Characterizing the plankton communities of Monterey Bay using eDNA metabarcoding

Environmental DNA (eDNA) is a promising new tool for monitoring marine ecosystem and will be an integral part of a marine biodiversity observation network. In particular, monitoring plankton communities will be of increasing importance, as they form the basis of marine food webs and dominate the biomass of these systems. This study examines eDNA metabarcoding data using the 18S rRNA and cytochrome oxidase I (COI) genes to examine plankton communities in Monterey Bay National Marine Sanctuary (MBNMS) along a latitudinal transect at depths ranging from 0 to 200 m. Plankton communities detected with eDNA were analyzed to determine their correlation with depth, distance from shore, and relation to a dynamic oceanographic front. Communities varied most significantly with depth across all samples, while distance from shore had a smaller but still significant effect. This study identifies drivers of differences in plankton communities as detected by eDNA, helping to inform targeted eDNA sampling to capture the highest amount of biodiversity.