What is the South Pacific Giro, the "marine desert" considered "the most hostile place of all the ocean" (and how comes the intriguing aquatic life that l & # 39; 39, live)?

In the middle of the Pacific Ocean, there is a vast area where natural conditions play against marine life.

It is a gigantic "marine desert" that scientists have termed "the most hostile place in the entire ocean".

It is known as the South Pacific Giro, which extends over 37 million square kilometers, from the coast of South America to New Zealand; and from Ecuador to the Antarctic Circumpolar Current. This equates to the addition of US, China and Russia.

On its surface you can see the most crystalline waters in the world, but this is only a sign of the sterility and sterility of this region.

It represents 10% of the total area of ​​the oceans, but it is still one of the least studied regions of our planet.

An expedition from the Max Planck Institute in Germany has revealed new clues about the place and the rare but particular lifestyle that inhabits it.

Extreme conditions

The Giro del Pacífico Sur is one of five huge systems of oceanic circular currents.

This current prevents the entry of more nutrient-rich waters that can come from other parts of the ocean, which is why their water is not "fertilized".

In this zone, the nutritious phytoplankton is found only at depths greater than 100 meters, which makes the surface so crystalline.

In the most remote areas of the "desert", far from any coast, the air does not carry organic particles from the earth, which does not contribute to feeding the water either.

The bottom of the tower contains the smallest amount of organic matter found in the deep sea.

And to this, we must add that in the region, the sun shines in a "dangerously high" way, according to experts. The UV levels in the tower are described as "extreme".

All of these factors make it difficult for the place to be inhabited by animals that abound in other parts of the world.

Research by the Max Planck Institute, however, has shown that in the midst of this desolate seascape, there were microorganisms that managed to survive despite adverse conditions.

For six weeks, a team of microbiologists traveled about 7,000 km in a boat between Chile and New Zealand, taking and badyzing samples of water during navigation.

These samples were taken between 20 and 5000 meters deep.

"Surprisingly, we found about one-third fewer cells in South Pacific surface waters compared to oceanic changes in the Atlantic," said marine microbiologist Bernhard Fuchs, co-author of the research, in a statement. .

"It's probably the smallest number of cells recorded in surface ocean waters."

Strange behaviour

According to the researchers, despite their small size, these organisms have a great influence on the dynamics of the ocean, as well as on global carbon cycles.

It is still unclear how these organisms survive in an environment with so few nutrients.

However, biologists have found cases of algae that establish symbiotic relationships with certain bacteria, with which they exchange essential substances such as nitrogen and sugars, although taking into account other nutrients, such as phosphorus and iron, remains mysterious. they are in these places.

During the course of exploration, they also realized that the "community" of organisms varied greatly with the increase in depth.

This is explained by the amount of light entering the water. The surprising thing, however, is that a highly photosynthetic organism called Prochlorococcus was found in very small amounts in surface water, where there is more light, and was more abundant at 150 meters deep, where it was darker.

The reverse occurred with another organism called AEGEAN-169, which until now had been detected only about 500 meters deep, but this time it was seen in a "particularly important "in the surface waters of the center of the turn.

"This is something we are definitely going to go further," said microbiologist Greta Reintjes, co-author of the research.

Although the South Pacific Giro still has many puzzles, scientists are confident that these discoveries will help to better understand the functioning of this ecosystem and its impact on the life cycles of the Earth.