Sargasso Sea

Sargasso Sea
López Miranda JL, Celis LB, Estévez M, Chávez V, van Tussenbroek BI, Uribe-Martí · Public domain · source
Name	Sargasso Sea
Location	North Atlantic Ocean
Type	sea
Area	~1,300,000 km²
Max-depth	~6,000 m

Sargasso Sea

The Sargasso Sea is a distinct region of the North Atlantic Ocean characterized by floating Sargassum seaweed, clear blue water, and a circulating system within the North Atlantic Gyre, situated between maritime regions associated with Bermuda, the Azores, the Canary Islands, and the eastern seaboard of North America. Descriptions of its boundaries, ecology, and cultural resonance link the sea to navigators such as Christopher Columbus, naturalists like Charles Darwin, and modern oceanographers affiliated with institutions including the Woods Hole Oceanographic Institution and the Scripps Institution of Oceanography.

Geography and boundaries

The region lies within the subtropical sector of the North Atlantic Ocean and is enclosed by the clockwise circulation of the Gulf Stream, the North Atlantic Current, the Canary Current, and the North Equatorial Current, creating a quasi-stable polygonal area near islands such as Bermuda, the Azores, and the Azores Current intersection. Cartographers and oceanographers from bodies like the National Oceanic and Atmospheric Administration and the British Admiralty have mapped its approximate limits, which span roughly between the latitude of Cape Hatteras and the approaches to the Azores Plateau, yielding an area estimated by some studies to be near 1,300,000 square kilometers. Historical mariners from fleets such as those of Spain and Portugal noted the region’s placid winds and weed mats during transatlantic voyages departing from ports like Seville and Lisbon.

Oceanography and physical characteristics

The Sargasso Sea’s hydrodynamics are governed by the larger North Atlantic Gyre and thermohaline processes influenced by water masses originating near the Gulf of Mexico and the Mediterranean Sea via exchanges modulated by the Azores Front and mesoscale eddies tracked by researchers at NASA and the European Space Agency. Its surface waters are among the clearest in the world, with low nutrient concentrations and high salinity comparable to measurements from the Bermuda Atlantic Time-series Study and instruments used by crews of the NOAA Ship Ronald H. Brown. Vertical structure includes a pronounced thermocline and nutrient-poor euphotic zone documented by profiling floats deployed by the Argo program and sampling campaigns conducted by teams from the Monterey Bay Aquarium Research Institute and the Plymouth Marine Laboratory.

Ecology and biodiversity

Biological communities center on floating mats of Sargassum that provide habitat for species such as the sargassumfish (Histrio histrio), juvenile stages of leatherback sea turtles, and pelagic invertebrates recorded by expeditions led by naturalists from the British Museum and museums like the Smithsonian Institution. The region supports migratory routes used by populations of American eel and European eel during complex life-cycle movements linked with spawning hypotheses involving islands like Bermuda and scientists including Einar Lea, while pelagic fishes such as tunaes and marlin frequent peripheral currents studied by fisheries managed under agreements involving the International Commission for the Conservation of Atlantic Tunas. Primary productivity is influenced by nitrogen fixation by cyanobacteria and epiphytic communities described by researchers affiliated with the Max Planck Society and the Royal Society.

History and human interaction

Accounts of the region appear in the logs of Christopher Columbus and navigators of the Age of Discovery who reported floating weed and calm winds, later entering literature by authors such as Jules Verne and J. R. R. Tolkien-era mythographers who evoked its mystique in seafaring lore preserved in collections at the British Library. Scientific exploration accelerated in the 19th and 20th centuries through voyages by vessels like the HMS Challenger and research cruises organized by institutions including the American Museum of Natural History and the Scripps Institution of Oceanography. The Sargassum habitat has influenced fisheries, shipping routes tracked by companies headquartered in London and New York City, and cultural representations in art held by the Metropolitan Museum of Art and the National Gallery.

Conservation and environmental issues

Contemporary concerns involve the influx of pelagic plastics documented by surveys from Ocean Conservancy and satellite monitoring by European Space Agency missions, as well as the episodic massive blooms of Sargassum affecting coastlines of nations such as Barbados, Trinidad and Tobago, and Ghana with socioeconomic impacts studied by researchers at the University of the West Indies and the University of Ghana. Climate-driven changes in circulation patterns and stratification observed by the Intergovernmental Panel on Climate Change and modeled by teams at the National Center for Atmospheric Research may shift productivity and species distributions, prompting policy discussions at forums including the United Nations and conservation NGOs like WWF. International efforts involving maritime governance institutions such as the International Maritime Organization and scientific collaborations led by the Global Ocean Observing System aim to monitor, mitigate, and manage threats including pollution, habitat alteration, and the conservation of migratory species protected under conventions like the Convention on Migratory Species.

Category:Seas of the Atlantic Ocean