TOPICS

We know the surface of Mars better than the bottom of the oceans

We know the surface of Mars better than the bottom of the oceans

By Lucas Gianre (UNC - MDZOL)

- From a scientific point of view, why is it important to investigate the sea?

- 75% of our planet is made up of seas that, among others, fulfill the function of regulating the Earth's climate system. In addition, the oceans are three-dimensional systems from the biological point of view: on the one hand there are benthic organisms, which live at the bottom and do not move; on the other, there are pelagics, which live in the water column, although they rise and fall but without settling on the bottom; and finally there is depth, which constitutes a separate dimension. If we take this classification into account, ocean systems make up 95% of those that can be found on the entire Earth.

- How much we do not know the marine world?

- What we ignore is vast. We know the surface of Mars better than the bottom of the oceans. Of the terrestrial environments, almost all chemical structures are known, in general terms; but every time species are removed from the sea, they are generally unknown, new and unpredictable.

- As for example benthic organisms ...

- Of course, because they cannot move from the bottom and it is difficult to reach them, to extract samples. This leads us to a limited vision, for example in documentaries, where calm and harmonious sea bottoms are shown, when in reality chemical wars are being unleashed there.

- A rather futuristic expression ...

- But there's nothing futuristic about it. Since benthic species - corals, starfish, sponges, urchins, etc. - are quiet, they are easy prey or can be attacked to occupy their space. To avoid this, benthics emit chemicals called secondary metabolites, which taste bad and prevent other organisms from sticking to them or growing on top of them. Among those that produce these "chemical weapons" are cucumbers or sponges, and many of the species that are living there depend on their effectiveness. On the other hand, these metabolites have a great biological activity: they are used as antiviral, anticancer and antibacterial.

- And what about the Argentine Sea?

- In general, the South Atlantic is one of the most unknown areas. From Europe and the east and west coasts of the United States, the knowledge is enormous. It has to do with the sampling efforts put forth by scientific institutions.

- How expensive is it to research the oceans?

- Exploring and studying marine environments in depth requires many resources. We must first take into account the different spaces: coastal environments; the intertidal (the strip that remains submerged when the low tide recedes); and then there is the sub-coastline, which are always submerged areas but with relatively little depth. They can be studied without many resources. But to investigate offshore, the question changes significantly: vessels and sophisticated sampling equipment are needed. In other words, many financial resources and also trained professionals are needed. In addition to all this, it is essential to have a plan.

- How do you evaluate the Pampa Azul plan launched by Argentina?

- It implies that for the first time we have an interdisciplinary, integrative and comprehensive plan to know and study different ecosystems within the Argentine Sea. It is planned to be developed in 10 years and with strong financial backing. It is a political decision. I believe that Pampa Azul is establishing a State policy regarding studying our sea.

- What was done before?

- There was very valuable work from institutes and universities, especially from the Patagonian provinces, which have been working in Marine Biology or Ecology for a long time. But there was never a comprehensive long-term national program.

- You have already started working at the Namuncurá bank, one of the five areas that the plan will focus on. What strikes you about this area?

- It is a very special place, but very little is known about it. In its vicinity there are up to three thousand meters deep, and the entire surface reaches up to ten thousand meters. The banks are mountains, but under water. And its peak ends about a hundred meters before reaching the surface. In general, their biological and scientific importance is enormous because they are environments with a lot of energy production. For this to happen, three things are needed in the sea: on the one hand, phytoplankton, that is, aquatic organisms –algae and protists– that serve as sources of oxygen and food for other species; sunlight; and nutrients, such as nitrogen, phosphorus, potassium, or iron. In the sea, these nutrients are mostly available in coastal areas, because of the rocks, the proximity to the terrestrial environment and because of the shallow depth. This dynamic makes what is produced and dies processed and available in the area where there is light. Therefore, these environments are recycled and generate a lot of energy. But at great depths, that recycling is not as efficient. From the point of view of energy production, they can be considered desert areas.

But in the case of this bank, there are marine currents loaded with nutrients from Antarctica that collide with this great mountain, the nutrients begin to rise and become available in the areas where there is light. Very rich ecosystems are generated, which are food sustenance for many species. They are spectacular places because we can see seagulls, whales, dolphins, penguins, a great variety of fish… Also in the bottom there is a great wealth of flora and benthic fauna.

- Coral reefs?

- There are many possibilities that they exist. The best known reefs are those in tropical waters, but several have recently been found in cold waters. And the Namuncurá Bank is an excellent place to host a cold reef. It would be one of the few in the South Atlantic. Reefs are areas of great diversity and abundance, because the corals that generate them build a structure at the bottom of the sea where many species can live.

- They are like small cities at the bottom of the sea ...

Exactly, they are impressive structures. They are built by polyps, very small organisms with a skeleton of calcium carbonate, a very hard compound. When one dies, another grows on top and forms a new house, so on. After hundreds or thousands of years, gigantic structures form from that rock, which is called calcite.

- After these 10 years, how can we translate this accumulated knowledge?

- We will gather a lot of knowledge, it will be impressive. In principle, we can answer a basic question: what do we have? Knowing the resources, we can plan what can be exploited, to what extent, and what needs to be conserved. Now, what is unknown is always a lot, something typical of science. When you answer a question, at least two more open. Ignorance never gets smaller, it is like running after a rainbow.

- Why did you choose to investigate the sea and not land environments?

- I imagined being in the sea, living underwater diving. I watched documentaries, Jack Cousteau, and said "I want to do that", be on a ship, on a boat, get involved in the environment. It was my fantasy. Even when I started studying, the difference between being on land or in the water was total. And that's why I chose Marine Biology. Then you realize that the only thing that changes is the technique, the sampling in this case, which takes you a couple of weeks a year. The rest are in the office. After all, biology is one.

Argenpress


Video: LIFE AT 11 KM DEEP? The history of exploration of the Mariana Trench (June 2021).