In the mid-North Atlantic, more than 950km from the coast of Florida (USA), there is a strange calm water area - where the waves are just long, flat and still waves. Without land, without coastline, without islands, this water area is still called by its own name: Sargasso Sea - the only "shoreless sea" on Earth.
On the water surface, each patch of narrow, brown sargassum is carpeted thanks to small balloons. In that dense vegetation, shrimp, fish, crabs and hundreds of other species take shelter, provide food and breed. Sargasso is also the only river named after a plant species, rather than a strip of land.
Since the Columbus period, crew have recognized this strange water area. In 1492, he wrote that ships could never feel the wind again, fearing that the fleet would be forever stranded. They did not know that the calm was right in the subtropical waters of the North Atlantic, where strong currents rolled around and gathered everything floating in the center of the vong.
It is this structure that makes rong sargassum converge, creating a separate sea area in the vast ocean - a phenomenon that cannot be found anywhere else.
From above, the Sargasso Sea looks like a 1,300km wide nursery, where the seaweed carpets are the "ecosphere island". They shelter, provide shelter, and provide food for countless species.
The Sargasso Sea plays an important role in Atlantic climate regulation. In the summer, the surface water is warm at 28-30 degrees Celsius; in the winter, it drops to 18-20 degrees Celsius. The warm water flows north, cold water flows south, creating a balance of heat and moisture between the two sides of the Atlantic.
It is also a natural carbon tank: Elderly creatures absorb CO2, then when they die, their shells sink to the bottom, locking carbon for centuries.
However, long-term records from the 1950s to present show that the average temperature has increased by about 1 degree Celsius since the 1980s. Warmer surfaces prevent water from mixing vertically, making it difficult for oxygen to go deep and nutrients to increase, threatening the ecosystem.
Located between major flows, this peaceful sea area also collects... plastic waste. A survey estimated 200,000 pieces of garbage per square meter, including nylon bags, bottle caps, and abandoned fishing nets.
The Sargasso Sea Committee - established in 2014 - calls the area a biodiversity paradise, calling on countries along the Atlantic to adjust their shipping routes to avoid dense areas and promote marine protection areas.
At the same time, governments are negotiating a treaty to reduce plastic pollution and protect the migration corridors passing through the area.
Because if the Sargasso Sea loses its special properties, the storms heading towards Europe may change direction. The Atlantic could even hold back more of Earth's excess heat.
