Changes in the benthic algal flora of Linosa Island (Straits of Sicily, Mediterranean Sea)

A study of the benthic algal macroflora of Linosa Island ( Straits of Sicily, Mediterranean Sea) is presented, aiming to verify possible floristic changes that have occurred in the area, last studied in 1973. We found noticeable changes in the benthic flora, which is now poorer in species than that recorded in the literature ( 233 species against 305), with a minor decrease in Phaeophyceae and Chlorophyta, and a more significant decrease in the number of Rhodophyta. Only 178 species in the present flora were reported previously, while 127 previously reported were not found during the present study. Conversely, 55 species were newly found. Several species of Fucales, like Cystoseira brachycarpa, C. sauvageauana, C. spinosa, C. zosteroides, Sargassum acinarium and S. trichocarpum, which are characteristic of the Mediterranean Sea photophilic communities on hard substrata and sensitive to any environmental changes, have disappeared.