Sargasso

The Sargasso, more commonly referred to as the Sargasso Sea, is a region of the western North Atlantic Ocean characterized by warm, relatively clear waters and large floating mats of brown seaweed from the genus Sargassum. The name derives from these seaweed mats, which provide a distinctive pelagic habitat within the central portion of the North Atlantic gyre.

Geographically, the Sargasso Sea lies within the North Atlantic subtropical gyre and is bounded indirectly by the surrounding currents: the Gulf Stream and North Atlantic Drift to the east, the Canary Current to the west, and the North Equatorial Current to the south. Its boundaries shift with seasonal and interannual changes in ocean circulation. Surface waters are typically warm, with low nutrients, creating relatively clear, calm conditions compared with adjacent coastal seas.

Ecologically, the floating Sargassum mats host a specialized, largely pelagic ecosystem. The seaweed provides shelter and food for numerous organisms, including certain fish such as the sargassum fish, crustaceans, mollusks, and many invertebrates, as well as juvenile stages of commercially important fish. The area is also associated with the life cycle of eels; European eels and possibly American eels are believed to spawn in the Sargasso Sea, where larvae drift westward to temperate shores. The region supports migratory species such as sea turtles and certain whale and dolphin populations.

Human pressures include pollution, plastic debris, and shifts in ocean circulation due to climate change, which can alter sargassum abundance and distribution. Large blooms of Sargassum in the Caribbean and western Atlantic have had ecological and economic impacts, prompting research and monitoring efforts. The Sargasso Sea has been the focus of conservation discussions given its unique pelagic habitat and the species that depend on it.