Fig. 6

The Principal Component Analysis (PCA) of data retrieved in the Gulf of Gaeta (GoG, blue points), the Gulf of Naples (GoN, green triangles), and the Gulf of Salerno (GoS, red squares) is shown in Fig. 1. a = PCA all variables together, including distances from the Allocated Zones for Aquaculture, drains, Marine Protected Areas, naval routes, and river mouths; b = PCA physical variables; c = PCA chemical variables; d = biological variables.