Effects of rising temperature on the viability of an important sea turtle rookery

• Published in: Nature climate change Vol. 4; no. 6; pp. 513 - 518
• Main Authors: Laloë, Jacques-Olivier, Cozens, Jacquie, Renom, Berta, Taxonera, Albert, Hays, Graeme C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-06-2014; Nature Publishing Group
• Subjects: 631/158/2165; 631/158/672; 704/106/694/2739; 704/158/2165; Air temperature; Animal and plant ecology; Animal, plant and microbial ecology; Aquatic reptiles; Beaches; Biological and medical sciences; Climate Change; Climate Change/Climate Change Impacts; Climatology. Bioclimatology. Climate change; Demecology; Earth, ocean, space; Environment; Environmental Law/Policy/Ecojustice; Exact sciences and technology; External geophysics; Fundamental and applied biological sciences. Psychology; General aspects; Global warming; Incubation; Intergovernmental Panel on Climate Change; Meteorology; Nesting; Population growth; Temperature measurement; Cape Verde Islands; Atlantic Ocean Islands; Atlantic Ocean; ASE, Atantic, Cape Verde Is; Dynamical climatology; Marine environment; Warming; Sex ratio; Climate change; Vertebrata; Population growth; Chelonia; Egg brooding; Reptilia; Sea turtle; Viability
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/nclimate2236

A warming world poses challenges for species with temperature-dependent sex determination, including sea turtles, for which warmer incubation temperatures produce female hatchlings. We combined
in situ
sand temperature measurements with air temperature records since 1850 and predicted warming scenarios from the Intergovernmental Panel on Climate Change to derive 250-year time series of incubation temperatures, hatchling sex ratios, and operational sex ratios for one of the largest sea turtles rookeries globally (Cape Verde Islands, Atlantic). We estimate that light-coloured beaches currently produce 70.10% females whereas dark-coloured beaches produce 93.46% females. Despite increasingly female skewed sex ratios, entire feminization of this population is not imminent. Rising temperatures increase the number of breeding females and hence the natural rate of population growth. Predicting climate warming impacts across hatchlings, male–female breeding ratios and nesting numbers provides a holistic approach to assessing the conservation concerns for sea turtles in a warming world.
A warming world poses challenges for species with temperature-dependent sex determination. The implications of increasingly skewed sex ratios for an important marine turtle rookery have been assessed. This study has identified how offspring sex ratio translates into future operational sex ratios and population size-up, and should help to guide conservation efforts.