Review of Non-Native Marine Plants in the Mediterranean Sea

Abstract

In this review 98 marine plant species probably introduced in the Mediterranean Sea have been inventoried (63 Rhodophyta, 20 Phaeophyceae, 11 Chlorophyta, 3 Dinophyta and 1 Spermatophyta). Of these 9 species are invasive and cause ecological or economic impacts. The main introduction vectors are aquaculture activities, the opening of the Suez Canal and maritime transport. Oyster transfer which is probably responsible for 44 introductions is the most important. The time scale evolution of exotic plants in the Mediterranean is exponential, with an increase of 50 species in the two last decades. The western Mediterranean basin is the most receptive zone with 67 non-native species, the majority of them of temperate or warm-temperate affinity with a Japanese or Pacific Ocean origin. In contrast, the 29 non-native species reported from the eastern Mediterranean are mainly warm-water or tropical species coming from the Red Sea or Indian Ocean. The Mediterranean is therefore turning into a reserve of Indo-Pacific species and in the future may become an important exporter of exotic species to other biogeographical regions.