Bioaccumulation, organotropism and toxicological risk of trace elements in Caretta caretta (Linnaeus, 1758)

Abstract

The present study compares the concentration of trace elements (TEs) found in different tissues and eggs of the loggerhead sea turtle, with a view to evaluating the potential toxicological risk for this important bioindicator species [1]. A total of 18 elements were analysed through inductively coupled plasma mass spectrometry (ICP - MS) from nine individuals of Caretta caretta that had been found stranded along the northwest coast of Sicily (Italy), as well as from the shells and yolks of six eggs from the island of Linosa (Sicily Strait, Mediterranean Sea). The elements analysed exhibited organotropism, with the highest bioaccumulation levels observed in the liver. The highest concentrations of iron were found in the livers, followed by zinc in the hearts and arsenic in the kidneys. While the levels of most trace elements were comparable to those previously documented, the elevated concentrations of arsenic and cadmium in the kidneys and liver suggest the potential for adverse effects associated with exposure to these non-essential elements. With regard to the eggs, the most prevalent elements in the yolk were zinc, iron, and barium, while iron, boron, and copper were the most abundant in the eggshell. As several of the trace elements identified in C. caretta eggs have not been previously analysed, comparisons with other studies in the literature have not been possible. The findings of this study represent a preliminary investigation that paves the way for further research in this area and emphasise the crucial role of multi-element biomonitoring in assessing potential threats to C. caretta adults and eggs, and their implications for the survival of this endangered species. Furthermore, this biomonitoring study enables the evaluation of prevailing TEs pollution levels, thereby supporting the formulation of appropriate environmental policies and regulations. Acknowledgements Funder: Project funded under the National Recovery and Resilience Plan (NRRP), Mission 4 Component 2 Investment 1.4 - Call for tender No. 3138 of 16 December 2021, rectified by Decree n.3175 of 18 December 2021 of Italian Ministry of University and Research funded by the European Union – NextGenerationEU; Award Number: Project code CN_00000033, Concession Decree No. 1034 of 17 June 2022 adopted by the Italian Ministry of University and Research, CUP B73C22000790001, Project title “National Biodiversity Future Center - NBFC”. Reference [1] D.Savoca, M. Arculeo, V. Arizza, A. Pace, R. Melfi, S. Caracappa, G. Caracappa, C. Vullo, I. Cambera, G. Visconti, V. Giudice; G. D’Oca, S. Messina, A. Maccotta (2022). Impact of Heavy Metals in Eggs and Tissues of C. caretta along the Sicilian Coast (Mediterranean Sea). Environments 2022, 9, 88.