Stato delle conoscenze nella laguna di Venezia di due alien species: Undaria pinnatifida e Sargassum muticum.

Among the numerous allochthonous algae recorded in the Lagoon of Venice on the hard substrata over the last 15-20 years, the Ochrophyta Undaria pinnatifida and Sargassum muticum are those with the highest degree of diffusion, abundance and competition level with the native species. In this paper cycles of development [life history] are described and the 2009 distribution are up-to-dated for the whole lagoon and particularly for the city of Venice, where the two species showed the greatest diffusion. Possible eradication techniques are discussed, considering both the experimentations performed locally and, at a wider scale, at other sites of the world.