Metals/Metalloids and Oxidative Status Markers in Saltwater Fish from the Ionic Coast of Sicily, Mediterranean Sea

The aim of the present work was the assessment of the environmental status of marine biota along the Sicilian ionic coast (Italy). Due to its complex habitat requirements, the fish fauna is a crucial indicator of the ecological integrity of aquatic systems at different scales, from micro-habitat to catchment. Besides environmental contaminants, biomarkers of oxidative stress answer to the Water Framework Directive’s challenges for improved detection of the impacts of chemical compounds on aquatic organisms. Highly consumed seafood species (Solea solea, Mullus barbatus, Sardina pilchardus and Scomber scombrus) were taken at the Gulf of Catania (Sicily). Levels of metals/metalloids (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, Zn) were estimated in muscle tissue as well as oxidative stress parameter such as malondialdehyde (MDA) and protein carbonyl (PC) derivatives in liver. The total metals/metalloids load indicated as Metal Pollution Index (MPI, unitless) were the following: 0.258 in S. pilchardus, 0.203 in S. scombrus, 0.123 in M. barbatus and 0.071 in S. solea. The greatest contribution was given by As (mean range 2.670–9.748 mg/kg wet weight) and Zn (mean range 2.169–4.736 wet weight) levels. Hg, Ni and Zn presented mean levels progressively higher, with increasing trophic position. From a chemical point of view, the analyzed species were healthy for human consumption and the risk to develop chronic systemic and carcinogenic effects was low; nevertheless, it has highlighted an oxidative stress condition.