P21-38 Heavy metals in the blue crabs (Callinectes sapidus) collected in coastal lagoons and shallow marine waters of Northwestern Adriatic Sea

Purpose: The Atlantic blue crab (Callinectes sapidus), endemic to the eastern coast of America, is listed among the worst invasive species introduced into the Mediterranean. It was reported in the Emilia-Romagna region lagoons (Italy) in 2015 [1], and in very recent times it colonized all the Italian coastal areas [2]. This species poses threat to shellfish farming and biodiversity. A potential mitigation strategy is the increase of the fishing pressure, using this species as a food source for humans and animals. However, a risk for human health is the possibility of crabs accumulating pollutants, such as heavy metals (HMs). HMs are an important indicator of pollution, especially in the aquatic environment, due to their high toxicity and persistence, non-biodegradability, tendency to bioaccumulate in the trophic chain (biomagnification). The aim of this study was to evaluated the concentrations of 6 elements (lead, cadmium, chromium, mercury, nickel, arsenic) in the edible tissues of crabs collected along the Emilia Romagna coasts. Methods: From August 2023 to March 2024, 30 samples were collected. All crabs were separated by sex, measured (carapace width), weighted and tissues pooled. An in-house triple quadrupole inductively coupled plasma mass spectrometry (TQ-ICP-MS) method was used to analyze 30 pool (15 for each sex) (152 specimens) of muscle and 30 pool of hepatopancreas, after a wet mineralization process with concentrated nitric acid. The method has been validated for detecting HMs in accordance with Regulation (EC) 333/2007 [3], with a limit of quantification (LOQ) of 5 μg/kg. The results obtained by males and females were compared for the concentration of HMs. Results: HMs investigated in muscle tissues and hepatopancreas of male and female C. sapidus individuals were Pb, Hg, Cd, Ni, As, and Cr. No sex-related differences were observed for any metal. Preliminary results showed no tissue-related differences for metals such as Hg, Cr and As. For Pb, Cd and Ni, significant differences for the hepatopancreas and muscle tissue (p<0.001) were observed. Pb concentration in the hepatopancreas was threefold higher than in the muscle, with an average concentration of 0.061 mg/kg. Cd concentrations were several times higher in the hepatopancreas (1.67 mg/kg) and were lower in muscle tissue (p<0.001). Ni concentrations were fivefold higher in thehepatopancreas (0.506 mg/kg) than in the muscle. The present study is a preliminary evaluation of the concentration of heavy metals in C. sapidus sampled along the coasts of Emilia Romagna. The results have shown that no significant differences are observed between male and female individuals. A different accumulation capacity of HMs in the analyzed tissues was observed. In particular, significant accumulation of metals such as Pb, Cd and Ni was demonstrated in the hepatopancreas, while low levels observed in the muscle. References [1] Manfrin, C., Chung, J., Turolla, E., & Giulianini, P. (2015). First occurrence of Callinectes sapidus (Rathbun, 1896) within the Sacca di Goro (Italy) and surroundings. Check List, 11(3), 1-4. [2] Tiralongo, F., Villani, G., Arciprete, R., & Mancini, E. (2021). Filling the gap on Italian records of an invasive species: first records of the Blue Crab, Callinectes sapidus Rathbun, 1896 (Decapoda: Brachyura: Portunidae), in Latium and Campania (Tyrrhenian Sea). Acta Adriatica, 62(1), 99-104. [3] Commission Regulation (EC) No 333/2007 of 28 March 2007 laying down the methods of sampling and analysis for the official control of the levels of lead, cadmium, mercury, inorganic tin, 3-MCPD and benzo(a)pyrene in foodstuffs (OJL 88, 29.3.2007, p. 29–38)