037 | Preliminary data on toxicological analysis in Caretta caretta eggs in Sicily, Italy

Rosaria Disclafani^1|2, Paola Galluzzo¹, Giorgia Schirò¹, Gianluca Gioia¹, Oleana Olga Prato³, Salvatrice Vizzini^2|4, Chiara Lomonaco^1|5, Elisa Maria Domenica Messina⁶, Vincenzo Monteverde¹, Salvatore Dara¹ | ¹Centro di Referenza Nazionale sul Benessere, Monitoraggio, Diagnostica delle Malattie delle Tartarughe Marine CReTaM, Istituto Zooprofilattico Sperimentale della Sicilia “A Mirri”, Palermo, Italy; ²Centro di Sostenibilità e Transizione Ecologica, Università di Palermo, Italy; ³WWF Italia, Roma, Italy; ⁴Dipartimento di Scienze della Terra e del Mare, Università di Palermo, Italy; ⁵Dipartimento di scienze Veterinarie Polo Universitario dell’Annunziata Università di Messina, Italy; ⁶Istituto Zooprofilattico Sperimentale della Sicilia “A. Mirri”, Palermo, Italy.

The Mediterranean Sea is a major nesting region for the Caretta caretta species. However, the populations of this species are threatened by human activities, including marine pollution [1]. The semi-enclosed nature of the Mediterranean makes it susceptible to pollution, serving as a reservoir for pollutants [2]. The aim of this study was to evaluate the concentration of heavy metals and trace elements in C. caretta eggs from nesting sites in Sicily (Italy). For this reason, 198 unhatched eggs from 15 nests sampled in different Sicilian provinces were analyzed: 7 in Siracusa, 4 in Palermo and 4 in Trapani. The following elements were examined for each nest analysed: lead (Pd), cadmium (Cd), copper (Cu), iron (Fe) and arsenic (As). The elements were determined using a 7700x series ICP-MS, following the procedure described in reference [3]. The total mean and standard deviations found for each metal were: Pb 0,014±0,018; Cd 0,017±0,016; Cu 0,25±0,156; Fe 4,668±1,492; As 0,495±0,167 mg/kg. As regards Cd and Pb, the highest concentrations were found in samples from the provinces of Siracusa and Palermo. In particular, Cd was found to have a concentration of 0.03 mg/kg in both provinces, while Pb had a higher concentration in the province of Palermo (0.04 mg/kg). With regard to the trace elements analysed, the samples from the Favignana nest showed higher concentrations of Cu (0.40 mg/kg) and As (0.64 mg/kg), while Fe showed higher concentrations in eggs from nests in the province of Siracusa (5.94 mg/kg). The data obtained showed the presence of heavy metals and trace elements in unhatched C. caretta eggs. Although the concentrations of Cd and Pb found in the provinces of Palermo and Siracusa are lower than the levels detected in the organs of beached individuals in the same areas [3], their presence can interfere with the endocrine system, potentially influencing embryonic development [4]. The geographical variability of trace elements suggests site-specific effects that could be linked to both local geochemistry and industrial inputs. In this regard, samples from Favignana showed significantly higher concentrations of Cu and As. Cu, in particular, could be related to the intense maritime traffic that characterises the area, negatively influencing the health of marine fauna and confirming that site-specific environmental conditions can cause critical levels of contamination [5]. The Siracusa samples showed significant levels of Fe, an element essential for embryonic erythropoiesis [6], but its high levels could be due to its proximity to local petrochemical industries. These results confirm the vulnerability of Sicilian nesting sites to chemical contamination, making it necessary to monitor them and evaluate their impact on hatching success.