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Fuentes MMPB, Santos AJB, Abreu-Grobois A, Briseño-Dueñas R, Al-Khayat J, Hamza S, Saliba S, Anderson D, Rusenko KW, Mitchell NJ, Gammon M, Bentley BP, Beton D, Booth DTB, Broderick AC, Colman LP, Snape RTE, Calderon-Campuzano MF, Cuevas E, Lopez-Castro MC, Flores-Aguirre CD, Mendez de la Cruz F, Segura-Garcia Y, Ruiz-Garcia A, Fossette S, Gatto CR, Reina RD, Girondot M, Godfrey M, Guzman-Hernandez V, Hart CE, Kaska Y, Lara PH, Marcovaldi MAGD, LeBlanc AM, Rostal D, Liles MJ, Wyneken J, Lolavar A, Williamson SA, Manoharakrishnan M, Pusapati C, Chatting M, Mohd Salleh S, Patricio AR, Regalla A, Restrepo J, Garcia R, Santidrián Tomillo P, Sezgin C, Shanker K, Tapilatu F, Turkozan O, Valverde RA, Williams K, Yilmaz C, Tolen N, Nel R, Tucek J, Legouvello D, Rivas ML, Gaspar C, Touron M, Genet Q, Salmon M, Araujo MR, Freire JB, Castheloge VD, Jesus PR, Ferreira PD, Paladino FV, Montero-Flores D, Sozbilen D, Monsinjon JR. Adaptation of sea turtles to climate warming: Will phenological responses be sufficient to counteract changes in reproductive output? GLOBAL CHANGE BIOLOGY 2024; 30:e16991. [PMID: 37905464 DOI: 10.1111/gcb.16991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 11/02/2023]
Abstract
Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a "middle of the road" scenario (SSP2-4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26-43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present-day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from -20 to -191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.
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Affiliation(s)
- M M P B Fuentes
- Marine Turtle Research, Ecology, and Conservation Group, Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida, USA
| | - A J B Santos
- Marine Turtle Research, Ecology, and Conservation Group, Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, Florida, USA
| | - A Abreu-Grobois
- Unidad Academica Mazatlan, Instituto de Ciencias del Mar y Limnologia, UNAM, Mazatlan, Sinaloa, Mexico
| | - R Briseño-Dueñas
- Unidad Academica Mazatlan, Instituto de Ciencias del Mar y Limnologia, UNAM, Mazatlan, Sinaloa, Mexico
| | - J Al-Khayat
- Environmental Science Centre, Qatar University, Doha, Qatar
| | - S Hamza
- Environmental Science Centre, Qatar University, Doha, Qatar
| | - S Saliba
- Environmental Science Centre, Qatar University, Doha, Qatar
| | - D Anderson
- Gumbo Limbo Nature Center, Boca Raton, Florida, USA
| | - K W Rusenko
- Gumbo Limbo Nature Center, Boca Raton, Florida, USA
| | - N J Mitchell
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - M Gammon
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| | - B P Bentley
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
| | - D Beton
- Society for Protection of Turtles, Gonyeli, Northern Cyprus
| | - D T B Booth
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | - A C Broderick
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - L P Colman
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - R T E Snape
- Society for Protection of Turtles, Gonyeli, Northern Cyprus
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - M F Calderon-Campuzano
- Programa de Protección y Conservación de Tortugas Marinas, Convenio FONATUR-Instituto de Ciencias del Mar y Limnología-UNAM, Mazatlán, Sinaloa, Mexico
| | - E Cuevas
- Instituto de Investigaciones Oceanologicas, Universidad Autonoma de Baja California, Ensenada, Mexico
| | - M C Lopez-Castro
- Pronatura Península de Yucatán, A. C. Programa para la Conservación de la Tortuga Marina, Mérida, Yucatán, Mexico
| | - C D Flores-Aguirre
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - F Mendez de la Cruz
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Y Segura-Garcia
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - A Ruiz-Garcia
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - S Fossette
- School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia
- Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Kensington, Western Australia, Australia
| | - C R Gatto
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - R D Reina
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - M Girondot
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique et Evolution, Gif-sur-Yvette, France
| | - M Godfrey
- North Carolina Wildlife Resources Commission, Beaufort, North Carolina, USA
- Duke Marine Laboratory, Nicholas School of Environment, Duke University, Beaufort, North Carolina, USA
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | | | - C E Hart
- Centro de Investigaciones Oceánicas del Mar de Cortés-Gran Acuario de Mazatlán, Mazatlán, Mexico
| | - Y Kaska
- Department of Biology, Faculty of Science, Pamukkale University, Denizli, Turkey
| | - P H Lara
- Fundação Projeto Tamar, Florianópolis, Brazil
| | | | - A M LeBlanc
- Georgia Southern University, Statesboro, Georgia, USA
| | - D Rostal
- Georgia Southern University, Statesboro, Georgia, USA
| | - M J Liles
- Asociacion ProCosta, San Salvador, El Salvador
| | - J Wyneken
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA
| | - A Lolavar
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA
| | - S A Williamson
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA
| | | | | | - M Chatting
- Environmental Science Centre, Qatar University, Doha, Qatar
- School of Civil Engineering, University College Dublin, Dublin, Ireland
| | - S Mohd Salleh
- School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | - A R Patricio
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
- Marine and Environmental Sciences Centre/ARNET-Aquatic Research Network, Ispa-Instituto Universitário de Ciências Psicológicas, Lisbon, Portugal
| | - A Regalla
- Instituto da Biodiversidade e das Áreas Protegidas, Dr. Alfredo Simão da Silva (IBAP), Bissau, Guinea-Bissau
| | - J Restrepo
- Sea Turtle Conservancy, Gainesville, Florida, USA
| | - R Garcia
- Sea Turtle Conservancy, Gainesville, Florida, USA
| | | | - C Sezgin
- Sea Turtle Research, Rescue and Rehabilitation Center (DEKAMER), Mugla, Turkey
| | - K Shanker
- Dakshin Foundation, Bangalore, India
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India
| | - F Tapilatu
- Research Center of Pacific Marine Resources-University of Papua (UNIPA), Manokwari, Papua Barat, Indonesia
| | - O Turkozan
- Department of Biology, Faculty of Science, Aydın Adnan Menderes University, Aydın, Turkey
| | - R A Valverde
- Sea Turtle Conservancy, Gainesville, Florida, USA
- Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana, USA
| | - K Williams
- Caretta Research Project, Savannah, Georgia, USA
| | - C Yilmaz
- Hakkari University, Vocational School of Health Services, Hakkari, Turkey
| | - N Tolen
- Universiti Malaysia Terengganu, Kuala Nerus, Malaysia
| | - R Nel
- Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Gqeberha, South Africa
| | - J Tucek
- Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Gqeberha, South Africa
| | - D Legouvello
- Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Gqeberha, South Africa
| | - M L Rivas
- Department of Biology, University of Cadiz, Cadiz, Spain
| | - C Gaspar
- Te Mana O Te Moana, Moorea-Maiao, French Polynesia
| | - M Touron
- Te Mana O Te Moana, Moorea-Maiao, French Polynesia
| | - Q Genet
- Te Mana O Te Moana, Moorea-Maiao, French Polynesia
| | - M Salmon
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA
| | - M R Araujo
- Ministerio de Medio Ambiente y Recursos Naturales, San Salvador, El Salvador
| | - J B Freire
- Fundação Espírito Santense de Tecnologia-FEST, Vitória, Espírito Santo, Brazil
| | | | - P R Jesus
- Econservation Estudos e Projetos Ambientais, Vitória, Espírito Santo, Brazil
| | - P D Ferreira
- Departamento de Gemologia, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil
| | - F V Paladino
- Purdue University Fort Wayne, Fort Wayne, Indiana, USA
| | | | - D Sozbilen
- Department of Veterinary, Acıpayam Vocational School, Pamukkale University, Denizli, Turkey
| | - J R Monsinjon
- Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Délégation Océan Indien (DOI), Le Port, La Réunion, France
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Charles KE, Morrall CE, Edwards JJ, Carter KD, Afema JA, Butler BP, Marancik DP. Environmental and Nesting Variables Associated with Atlantic Leatherback Sea Turtle ( Dermochelys coriacea) Embryonic and Hatching Success Rates in Grenada, West Indies. Animals (Basel) 2023; 13:ani13040685. [PMID: 36830474 PMCID: PMC9951857 DOI: 10.3390/ani13040685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/20/2023] [Accepted: 02/02/2023] [Indexed: 02/18/2023] Open
Abstract
Annual monitoring of leatherback sea turtle (Dermochelys coriacea) nesting grounds in Grenada, West Indies has identified relatively low hatch rates compared to worldwide trends. This study investigated the impact of selected environmental variables on leatherback sea turtle embryonic development and hatching success rates on Levera Beach in Grenada between 2015-2019. The mean number of nests per year and eggs per nest were 667.6 ± 361.6 and 80.7 ± 23.0 sd, respectively. Within excavated nests, 35.6% ± 22.0 sd of eggs successfully developed embryos and 30.6% ± 22.6 sd of eggs successfully hatched. The number of eggs per nest, along with embryo and hatching success rates, differed by nesting year. Embryo development success rate was associated with nest location, and both embryo development and hatching success rates were positively associated with nest depth and negatively associated with the percentage of eggs exhibiting microbial growth and with the presence of inspissated yolk. There was no embryo development or hatchling success association with month of the nesting season, distance from the high-water mark, distance from vegetation, nor maternal carapace length. The mean nest temperature was 31.7 °C ± 1.64 sd and mean temperatures during the middle third of egg incubation suggest clutches are highly skewed towards a preponderance of female hatchlings. Histopathologic findings in hatchling mortalities included severe, acute, multifocal, heterophilic bronchopneumonia with intralesional bacteria in 4/50 (8%) hatchlings. Data from this study guide conservation strategies by identifying risk factors and further avenues of research needed to support reproductive success of leatherback sea turtles in Grenada and the greater Caribbean region.
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Affiliation(s)
- Kate E. Charles
- Department of Pathobiology, School of Veterinary Medicine, St. George’s University, True Blue, West Indies, Grenada
- Ocean Spirits, Inc., West Indies, Grenada
- Correspondence: ; Tel.: +1473-537-2512
| | - Clare E. Morrall
- Ocean Spirits, Inc., West Indies, Grenada
- Department of Biology, Ecology, and Conservation, School of Arts and Sciences, St. George’s University, True Blue, West Indies, Grenada
| | - Jonnel J. Edwards
- Department of Pathobiology, School of Veterinary Medicine, St. George’s University, True Blue, West Indies, Grenada
| | - Kenrith D. Carter
- Ocean Spirits, Inc., West Indies, Grenada
- Dr Carter Veterinary Services, West Indies, Grenada
| | - Josephine A. Afema
- Department of Pathobiology, School of Veterinary Medicine, St. George’s University, True Blue, West Indies, Grenada
| | - Brian P. Butler
- Department of Pathobiology, School of Veterinary Medicine, St. George’s University, True Blue, West Indies, Grenada
| | - David P. Marancik
- Department of Pathobiology, School of Veterinary Medicine, St. George’s University, True Blue, West Indies, Grenada
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3
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Gatto CR, Reina RD. A review of the effects of incubation conditions on hatchling phenotypes in non-squamate reptiles. J Comp Physiol B 2022; 192:207-233. [PMID: 35142902 PMCID: PMC8894305 DOI: 10.1007/s00360-021-01415-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 09/15/2021] [Accepted: 10/03/2021] [Indexed: 11/28/2022]
Abstract
Developing embryos of oviparous reptiles show substantial plasticity in their responses to environmental conditions during incubation, which can include altered sex ratios, morphology, locomotor performance and hatching success. While recent research and reviews have focused on temperature during incubation, emerging evidence suggests other environmental variables are also important in determining hatchling phenotypes. Understanding how the external environment influences development is important for species management and requires identifying how environmental variables exert their effects individually, and how they interact to affect developing embryos. To address this knowledge gap, we review the literature on phenotypic responses in oviparous non-squamate (i.e., turtles, crocodilians and tuataras) reptile hatchlings to temperature, moisture, oxygen concentration and salinity. We examine how these variables influence one another and consider how changes in each variable alters incubation conditions and thus, hatchling phenotypes. We explore how incubation conditions drive variation in hatchling phenotypes and influence adult populations. Finally, we highlight knowledge gaps and suggest future research directions.
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Affiliation(s)
- Christopher R Gatto
- School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, VIC, 3800, Australia.
| | - Richard D Reina
- School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, VIC, 3800, Australia
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4
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Matthews BL, Gatto CR, Reina RD. Effects of moisture during incubation on green sea turtle (Chelonia mydas) development, morphology and performance. ENDANGER SPECIES RES 2021. [DOI: 10.3354/esr01159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
While the effect of temperature on embryonic development in sea turtles has been well studied over recent years, our understanding of the effect of substrate moisture, another important environmental variable, is limited. High sand moisture decreases nest temperature through evaporative and direct cooling during rainfall, but its direct effect on hatchling development, morphology and performance is unclear. To address this knowledge gap, we incubated 40 green sea turtle Chelonia mydas clutches in a beach hatchery under either high (~8% v/v) or low (~5% v/v) sand moisture concentrations for the duration of embryonic development. In half of the clutches, temperature sensors were deployed to measure any effect of sand moisture on nest temperature. As hatchlings emerged, we measured body size and locomotory performance during the first 24 h, an important period of frenzied activity for sea turtles. We excavated clutches post-emergence to determine hatching success, emergence success and to determine the stage of embryonic death for unsuccessful eggs. High moisture concentrations increased incubation duration, decreased nest temperature and had marginal effects on hatchling morphology, but no effect on hatching success, stage of embryonic death, crawling speed or initial swimming performance. However, after 24 h of swimming, hatchlings from high-moisture clutches produced less mean swim thrust and spent less time powerstroking than hatchlings from low-moisture clutches, suggesting reduced swimming endurance and potentially impacting the ability of hatchlings to successfully disperse. The effect of moisture on nest temperature and hatchling endurance highlights the importance of considering rainfall patterns when predicting future impacts of climate change on sea turtle populations.
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Affiliation(s)
- BL Matthews
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - CR Gatto
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - RD Reina
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
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5
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Vilaça ST, Piccinno R, Rota‐Stabelli O, Gabrielli M, Benazzo A, Matschiner M, Soares LS, Bolten AB, Bjorndal KA, Bertorelle G. Divergence and hybridization in sea turtles: Inferences from genome data show evidence of ancient gene flow between species. Mol Ecol 2021; 30:6178-6192. [PMID: 34390061 PMCID: PMC9292604 DOI: 10.1111/mec.16113] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 07/26/2021] [Indexed: 11/30/2022]
Abstract
Reconstructing past events of hybridization and population size changes are required to understand speciation mechanisms and current patterns of genetic diversity, and ultimately contribute to species' conservation. Sea turtles are ancient species currently facing anthropogenic threats including climate change, fisheries, and illegal hunting. Five of the seven extant sea turtle species are known to currently hybridize, especially along the Brazilian coast where some populations can have ~32%-42% of hybrids. Although frequently observed today, it is not clear what role hybridization plays in the evolutionary diversification of this group of reptiles. In this study, we generated whole genome resequencing data of the five globally distributed sea turtle species to estimate a calibrated phylogeny and the population size dynamics, and to understand the role of hybridization in shaping the genomes of these ancient species. Our results reveal discordant species divergence dates between mitochondrial and nuclear genomes, with a high frequency of conflicting trees throughout the nuclear genome suggesting that some sea turtle species frequently hybridized in the past. The reconstruction of the species' demography showed a general decline in effective population sizes with no signs of recovery, except for the leatherback sea turtle. Furthermore, we discuss the influence of reference bias in our estimates. We show long-lasting ancestral gene flow events within Chelonioidea that continued for millions of years after initial divergence. Speciation with gene flow is a common pattern in marine species, and it raises questions whether current hybridization events should be considered as a part of these species' evolutionary history or a conservation issue.
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Affiliation(s)
| | - Riccardo Piccinno
- Department of Sustainable Agro‐ecosystems and BioresourcesFondazione Edmund MachTrentoItaly
| | - Omar Rota‐Stabelli
- Department of Sustainable Agro‐ecosystems and BioresourcesFondazione Edmund MachTrentoItaly
| | - Maëva Gabrielli
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | - Andrea Benazzo
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
| | | | - Luciano S. Soares
- Archie Carr Center for Sea Turtle Research and Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | - Alan B. Bolten
- Archie Carr Center for Sea Turtle Research and Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | - Karen A. Bjorndal
- Archie Carr Center for Sea Turtle Research and Department of BiologyUniversity of FloridaGainesvilleFLUSA
| | - Giorgio Bertorelle
- Department of Life Sciences and BiotechnologyUniversity of FerraraFerraraItaly
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6
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Patrício AR, Hawkes LA, Monsinjon JR, Godley BJ, Fuentes MMPB. Climate change and marine turtles: recent advances and future directions. ENDANGER SPECIES RES 2021. [DOI: 10.3354/esr01110] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Climate change is a threat to marine turtles that is expected to affect all of their life stages. To guide future research, we conducted a review of the most recent literature on this topic, highlighting knowledge gains and research gaps since a similar previous review in 2009. Most research has been focussed on the terrestrial life history phase, where expected impacts will range from habitat loss and decreased reproductive success to feminization of populations, but changes in reproductive periodicity, shifts in latitudinal ranges, and changes in foraging success are all expected in the marine life history phase. Models have been proposed to improve estimates of primary sex ratios, while technological advances promise a better understanding of how climate can influence different life stages and habitats. We suggest a number of research priorities for an improved understanding of how climate change may impact marine turtles, including: improved estimates of primary sex ratios, assessments of the implications of female-biased sex ratios and reduced male production, assessments of the variability in upper thermal limits of clutches, models of beach sediment movement under sea level rise, and assessments of impacts on foraging grounds. Lastly, we suggest that it is not yet possible to recommend manipulating aspects of turtle nesting ecology, as the evidence base with which to understand the results of such interventions is not robust enough, but that strategies for mitigation of stressors should be helpful, providing they consider the synergistic effects of climate change and other anthropogenic-induced threats to marine turtles, and focus on increasing resilience.
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Affiliation(s)
- AR Patrício
- MARE - Marine and Environmental Sciences Centre, ISPA - Instituto Universitário, 1149-041 Lisbon, Portugal
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK
| | - LA Hawkes
- Hatherley Laboratories, College of Life and Environmental Sciences, University of Exeter, Streatham Campus, Exeter EX4 4PS, UK
| | - JR Monsinjon
- Department of Zoology and Entomology, Rhodes University, Grahamstown 6139, South Africa
| | - BJ Godley
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn TR10 9FE, UK
| | - MMPB Fuentes
- Marine Turtle Research, Ecology and Conservation Group, Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
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7
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Maurer AS, Seminoff JA, Layman CA, Stapleton SP, Godfrey MH, Reiskind MOB. Population Viability of Sea Turtles in the Context of Global Warming. Bioscience 2021. [DOI: 10.1093/biosci/biab028] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Sea turtles present a model for the potential impacts of climate change on imperiled species, with projected warming generating concern about their persistence. Various sea turtle life-history traits are affected by temperature; most strikingly, warmer egg incubation temperatures cause female-biased sex ratios and higher embryo mortality. Predictions of sea turtle resilience to climate change are often focused on how resulting male limitation or reduced offspring production may affect populations. In the present article, by reviewing research on sea turtles, we provide an overview of how temperature impacts on incubating eggs may cascade through life history to ultimately affect population viability. We explore how sex-specific patterns in survival and breeding periodicity determine the differences among offspring, adult, and operational sex ratios. We then discuss the implications of skewed sex ratios for male-limited reproduction, consider the negative correlation between sex ratio skew and genetic diversity, and examine consequences for adaptive potential. Our synthesis underscores the importance of considering the effects of climate throughout the life history of any species. Lethal effects (e.g., embryo mortality) are relatively direct impacts, but sublethal effects at immature life-history stages may not alter population growth rates until cohorts reach reproductive maturity. This leaves a lag during which some species transition through several stages subject to distinct biological circumstances and climate impacts. These perspectives will help managers conceptualize the drivers of emergent population dynamics and identify existing knowledge gaps under different scenarios of predicted environmental change.
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Affiliation(s)
- Andrew S Maurer
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, in the United States; he is also a research associate with the Jumby Bay Hawksbill Project in Antigua, West Indies
| | - Jeffrey A Seminoff
- Marine Turtle Ecology and Assessment Program, National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center, La Jolla, California, United States
| | - Craig A Layman
- Center for Energy, Environment, and Sustainability, Wake Forest University, in Winston-Salem, North Carolina, in the United States
| | - Seth P Stapleton
- Conservation and animal health sciences, Minnesota Zoo, Apple Valley, Minnesota; he is also an adjunct faculty member in the Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, in Minneapolis, Minnesota, in the United States
| | - Matthew H Godfrey
- North Carolina Wildlife Resources Commission, Raleigh, North Carolina, United States
| | - Martha O Burford Reiskind
- Martha Burford Reiskind is an assistant professor in the Department of Biological Sciences and the director of the Genetics and Genomics Scholars program, North Carolina State University, Raleigh, North Carolina, United States
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8
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Chatting M, Hamza S, Al-Khayat J, Smyth D, Husrevoglu S, Marshall CD. Feminization of hawksbill turtle hatchlings in the twenty-first century at an important regional nesting aggregation. ENDANGER SPECIES RES 2021. [DOI: 10.3354/esr01104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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.
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Affiliation(s)
- M Chatting
- Environmental Science Center, Qatar University, Doha 2713, Qatar
| | - S Hamza
- Environmental Science Center, Qatar University, Doha 2713, Qatar
| | - J Al-Khayat
- Environmental Science Center, Qatar University, Doha 2713, Qatar
| | - D Smyth
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey LL59 5EY, UK
| | - S Husrevoglu
- Institute of Marine Sciences, Middle East Technical University, Erdemli, Mersin 33731, Turkey
| | - CD Marshall
- Department of Marine Biology, Department of Wildlife and Fisheries Sciences, Gulf Center for Sea Turtle Research, Texas A&M University, Galveston, Texas 77553, USA
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9
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Choi E, Charles KE, Charles KL, Stewart KM, Morrall CE, Dennis MM. Leatherback Sea Turtle (Dermochelys coriacea) Embryo and Hatchling Pathology in Grenada, with Comparison to St. Kitts. CHELONIAN CONSERVATION AND BIOLOGY 2020. [DOI: 10.2744/ccb-1395.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Esther Choi
- Center for Conservation Medicine and Ecosystem Health, Ross University School of Veterinary Medicine, PO Box 334, Basseterre, St. Kitts, West Indies [; ; ]
| | | | | | - Kimberly M. Stewart
- Center for Conservation Medicine and Ecosystem Health, Ross University School of Veterinary Medicine, PO Box 334, Basseterre, St. Kitts, West Indies [; ; ]
| | | | - Michelle M. Dennis
- Center for Conservation Medicine and Ecosystem Health, Ross University School of Veterinary Medicine, PO Box 334, Basseterre, St. Kitts, West Indies [; ; ]
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10
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Effects of local climate on loggerhead hatchling production in Brazil: Implications from climate change. Sci Rep 2019; 9:8861. [PMID: 31222177 PMCID: PMC6586835 DOI: 10.1038/s41598-019-45366-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 05/30/2019] [Indexed: 11/24/2022] Open
Abstract
Sea turtle eggs are heavily influenced by the environment in which they incubate, including effects on hatching success and hatchling viability (hatchling production). It is crucial to understand how the hatchling production of sea turtles is influenced by local climate and how potential changes in climate may impact future hatchling production. Generalized Additive Models were used to determine the relationship of six climatic variables at different temporal scales on loggerhead turtle (Caretta caretta) hatchling production at seventeen nesting beaches in Bahia, Espirito Santo, and Rio de Janeiro, Brazil. Using extreme and conservative climate change scenarios throughout the 21st century, potential impacts on future hatching success (the number of hatched eggs in a nest) were predicted using the climatic variable(s) that best described hatchling production at each nesting beach. Air temperature and precipitation were found to be the main drivers of hatchling production throughout Brazil. CMIP5 climate projections are for a warming of air temperature at all sites throughout the 21st century, while projections for precipitation vary regionally. The more tropical nesting beaches in Brazil, such as those in Bahia, are projected to experience declines in hatchling production, while the more temperate nesting beaches, such as those in Rio de Janeiro, are projected to experience increases in hatchling production by the end of the 21st century.
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11
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Crash in sea-turtle births stumps ecologists. Nature 2017. [DOI: 10.1038/nature.2017.22748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Rafferty AR, Johnstone CP, Garner JA, Reina RD. A 20-year investigation of declining leatherback hatching success: implications of climate variation. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170196. [PMID: 29134057 PMCID: PMC5666240 DOI: 10.1098/rsos.170196] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 09/07/2017] [Indexed: 06/07/2023]
Abstract
Unprecedented increases in air temperature and erratic precipitation patterns are predicted throughout the twenty-first century as a result of climate change. A recent global analysis of leatherback turtle hatchling output predicts that the nesting site at Sandy Point National Wildlife Refuge (SPNWR) will experience the most significant regional climate alterations. We aimed to identify how local air temperatures and precipitation patterns influenced within-nest mortality and overall hatchling output at this site between 1990 and 2010. We show that while the greatest mortality occurred during the latest stages of development (stage three), the rate of embryo mortality was highest during the initial stages (stage zero) of development (approx. 3.8 embryos per day per clutch). Increased mortality at stage three was associated with decreased precipitation and increased temperature during this developmental period, whereas precipitation prior to, and during stage zero had the greatest influence on early mortality. There was a significant decline in overall hatching success (falling from 74% to 55%) and emergence rate (calculated from the number of hatchlings that emerged from the nest as a percentage of hatched eggs) which fell from 96% to 91%. However, there was no trend observed in local temperature or precipitation during this timeframe, and neither variable was related to hatching success or emergence rate. In conclusion, our findings suggest that despite influencing within-nest mortality, climatic variability does not account for the overall decline in hatchling output at SPNWR from 1990 to 2010. Further research is therefore needed to elicit the reasons for this decline.
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Affiliation(s)
| | | | - Jeanne A. Garner
- West Indies Marine Animal Research and Conservation Service, Frederiksted, St Croix, US Virgin Islands
| | - Richard D. Reina
- School of Biological Sciences, Monash University, Melbourne, Australia
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