Ship ballast water as a main vector of marine introductions in the Mediterranean Sea

Marine invasive species are currently recognized as one of the most significant threats to global biodiversity. Marine bioinvasions are more likely in the Mediterranean Sea because of its wide temperature range, degraded habitats, historical and high volume of shipping traffic, and high occurrence of aquaculture. One of the main vectors of marine introductions globally and Mediterranean-wide is commercial shipping. Of the 3,000–4,000 species transferred around the world via commercial vessels, approximately 30% of these species may have been redistributed in the Mediterranean. Ships and marine invasive species arriving in the Mediterranean are mainly from temperate to cold-water regions. Standardized research and management approaches between countries are required to address the threat of ballast water borne marine invasives on a global scale. Regionally, a Mediterranean program involving the different states is currently needed to develop a common line of research and management operations.