The applicability of eDNA metabarcoding approaches for sessile benthic surveying in the Kimberley region, north-western Australia

The application of environmental DNA technologies is a promising new approach to rapidly audit biodiversity across large-scale, remote regions. Here, we examine the efficacy of a dual-assay eDNA metabarcoding approach for sessile benthic bioassessments in the turbid waters of the Lalang-garram Marine Parks, in the inshore Kimberley region, north-western Australia. We ask three principal questions: 1. Is the eDNA released by sessile benthic taxa (i.e. hard and soft corals, sponges and tunicates) locally detectable? 2.  What level of taxonomic resolution is afforded by eDNA metabarcoding using the ITS2 region? and 3. How well does eDNA metabarcoding compare to conventional benthic survey techniques, such as belt and point-intercept transects? We report that a dual-assay eDNA metabarcoding approach is capable of detecting approximately 70% of the local benthic taxa (i.e. at a species, genus level etc) identified at the surveyed locations. It is, however, not as effective at the individual/...