Sargasso Sea is characterized by

The Sargasso Sea is a unique region within the North Atlantic Subtropical Gyre, characterized primarily by its typical marine vegetation, specifically the free-floating brown macroalgae known as Sargassum [1]. Unlike other seas defined by land boundaries, it is bounded by four major ocean currents: the Gulf Stream, North Atlantic, Canary, and North Atlantic Equatorial currents [1]. These currents trap and concentrate the holopelagic Sargassum, which reproduces vegetatively on the high seas rather than on the ocean floor. This dense accumulation of seaweed creates a 'golden floating rainforest' that provides a vital habitat for diverse marine species, including sea turtles, eels, and various fish. While the sea does exhibit high salinity and warm surface temperatures due to high insolation and limited mixing in the gyre, its most defining and namesake characteristic is this specific marine vegetation [4].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 32: Ocean Movements Ocean Currents And Tides > The Sargasso Sea – A Sea Without a Land Boundary > p. 492
2. [4] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 33: Ocean temperature and salinity > General Behaviour > p. 517