Trialling seawater irrigation to combat the high nest temperature feminisation of green turtle Chelonia mydas hatchlings

Abstract

Global increases in beach sand temperatures are predicted to skew hatchling sexratios of marine turtle populations towards female bias. Currently, shade structures and fresh-water irrigation are management strategies used to cool nest temperatures, but require resources that are limited at remote rookeries. Here, we report on a novel investigation that used seawater irrigation as a sand-cooling method. Various volumes of seawater were applied to sand to deter-mine the optimal application required to lower sand temperatures at nest depth to produce male-biased sex ratios.