Trace Elements and Persistent Organic Pollutants in Unhatched Loggerhead Turtle Eggs from an Emerging Nesting Site along the Southwestern Coasts of Italy, Western Mediterranean Sea

Abstract

Marine pollution is one of the major threats affecting loggerhead turtles, which due to their long life span, highly migratory behavior, and carnivorous diet, may be exposed to elevated levels of toxic elements throughout their life. The transfer of chemicals from mothers to their offspring is of particular conservation concern because it may affect embryonic development and hatching success. In this study, the concentrations of 16 toxic and potentially toxic trace elements, 6 indicator polychlorinated biphenyls (PCBs), and organochlorine pesticide residues (OCPs) were determined in 138 eggs from 46 loggerhead turtle nests laid during the 2021 nesting season in Campania, Italy, western Mediterranean Sea. The possible impact of pollutant levels on hatching success and early embryonic death was also investigated. Trace element analysis was performed using an ICP-MS, except for mercury, which was determined using a Direct Mercury Analyzer® (DMA). PCBs and OCPs were analyzed with high-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC-HRMS) and gas chromatography tandem quadrupole mass spectrometry GC-MS /MS, respectively. The concentrations of essential elements in the eggs were higher than those of non-essential elements. In addition, the highly chlorinated PCBs (153, 138, and 180) contributed the most to the total PCBs, while OCPs were not detected. No correlations were found between contaminant concentrations and reproductive parameters (hatching success and no obvious embryos). The results obtained suggest that the levels of contaminants found in the eggs do not affect the reproductive success of the species in the study area.