Variables affecting the plankton network in Mediterranean ports

Attention on port waters is increasing since these economically important infrastructures are embedded in the coastal environment and their management needs to be considered in the monitoring programmes of coastal ecosystems. To implement the sustainable development (blue growth) of port areas, a general knowledge on the ongoing processes in their waters needs to be obtained, considering both abiotic and biotic variables. The present study aimed at inspecting the relationships among plankton components to provide insights into the ecology of ports. Seasonal samplings were carried out in three Mediterranean touristic ports where bacterio-, phyto- and zoo-plankton were simultaneously assessed at a large spatial scale and compared with respect to environmental variables and anthropogenic inputs. Factor analysis revealed the effects of load of inland waters, seasonality, water turbulence and hydrocarbon pollution on the planktonic components and zooplankton variability in port sectors characterized by different depths and uses. •Ports are impacted coastal areas and their waters need to be monitored.•Plankton communities are abundant and composite in port waters.•Bacterioplankton, phytoplankton and zooplankton constitute a complex network.•Plankton networks depend on nutrient load, water turbulence, seasonality and hydrocarbons.•Plankton networks usefully contribute to the monitoring of port areas.