Ocean & Coastal Management 49 (2006) 947–960 Shipping traffic and introduction of non-indigenous organisms: Study case in two Italian harbours Maria Monia Flagella à , Alessio Soria, Maria Cristina Buia Benthic Ecology Laboratory, Stazione Zoologica ‘Anton Dohrn’, Punta S. Pietro 80077 Ischia, Naples, Italy Abstract In order to study the role of ballast water in introducing non-indigenous organisms in the Mediterranean Sea, the maritime traffic was analysed in the harbours of Naples and Salerno, which are important commercial ports in southern Italy. The 2001 data concerning the number of ships, the cruises’ length and the source of arrivals, were taken from harbours’ offices logbooks. In both harbours, the Mediterranean traffic was higher compared to the world sea-borne traffic that was mainly coming from North East Atlantic countries. The mean length of travels was of 1 week while the longest voyages were from Australia (3 weeks). A theoretical amount of ballast waters discharged during 1 year was provided by using an European model. A total of 55,738 and 118,339 ton of foreign ballast water are released annually in Naples and Salerno, respectively, to which theoretically correspond the entry of 4,977,403 (Naples) and 10,366,496 (Salerno) phytoplanktonic specimens. r 2006 Elsevier Ltd. All rights reserved. 1. Introduction Shipping activities represent in marine environment important vectors of non- indigenous species [1,2]. The transport can occur through ships’ hulls (fouling), in ships’ ballast tanks or by other parts of vessels such as propeller or anchor [3]. Lately, the focus of many researches has been dedicated to ballast water since it has been estimated that 3000–4000 species are transported daily throughout the world in the holds of ships [4]. In ballast water tanks, huge quantities of water (thousand of tons) are pumped onto ships at ARTICLE IN PRESS www.elsevier.com/locate/ocecoaman 0964-5691/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.ocecoaman.2006.08.009 à Corresponding author. Tel.: +39 0815833521; fax: +39 081984201. E-mail address: flagella@szn.it (M.M. Flagella).