ARE MARINE PROTECTED AREAS (MPAs) EFFECTIVE IN PROTECTING FROM INVASIVE SPECIES? THE CASE STUDY OF CAULERPA CYLINDRACEA SONDER (CAULERPALES, CHLOROPHYTA) AT EGADI ISLANDS MPA

The main purpose of Marine Protected Areas (MPAs) is biodiversity conservation. The effects that invasive species have on MPAs, and vice versa, are still not completely known, even though their assessment is crucial for MPA management and conservation purposes. In this respect, monitoring plans are essential and the involvement of citizen scientists may be fundamental. Our experience of Caulerpa cylindracea Sonder 1845 monitoring within the Egadi Islands MPA highlighted that the alga is widespread within the MPA, mainly at Favignana Island, also threatening valuable habitats such as vermetid reef and coralligenous formations. Moreover, Favignana is the island of the Aegadian archipelago most affected by the introduction of non-indigenous species. Since invasive species are likely to continue to expand, and further arrivals are to be expected, additional management actions (e.g. concerning tourism activities) should be taken in MPAs to effectively control invasive species.