On the basis of bibliographical revisions and the monitoring program, 4 introduced species are recorded for the Port of Ensenada, Baja California, Mexico: Sargassum muticum and S. filicinum,Grateloupia turuturu and Grateloupia lanceolata, which exhibit an invasive behavior for their abundance. These species grow seasonally over intertidal rocks, on the hulls of ships and on different substrates from the Port facilities, competing for space with the native species.