Date

2017-10-11

Author

Oğul, Fatıma Nur

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As ancient species, living sea turtles history laid back to 110 milion years. There are seven sea turtle species occupying different niches among the Earth’s oceans. There are two species of sea turtles breeding in the Mediterranean Sea; loggerhead turtle; Caretta caretta, green turtle; Chelonia mydas. The Mediterranean subpopulations of green and loggerhead turtle are in IUCN Red list and categorized as critically endangered and least concern respectively. The first step to protect these species is learning more of their biology and ecology. Although there are many studies conducted on ecology and conservation of sea turtles, application of new technologies to sea turtle monitoring and understanding sea turtle population genetics at finer spatial scales are still needed. At the base of this concern the aim this thesis was; understanding the sea turtle populations’ genetic structure and testing a new monitoring method on sea turtle hatchlings emergence behavior at the eastern Mediterranean, that are explained under two chapters respectively. In the first chapter, to understand the genetic structure of sea turtle populations in the Eastern Mediterranean, a nuclear DNA intron marker (R35: RNA Fingerprint Protein) and a mitochondrial DNA marker (COI) were used for sea turtle populations. Samples were collected from Antalya-Belek, Mersin-Erdemli, Hatay-Samandağ and Northern Cyprus from loggerhead, green turtle and softsheled Nile turtle as an out group. A non-invasive sampling method was used that based on sampling muscle and dermal tissues from dead hatchlings. The results were compared with the database samples to understand relationships between them. In the present study, 115 haplotypes were revealed from 240 sequences with 50 and 54 private haplotypes for loggerhead and green turtle respectively. The highest amount of polymorphism and haplotype observed among Mersin (METU Erdemli Campus) loggerhead turtle population. According to gene flow (Nm) and genetic differentiation (Fst) estimations eastern Mediterranean green turtle populations grouped as Antalya and Hatay/Mersin/North Cyprus nesting colonies while loggerhead turtle grouped as Mersin/Antalya and North Cyprus. Furthermore, in total 30 hybrid individuals detected from Antalya and Mersin samples, as the result of interbreeding between female loggerhead and male green turtle. Additionally, multiple paternity observed on 9 loggerhead turtle nests among hybridization events with at least two males; one is loggerhead, one is green turtle. In the second chapter, to understand the emergence patterns and behavior of hatchlings, IR cameras were installed on one green and four loggerhead turtle nests located in METU Erdemli Campus during 2014 and 2015 nesting season. Hatchling emergences were recorded continuously and analyzed temporal pattern, incubation duration and group emergence pattern accordingly. According to results; hatchlings emerged from the nests asynchronously in varying numbers of groups and different group sizes. 98.6% of hatchlings emerged during night with a peak activity between 21:00 and 00:00. Total emergence activity continued at least 60-65 days after the egg deposition and 1-22 days and after the first emergence. The present study provides a better understanding of genetic structure of eastern Mediterranean sea turtle populations. According to the study each nesting beach should be considered as different management units in the eastern Mediterranean. Furthermore, even small beaches such as METU Erdemli Campus beach, may have significant contribution into the metapopulations in varied ways. On the other hand implementation of IR camera provided accurate and extensive information about hatchling behavior. IR camera is a promising complementary tool which will facilitate a better management policy along restricted areas such as METU Erdemli Campus.

Subject Keywords

Chelonia mydas, Caretta caretta, Population Genetic, Conservation, IR camera

URI

https://hdl.handle.net/11511/95090

Collections

Graduate School of Marine Sciences, Thesis