Brief Summary

“[T]halli are highly differentiated into holdfast, cylindrical main axis, leaflike blades, and airbladders in the axil of blades. This genus is widely spread in temperate, tropical, and subtropical waters in both intertidal and subtidal zones. Some forms are free-floating, sometimes occurring in extensive rafts that harbor distinctive communities of organisms adapted to the buoyant Sargassum habitat. These occur in the Sargasso Sea off the western coast of Africa. During the 1940s, Sargassum muticum spread from Japan to the northern pacific coast of the US, and by the 1970s had made its way south to California. This species of Sargassum has also spread to Europe, probably on oysters destined for aquaculture operations. Sargassum forms nuisance growths in harbors and on beaches, and it can quickly spread to new areas due to the floatation capabilities conferred by its many air bladders. Other features contributing to rapid spread include fast growth rate, fertility in the first year and monoecious reproduction.” (Graham & Wilcox, 2000)