Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change
Nest temperature is the predominant driver of emergence success and primary sex ratios in sea turtles, with female offspring produced at higher temperatures due to temperature-dependent sex determination. However, emergence success and primary sex ratios are unfeasible to measure at scale, making me...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2024-06-01
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| Series: | Global Ecology and Conservation |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2351989424000702 |
| _version_ | 1797281180290121728 |
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| author | Malindi Gammon Blair Bentley Sabrina Fossette Nicola J. Mitchell |
| author_facet | Malindi Gammon Blair Bentley Sabrina Fossette Nicola J. Mitchell |
| author_sort | Malindi Gammon |
| collection | DOAJ |
| description | Nest temperature is the predominant driver of emergence success and primary sex ratios in sea turtles, with female offspring produced at higher temperatures due to temperature-dependent sex determination. However, emergence success and primary sex ratios are unfeasible to measure at scale, making methods to estimate these life-history traits from predicted sand temperatures highly desirable for long-term conservation planning in the context of climate change. To address this, we used a mechanistic microclimate model to predict hourly sand temperatures, over 32 nesting seasons since 1986, at 402 West Australian beaches supporting nesting by flatback turtles (Natator depressus). Predicted sand temperatures indicated that ∼70% of these beaches carried a 'very low' to 'intermediate' risk of subjecting embryos to thermal stress. By combining these temperature predictions with a physiological model, current and future emergence success and sex ratios were projected for ten different beaches spanning a range of thermal microclimates, under various climate change scenarios. Under recent climate conditions, emergence success averaged 76%, but declined to 63% and 37% with a 2°C and 4°C increase in air temperature, respectively. The sex ratios of hatchlings varied by location, but extremely skewed sex ratios were anticipated in a 4°C warming scenario. Our projections reveal that 'high risk' nesting beaches will regularly experience clutch failure as climate change progresses, while cooler beaches offer long-term nesting potential and require protection from additional anthropogenic impacts. These projections, covering an entire genetic stock, supply demographic data for assessing extinction risks and this method can be applied to sea turtle populations worldwide. |
| first_indexed | 2024-03-07T16:53:47Z |
| format | Article |
| id | doaj.art-2f90b213e42d427ca66fe9e50df967f5 |
| institution | Directory Open Access Journal |
| issn | 2351-9894 |
| language | English |
| last_indexed | 2024-03-07T16:53:47Z |
| publishDate | 2024-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Global Ecology and Conservation |
| spelling | doaj.art-2f90b213e42d427ca66fe9e50df967f52024-03-03T04:29:46ZengElsevierGlobal Ecology and Conservation2351-98942024-06-0151e02866Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate changeMalindi Gammon0Blair Bentley1Sabrina Fossette2Nicola J. Mitchell3School of Biological Sciences, The University of Western Australia, Australia; The Ocean’s Institute, The University of Western Australia, Australia; The Department of Biodiversity Conservation and Attractions, Marine Science Program, Biodiversity and Conservation Science, Western Australia, Australia; Corresponding author at: School of Biological Sciences, The University of Western Australia, Australia.School of Biological Sciences, The University of Western Australia, Australia; Department of Environmental Conservation, University of Massachusetts Amherst, Amherst, MA 01003, USASchool of Biological Sciences, The University of Western Australia, Australia; The Ocean’s Institute, The University of Western Australia, Australia; The Department of Biodiversity Conservation and Attractions, Marine Science Program, Biodiversity and Conservation Science, Western Australia, AustraliaSchool of Biological Sciences, The University of Western Australia, Australia; The Ocean’s Institute, The University of Western Australia, AustraliaNest temperature is the predominant driver of emergence success and primary sex ratios in sea turtles, with female offspring produced at higher temperatures due to temperature-dependent sex determination. However, emergence success and primary sex ratios are unfeasible to measure at scale, making methods to estimate these life-history traits from predicted sand temperatures highly desirable for long-term conservation planning in the context of climate change. To address this, we used a mechanistic microclimate model to predict hourly sand temperatures, over 32 nesting seasons since 1986, at 402 West Australian beaches supporting nesting by flatback turtles (Natator depressus). Predicted sand temperatures indicated that ∼70% of these beaches carried a 'very low' to 'intermediate' risk of subjecting embryos to thermal stress. By combining these temperature predictions with a physiological model, current and future emergence success and sex ratios were projected for ten different beaches spanning a range of thermal microclimates, under various climate change scenarios. Under recent climate conditions, emergence success averaged 76%, but declined to 63% and 37% with a 2°C and 4°C increase in air temperature, respectively. The sex ratios of hatchlings varied by location, but extremely skewed sex ratios were anticipated in a 4°C warming scenario. Our projections reveal that 'high risk' nesting beaches will regularly experience clutch failure as climate change progresses, while cooler beaches offer long-term nesting potential and require protection from additional anthropogenic impacts. These projections, covering an entire genetic stock, supply demographic data for assessing extinction risks and this method can be applied to sea turtle populations worldwide.http://www.sciencedirect.com/science/article/pii/S2351989424000702Flatback turtleNatator depressusPilbaraNorth West ShelfNicheMapRThermal risk assessment |
| spellingShingle | Malindi Gammon Blair Bentley Sabrina Fossette Nicola J. Mitchell Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change Global Ecology and Conservation Flatback turtle Natator depressus Pilbara North West Shelf NicheMapR Thermal risk assessment |
| title | Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change |
| title_full | Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change |
| title_fullStr | Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change |
| title_full_unstemmed | Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change |
| title_short | Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change |
| title_sort | reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change |
| topic | Flatback turtle Natator depressus Pilbara North West Shelf NicheMapR Thermal risk assessment |
| url | http://www.sciencedirect.com/science/article/pii/S2351989424000702 |
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