Accumulation of heavy metals in green turtle (chelonia mydas) hatchlings and their effects on hatching success

This study was conducted on the Sugözü Beaches (Adana), an important nesting site for the endangered Chelonia mydas (Green turtle). The aim of the research was to evaluate the potential effects of heavy metal accumulation in the nest environment and in the tissues of hatchlings on the hatching success of green turtles. Additionally, the study aimed to determine the transport mechanisms via maternal transfer or environmental exposure, as well as the accumulation patterns of heavy metals in different tissues. For this purpose, the concentrations of arsenic (As), mercury (Hg), lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), and barium (Ba) were analyzed in liver, muscle, carapace, brain, yolk, and kidney-gonad complex (KGC) tissues of hatchlings, as well as in nest sand, eggshells, and cloacal fluid samples collected from nesting females, using Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES). When examining the average heavy metal concentrations that showed the highest accumulation in different tissue and sample types, Cu (31.62 ppm) and Hg (14.48 ppm) were found at the highest levels in the liver, As (4.84 ppm) and Zn (129.6 ppm) in the muscle, Ba (70.75 ppm) in the carapace, and Mn (337.02 ppm), Fe (9349 ppm), and Pb (1.91 ppm) in the nest sand. In the study, potential maternal transfer was highlighted for the elements As, Ba, Hg, Zn, and Cu, while certain toxic heavy metals (Pb, Ba) were found to negatively affect hatching success by reducing hatching rates. Additionally, some essential heavy metals (Fe, Mn) were found to have supportive effects on hatching success at certain levels, whereas in some cases, essential metals (Zn, Cu) were found to cause toxic effects, thereby reducing hatching success. In conclusion, this study revealed the accumulation patterns of heavy metals, which are environmental pollutants that can affect the hatching success of sea turtles, in different tissues, their potential transition and transfer mechanisms, and their relationships with hatching success, demonstrating the presence of significant correlations related with tissue and nest parameters. The findings emphasize the potential threats of heavy metal pollution in terms of conservation biology and habitat management, contributing to the development of strategies for the protection of sea turtles. Keywords: Accumulation, Chelonia mydas, Hatching Success, Heavy Metals, Pollution