OLD AND NEW BIOINVASIONS IN THE CALABRIAN TYRRHENIAN COASTS

The Mediterranean basin, a crossing area between western and eastern countries has became in these last years a marine region of transition and mixture for local biota where old and new biological invasions are changing the native structure and functioning of coastal ecosystems. The outcome of this study has shown that two macroalgal indopacific species, entering into the basin through Suez Canal, are actually spreading in the Western area of the basin. Amongst these, there is an old acquaintance named Caulerpa cylindracea, spreading all along the Calabrian Tyrrhenian coasts and a new one, known as Caulerpa taxifolia var. disticophylla, recently reported in a southern station of the regional coastline. Both species are reported in locations close to harbours and/or wet docks for a dispersal mechanism, via boating traffic, highlighting the great tolerance of these species to high level of pollution and sedimentation. The results confirm the extreme invasive behaviour of these alien species not only in the Calabrian Tyrrhenian coasts but also in the Western basin suggesting a process of tropicalization in the Mediterranean biota, actually ongoing.