Dream - Many fish in the sea? Definitely. But don't expect to find fish in the "dead zone" in the Atlantic Ocean discovered by scientists about eight years ago. In that area, it is difficult for fish to survive. According to Popular Science, in a paper published in Biogeosciences, researchers describe the dead zone as a swirling vortex measuring about 100 miles long - more than 160 kilometers. The vortex can rotate for months, moving from one point to another. The horror of this mysterious vortex has already been analyzed by researchers.

Usually, dead zones form in relatively shallow waters. For example, in lakes or along coastlines, during certain seasons. One of the largest dead zones in the world is located in the Gulf of Mexico, which forms during the summer. During that summer season, the area contains a lot of food originating from the Mississippi River Delta. The abundance of nutrients becomes an ideal place for the growth of algae. Algae will multiply in large numbers. The algae then become food for microorganisms, causing the water to turn into a kind of waste.

The death zone found in the middle of the Atlantic Ocean rotates rapidly. This process makes it difficult for oxygen to enter the whirlpool of water. The fast rotation of the whirlpool makes oxygen exchange challenging. Oxygen cannot penetrate the boundary between the current of water and the surrounding seawater. "In addition, the water rotation forms a very shallow layer -- several tens of meters -- above the whirlpool water, which supports the intensive growth of plants," said Johannes Karstensen, the researcher who wrote the report.

The researchers even found dead zones with no oxygen at all. The maximum oxygen concentration they found was 0.3 millimeters per liter of seawater. Prior to the publication of this study, the oxygen concentration in the North Atlantic was around 1 millimeter per liter of seawater. In the paper, Karstensen expressed concern that the moving dead zone in the North Atlantic could pose a danger to the residents of Cape Verde. This is because some of the dead zones studied were located less than 100 kilometers away from Cape Verde.