The Mediterranean introduced pearl oyster Pinctada radiata: can an invasion be changed into a gain in a climate...

The pearl oyster Pinctada radiata is considered among the 100 most invasive species in the Mediterranean Sea. Recently, a dramatic increase in P. radiata abundance has been recorded in the Mar Grande of Taranto (Ionian Sea) due to recurring heatwaves. This study investigated the structure and recruitment dynamics of P. radiata obtained in collectors made of plastic nets or coconut fibers within an Integrated Multi-Trophic Aquaculture (IMTA) system in the Mar Grande of Taranto. Furthermore, its nutritional value in terms of fatty acids and its chemical and microbiological quality were analysed in light of its potential commercial exploitation. The results revealed that the best growth performance was achieved with plastic nets. Reproduction occurred throughout the year with a peak in summer. The fatty acid profile of P. radiata at all sampling times revealed the predominance of PUFAs and SFAs over MUFAs. The pearl oyster was found to be a valuable source of omega-3 polyunsaturated fatty acids, as also evidenced by the high ∑ω3/ω6 ratios (range 2.81-4.51). Finally, the oyster quality was good from a microbiological and chemical point of view (PCB ICES-6 concentrations were below established European limits). In this scenario, the exploitation of this species is recommended for several reasons, including its decline in the area of origin and the creation of a market for human consumption and pearl production in the Mediterranean areas, where the species is finding an improved environmental situation due to global warming.