Sex Ratio Estimation of Green Turtle Hatchlings in Kazanlı Beach, Türkiye

Onur Candan

Article Details

Sex Ratio Estimation of Green Turtle Hatchlings in Kazanlı Beach, Türkiye

Authors:

Onur Candan

Publisher:

Bitlis Eren University

Main Topics:

Animal Developmental and Reproductive Biology

Journal:

Bitlis Eren Üniversitesi Fen Bilimleri Dergisi Vol.12 Issue 4, pp.1310-1318

Document Type:

Article

Publication Date:

12/2023

Document Language:

English

Document ID (Org No.):

2001306401

pISSN:

2147-3129

Keywords:

Abstract:

 Sea turtles are distributed worldwide, mostly in the tropical and subtropical waters. All seven species of sea turtles in the world have temperature-dependent sex determination. The pivotal temperature for hatchlings with a female:male ratio of 1:1 is usually around 29C. Female hatchlings are observed at values higher than the pivotal temperature and male hatchlings at lower values. It is expected that wildlife threatened by global warming will be more severely affected, especially species that sex is determined by temperature. This study was carried out by measuring air, sand and nest temperatures during two nesting seasons at Kazanlı Beach, one of the largest nesting sites of Chelonia mydas Green turtle in the Mediterranean. Sand grain size was also measured, and gonads of dead hatchlings were examined histologically. Both sand n4 and nest n6 temperatures were above the pivotal temperature between 29.1-31.6C in the study area. According to the estimation based on temperatures, hatchlings were female 50 biased. Of the hatchling samples, 75 were examined histologically. According to histological examination, the female:male ratio was 2:1. According to the direct examination and indirect estimation; the sex ratio of green turtle hatchlings in Kazanlı Beach, one of the highest hatchling producing nesting sites of the Mediterranean, was reported for the first time in this study. There is a need to fill the data gaps regarding sex ratios, especially for major beaches with high hatchling production. Knowing the temperature profiles in and around the nest and sex ratios of hatchlings is critical for the development of conservation measures for endangered sea turtles.

 Sea turtles are distributed worldwide, mostly in the tropical and subtropical waters. All seven species of sea turtles in the world have temperature-dependent sex determination. The pivotal temperature for hatchlings with a female:male ratio of 1:1 is usually around 29C. Female hatchlings are observed at values higher than the pivotal temperature and male hatchlings at lower values. It is expected that wildlife threatened by global warming will be more severely affected, especially species that sex is determined by temperature. This study was carried out by measuring air, sand and nest temperatures during two nesting seasons at Kazanlı Beach, one of the largest nesting sites of Chelonia mydas Green turtle in the Mediterranean. Sand grain size was also measured, and gonads of dead hatchlings were examined histologically. Both sand n4 and nest n6 temperatures were above the pivotal temperature between 29.1-31.6C in the study area. According to the estimation based on temperatures, hatchlings were female 50 biased. Of the hatchling samples, 75 were examined histologically. According to histological examination, the female:male ratio was 2:1. According to the direct examination and indirect estimation; the sex ratio of green turtle hatchlings in Kazanlı Beach, one of the highest hatchling producing nesting sites of the Mediterranean, was reported for the first time in this study. There is a need to fill the data gaps regarding sex ratios, especially for major beaches with high hatchling production. Knowing the temperature profiles in and around the nest and sex ratios of hatchlings is critical for the development of conservation measures for endangered sea turtles.

 Sea turtles are distributed worldwide, mostly in the tropical and subtropical waters. All seven species of sea turtles in the world have temperature-dependent sex determination. The pivotal temperature for hatchlings with a female:male ratio of 1:1 is usually around 29C. Female hatchlings are observed at values higher than the pivotal temperature and male hatchlings at lower values. It is expected that wildlife threatened by global warming will be more severely affected, especially species that sex is determined by temperature. This study was carried out by measuring air, sand and nest temperatures during two nesting seasons at Kazanlı Beach, one of the largest nesting sites of Chelonia mydas Green turtle in the Mediterranean. Sand grain size was also measured, and gonads of dead hatchlings were examined histologically. Both sand n4 and nest n6 temperatures were above the pivotal temperature between 29.1-31.6C in the study area. According to the estimation based on temperatures, hatchlings were female 50 biased. Of the hatchling samples, 75 were examined histologically. According to histological examination, the female:male ratio was 2:1. According to the direct examination and indirect estimation; the sex ratio of green turtle hatchlings in Kazanlı Beach, one of the highest hatchling producing nesting sites of the Mediterranean, was reported for the first time in this study. There is a need to fill the data gaps regarding sex ratios, especially for major beaches with high hatchling production. Knowing the temperature profiles in and around the nest and sex ratios of hatchlings is critical for the development of conservation measures for endangered sea turtles.

 Sea turtles are distributed worldwide, mostly in the tropical and subtropical waters. All seven species of sea turtles in the world have temperature-dependent sex determination. The pivotal temperature for hatchlings with a female:male ratio of 1:1 is usually around 29C. Female hatchlings are observed at values higher than the pivotal temperature and male hatchlings at lower values. It is expected that wildlife threatened by global warming will be more severely affected, especially species that sex is determined by temperature. This study was carried out by measuring air, sand and nest temperatures during two nesting seasons at Kazanlı Beach, one of the largest nesting sites of Chelonia mydas Green turtle in the Mediterranean. Sand grain size was also measured, and gonads of dead hatchlings were examined histologically. Both sand n4 and nest n6 temperatures were above the pivotal temperature between 29.1-31.6C in the study area. According to the estimation based on temperatures, hatchlings were female 50 biased. Of the hatchling samples, 75 were examined histologically. According to histological examination, the female:male ratio was 2:1. According to the direct examination and indirect estimation; the sex ratio of green turtle hatchlings in Kazanlı Beach, one of the highest hatchling producing nesting sites of the Mediterranean, was reported for the first time in this study. There is a need to fill the data gaps regarding sex ratios, especially for major beaches with high hatchling production. Knowing the temperature profiles in and around the nest and sex ratios of hatchlings is critical for the development of conservation measures for endangered sea turtles.

Article Details

Sex Ratio Estimation of Green Turtle Hatchlings in Kazanlı Beach, Türkiye

Authors:

Onur Candan

Publisher:

Bitlis Eren University

Main Topics:

Animal Developmental and Reproductive Biology

Journal:

Bitlis Eren Üniversitesi Fen Bilimleri Dergisi Vol.12 Issue 4, pp.1310-1318

Document Type:

Article

Publication Date:

12/2023

Document Language:

English

Document ID (Org No.):

2001306401

pISSN:

2147-3129

Chelonia mydas

Mediterranean Sea

Temperature-dependent sex determination

Thermal profiles

Sex ratio

Gonadal Histology

Issues

Article Details

Sex Ratio Estimation of Green Turtle Hatchlings in Kazanlı Beach, Türkiye

Authors: Onur Candan

Publisher: Bitlis Eren University

Main Topics: Animal Developmental and Reproductive Biology

Journal: Bitlis Eren Üniversitesi Fen Bilimleri Dergisi Vol.12 Issue 4, pp.1310-1318

Document Type: Article

Publication Date: 12/2023

Document Language: English

Document ID (Org No.): 2001306401

pISSN: 2147-3129

Chelonia mydas

Mediterranean Sea

Temperature-dependent sex determination

Thermal profiles

Sex ratio

Gonadal Histology

Issues

Authors:

Onur Candan

Publisher:

Bitlis Eren University

Main Topics:

Animal Developmental and Reproductive Biology

Journal:

Bitlis Eren Üniversitesi Fen Bilimleri Dergisi Vol.12 Issue 4, pp.1310-1318

Document Type:

Article

Publication Date:

12/2023

Document Language:

English

Document ID (Org No.):

2001306401

pISSN:

2147-3129