The Fucalean Forests of the Island of Lampedusa (Pelagie Islands Marine Protected Area, Central Mediterranean): Past and Present Diversity and Distribution

This study explored the occurrence, density, and distribution of Fucales along the island of Lampedusa, almost 30 years after the latest studies conducted on the marine vegetation of this island. To carry out this study, we conducted a monitoring activity in 18 sites through both scuba dives and snorkeling. During this study, a total of 13 species (three belonging to <i>Cystoseira</i> sensu strictu (s.s.), five to <i>Ericaria</i>, two to <i>Gongolaria</i>, and finally three to <i>Sargassum</i>) were observed. Nine species were previously reported, four taxa <i>(E. brachycarpa</i>, <i>E. funkii</i>, <i>E. giacconei</i>, and <i>S.</i> cf <i>furcatum</i>) were reported here for the first time in Lampedusa, and six species have not been found anymore. <i>Ericaria giacconei</i> may have always been present on Lampedusa Island, but it might have been misidentified in the past. The record on the island of Lampedusa extends the known distribution range of this species. The presence of <i>S.</i> cf <i>furcatum</i>, a non-indigenous species that is recently expanding in the Mediterranean Sea, could be considered further proof of ongoing seawater warming. In conclusion, we found that the predominant species’ association described in the past for the island of Lampedusa has remained unchanged in terms of species and biodiversity found in the studied sites. Nevertheless, we observed some changes in the Fucalean species, in particular a reduction in the canopy density values of some deep species. Therefore, we believe that the zonation pattern of the MPA should be revised, paying more attention to the conservation of fucalean species. Moreover, it will be important to manage and control the populations of the rabbitfishes, mitigating their impacts on the fucalean stands of the island.