Authors: Cook, Heath; Therkildsen, Nina;Bemis, William;

Sandy beach ecosystems make up over 70% of the world’s open-ocean coastlines and provide important ecological, economic, recreational, and cultural services. Threats to these ecosystems continue to accelerate including climate change, sea level rise, global population growth, and coastal development. However, the traditional marine biomonitoring method, the seine net has many problems, for example, it is not effective in heavy waves, misses highly mobile large predators, and is challenging to deploy on a crowded beach. Emerging technologies may provide a solution and this study uses environmental DNA (eDNA) metabarcoding to survey the biodiversity of surf zone fauna. eDNA metabarcoding is successful at detecting surf zone fish and invertebrate species with some surprising detections. Though results are mixed in distinguishing species utilising different habitats within the surf zone. Finally, this study aims to inform beach managers of another potential tool for aiding the conservation of these important but difficult ecosystems.