Monitoring of the Quality of the Environment and Mussels in an Integrated Multitrophic Aquaculture System in the Gulf of Taranto

The aim of this study was to determine the microbiological and nutritional quality and the PCBs content of Mytilus galloprovincialis (Lamarck, 1819) reared at two different depth (surface and bottom: 12 m) in an integrated multitrophic aquaculture system (IMTA) realized in the Gulf of Taranto where the mussels were co-cultured with other bioremediator organisms such as polychaetes and macroalgae located around the fish cages. In addition, in order to verify the effectiveness of the realized system in bioremediating the environment, in July 2023, after the implementation of the experimental IMTA plant, a survey concerning the microbiological quality, the phytoplankton abundance, the physico-chemical parameters of the seawater as well as the polychlorinated biphenyls (PCBs) concentration in the sediments was conducted. In the seawater samples temperature was 29.3°C at the surface and 24°C at the bottom. Total coliforms were 2MPN/100ml, faecal Enterococci 4 MPN/100ml, faecal coliform, Escherichia coli, Salmonella spp. and Pseudomonas spp. were absent, phytoplankton abundance was 1.2 x 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> cells 1<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>. In the sediment target PCBs were 31±4.1pg/kg. Mussels resulted of good quality from a microbiological and nutritional point of view. Microbial pollution indicators and target PCBs were below the limit set by European legislation. Mussels showed a protein content between 5.35-5.77 g/100g, a total lipid content between 1.40-1.44 mg/g, high levels of polyunsaturated fatty acids of omega 3 series and an optimal omega 3/omega 6 ratio (3.27 -3.63). Thus, mussels co-culture in the IMTA system represents a new fashinating approach in order to increase mussel production in the Mar Grande of Taranto with economic and ecological relapses since mussel farming remains one of the least impacting methods of producing food of animal origin. However, further investigations are needed to overcome the phenomenon of “heat waves” which leads to high mussels mortality representing a constrain for the reaching of the commercial size.