How is the Sargasso Sea different from other seas in the world? Find out its secret

In the vast waters of the Atlantic, there is a sea unlike any other – the Sargasso Sea. It is not surrounded by any land, and is bounded by ocean currents. It is the only place of its kind in the world, with its own unique ecosystem, which has intrigued travelers, scientists and nature lovers for centuries, as well as stimulating the imagination, becoming the source of numerous legends and mysterious stories.

Where is the Sargasso Sea located?

The Sargasso Sea does not fit into the traditional framework of bodies of water that we know from geography lessons or maps. There is no land here – not a patch of coastline or an island – just an endless expanse of water. It is in the Atlantic Ocean, in the middle of the North Atlantic Gyre, the system of currents that form its natural boundaries. To the west flows the powerful Gulf Stream, called the Golfstrom, which carries warm waters from the Gulf of Mexico toward the coast of Europe. To the east, it is bounded by the cooler Canary Current, flowing down along Africa. To the north, the North Atlantic Drift Current, and to the south, this watery circle is closed by the North Atlantic Current.

These boundaries live a life of their own – they ripple, expand and contract with the force of the currents, giving the sea an almost organic character, estimated to cover an area of about 6-7 million km² and reach a depth of 1.5-7 thousand. m.

Sargasso Sea ecosystem

At the heart of the Sargasso Sea is sargassum seaweed, a brown algae that floats on the surface, forming vast golden carpets that stretch for tens and sometimes hundreds of kilometers. Contrary to popular belief, which might suggest that they are rooted to the bottom, these seaweeds drift freely, driven by ocean currents and wind. Golden mats of sargassum are true oases of life, attracting a variety of marine organisms. They provide shelter and food sources for many species, including endemic ones such as the sargasso anglerfish(Histrio histrio) and the tiny crab Planes minutus, which moves deftly among the seaweeds.

The Sargasso Sea also plays a key role in the life cycle of eels – both European(Anguilla anguilla) and American(Anguilla rostrata). These fish, after spending years in rivers and lakes, undertake a grueling journey of thousands of kilometers to spawn in this very sea. Later, their transparent larvae, called leptocephals, are carried by currents back toward the coasts, completing one of nature’s most fascinating migratory cycles.

The waters of the Sargasso Sea are crystal clear, with visibility reaching tens of meters (up to 60 meters), but poor in nutrients such as nitrogen and phosphorus, due to the lack of inflow from rivers or land. As a result, life is mainly concentrated on the surface, around the seaweed. This creates a unique ecosystem that differs from typical oceanic environments – with the dominance of benthic organisms or deep-sea plankton.

Legends and mysteries of the Sargasso Sea

The Sargasso Sea has fired the imagination for centuries, becoming a source of myths and stories passed down from generation to generation. The lack of land, the dense seaweed covering the surface and the almost dead silence of the waters, due to its location in a low wind zone, have made it a place that gives birth to stories full of horror and evokes fascination.

The most well-known legend links it to the Bermuda Triangle – the area between Bermuda, Florida and Puerto Rico, where mysterious disappearances of ships and aircraft were reported in the 20th century. Although science explains these phenomena by currents, eddies and methane eruptions from the bottom, for many the Sargasso Sea remains a mysterious, almost supernatural place.

At the time of the great sailing expeditions, in the 15th and 16th centuries, the Sargasso Sea caused trepidation among sailors. Christopher Columbus, who was one of the first Europeans to cross it in 1492, described in his diaries the floating fields of sargassum that stretched to the horizon and seemed to imprison his caravel in a windless trap. The sailors of that era, not understanding the dynamics of the currents or the nature of the seaweed, feared that these golden mats would hold them forever, condemning them to drift in the vastness.

There were also those who floated fantastic theories that it was the remnants of a sunken Atlantis, whose ruins would lie beneath the surface, while others believed the seaweed hid sea monsters – giant snakes or krakens – ready to drag ships into the abyss. A literary vestige of these mysteries is Jean Rhys’s 1966 novel Wide Sargasso Sea, which, while telling the story of human destiny, draws metaphors from the melancholy and isolation of the sea. Today, the Sargasso Sea attracts scientists who study its currents and ecosystem, but ancient legends still lend it an aura of mystery.

Challenges of modern times

The uniqueness of the Sargasso Sea does not protect it from the challenges of the 21st century, which are increasingly making their mark on this isolated ecosystem. In recent decades, the overproduction of sargassum seaweed, fueled by global warming and nitrogen runoff from land – mainly from fertilizers used in agriculture – is causing a massive influx of it onto the coasts of the Caribbean, the Gulf of Mexico and even West Africa. These golden mats, once a symbol of harmony, now linger on beaches in thick layers, emitting a hydrogen sulfide smell and threatening tourism, fishing and local communities that depend on the sea.

What was once a natural cycle is now spiraling out of control, turning the sargasso into a problem of international proportions. And in the Sargasso Sea itself, the wastes of the modern world are accumulating – microplastics from the breakdown of larger trash are embedded in mats of seaweed, creating a toxic environment for the organisms that inhabit it. Studies show that the fines are eaten by fish and crustaceans, and thus enter the food chain, even reaching humans. On top of that, climate change is disrupting ocean currents, which could affect the stability of sea boundaries and the distribution of sargassum, adding to the chaos in this fragile ecosystem.