Sargassum is a genus of large brown algae that includes over 300 species. Two prevalent species in the Atlantic Sargassum natans and Sargassum fluitans, are found in free-floating mats, held afloat by gas-filled bladders. The floating sargassum provides food and protection for a range of marine wildlife, including fish, mammals, marine birds and crabs. It serves as a critical habitat for threatened loggerhead sea turtles and as a nursery area for a variety of commercially important fish.