Advancing AIS detection technologies
One of the most challenging aspects of managing aquatic invasive organisms is that they are difficult to measure. At times, AIS managers don’t even know if these species are present until their populations are large enough to create problems. Dr. Jessica Eichmiller, a post-doctoral researcher working with Dr. Peter Sorensen, is leading the Center’s research to develop a method to measure the abundance of invasive carp using environmental DNA (eDNA) – fragments of DNA shed by organisms in water. Using molecular methods to detect eDNA is non-invasive, rapid, and potentially more sensitive than traditional census techniques. As state and federal Asian carp surveillance efforts increase in Minnesota’s waters, the Minnesota Aquatic Invasive Species Research Center wants to answer: what does a positive (or negative) detection of eDNA mean?
MAISRC researchers are using common carp as a model species to understand eDNA, for several reasons: carp is abundant in Minnesota, are actively being managed, and have been the focus of previous behavioral and population research by resident scientists, Sorensen and Bajer. Using a sensitive molecular assay specific for common carp mitochondrial DNA, developed by Eichmiller, researchers sampled a lake with a high biomass of common carp. They found that eDNA distribution was extremely patchy and strongly correlated with distribution of fish. This research showed that knowledge of fish behavior, when used to guide eDNA sampling, can greatly improve the probability of species detection. The results of this study were recently published in the online journal Plos One. Read Eichmiller’s paper, “The Relationship between the Distribution of Common Carp and Their Environmental DNA in a Small Lake,” here.
Understanding how eDNA is distributed in the environment can help researchers design sampling schemes to target eDNA, and will thus improve the reliability of techniques to detect, and then ideally to control, invasive carp.