North Atlantic
The Sargasso Sea is located in the North Atlantic Ocean between 70 and 40 degrees west longitude and 25 and 35 degrees north latitude. It is bounded by the Gulf Stream, the North Atlantic Current, the Canary Current, and the North Atlantic Equatorial current.  2(b) Image depicts seamounts occurring in the Northwest Atlantic. The northwestern portion of the Sargasso Sea is bisected by the New England Seamount Chain. The dashed line denotes approximate area within Sargasso Sea. White arrow notes location of Bermuda. (Lamont Doherty Earth Observatory, Earth Institute at Colombia University, original image generated with Bill Haxby's GeoMapApp and slightly modified with dashed line and arrow here).  (NOAA Photo Library. ). The Sargasso Sea is located entirely within the Atlantic Ocean and characterized by the presence of holopelagic Sargassum. Holopelagic Sargassum is free-floating algae that remains in the open ocean for its entire life cycle. The Gulf Stream establishes the Sargasso Sea’s western boundary, while the Sea is further defined to the north by the North Atlantic Current, to the east by the Canary Current, and to the south by the North Atlantic Equatorial Current. . While there are many different types of algae found floating in the ocean all around world, the Sargasso Sea is unique in that it harbors species of sargassum that are 'holopelagi' - this means that the algae not only freely floats around the ocean, but it. on the high seas. Mats of free-floating sargassum, a common seaweed found in the Sargasso Sea, provide shelter and habitat to many animals. Image credit: University of Southern Mississippi Gulf Coast Research Laboratory. The Sargasso Sea in the North Atlantic is bounded by the Gulf Stream on the west, the North Atlantic Current on the north, the Canary Current on the east, and the North Equatorial Current on the south. The Sargasso Sea is a region in the gyre in the middle of the North Atlantic Ocean. It is the only sea on Earth which has no coastline. The Sargasso Sea is 1,107 km wide and 3,200 km long (700 statute miles wide and 2,000 statute miles long). It stretches from roughly 70 degrees west to 40 degrees west, and from 20 degrees north to 35 degrees north More precisely, the Sargasso Sea is located in the middle of North Atlantic Ocean bounding the Great Antilles on the south, the Gulf stream on the west, and Bermuda on the north (Teal & Teal, 1975). These currents move around the Sargasso sea in a clockwise orientation. Because it is not bounded by coastline and is surrounded by strong currents, the Sargasso Sea is considered an isolated, oligotrophic (little to sustain life) area. The surrounding currents provide a strong physical boundary separating the Sargasso sea from the more nutrient-rich waters of the North America shelf. The Sargasso Sea, located entirely within the Atlantic Ocean, is the only sea without a land boundary. Mats of free-floating sargassum, a common seaweed found in the Sargasso Sea, provide shelter and habitat to many animals. Image credit: University of Southern Mississippi Gulf Coast Research Laboratory. There's a bit more to the Sargasso Sea than there is to the Bermuda Triangle, though--not that that's saying much. The Sargasso Sea is a 2,000,000-square-mile ellipse-shaped region of the North Atlantic Ocean extending south and east of Bermuda. It's called the Sargasso sea because comparatively large amounts of seaweed of the genus Sargassum can be seen floating on the surface. 
http://geography.about.com/od/globalproblemsandissues/a/trashislands.htm http://gobi.org/Our%20Work/rare-2 http://www.gc.noaa.gov/gcil_mpa_sargasso_sea.html http://oceanservice.noaa.gov/facts/sargassosea.html https://en.wikipedia.org/wiki/Sargasso_Sea http://microbewiki.kenyon.edu/index.php/Sargasso_Sea http://oceanservice.noaa.gov/facts/sargassosea.html http://www.straightdope.com/columns/read/2024/whats-the-story-on-the-sargasso-sea
where is sargasso sea located