Development of Genetic Markers for Environmental DNA (eDNA) Monitoring of Sturgeon
Summary
EXECUTIVE SUMMARY: All living organisms shed DNA into the environment. Recent studies have demonstrated that environmental water samples can be effectively assayed for the DNA of target organisms. The DNA contained in these samples is commonly referred to as environmental DNA or eDNA. Because DNA assays can be sensitive to very small amounts of genetic material, eDNA surveys have the potential to detect sites where target organisms occur at very low abundances, potentially even when organisms are too rare for conventional survey methods to effectively detect them. We designed and tested twelve new eDNA markers for aquatic eDNA surveys of North American sturgeon. Eight of the markers are general for all North American sturgeon (i.e., [...]
Summary
EXECUTIVE SUMMARY: All living organisms shed DNA into the environment. Recent
studies have demonstrated that environmental water samples can be effectively assayed for the
DNA of target organisms. The DNA contained in these samples is commonly referred to as
environmental DNA or eDNA. Because DNA assays can be sensitive to very small amounts of
genetic material, eDNA surveys have the potential to detect sites where target organisms occur at
very low abundances, potentially even when organisms are too rare for conventional survey
methods to effectively detect them. We designed and tested twelve new eDNA markers for
aquatic eDNA surveys of North American sturgeon. Eight of the markers are general for all
North American sturgeon (i.e., not genus- or species-specific), two are specific to
Scaphirhynchus sturgeon, and two are specific to white sturgeon (Acipenser transmontanus). The
Scaphirhynchus marker could identify sites where endangered species like the pallid (S. albus) or
Alabama (S. suttkusi) sturgeon might occur. Positive detections with the general sturgeon marker
combined with the absence of positive detections with the white sturgeon marker could be used
to discern if green sturgeon (A. medirostris) might occur at a location. All sturgeon markers were
tested for specificity against a battery of 32 non-target fish species common to the Mississippi
and Illinois River watersheds and the “sensitivity” or limit of detection for each marker was
determined with assays of increasingly dilute solutions of target DNA. Four of the general
sturgeon markers were used to assay 88 water samples from the Lower Mississippi River for
sturgeon eDNA and resulted in 3 positive detections. While additional optimization of sturgeonspecific
sampling protocols and marker assays is advised prior to use of these markers for
sturgeon eDNA surveys, the newly designed markers represent a significant step forward in the
use of eDNA in sturgeon monitoring and management.
