The redlip blenny Ophioblennius atlanticus is an eastern Atlantic fish, distributed in oceanic islands and along the West-Coast of Africa, from Senegal to Angola. Fishes of the family Blenniidae, commonly known as combtooth blennies, are distributed worldwide, reaching their highest diversity in tropical and subtropical waters. This family currently includes 406 valid species and, to date, a total of 19 species have been recorded from Italian seas, most of which inhabit very shallow waters.

So far, and to our best knowledge, other three species of exotic blennies have been reported from the Mediterranean Sea. These are Omobranchus punctatus, recorded only once within the harbour of Ashod in Israel; Parablennius thysanius, recorded only once in the harbour of Antalya, Turkey and Petroscirtes ancylodo, firstly reported from Nizzanim, Israel and later in the Levantine basin. None of these species has established successful populations in the Mediterranean Sea, and biotic resistance is theoretically considered to be very high for this family. Being a species of sub-tropical origin, rising water temperatures are expected to increase habitat suitability for O. atlanticus. As for other exotic blennies, O. atlanticus might be easily transported through ballast waters or directly by ships, which are known to be one of the main vectors for marine bio-invasions.

Yet, further monitoring activities need to be regularly conducted, especially in proximity of Marine Protected Areas (MPAs). Furthermore, many Mediterranean MPAs are located in proximity to major ports and experience similar challenges, including the scarcity of information on management practices and a lack of trained local staff to effectively detect new introductions. It is therefore advisable to train MPA teams to identify non-indigenous organisms. This will improve our potential for early detection and rapid response, which is a desired approach for managing the issue of biological invasions in European seas and beyond. A more direct action concerning marine bio-invasions is also demanded globally, as stated by the Aichi Target 9 of the Convention on Biological Diversity (CBD 2015) and regionally, by the “Descriptor 2” of the European Union Marine Strategy Framework Directive (EU 2008). For these reasons, and in consideration of the rapidity and magnitude of biotic changes, NIS species should be taken into serious consideration in monitoring activities and management plans of Mediterranean MPAs.