Quantifying human use of sandy shores with aerial remote sensing technology: The sky is not the limit

Understanding the use of sandy beaches underpins strategies for effective management of this valuable ecosystem. In this context, remote-sensing platforms and aerial imagery could, theoretically, provide novel and cost-effective solutions to identify and map beach visitor use. Recreational beach use patterns were examined using data collected via an established drone-based method and from commercial orthomosaic images collected via crewed aircraft to assess the practicality of these methods. Our study encompassed similar to 780 km of east Australian coastline and assessed 73,021 beach visitors to find similar participation rates in sunbathing (46.3 vs 47.7%), walking (21.8 vs 18.6%), swimming (20.9 vs 19.5%), surfing (10.7 vs 14.0%) and fishing (0.3 vs 0.1%) when measured by drones or crewed aircraft, respectively. The larger spatial coverage of crewed aircraft was a distinct advantage that allowed mapping of geographic patterns in beach use for thirteen sites separated by 100s of kilometres. Beach visitation was significantly influenced by season, weekend/public holidays, temperature, solar radiation, beach area, size of households adjacent to beaches, and time of day. Both drones and crewed aircraft are practicable tools for sandy shore management, providing complementary solutions to generate visitor-use data at multiple scales that can be used to optimise recreational service provisions and better support environmental conservation strategies.