The Gulf of Milazzo (north-eastern Sicily) has been recognized as Italian Site of National Interest (SNI; areas characterized by high level of contamination with potential effects on human health) in 2005 because of its high level of pollution. In this study we measured the concentration of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polyBrominated diphenyl ether (PBDE) in seawater and sediments sampled from the Gulf of Milazzo in order to assess (i) the environmental status of contamination, and (ii) cancer and non-cancer human health risk potentially due to dermal absorption from contaminated seawater and/or ingestion of contaminated fish. Particularly, POPs content in pelagic and demersal fish of different size classes (small, medium, and large) were estimated, starting from the measured seawater and sediments concentrations, using the KABAM model. In particular, Monte Carlo simulation techniques were applied to address uncertainty in assessment of the risk and to provide quantitative estimates of probability of exposition. Ingestion of contaminated pelagic and demersal fish was the dominant pathway of exposition with high probability of significant cancer risk (Ingestion Cancer Risk >10^–4) and significant non-cancer risk (Hazard Index >1). No human health risks emerged to be associated to dermal adsorption from contaminated seawater. Benzo(a)pyrene show the highest Ingestion Cancer Risk with respect to the other PAHs, while the highest Hazard Index for non-cancerogenic molecules was estimated for the PBDE47 congener.

The protein, essential amino acid, and fatty acid composition of European pilchard (Sardina pilchardus), European hake (Merluccius merluccius), surmullet (Mullus surmuletus), red mullet (Mullus barbatus), and deep water rose shrimp (Parapenaeus longirostris) from the central Mediterranean Sea were investigated. All the species showed an essential amino acid content of about 50% of total amino acids, while the protein and total fatty acids content varied from 19.9 to 24.8% and from 1.4 to 5.1%, respectively. The fatty acid profile mainly followed the order SFA (39.1–52.6%) > PUFA (21.0–39.3%) > MUFA (15.6–24.3%). Palmitic and stearic acids were predominant among saturated fatty acids (38–52% and 21–25%, respectively), while palmitoleic and oleic acids were the most represented of the total monounsaturated acids (10–21% and 55–68%, respectively). All the species, as expected, showed a more significant proportion of n-3 PUFA (EPA + DHA) of about 81–93% of the total PUFA, with the highest values was found in European pilchard. Also, several fat quality index values, such as n-6/n-3 ratio, PUFA/SFA, the index of atherogenicity (IA), the index of thrombogenicity (IT), the hypocholesterolemic/hypercholesterolemic ratio (HH), and fish lipid quality/flesh lipid quality (FLQ) were calculated to assess the nutritional quality. All the obtained results, along with the fat quality indexes, indicated the excellent nutritional values of the selected species.

The administration of nutraceutical substances to fish diet can help to control disease outbreaks in aquaculture practices, thereby promoting sustainability and food safety. In particular, some substances have the potential to alleviate the effects of trace metals toxicity in fish also by reducing metal accumulation in tissues. This study evaluates, for the first time, the effect of nutraceutical substances on bioaccumulation mechanisms of mercury (Hg) in tissues and organs of farmed gilthead seabream (Sparus aurata) by mesocosm experimentation. The kinetics of bioaccumulation in muscle, gills, gut, liver and kidney and the detoxification efficiency were also assessed. Fish were fed with three different diets: a commercial diet used as control (CD); a diet enriched with short chain fatty acids (SCFA) and extract of Castanea sativa (D1); a diet enriched with yeast Saccharomyces cerevisiae and extract of Schinopsis balansae (D2). All groups were exposed to sub-lethal concentrations of mercury. After 20 days of exposure, mercury levels in different organs and tissues clearly revealed the effectiveness of yeast and plant extracts in limiting the metal bioaccumulation in fish fed with D2 through mercury absorption and then elimination by feces. In contrast, the D1 seems to not reduce the Hg bioaccumulation in fish tissues. This can be attributed to the high affinity of SCFA for mercury, leading to the formation of organometallic compounds absorbed by the fish tissues. This mechanism potentially counteracts the efficiency of tannins contained in the extract plant on mercury removal. This study clearly demonstrates that the use of diets enriched with yeast and/or plant extracts rich in tannins are a useful bioremediation strategy to reduce trace metals bioaccumulation in farmed fish, thus preserving their health status from intoxication, their commercial values, and consequently the health of consumers.