Expanding the temporal and spatial scales of environmental DNA research with autonomous sampling

Abstract Environmental DNA (eDNA) is an emerging and powerful method for use in marine research, conservation, and management, yet time‐ and resource‐intensive protocols limit the scale of implementation. Long‐range autonomous underwater vehicles equipped with autonomous environmental sample processors (LRAUV‐ESPs) provide a new means for scaling up marine eDNA sample collection and processing. Here, we used eDNA metabarcoding of four marker genes (mitochondrial 12S rRNA, bacterial and archaeal 16S rRNA, nuclear 18S rRNA, and mitochondrial COI), which encompass the diversity of marine species from microbes to vertebrates, to demonstrate the efficacy of an LRAUV‐ESP in sampling eDNA and assessing community structure in the Monterey Bay National Marine Sanctuary. The sequencing results from samples that were autonomously collected were comparable with those collected from a ship at similar locations, times, and depths, supporting previous results that found no significant differences using targeted qPCR. This study demonstrates the potential of equipping autonomous underwater vehicles with ESPs to greatly expand the scale of eDNA sample collection and processing and provide much needed information regarding the changing spatial and temporal patterns of marine biodiversity, especially in many data‐poor regions of the world's oceans.