Environmental and anthropogenic factors affecting nesting site selection by sea turtles

Understanding the environmental and anthropogenic factors that affect nesting site selection by sea turtles is key to maintaining priority conservation areas. The species Lepidochelys olivacea, Caretta caretta, and Eretmochelys imbricata nest annually on the island of Comandatuba (Una, northeastern Brazil), where this survey was conducted. We evaluated the temporal and spatial distribution of nests during the seasons 2008/2009 to 2014/2015 and 2017/2018. In the last season, we further examined the environmental and anthropogenic factors that influence different nesting performances. We selected six sample areas with different nesting events (high, medium, and low), and recorded the following characteristics: beach slope, sediment grain size, vegetation richness, type of dune, anthropization, and final nest condition. A significant occurrence of nesting was observed in November and December . The spatial distribution of the nests varied over the seasons, with a greater tendency to nest in the south of the island. Higher frequency of anthropization and low slope of the beach were significant factors for areas with a smaller number of nests. Predation of turtle nests may be associated with areas of greater anthropization. Our findings have implications for the conservation and monitoring of nesting sites during reproduction seasons and provide further insight into the nesting dynamics of marginal sea turtle populations.