Sargasso Sea: The Only Sea Without Shores

Sargasso Sea surrounded by currents

Floating Seaweed (Sargassum)

 Sargasso Sea is a unique and mysterious area in the North Atlantic Ocean. It's defined by the boundary currents that surround it: the Gulf Stream in the west, the North Atlantic Current in the north, the Canary Current in the east, the North Atlantic Equatorial Current in the south. It stretches from 20 degrees N to 35 degrees N, and 40 degrees W to 70 degrees W. It is strewn with free-floating seaweed of the genus Sargassum, after which it was named by Portuguese sailors in the 15th century.

Weaker horses were thrown overboard to save water
for better ones

 The sea is a warm lens-shaped body of water sitting on top of cooler water, and is higher by a meter in its middle than around its edges. It is a biological desert with low nutrients; the floating seaweed actually grows in near-shore areas before being carried out by currents to the Sargasso. The sea's dangerous reputation comes from its location in the almost windless Horse latitudes between 30 and 35 degrees N; the air in this region is often so still that sailing ships were becalmed and stranded there for months at a time, thus prolonging the voyage and resulting in water shortages. Weaker horses were thrown overboard to save water for better ones or even slaughtered for fresh meat.

  Sailors mistakenly thought that sailing ships drifted endlessly because they were entangled in the weeds. Adding to their fears, small shipworms in tropical waters sometimes turned the sides of a becalmed ship into a rotted mass. The shipworm's ability to digest cellulose enabled it to bore into submerged wood faster than kids ate candy. Over time, the seaweed and its fauna were transformed in stories into monsters and giant squid that could take down any ship. At present, even though ships travel frequently through Sargasso Sea and people even go diving there, the stories made up by long dead superstitious sailors still live on. What can I say, the public loves a mystery. On the bright side, these stories inspired a lot of great fictitious plots and novels that many enjoy.


 GOBI (Global Ocean Biodiversity Initiative) recently proposed Sargasso Sea as an EBSA (Environmentally and Biologically Significant Area) because of its following properties:

• Unique in the world as the only area that is a center of distribution for a self-sustaining community of holopelagic drift algae.
• Provides a structured habitat for a wide range of fauna, including endemic, threatened, and commercially important species.
• Spawning site and migratory route for several species (eels, marlin, tuna, loggerhead sea turtles, humpback whales)

 My favorite species in the sargassum's fauna is the Histrio histrio because it's a perfect example of symbiosis. It's an ambush predator that mimics the color and texture of the seaweed to avoid being seen; thank god they're much smaller than us!

Histrio histrio (Sargassumfish)