An updated overview of biological invasions in Sicilian Islands (Southern Mediterranean Sea)

Non-indigenous species (NIS), pointed out as a major threat to biodiversity, may become invasive alien species (IAS) and may cause biodiversity loss and ecosystem service changes. In the Mediterranean Sea, Islands, which represent hotspots of biodiversity, are particularly vulnerable to biological invasions. As a result of their geographical location at the crossroads between the Western and Eastern Mediterranean - plus exposure to heavy maritime traffic, Sicily and its surrounding Islands spread in Southern Mediterranean, most of which host MPAs, are particularly prone to NIS invasions. A total of 45 non-indigenous and cryptogenic species was recorded for the Sicilian Islands (21 Macrophytes, 13 Invertebrates and 11 Fish), with the Pelagian Islands (26: 12 Macrophytes, 6 Invertebrates and 8 Fish) and the Egadi Islands (21: 11 Macrophytes, 6 Invertebrates and 4 Fish) registering the highest number.