Abstract

The impact of remotely piloted aircraft systems (RPAS) on marine mammals remains poorly documented despite their increasing use. In the high-Arctic Archipelago of Svalbard, where marine mammals face increasing pressure from climate change and expanding tourism, the use of RPAS remains largely unregulated. In this study we assessed the impacts of RPAS across a range of species to provide science-based management advice, using a variety of aircraft sizes and approach strategies. We explored RPAS sound levels and animal behavior prior to and after flights. Preexperimental alertness influenced sensitivity to disturbance notably. Harbor seals were more sensitive during prebreeding than during molting, reacting at distances of 80 m, whereas walruses responded at distances 50 m. Polar bears reacted to the sound of RPAS during take-off at 300 m, although response levels were relatively low. White whales reacted to the sight of RPAS when flown ahead of the pod, below 15 m. Variations in sound levels typical in overhead descents and manual flights increased disturbance potential more than RPAS size; preprogrammed flight paths are advised. Our study highlights factors that can influence sensitivity to RPAS including tidal state and swell, the presence of young individuals, ambient noise levels, and RPAS approach strategies.