Aerial Drone Surveys Reveal the Efficacy of a Protected Area Network for Marine Megafauna and the Value of Sea Turtles as Umbrella Species

Abstract

Quantifying the capacity of protected area networks to shield multiple marine megafauna with diverse life histories is complicated, as many species are wide-ranging, requiring varied monitoring approaches. Yet, such information is needed to identify and assess the potential use of umbrella species and to plan how best to enhance conservation strategies. Here, we evaluated the effectiveness of part of the European Natura 2000 protected area network (western Greece) for marine megafauna and whether loggerhead sea turtles are viable umbrella species in this coastal region. We systematically surveyed inside and outside coastal marine protected areas (MPAs) at a regional scale using aerial drones (18,505 animal records) and combined them with distribution data from published datasets (tracking, sightings, strandings) of sea turtles, elasmobranchs, cetaceans and pinnipeds. MPAs covered 56% of the surveyed coastline (~1500 km). There was just a 22% overlap in the distributions of the four groups from aerial drone and other datasets, demonstrating the value of combining different approaches to improve records of coastal area use for effective management. All four taxonomic groups were more likely to be detected inside coastal MPAs than outside, confirming sufficient habitat diversity despite varied life history traits. Coastal habitats frequented by loggerhead turtles during breeding/non-breeding periods combined overlapped with 76% of areas used by the other three groups, supporting their potential use as an umbrella species. In conclusion, this study showed that aerial drones can be readily combined with other monitoring approaches in coastal areas to enhance the management of marine megafauna in protected area networks and to identify the efficacy of umbrella species.

Priorities for Mediterranean marine turtle conservation and management in the face of climate change

“…These results indicate distrust in the slow pace of institutional change (Lonsdale et al, 2017). In many cases, the legislative tools are already in place (Dickson et al, 2022;Girard et al, 2022), but enforcement and monitoring of the efficiency of measures are lacking, while the spatial coverage by MPAs remains rather limited in the region (Gomei et al, 2019). In other words, while MPAs can shield wildlife and habitats from many pressures, actual practice is needed.…”

“…Potential spatial shifts in foraging ground (Chatzimentor et al, 2021) and likely energetic changes in migration patterns due to climate change (Petsas et al, 2023) further support the need for accelerating research on the marine habitats of marine turtles, particularly in areas with high human use (e.g. fisheries, marine traffic) (Dickson et al, 2022). Changes to foraging habitat distribution and/or prey species presence could have a direct effect on the energetic budget of marine turtles, negatively impacting fitness, somatic growth, time to reach sexual maturity and breeding frequency (remigration intervals, typically 1 year for males and 2-3 for females in the Mediterranean; Hays et al, 2014).…”

Unmanned Aerial Vehicles (UAVs) in Marine Mammal Research: A Review of Current Applications and Challenges

“…Rotary-wing UAVs have mainly been used for monitoring small coastal and river dolphin populations [18,38,39,49,78,105,106] (see Table 1). These UAVs have also been used to survey megafauna (e.g., cetaceans, turtles, and sharks) in marine protected areas [21]. The flying altitudes in these studies ranged from 20 to 60 m.…”

Assessment of Methods for Propeller Performance Calculation at High Incidence Angles

“…If from one side such kind of vehicle is now well established for leisure and cinematography, the number of possibilities regarding their application for the benefit of the environment and the mankind increases constantly. Recently, there has been studies regarding the use of drones to detect forest pathogens [1], to manage wildfires operating as swarms [2] and in a blockchain framework [3], to help in epidemic situations [4], and even to evaluate the potential of selecting an umbrella specie to conserve the marine Megafauna [5]. Winged vertical takeoff and landing (VTOL) UAVs stands out as they feature longer flight ranges, speeds and payload capacity, while maintaining the capability of taking off and landing without needing a long runaway.…”