Sargasso Sea

The Sargasso Sea is an area of the North Atlantic, roughly between 20° and 35° north latitude and 30° and 70° west longitude. Unlike seas defined partly by land, its boundaries are set by currents in the clockwise circulation of the North Atlantic Subtropical Gyre. The Gulf Stream forms its western boundary; the North Atlantic Current, Canary Current and North Atlantic Equatorial Current mark its northern, eastern and southern limits, respectively. These edges shift with the currents and are not fixed coastlines.

The sea takes its name from Sargassum, a genus of brown algae that floats at the surface. In this region, holopelagic Sargassum remains in the open ocean throughout its life cycle rather than attaching to the seabed. Floating mats offer food, shelter and nursery habitat to animals including young sea turtles, shrimp, crabs and fish. The area is also used by migratory wildlife and provides spawning habitat for eels. The open water itself can be relatively low in plankton, so the floating mats create habitat that is especially important within this ocean environment.

The Sargasso Sea supports interconnected marine life and is part of a wider high-seas ecosystem. Shipping, fishing, plastic and other pollution, harvesting of Sargassum, climate change and ocean acidification are among the pressures identified by scientific and conservation bodies. Because much of the ecosystem lies beyond the jurisdiction of any one country, effective protection depends on cooperation among governments and international organizations.

The Sargasso Sea Commission works with governments and other partners to promote the conservation of this open-ocean ecosystem. Established in 2014 following the Hamilton Declaration on Collaboration for the Conservation of the Sargasso Sea, the commission is an international cooperation initiative rather than a national authority governing the whole sea. Its work highlights the challenge of coordinating conservation in waters whose ecological connections cross jurisdictional boundaries.