qPCR) methods have successfully revealed the presence of individual species of interest, including the terrestrial toad species Bufo japonicus formosus in Hokkaido, Japan and invasive crayfish in Baden-Württemberg, Germany (18,19).…”