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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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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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Rowe CL, Liang D, Woodland RJ. Effects of constant and fluctuating incubation temperatures on hatching success and hatchling traits in the diamondback terrapin (Malaclemys terrapin) in the context of the warming climate. J Therm Biol 2020; 88:102528. [PMID: 32126003 DOI: 10.1016/j.jtherbio.2020.102528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 10/25/2022]
Abstract
As global temperatures continue to rise, so too will the nest temperatures of many species of turtles. Yet for most turtle species, including the estuarine diamondback terrapin (Malaclemys terrapin), there is limited information on embryonic sensitivity to elevated temperature. We incubated eggs of M. terrapin at three, mean temperatures (31, 34, 37 °C) under two thermal exposure regimes (constant or semi-naturally fluctuating temperature) and measured hatching success, developmental rate, and hatchling size. Hatching success was 100% at 31 °C and 67% at 34 °C, respectively; at 37 °C, all eggs failed early in the incubation period. These values were unaffected by exposure regime. The modeled LT50 (temperature that was lethal to 50% of the test population) was 34.0 °C in the constant and 34.2 °C in the fluctuating thermal regime, reflecting a steep decline in survival between 33 and 35 °C. Hatchlings having been incubated at a constant 34 °C hatched sooner than those incubated at 31 °C under either constant or fluctuating temperature. Hatchlings were smaller in straight carapace length (CL) and width after having been incubated at 34 °C compared to 31 °C. Larger (CL) hatchlings resulted from fluctuating temperature conditions relative to constant temperature conditions, regardless of mean temperature. Based upon recent temperatures in natural nests, the M. terrapin population studied here appears to possess resiliency to several degrees of elevated mean nest temperatures, beyond which, embryonic mortality will likely sharply increase. When considered within the mosaic of challenges that Maryland's M. terrapin face as the climate warms, including ongoing habitat losses due to sea level rise and impending thermal impacts on bioenergetics and offspring sex ratios, a future increase in embryonic mortality could be a critical factor for a population already experiencing ecological and physiological challenges due to climate change.
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Affiliation(s)
- Christopher L Rowe
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, 146 Williams Street, P.O. Box 38, Solomons, MD, 20688, USA.
| | - Dong Liang
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, 146 Williams Street, P.O. Box 38, Solomons, MD, 20688, USA
| | - Ryan J Woodland
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, 146 Williams Street, P.O. Box 38, Solomons, MD, 20688, USA
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Fleming KA, Perrault JR, Stacy NI, Coppenrath CM, Gainsbury AM. Heat, health and hatchlings: associations of in situ nest temperatures with morphological and physiological characteristics of loggerhead sea turtle hatchlings from Florida. CONSERVATION PHYSIOLOGY 2020; 8:coaa046. [PMID: 32523697 PMCID: PMC7269062 DOI: 10.1093/conphys/coaa046] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/05/2020] [Accepted: 05/06/2020] [Indexed: 05/20/2023]
Abstract
Incubation temperatures, in addition to an embryo's genetic makeup, are critical in many aspects of adequate sea turtle embryonic development. The effects of high and low incubation temperatures on hatchling quality have been previously examined; however, many of these studies were conducted on relocated or laboratory-reared nests, which do not accurately reflect natural nest temperature fluctuations. To observe the impacts of varying in situ incubation temperatures on loggerhead sea turtle (Caretta caretta) hatchling morphology, various health variables and locomotor performance, temperature data loggers were deployed in 15 loggerhead nests on Juno Beach, Florida, between May and July 2018. Over the course of the study period, 10 morphological traits were measured, blood analytes and heart rate were assessed for the establishment of reference intervals and the self-righting response in seawater was evaluated. Warmer months were associated with smaller body size and higher body condition index, larger umbilical scar size, slower righting time, lower heart rates and higher packed cell volume, hemoglobin, total solids, total white blood cell count, absolute heterophils and absolute basophils. These findings provide evidence that higher in situ incubation temperatures have the potential to adversely affect hatchlings from warmer nests due to increased risk of predation from smaller body sizes, decreased physical responses and overall fitness, altered hemodynamic balance (e.g. dehydration) and potential inflammation and/or stress. With rising temperatures, we predict sea turtle hatchlings may have increasing risks of developing suboptimal physiological features affecting overall fitness and ultimately survival. These results demonstrate that rising environmental temperatures can negatively impact sea turtle hatchlings, thus representing additional stress on sea turtle populations and contributing to our understanding of potential pathophysiological effects of climate change on the delicate life-stage class of the sea turtle hatchling. This information will be useful for formulating effective future sea turtle management plans.
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Affiliation(s)
- Kelsey A Fleming
- Department of Biological Sciences, University of South Florida St. Petersburg, St. Petersburg, FL 33701, USA
| | | | - Nicole I Stacy
- Aquatic, Amphibian, and Reptile Pathology Program, Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32608, USA
| | | | - Alison M Gainsbury
- Department of Biological Sciences, University of South Florida St. Petersburg, St. Petersburg, FL 33701, USA
- Corresponding author: Department of Biological Sciences, University of South Florida St. Petersburg, St. Petersburg, FL 33701, USA.
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Usategui-Martín A, Liria-Loza A, Miller JD, Medina-Suárez M, Jiménez-Bordón S, Pérez-Mellado V, Montero D. Effects of incubation temperature on hatchling performance and phenotype in loggerhead sea turtle Caretta caretta. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00935] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Duncan EM, Arrowsmith J, Bain C, Broderick AC, Lee J, Metcalfe K, Pikesley SK, Snape RTE, van Sebille E, Godley BJ. The true depth of the Mediterranean plastic problem: Extreme microplastic pollution on marine turtle nesting beaches in Cyprus. MARINE POLLUTION BULLETIN 2018; 136:334-340. [PMID: 30509815 DOI: 10.1016/j.marpolbul.2018.09.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/10/2018] [Accepted: 09/11/2018] [Indexed: 05/29/2023]
Abstract
We sampled 17 nesting sites for loggerhead (Caretta caretta) and green turtles (Chelonia mydas) in Cyprus. Microplastics (<5 mm) were found at all locations and depths, with particularly high abundance in superficial sand. The top 2 cm of sand presented grand mean ± SD particle counts of 45,497 ± 11,456 particles m-3 (range 637-131,939 particles m-3). The most polluted beaches were among the worst thus far recorded, presenting levels approaching those previously recorded in Guangdong, South China. Microplastics decreased with increasing sand depth but were present down to turtle nest depths of 60 cm (mean 5,325 ± 3,663 particles m-3. Composition varied among beaches but hard fragments (46.5 ± 3.5%) and pre-production nurdles (47.8 ± 4.5%) comprised most categorised pieces. Particle drifter analysis hindcast for 365 days indicated that most plastic likely originated from the eastern Mediterranean basin. Worsening microplastic abundance could result in anthropogenically altered life history parameters such as hatching success and sex ratios in marine turtles.
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Affiliation(s)
- Emily M Duncan
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK; Marine Ecology and Biodiversity, Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth, UK
| | - Jessica Arrowsmith
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Charlotte Bain
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Annette C Broderick
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Jonathon Lee
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Kristian Metcalfe
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Stephen K Pikesley
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK
| | - Robin T E Snape
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK; Society for Protection of Turtles, PK 42, Mersin 10, Turkey
| | - Erik van Sebille
- Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands.
| | - Brendan J Godley
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall, UK.
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Affiliation(s)
- David T. BOOTH
- School of Biological Sciences; The University of Queensland; St Lucia Queensland Australia
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Rees AF, Alfaro-Shigueto J, Barata PCR, Bjorndal KA, Bolten AB, Bourjea J, Broderick AC, Campbell LM, Cardona L, Carreras C, Casale P, Ceriani SA, Dutton PH, Eguchi T, Formia A, Fuentes MMPB, Fuller WJ, Girondot M, Godfrey MH, Hamann M, Hart KM, Hays GC, Hochscheid S, Kaska Y, Jensen MP, Mangel JC, Mortimer JA, Naro-Maciel E, Ng CKY, Nichols WJ, Phillott AD, Reina RD, Revuelta O, Schofield G, Seminoff JA, Shanker K, Tomás J, van de Merwe JP, Van Houtan KS, Vander Zanden HB, Wallace BP, Wedemeyer-Strombel KR, Work TM, Godley BJ. Are we working towards global research priorities for management and conservation of sea turtles? ENDANGER SPECIES RES 2016. [DOI: 10.3354/esr00801] [Citation(s) in RCA: 175] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Male hatchling production in sea turtles from one of the world's largest marine protected areas, the Chagos Archipelago. Sci Rep 2016; 6:20339. [PMID: 26832230 PMCID: PMC4735811 DOI: 10.1038/srep20339] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 12/30/2015] [Indexed: 11/08/2022] Open
Abstract
Sand temperatures at nest depths and implications for hatchling sex ratios of hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) nesting in the Chagos Archipelago, Indian Ocean are reported and compared to similar measurements at rookeries in the Atlantic and Caribbean. During 2012–2014, temperature loggers were buried at depths and in beach zones representative of turtle nesting sites. Data collected for 12,546 days revealed seasonal and spatial patterns of sand temperature. Depth effects were minimal, perhaps modulated by shade from vegetation. Coolest and warmest temperatures were recorded in the sites heavily shaded in vegetation during the austral winter and in sites partially shaded in vegetation during summer respectively. Overall, sand temperatures were relatively cool during the nesting seasons of both species which would likely produce fairly balanced hatchling sex ratios of 53% and 63% male hatchlings, respectively, for hawksbill and green turtles. This result contrasts with the predominantly high female skew reported for offspring at most rookeries around the globe and highlights how local beach characteristics can drive incubation temperatures. Our evidence suggests that sites characterized by heavy shade associated with intact natural vegetation are likely to provide conditions suitable for male hatchling production in a warming world.
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Treidel LA, Carter AW, Bowden RM. Temperature experienced during incubation affects antioxidant capacity but not oxidative damage in hatchling red-eared slider turtles (Trachemys scripta elegans). J Exp Biol 2015; 219:561-70. [DOI: 10.1242/jeb.128843] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/01/2015] [Indexed: 11/20/2022]
Abstract
Our understanding of how oxidative stress resistance phenotypes are affected by the developmental environment is limited. One component of the developmental environment, which is likely central to early life oxidative stress among ectothermic and oviparous species, is that of temperature. We investigated how incubation temperature manipulations affect oxidative damage and total antioxidant capacity (TAC) in red-eared slider turtle (Trachemys scripta elegans) hatchlings. First, to determine if temperature fluctuations elicit oxidative stress, eggs from clutches were randomly assigned to either a constant (29.5°C) or daily fluctuating temperature incubation (28.7±3°C) treatment. Second, to assess the effect of temperature fluctuation frequency on oxidative stress, eggs were incubated in one of three fluctuating incubation regimes; 28.7±3°C fluctuations every 12 (Hyper), 24 (Normal), or 48 hours (Hypo). Third, we tested the influence of average incubation temperature by incubating eggs in a daily fluctuating incubation temperature regime with a mean temperature of 26.5°C (Low), 27.1°C (Medium), or 27.7°C (High). Although the accumulation of oxidative damage in hatchlings was unaffected by any thermal manipulation, TAC was affected by both temperature fluctuation frequency and average incubation temperature. Individuals incubated with a low frequency of temperature fluctuations had reduced TAC, while incubation at a lower average temperature was associated with enhanced TAC. These results indicate that while sufficient to prevent oxidative damage, TAC is influenced by developmental thermal environments, potentially due to temperature mediated changes in metabolic rate. The observed differences in TAC may have important future consequences for hatchling fitness and overwinter survival.
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Affiliation(s)
- L. A. Treidel
- School of Biological Sciences, Illinois State University Normal IL, 61761, USA
| | - A. W. Carter
- School of Biological Sciences, Illinois State University Normal IL, 61761, USA
| | - R. M. Bowden
- School of Biological Sciences, Illinois State University Normal IL, 61761, USA
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