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Gammon M, Fossette S, McGrath G, Mitchell N. A Systematic Review of Metabolic Heat in Sea Turtle Nests and Methods to Model Its Impact on Hatching Success. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.556379] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Sönmez B. Relationship between Metabolic Heating and Nest Parameters in Green Turtles (Chelonia mydas, L. 1758) on Samandağ Beach, Turkey. Zoolog Sci 2018; 35:243-248. [PMID: 29882496 DOI: 10.2108/zs180003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Acquiring information about metabolic heating is necessary for the improved understanding of nesting beaches. However, there are limited studies on metabolic heating of green turtle (Chelonia mydas, L. 1758) on Mediterranean beaches. The present study sought to determine the metabolic heating, and its effect on the feminization of green turtle hatchlings during 2016 and 2017 nesting season on Samandağ Beach, Hatay, Turkey. Moreover, the relations between metabolic heating and nest parameters, and spatio-temporal differences of metabolic heating were evaluated. Nest temperatures were recorded by using data loggers placed at the center of nests (n = 18), and the same depth was used to determine the sand temperature that was 50 cm back of the egg chamber. The mean incubation duration was calculated as 51.1 days, and the mean distance of nests from sea and the mean nest depth were measured as 32.4 meters and 67.70 cm, respectively. The mean numbers of embryo that is early, middle and late embryonic stages were found as 110.8, 93.2 and 93.05, respectively. The mean clutch size was found as 110.8. Mean metabolic heating was 0.37°C in the middle third of incubation for both years. The metabolic heating in both years was close to the as reported in the other green turtles nesting beaches in the Mediterranean. The feminization effect of metabolic heating was calculated as 6.8% in the green turtle nests on Samandağ Beach. Metabolic heating did not vary spatially, and the clutch size was the most important factor in metabolic heating and explained a large proportion of the variation in metabolic heating.
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Affiliation(s)
- Bektaş Sönmez
- Cumhuriyet University, Suşehri Timur Karabal Vocational Training School, 58600, Suşehri, Sivas, Turkey
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Rees ALF, Carreras C, Broderick AC, Margaritoulis D, Stringell TB, Godley BJ. Linking loggerhead locations: using multiple methods to determine the origin of sea turtles in feeding grounds. MARINE BIOLOGY 2017; 164:30. [PMID: 28133395 PMCID: PMC5236075 DOI: 10.1007/s00227-016-3055-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 12/05/2016] [Indexed: 06/06/2023]
Abstract
Many marine megavertebrate taxa, including sea turtles, disperse widely from their hatching or birthing locations but display natal homing as adults. We used flipper tagging, satellite tracking and genetics to identify the origin of loggerhead turtles living in Amvrakikos Gulf, Greece. This location has been identified as hosting regionally important numbers of large-juvenile to adult sized turtles that display long-term residency and/or association to the area, and also presents a male biased sex ratio for adults. A total of 20 individuals were linked to nesting areas in Greece through flipper tagging and satellite telemetry, with the majority (16) associated with Zakynthos Island. One additional female was tracked from Amvrakikos Gulf to Turkey where she likely nested. Mitochondrial DNA mixed stock analyses of turtles captured in Amvrakikos Gulf (n = 95) indicated 82% of individuals originated from Greek nesting stocks, mainly from Zakynthos Island (63%), with lesser contributions from central Turkey, Cyprus and Libya. These results suggest that the male-biased sex ratio found in Amvrakikos Gulf may be driven by the fact that males breed twice as frequently on Zakynthos, resulting in their using foraging grounds of greater proximity to the breeding site. Conservation measures in localised foraging habitats for the protection of marine vertebrates, such as sea turtles, may have positive impacts on several disparate breeding stocks and the use of multiple methods to determine source populations can indicate the relative effectiveness of these measures.
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Affiliation(s)
- ALan F. Rees
- ARCHELON, the Sea Turtle Protection Society of Greece, Solomou 57, 104 32 Athens, Greece
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE UK
| | - Carlos Carreras
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE UK
- Department of Genetics, Microbiology and Statistics and IRBio, University of Barcelona, Av.Diagonal 643, 08028 Barcelona, Spain
| | - Annette C. Broderick
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE UK
| | - Dimitris Margaritoulis
- ARCHELON, the Sea Turtle Protection Society of Greece, Solomou 57, 104 32 Athens, Greece
| | - Thomas B. Stringell
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE UK
| | - Brendan J. Godley
- Marine Turtle Research Group, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE UK
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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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Önder BF, Candan O. The feminizing effect of metabolic heating in Green Turtle (Chelonia mydas) clutches in the eastern Mediterranean. ZOOLOGY IN THE MIDDLE EAST 2016. [DOI: 10.1080/09397140.2016.1202927] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Betül F. Önder
- Department of Biology, Faculty of Arts and Science, Ordu University, Ordu, Turkey
| | - Onur Candan
- Department of Biology, Faculty of Arts and Science, Ordu University, Ordu, Turkey
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Candan O, Kolankaya D. Sex Ratio of Green Turtle (Chelonia mydas) Hatchlings at Sugözü, Turkey: Higher Accuracy with Pivotal Incubation Duration. CHELONIAN CONSERVATION AND BIOLOGY 2016. [DOI: 10.2744/ccb-1132.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Sarı F, Kaska Y. Loggerhead sea turtle hatchling sex ratio differences between two nesting beaches in Turkey. Isr J Ecol Evol 2015. [DOI: 10.1080/15659801.2015.1047681] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Hatchling sex ratios of loggerhead sea turtles (Caretta caretta) were estimated on two main nesting beaches (Dalyan Beach and Göksu Delta) in Turkey using three methods: nest temperature, incubation period and gonad histology. The electronic temperature recorders were placed in 35 selected nests. The mean nest temperature in the middle third of the incubation period was calculated as 29.5 °C on Dalyan Beach and as 31 °C on Göksu Delta. Incubation periods on Dalyan Beach and Göksu Delta were found as 52.9 days and 50.4 days, respectively. Gonad histology method was used only on Dalyan Beach and it was determined that 235 (55.6%) hatchlings were female out of 423 histologically examined hatchlings. Using nest temperatures and incubation periods, sex ratios on Dalyan Beach were estimated as 61% and 69.3%, and on Göksu Delta as 81% and 73.1%, respectively. In light of our sex ratio results, Dalyan Beach has a relatively high proportion of male hatchlings possibly due to its relatively western location. Our findings indicate that Dalyan Beach is an important nesting beach for loggerhead sea turtles in the eastern Mediterranean not only in terms of nest numbers and hatching success but also for its high proportion of male hatchlings. As for the methods used in this study, for further studies, we can suggest that nest temperature method provides the most accurate sex ratio result compared with incubation period and gonad histology methods, if temperature-recorded nests are selected in a manner of representing temporal distribution of the total nests on study beach.
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