Macrozoobenthos in the Adriatic Sea ports: Soft-bottom communities with an overview of non-indigenous species.

The present paper is a contribution to the first initiative of the Port Baseline Survey (PBS) for Non-indigenous species (NIS) in the Mediterranean Sea. It presents a report on the soft-bottom macrobenthos from the five Adriatic ports: Bari, Ancona (Italy), Koper (Slovenia), Pula, Rijeka (Croatia), with a focus on the presence and contribution of NIS to native assemblages. Out of 451 species identified, only four were common to all ports. A total of eight NIS were recorded, five in surveyed ports and three in the lagoon connected to the Port of Koper. The highest number of NIS was recorded in Bari, and the highest abundance in Ancona and Bari. Generally, the number, abundance and contribution of NIS seems too low to cause a substantial impact on native communities in surveyed ports. The suitability of methods adopted for PBS for soft-bottom NIS was discussed and suggestion for methodological improvement is provided.

Non-indigenous macrozoobenthic species on hard substrata of selected harbours in the Adriatic Sea.

The intense shipping traffic characterising the Adriatic Sea favours the spread of marine organisms. Yet, a study of 12 Adriatic ports (4 on the western side and 8 on the eastern side of the basin) found that non-indigenous species (NIS) accounted for only 4% of the benthic communities settled on hard substrates. The cirripeds Amphibalanus amphitrite and Balanus trigonus, found in 8 harbours, were the most common invaders followed by Amphibalanus eburneus, the ascidian Styela plicata, and the bivalve Magallana gigas. The highest percentage of NIS was recorded in Venice and Ploce, the harbours with the least rich native communities; the lowest percentage was retrieved in Trieste, Koper, Pula, and Rijeka, the harbours hosting the highest species diversity. In contrast, the ports of Bari and Ancona showed both high NIS percentages and highly diversified communities.

Effects of Costa Concordia shipwreck on epiphytic assemblages and biotic features of Posidonia oceanica canopy.

This research provides first information about Posidonia oceanica canopy in the area affected by Costa Concordia wreck. Percentage cover of algal and animal taxa on the leaves was estimated and biotic features of the meadow were measured in the period just after the shipwreck until its removal from the impacted site. Changes in epiphytic assemblages and some biotic features were detected in the Disturbed site compared with Control ones, highlighting effects due to the wreck presence and activities related to its removal. A temporary decrease of encrusting macroalgae and an increase of erected macroalgae and foraminifers, as well as a temporary increase of tip erosion of the canopy were detected in the Disturbed site. The obtained results were discussed and hypotheses about possible synergic effects occurred near the wreck were commented.