What is the Sargasso Sea?
Quick answer
The Sargasso Sea is a region of the North Atlantic Ocean known for its floating mats of golden-brown sargassum seaweed. It’s the only sea in the world with no land coastline: instead, it’s bounded by ocean currents, including the Gulf Stream. Its calm, clear blue water is a vital nursery for eels, sea turtles and many fish.
Key facts
- Location
- North Atlantic, around Bermuda
- Area
- Roughly 2 million km² or more, varying with currents
- Boundaries
- Ocean currents of the North Atlantic Gyre
- Named after
- Sargassum seaweed
A sea bounded by currents
| Side | Current |
|---|---|
| West | The Gulf Stream; see what the Gulf Stream is |
| North | The North Atlantic Current |
| East | The Canary Current |
| South | The North Atlantic Equatorial Current |
Together, these currents form the North Atlantic Gyre, a huge circular system that slowly swirls around the Sargasso Sea. Bermuda is the only land within it.
Sargassum: a floating forest
Unlike most seaweed, sargassum never attaches to the seafloor. Small, air-filled bladders keep it afloat. The floating mats shelter:
- Baby sea turtles, which hide and feed there in their early “lost years”
- Fish, crabs and shrimp, some found only in sargassum
- The sargassum fish, perfectly camouflaged among the weed
Where eels are born
European and American eels travel thousands of kilometers to the Sargasso Sea to spawn. Their tiny, leaf-shaped larvae then drift on currents back to rivers in Europe and North America. No one has ever directly observed eels spawning in the wild there, one of nature’s enduring mysteries.
Columbus and sailors’ legends
Christopher Columbus crossed the Sargasso Sea in 1492, and his crew worried the seaweed would trap their ships. Because winds are often weak there, sailing ships could be stuck for days, leading to legends of ships trapped forever and of the “Bermuda Triangle.”
Today’s challenges
The Sargasso Sea collects floating plastic from the surrounding currents. In recent years, huge sargassum blooms have also washed onto Caribbean and Mexican beaches. In 2014, several countries signed the Hamilton Declaration to help protect the Sargasso Sea.
For the North Atlantic’s underwater mountains, see the Mid-Atlantic Ridge.
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