EVALUATING THREATS TO GREEN TURTLES (Chelonia mydas) ON A COASTAL REEF
Protected areas; sea turtles; drones; conservation; fibropapillomatosis
The increasing human population in coastal areas has intensified several threats to marine biodiversity, from unregulated fishing activities to the degradation of coastal ecosystems. In Brazil, marine protected areas have been essential for regulating the use of public coastal areas and mitigating impacts on a range of socially and economically important species. Here, we sought to understand the spatial distribution of green turtles and threats within the most extensive Brazilian federal marine protected area. We also investigate which threats are related with green turtles’ density and mortality rate. For this, we used aerial images taken by survey drones to identify green turtles and their location. We also used a database of stranded turtles with information on fibropapillomathosis presence/absence and severity, quantity of plastic ingested, and quantity of plant species ingested. All data were divided into sampling units along the protection area and statistically analyzed, seeking to understand their relationship. Our results indicated that green turtles are distributed along the entire coast and successfully identified the central and southern regions of the Costa dos Corais Protection Area (APACC) as the locations with higher density of individuals. Also, we observed that urbanization is associated with an impoverished diet, incidence of fibropapillomatosis and litter ingestion. Unexpectedly, fishing pressure was not related with mortality rates. Finally, our heat map of threats points to the city of Japaratinga as a priority area for the intensification of conservation actions within the APACC since it has multiple threats and a high density of turtles.