Biomonitoring of zooplankton community in North-western Mediterranean Sea (Gulf of Salerno): the status during a dredging operation

We monitored the zooplankton community in the Salerno Gulf during a dredging operation, between 2020 and 2021, to study the spatial and temporal distribution. Salerno has upgraded its harbour, marking it as Europe’s most significant effort in marine sediment mobilization, and an environmental impact assessment protocol was developed to monitor the direct effects of dredging. During the present study the zooplankton community was dominated by copepods, with the main genera identified being Acartia, Clausocalanus, Corycaeus, Oncaea and Oithona. While the distributions of these genera remained consistent across the studied areas, variations in abundance were observed between the potentially impacted regions and the surrounding areas, likely linked to the dredging operations. One of the goals of this biomonitoring was to check for the presence of non-indigenous species. Two new records were discovered: the epipelagic harpacticoid Distioculus minor, which had not previously been found in this area, and the non-indigenous calanoid Pseudodiaptomus marinus. Further studies are needed to monitor the presence and potential dispersal of these new species, as well as the recovery of native species, to document a community that has not been previously recorded.