The only named sea with no coast is a seaweed gyre
The Sargasso Sea is a North Atlantic region boxed by four currents—the Gulf Stream, North Atlantic Current, Canary Current, and North Atlantic Equatorial Current—forming a clockwise gyre. It is the sole named sea without land borders, marked by brown Sargassum and oddly calm blue water.
The four currents that fence it in, the Gulf Stream to the west, the North Atlantic Current to the north, the Canary Current to the east and the North Atlantic Equatorial Current to the south, make up the North Atlantic Gyre. The sea lies roughly between 20° and 35° N and 40° and 70° W, about 1,100 kilometres wide and 3,200 long, with Bermuda near its western fringe. Because currents shift, so do its edges; a 2011 study using currents, weed and seabed shape put it at about 4.16 million square kilometres, centred near 30° N, 60° W.
Portuguese sailors named it for sargaço seaweed, and Columbus worried in 1492 that the floating mats signalled hidden shallows. The fourth-century poet Avienius, drawing on the lost voyage of Himilco in the fifth century BCE, had already described weedy, windless Atlantic waters. The weed rarely troubles ships; old tales of vessels stuck fast owe more to the calm winds of the horse latitudes. In 1609 the English ship Sea Venture was driven ashore on Bermuda, and the sea has also seen whaling and fishing.
Johannes Schmidt’s Dana expeditions of 1920 to 1922 showed that European eels spawn here. American eels and American conger eels do the same: larvae hatch in the sea, drift to Europe or North America, and return as adults to breed, European young taking about three years to reach British waters. William Beebe and Otis Barton’s bathysphere dive of 1932 relayed sightings of deep animals by radio.
Young loggerhead turtles are thought to ride the Gulf Stream here and shelter in the weed until grown, and the sargassum fish, a frogfish, is camouflaged to vanish among the fronds.
Source: Sargasso Sea
