Seaports are recipients of myriad organic and inorganic pollutants that directly or indirectly
released into marine environment. Recently, maritime transport and associated port activities
are recognized as increasing source of environmental threats, with ballast water as one of main
vectors for initial transport of non-indigenous species (NIS). The goal of this study was to
characterize benthic communities associated with hard- and soft-bottom habitats from the
four North Adriatic seaports and to check the presence of non-indigenous species. The
sampling strategy and methodology followed modified CRIM Protocol (Hewitt and Martin, 2001). Total of 17 higher macrobenthic taxa, and 75 species were identified from the hard
substrata, and much less (10 higher taxa, 36 species) from the soft bottom. The results of
univariate analyses suggested occurrence of modified and impoverished soft-bottom
macrofauna and rather diverse hard bottom fauna. Multivariate analysis indicated significant
differences of macrofauna communities among surveyed ports. In total, seven NIS were
detected, all belonging to polychaetes. One of them, Platynereis nadiae was recorded for the
first time from the Adriatic Sea and it was found in ports of Bakar, Omišalj and Rijeka. Six NIS
were reported from the port of Raša: Hydroides dianthus, H. elegans, H. stoichadon,
Leiochrides australis, Protolaeospira striata and Pileolaria berkelyana, and the last one was
recorded for the first time in the Adriatic Sea
