Nonindigenous species along the Apulian coast, Italy

Thirty-eight nonindigenous marine species (NIS) (macroalgae, sponges, hydrozoans, molluscs, polychaetes, crustaceans, ascidiaceans and fish), are reported from the Apulian coast of Italy. Shipping, aquaculture and migration through the Suez Canal are the main pathways of introduction of the NIS. In Apulian waters, 21% of NIS are occasional, 18% are invasive and 61% are well-established. It is highly probable that more NIS will arrive from warm-water regions, because Mediterranean waters are warming. Furthermore, some of the successful NIS must have the ability to become dormant in order to survive adverse conditions, either seasonal or during long journeys in ballast waters. The identification of NIS depends greatly on the available taxonomic expertise; hence the paucity of taxonomists hinders our knowledge of NIS in our seas. We propose the creation and maintenance of a network of observatories across the Mediterranean to monitor the changes that take place along its coasts.