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Simantiris N. The impact of climate change on sea turtles: Current knowledge, scientometrics, and mitigation strategies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171354. [PMID: 38460688 DOI: 10.1016/j.scitotenv.2024.171354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/11/2024]
Abstract
Sea turtles are one of the most significant groups of marine species, playing a key role in the sustainability and conservation of marine ecosystems and the food chain. These emblematic species are threatened by several natural and anthropogenic pressures, and climate change is increasingly reported as one of the most important threats to sea turtles, affecting sea turtles at all stages of their life cycle and at both their marine and coastal habitats. The effect of climate change is expressed as global warming, sea-level rise, extreme storms, and alterations in predation and diseases' patterns, posing a potentially negative impact on sea turtles. In this systematic review, the author presented the current knowledge and research outcomes on the impact of climate change on sea turtles. Moreover, this study determined trends and hotspots in keywords, country collaborations, authors, and publications in the field through a scientometric analysis. Finally, this article reviewed proposed mitigation strategies by researchers, marine protected area (MPA) managers, and non-governmental organizations (NGOs) to reduce the impact of climate change on the conservation of sea turtles.
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Affiliation(s)
- Nikolaos Simantiris
- MEDASSET (Mediterranean Association to Save the Sea Turtles), Likavittou 1C, Athens, 10632, Greece; Ionian University, Department of Informatics, Corfu, 49132, Greece.
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Williamson SA, Hoover AL, Evans RG, Shillinger GL, Bailey H, Bruno RS, Bandimere A, Reina RD. Effects of postovipositional hypoxia and hyperoxia on leatherback turtle reproductive success and hatchling performance. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2023; 339:939-950. [PMID: 37545193 DOI: 10.1002/jez.2743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/08/2023]
Abstract
Leatherback egg clutches typically experience lower hatching success (~50%) than those of other sea turtle species (>70%). The majority of embryonic death (>50%) occurs at early stages of development, possibly because embryos fail to break preovipositional embryonic arrest after oviposition. The embryonic arrest is maintained by hypoxia in the oviduct and following oviposition increased availability of oxygen is the trigger that breaks arrest in all turtle species studied to date. We conducted an ex situ incubator experiment and an in situ hatchery experiment to examine the influence of oxygen availability on hatching success and hatchling traits in leatherbacks. After oviposition, eggs (n = 1005) were incubated in either normoxia (21% O2 ), hyperoxia (32%-42% O2 ) for 5 days, or hypoxia (1% O2 ) for 3 or 5 days. As with other turtles, hypoxic incubation maintained embryos in arrest, equivalent to the time spent in hypoxia. However, extending arrest for 5 days resulted in greater early-stage death and a significant decrease in hatching success (4% 5-day hypoxia vs. 72% normoxia). Eggs placed in incubators had greater hatching success than those placed into hatchery nests (67% vs. 47%, respectively). We found no impact of hyperoxia on the stage of embryonic death, hatching success, hatchling phenotype, exercise performance, or early dispersal. Our findings indicate that delayed nesting and the subsequent extension of embryonic arrest may negatively impact embryonic development and therefore the reproductive success of leatherbacks. They also indicate that incubation under hyperoxic conditions is unlikely to be a useful method to improve hatching success in this species.
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Affiliation(s)
- Sean A Williamson
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Aimee L Hoover
- Upwell, Monterey, California, USA
- Chesapeake Biological Laboratory, University of Maryland Centre for Environmental Science, Solomons, Maryland, USA
| | - Roger G Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia
- Preclinical Critical Care Unit, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Helen Bailey
- Chesapeake Biological Laboratory, University of Maryland Centre for Environmental Science, Solomons, Maryland, USA
| | - Renato Saragoça Bruno
- Turtle Love, Barra de Parismina, Limon, Costa Rica
- Pacuare Reserve, Ecology Project International, Limon, Costa Rica
| | | | - Richard D Reina
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
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3
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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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Unda-Díaz NM, Phillips-Farfán BV, Nava H, Lopez-Toledo L, Murata C, Lajud N, Herrera-Vargas MA, Arreola Camacho CA, Torner L, Fuentes-Farías AL, Meléndez-Herrera E. Negative Effects on Neurogenesis, Ovariogenesis, and Fitness in Sea Turtle Hatchlings Associated to ex situ Incubation Management. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.850612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sea turtle egg relocation and hatchery incubation (hereafter termed ex situ incubation) is an effective strategy to protect clutches when in situ egg incubation is not viable. Nevertheless, it negatively affects the ontogenesis of male gonads and brain areas homologous to the mammalian hippocampus, as well as body size and fitness. Thus, it is imperative to analyze the effects of ex situ incubation on other developmental aspects and extend these observations to females. This work evaluated the effect of ex situ management on neurogenesis (cell proliferation in the dorsal and medial ventricular zones, neuronal integration in the dorsomedial and medial cortices), ovary cell proliferation, body size (mass and length) and self-righting ability. Additionally, this study examined if the incubation microenvironment is different between in situ and ex situ nests and whether it could contribute to explain the biological traits. An analysis of principal components showed differences in biological variables of hatchlings between in situ and ex situ clutches, driven by contrasting temperatures and silt composition. Each biological variable was also analyzed with linear mixed models using in situ vs. ex situ clutches, abiotic variables and their interaction. Turtles from ex situ clutches showed: (1) fewer proliferating cells in the dorsal and medial ventricular zones; (2) less mature neurons in the dorsomedial and medial cortices; (3) ovaries with a lesser number of proliferating cells; (4) lower body mass and length at emergence; and (5) slower self-righting time. Together, the results suggest that ex situ incubation in hatcheries is related to a slowing down of neurogenesis, ovariogenesis, body size and self-righting ability in hatchlings. Future studies should evaluate the effect of ex situ incubation on cognitive and reproductive performance to understand the long-term consequences of altered organogenesis. These studies should also disentangle the differential contribution of egg movement, reburial, nesting environment and parental origin to development. This information would likely result in better conservation strategies for sea turtles.
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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] [MESH Headings] [Grants] [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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Abstract
AbstractOne of the largest nesting colonies of the Vulnerable loggerhead sea turtle Caretta caretta is in Cabo Verde. Here we present the first comprehensive study of loggerhead turtle nesting on the island of Maio in Cabo Verde. During 2016–2019 we monitored 38 km of undeveloped sandy beaches that have minimal artificial lighting and where all nesting on Maio takes place. We counted 4,063 nests in 2016, 5,429 in 2017, 14,364 in 2018 and 7,937 in 2019. The estimated total number of females was 1,016, 1,357, 3,591 and 1,984 in each of these years, respectively. Our findings suggest there are more loggerhead turtles nesting in Cabo Verde than previously estimated, and that this could be the species’ largest nesting subpopulation (followed by Florida, USA and Oman). The inter-annual hatching success (the proportion of eggs producing hatchlings) was 29–38% for the whole island but varied between sites. Our study of 250 clutches showed that flooding affected 38–61% and predation by crabs 40–42%, with hatching success on different beaches in the range of 1–59%. Poaching of eggs was rare (< 2% of clutches), but dogs predated 68.4% of all clutches on the beach nearest the largest human settlement. We evaluated different nest management strategies at multiple sites and estimated productivity of hatchlings (the number of hatchlings that would reach the sea for each management strategy), finding that hatcheries are not always the best option for nest management. As the beaches on Maio are relatively undisturbed, and there is a high abundance and density of turtle nests, the island should be protected as a globally important site for the conservation of the loggerhead turtle, and of coastal biodiversity more broadly.
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Abstract
Turtles and tortoises (chelonians) have been integral components of global ecosystems for about 220 million years and have played important roles in human culture for at least 400,000 years. The chelonian shell is a remarkable evolutionary adaptation, facilitating success in terrestrial, freshwater and marine ecosystems. Today, more than half of the 360 living species and 482 total taxa (species and subspecies combined) are threatened with extinction. This places chelonians among the groups with the highest extinction risk of any sizeable vertebrate group. Turtle populations are declining rapidly due to habitat loss, consumption by humans for food and traditional medicines and collection for the international pet trade. Many taxa could become extinct in this century. Here, we examine survival threats to turtles and tortoises and discuss the interventions that will be needed to prevent widespread extinction in this group in coming decades.
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García-Grajales J, Meraz-Hernando J, Arcos García J, Ramírez-Fuentes E. Influence of nest temperature on morphology of Leatherback Turtle (Dermochelys coriacea) hatchlings incubated in hatcheries in Oaxaca, Mexico. CAN J ZOOL 2021. [DOI: 10.1139/cjz-2020-0083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The influence of nest incubation temperatures on carapace shape and morphological traits of Leatherback Turtle (Dermochelys coriacea (Vandelli, 1761)) hatchlings incubated in two hatcheries in Oaxaca, Mexico, was evaluated. This study was carried out from October 2016 through May 2017. On each beach, there are community groups consisting of volunteers not affiliated with universities who protect and relocate the nests to increase hatching success. In each translocated nest, a data logger was placed in the centre of the egg mass. Hatchlings were collected as they emerged from each nest. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis; also, hatchlings were weighed and their bodies measured. The mean temperature of 12 nests in each hatchery was recorded, with no significant differences between hatcheries. The principal component analysis revealed an overlapping of the carapace shape under different temperature durations. Temperature had a significant influence on hatchling morphology. Higher mean incubation temperatures produced hatchlings with low mass, smaller appendages, narrower carapace widths, and shorter flipper lengths. Lower mean incubation temperatures produced hatchlings with greater mass, wider appendage widths, wider carapace widths, and longer flipper lengths. Results indicate that the Leatherback hatchlings incubated in hatcheries demonstrate morphology that varies in relation to nest incubation temperature in a similar way to hatchlings produced in natural environments.
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Affiliation(s)
- J. García-Grajales
- Instituto de Recursos, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
| | - J.F. Meraz-Hernando
- Instituto de Recursos, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
| | - J.L. Arcos García
- Instituto de Industrias, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
| | - E. Ramírez-Fuentes
- Instituto de Recursos, Univesidad del Mar, Km. 2.5, Carretera Federal Puerto Escondido – Sola de Vega, Puerto Escondido 71980, Oaxaca, México
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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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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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Incubation and water temperatures influence the performances of loggerhead sea turtle hatchlings during the dispersal phase. Sci Rep 2018; 8:11911. [PMID: 30093615 PMCID: PMC6085310 DOI: 10.1038/s41598-018-30347-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 07/24/2018] [Indexed: 11/13/2022] Open
Abstract
Artificial manipulation of incubation temperature has been proposed as a potential strategy for mitigating the effects of climate change on sea turtles for which sex determination is temperature-dependent, but thermal manipulation may also affect hatchling survival. Here, we demonstrated that incubation and water temperatures influenced several performance traits that contribute to the survival of loggerhead sea turtles (Caretta caretta) during the post-hatchling dispersal phase. Hatchlings from warm incubation temperatures (31 °C) had significantly shorter incubation periods, higher initial swimming performance, lower sustained swimming performance, and lower growth rates during the first three weeks post-hatching, as well as higher blood glucose concentrations, than those from cool incubation temperatures (27.5 °C). Hatchlings in warm water temperatures (30 °C) exhibited significantly greater swimming performance than those in cool water temperatures (27 °C). Our results indicated that altering incubation temperatures indirectly influences the survival of loggerhead hatchlings by modifying their swimming performance and growth rates, which may affect hatchling predator-avoidance capability. Moreover, thermal manipulation may alter the incubation period, exposing hatchling to water temperatures that they would not otherwise normally experience, which may affect swimming performance. Our results suggest that such conservation strategies may influence their survival, and thus should be carefully considered.
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Fuentes MM, Monsinjon J, Lopez M, Lara P, Santos A, dei Marcovaldi MA, Girondot M. Sex ratio estimates for species with temperature-dependent sex determination differ according to the proxy used. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2017.09.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Santidrián Tomillo P, Saba VS, Lombard CD, Valiulis JM, Robinson NJ, Paladino FV, Spotila JR, Fernández C, Rivas ML, Tucek J, Nel R, Oro D. Global analysis of the effect of local climate on the hatchling output of leatherback turtles. Sci Rep 2015; 5:16789. [PMID: 26572897 PMCID: PMC4648107 DOI: 10.1038/srep16789] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 10/12/2015] [Indexed: 11/16/2022] Open
Abstract
The most recent climate change projections show a global increase in temperatures along with precipitation changes throughout the 21st century. However, regional projections do not always match global projections and species with global distributions may exhibit varying regional susceptibility to climate change. Here we show the effect of local climatic conditions on the hatchling output of leatherback turtles (Dermochelys coriacea) at four nesting sites encompassing the Pacific, Atlantic and Indian Oceans. We found a heterogeneous effect of climate. Hatchling output increased with long-term precipitation in areas with dry climatic conditions (Playa Grande, Pacific Ocean and Sandy Point, Caribbean Sea), but the effect varied in areas where precipitation was high (Pacuare, Caribbean Sea) and was not detected at the temperate site (Maputaland, Indian Ocean). High air temperature reduced hatchling output only at the area experiencing seasonal droughts (Playa Grande). Climatic projections showed a drastic increase in air temperature and a mild decrease in precipitation at all sites by 2100. The most unfavorable conditions were projected for Sandy Point where hatching success has already declined over time along with precipitation levels. The heterogeneous effect of climate may lead to local extinctions of leatherback turtles in some areas but survival in others by 2100.
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Affiliation(s)
- Pilar Santidrián Tomillo
- Population Ecology Group, Institut Mediterrani d' Estudis Avançats, IMEDEA (CSIC-UIB), Miquel Marquès, 21, 07190, Esporles, Mallorca, Spain
| | - Vincent S Saba
- National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center, c/o Geophysical Fluid Dynamics Laboratory, 201 Forrestal Road, Princeton University Forrestal Campus, Princeton, New Jersey, USA
| | | | | | - Nathan J Robinson
- Department of Biology, Indiana-Purdue University, Fort Wayne, Indiana, USA
| | - Frank V Paladino
- Department of Biology, Indiana-Purdue University, Fort Wayne, Indiana, USA
| | - James R Spotila
- Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, Pennsylvania, USA
| | | | - Marga L Rivas
- Universidad de Granada, Campus Fuentenueva s/n, Granada, Spain
| | - Jenny Tucek
- Department of Zoology, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa
| | - Ronel Nel
- Department of Zoology, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa
| | - Daniel Oro
- Population Ecology Group, Institut Mediterrani d' Estudis Avançats, IMEDEA (CSIC-UIB), Miquel Marquès, 21, 07190, Esporles, Mallorca, Spain
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14
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Santidrián Tomillo P, Genovart M, Paladino FV, Spotila JR, Oro D. Climate change overruns resilience conferred by temperature-dependent sex determination in sea turtles and threatens their survival. GLOBAL CHANGE BIOLOGY 2015; 21:2980-8. [PMID: 25929883 DOI: 10.1111/gcb.12918] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/06/2015] [Accepted: 02/18/2015] [Indexed: 05/15/2023]
Abstract
Temperature-dependent sex determination (TSD) is the predominant form of environmental sex determination (ESD) in reptiles, but the adaptive significance of TSD in this group remains unclear. Additionally, the viability of species with TSD may be compromised as climate gets warmer. We simulated population responses in a turtle with TSD to increasing nest temperatures and compared the results to those of a virtual population with genotypic sex determination (GSD) and fixed sex ratios. Then, we assessed the effectiveness of TSD as a mechanism to maintain populations under climate change scenarios. TSD populations were more resilient to increased nest temperatures and mitigated the negative effects of high temperatures by increasing production of female offspring and therefore, future fecundity. That buffered the negative effect of temperature on the population growth. TSD provides an evolutionary advantage to sea turtles. However, this mechanism was only effective over a range of temperatures and will become inefficient as temperatures rise to levels projected by current climate change models. Projected global warming threatens survival of sea turtles, and the IPCC high gas concentration scenario may result in extirpation of the studied population in 50 years.
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Affiliation(s)
- Pilar Santidrián Tomillo
- Population Ecology Group, Institut Mediterrani d' Estudis Avançats, IMEDEA (CSIC-UIB), Miquel Marquès, 21, 07190, Esporles, Mallorca, Spain
- The Leatherback Trust, Goldring-Gund Marine Biology Station, Playa Grande, Costa Rica
| | - Meritxell Genovart
- Population Ecology Group, Institut Mediterrani d' Estudis Avançats, IMEDEA (CSIC-UIB), Miquel Marquès, 21, 07190, Esporles, Mallorca, Spain
| | - Frank V Paladino
- The Leatherback Trust, Goldring-Gund Marine Biology Station, Playa Grande, Costa Rica
- Department of Biology, Indiana-Purdue University, Fort Wayne, 46805, IN, USA
| | - James R Spotila
- The Leatherback Trust, Goldring-Gund Marine Biology Station, Playa Grande, Costa Rica
- Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, 19104, PA, USA
| | - Daniel Oro
- Population Ecology Group, Institut Mediterrani d' Estudis Avançats, IMEDEA (CSIC-UIB), Miquel Marquès, 21, 07190, Esporles, Mallorca, Spain
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15
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Santidrián Tomillo P, Saba VS, Blanco GS, Stock CA, Paladino FV, Spotila JR. Climate driven egg and hatchling mortality threatens survival of eastern Pacific leatherback turtles. PLoS One 2012; 7:e37602. [PMID: 22649544 PMCID: PMC3359293 DOI: 10.1371/journal.pone.0037602] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Accepted: 04/23/2012] [Indexed: 11/19/2022] Open
Abstract
Egg-burying reptiles need relatively stable temperature and humidity in the substrate surrounding their eggs for successful development and hatchling emergence. Here we show that egg and hatchling mortality of leatherback turtles (Dermochelys coriacea) in northwest Costa Rica were affected by climatic variability (precipitation and air temperature) driven by the El Niño Southern Oscillation (ENSO). Drier and warmer conditions associated with El Niño increased egg and hatchling mortality. The fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC) projects a warming and drying in Central America and other regions of the World, under the SRES A2 development scenario. Using projections from an ensemble of global climate models contributed to the IPCC report, we project that egg and hatchling survival will rapidly decline in the region over the next 100 years by ∼50–60%, due to warming and drying in northwestern Costa Rica, threatening the survival of leatherback turtles. Warming and drying trends may also threaten the survival of sea turtles in other areas affected by similar climate changes.
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