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ESR 44:149-158 (2021)  -  DOI: https://doi.org/10.3354/esr01104

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

Mark Chatting1,*, Shafeeq Hamza1, Jassim Al-Khayat1, David Smyth2, Sinan Husrevoglu3, Christopher D. Marshall4

1Environmental Science Center, Qatar University, Doha 2713, Qatar
2School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey LL59 5EY, UK
3Institute of Marine Sciences, Middle East Technical University, Erdemli, Mersin 33731, Turkey
4Department of Marine Biology, Department of Wildlife and Fisheries Sciences, Gulf Center for Sea Turtle Research, Texas A&M University, Galveston, Texas 77553, USA
*Corresponding author:

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, termed temperature-dependent sex determination. This study aimed to estimate historical, and forecast future, primary sex ratios of hawksbill turtle Eretmochelys imbricata hatchlings at an important nesting ground in northeastern Qatar. Incubation temperatures from the Arabian/Persian Gulf were measured over 2 nesting seasons. Climate data from same period were regressed with nest temperatures to estimate incubation temperatures and hatchling sex ratios for the site from 1993 to 2100. Future hatchling sex ratios were estimated for 2 climate forecasts, one mid-range (SSP245) and one extreme (SSP585). 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% under the mid-range scenario and 87.9% ± 5.4% under the high-range scenario. In addition, predicted female hatchling production was >90% from 2054 and 2052 for SSP245 and SSP585, respectively. These results show that hawksbill primary sex ratios in Qatar are at risk of significant feminization by the year 2100 and that hawksbill turtle incubation temperatures in an extreme, understudied environment are already comparable to those predicted in tropical rookeries during the latter half of the 21st century. These results can help conservationists predict primary sex ratios for hawksbill turtles in the region in the face of 21st-century climate change.


KEY WORDS: Marine turtles · Eretmochelys imbricata · Arabian/Persian Gulf · Climate change · Sex ratios · Temperature-dependent sex determination


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Cite this article as: Chatting M, Hamza S, Al-Khayat J, Smyth D, Husrevoglu S, Marshall CD (2021) Feminization of hawksbill turtle hatchlings in the twenty-first century at an important regional nesting aggregation. Endang Species Res 44:149-158. https://doi.org/10.3354/esr01104

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