Potential effects of future high tides on sea turtle nesting

Sandy beaches are the preferred nesting habitat for sea turtles. Multiple climate change events may, however, impact this habitat, since the projected increase in the intensity and frequency of high tides because of rises in sea level and storm events may cause a higher rate of flooding of nests. Knowledge regarding future scenarios of tidal inundation and nest-site selection is required to design action plans with which to protect suitable habitats. The objectives of this study were to quantify the impact of high tides and their trends on the nesting of two endangered sea turtle species, Eretmochelys imbricata and Chelonia mydas , in Ecuador, and to assess their potential influence on hatching success. We measured microhabitat characteristics along seven beaches on which sea turtles nest on the mainland coast of Ecuador. The tidal data and the hatching success of 199 nests were monitored from 2013 to 2020. We observed a positive trend in future high tide occurrences, which are a key factor in explaining nest hatching success. This increase in high tide might cause a reduction in the hatching success of these endangered species of sea turtles; with the E. imbricata being the species most affected by this threat. Considering that these species are threatened, estimations of the potential risk of climate events on their reproductive success might contribute to management strategies, and in turn, to the conservation of their populations.