Feminization of hawksbill turtle hatchlings in the twenty-first century at an important regional nesting aggregation

Abstract

Projected climate change is forecasted to have significant effects on biological systems worldwide. Marine turtles in particular may be vulnerable, as the sex of their offspring is determined by their incubating temperature. This study is aimed to estimate historical and forecast future, primary sex ratios of hawksbill turtle hatchlings, Eretmochelys imbricata, in Qatar. Incubation temperatures were measured over two nesting seasons. Climate data from same period was regressed with nest temperatures to estimate incubation temperatures and hatchling sex ratios for the site from 1993 to 2100. Historical climate data showed female-biased sex ratios of 73.2 ±12.1% from 1993 to 2017. Female biases from 2018 to 2100 averaged 85.7% ±6.7%. In addition, predicted female hatchling production was >90% from 2054. These results show that hawksbill primary sex ratios in Qatar are at risk of significant feminization by the year 2100.