Mother-Hatchling Isotopic Relationship in Green Turtle: Isotopic Niche-based Modelling

The isotopic discrimination between a mother and her hatchlings has been modelled in various vertebrates, including sea turtles. In addition to the linear relation between δ¹³C and δ¹⁵N isotope values of the mother - hatchling couple, there is missing data on the combined effects of both isotopes, which represent ecological niches of a species. The stable δ¹³C and δ¹⁵N isotope signatures of live hatchlings and their mother's epidermis tissues were used in green turtles. The samples were taken from three main breeding beaches, Akyatan, Sugözü and Samandağ in Türkiye during the 2020 nesting season. δ¹⁵N and δ¹³C values of hatchlings were not significantly different from those of mothers. Significant relationships were found between hatchlings and their mothers in terms of δ¹³C value. Furthermore, when the hatchling isotopic niche size is known, the condition probabilities of estimating the mother's isotopic niche size were 85.16% and 92.88% with the 0.95 and 0.99 alpha levels. In addition to showing a linear relationship between hatchlings and their mother's single isotopic composition, the current study offers a novel insight that proposes a niche overlap concept using two isotopes to comprehend the mother-hatchling relationship of green turtles living in the eastern Mediterranean.