Benthic communities in three Mediterranean touristic ports: MAPMED project.

Background: Mediterranean ports are sources of significant economic activity and at the same time they act as recipients of considerable anthropogenic disturbance and pollution. Polluted and low-in-oxygen sediments can negatively impact benthic biodiversity and favour recruitment of opportunistic or invasive species. Macrobenthic communities are an important component of the port biota and can be used as environmental quality indicators. However, a baseline database for benthic biodiversity in Mediterranean ports has not yet been widely established. New information: Macrobenthic assemblages were recorded in three Mediterranean touristic ports under the framework of the ENPI CBC MED project MAPMED (MAnagement of Port Areas in the MEDiterranean Sea Basin). Samples were collected from Cagliari (Sardinia, Italy), Heraklion (Crete, Greece) and El Kantaoui (Tunisia) ports during February, May and September 2012. The sampling stations were selected according to the different sectors within each port (i.e. leisure, fishing, passenger/cargo vessels and shipyard). A total of 277 taxa belonging to 12 phyla were found, of which the 96 taxa were present in all three ports. El Kantaoui port hosted the highest number of macrobenthic taxa. Mollusca were the most abundant group (34%) in all ports. The highest percentage of opportunistic taxa per station was found before the touristic period in the shipyard of Heraklion port (89.3%).

Spatio-temporal benthic biodiversity patterns and pollution pressure in three Mediterranean touristic ports.

The Mediterranean Sea is one of the busiest areas worldwide in terms of maritime activity, facing considerable anthropogenic disturbance, such as pollution by hydrocarbons and heavy metals. The present study has evaluated the environmental and benthic biodiversity characteristics of three touristic ports, Cagliari (Sardinia, Italy), Heraklion (Crete, Greece) and El Kantaoui (Tunisia), based on the combined assessment of physical parameters, chemical variables (i.e. nutrients, pigments), sediment pollution and macrobenthic biodiversity. Different port sectors (leisure, fishing, passenger, cargo, shipyard) and different seasons (winter, before touristic period, after touristic period) were compared. Salinity and sediment concentration of copper and antimony were the three environmental parameters most highly correlated with benthic species composition and diversity. Both the environmental variables and the benthic biodiversity patterns were significantly different between the three ports (i.e. different geographical locations). Heraklion port was heavily polluted by AHs in surface and anoxic sediments and had the highest percentage of opportunistic species, while Cagliari had the highest levels of PAHs and UCM and low species richness. El Kantaoui port was less polluted and characterised by a richer biodiversity. The shipyard sector in Heraklion port was significantly different from all other sectors in terms of abiotic and biotic parameters. Physico-chemical and pollution variables recorded during the period after tourism (late summer) were significantly different from the ones recorded in winter. Seasonal differences were not significant between benthic species diversity patterns, but were revealed when the patterns derived from the aggregation of higher taxonomic levels were compared. The present study indicates that a regular-basis monitoring plan including evaluation of environmental health based on benthic biodiversity, can provide a basis for perceiving changes and reveal the degree of anthropogenic disturbance in port environments.

Protozoan parasites in cultured mussels Mytilus galloprovincialis in the Thermaikos Gulf (north Aegean Sea, Greece).

The protozoans Ancistrum mytili (Oligohymenophorea: Ancistridae) and Marteilia refringens/maurini (Marteiliidea: Marteiliidae) were found parasitizing cultured mussels Mytilus galloprovincialis L. in the Thermaikos Gulf (north Aegean Sea, Greece). The former did not affect the condition index of infected mussels, in contrast to the latter, which did so and which also induced hemocyte infiltration in the affected digestive epithelium. The prevalence of both parasites was relatively high in a polluted area.