Saronikos Gulf: a hotspot area for alien species in the Mediterranean Sea

Abstract

Shipping is the greatest pathway of non-indigenous species (NIS) introductions, and port areas are considered as alien hotspots. In this study, we analyzed data covering a 112-year period and found that Saronikos Gulf in Greece, hosting one of the largest container port terminals in Europe, is a hotspot of NIS introductions. To date, 89 NIS have been recorded, of which 8 are characterized as invasive. Most species belong to the taxonomic group of Mollusca (33%), followed by Pisces (22%). For the first time in the Mediterranean Sea, we report the presence of the micromolluscs Sinezona plicata (Hedley, 1899) and Ringicula sp. Moreover, we provide evidence for the trend of NIS introduction in the Saronikos Gulf across the past 70 years, the pathways of introduction and their importance through time, as well as the distribution of the most invasive species in the Saronikos Gulf. The information provided herein can assist the implementation of the EU Marine Strategy Framework Directive and inform NIS management. As Transport-Stowaway remains the main pathway of NIS introduction in the Saronikos Gulf, our principal recommendation is to reinforce regulations for the adoption of better antifouling practices and more effective ballast water treatment and management.