Marine Edna Sampling from Submerged Surfaces

Abstract

Environmental DNA (eDNA) analyses of species present in marine environments is the most effective biological diversity measurement tool currently available. eDNA sampling methods are an intrinsically important part of the eDNA biodiversity analysis process. Methods for sampling eDNA from marine environments started as standard microbiological water filtration methods, but have evolved over time into a diverse group of active and passive sampling procedures, each with their own strengths and weaknesses. There is still a need to identify and develop eDNA sampling methods that are as rapid, affordable, versatile and practical as possible. Optimal outcomes of eDNA biodiversity surveys come from studies employing high levels of sampling replication, so any methods that make sampling faster and cheaper will improve scientific outcomes. eDNA sampling methods that can be applied more widely will also enable sampling from a greater range of substrates, resulting in detection of a wider range of organisms. In this study, we compared diversity detection by several methods for sampling eDNA from submerged marine surfaces: polyurethane foam, nylon swabs, microfibre paint rollers, and sediment scoops. All of the methods produced a diverse range of species identifications. We found that widely-available small paint rollers were an effective, readily available and affordable method for sampling eDNA from underwater marine surfaces. This approach enables the sampling of marine eDNA using extended poles, or potentially by remotely operated vehicles, where surface sampling by hand is impractical.

Keywords: environmental DNA, metabarcoding, biodiversity, detection, invasive marine species