Many people may think "What is interesting about the sea? It is only salt water" but they are wrong, it is a very interesting place, so today I will explain some reasons (or at least those that are known until now).
The sea covers most of the surface of our planet, approximately 70% of it is covered with water, so it is not surprising that it also has many more living species than those that inhabit the earth, including the largest known animal, the blue whale. Its wide variety of life may be due to the fact that human activity is just beginning to affect marine ecosystems, compared to the years we have been polluting the air and soil.
All marine species that have been discovered today inhabit only in the 10% of the oceans we have explored, just imagine how many are still to be discovered. If something is certain is that the more we discover more strange and unique are, some seem taken from the mind of the famous fiction writer Howard Phillips Lovecraft.
But of course, we do not have the necessary technology to investigate it better (you would be surprised to see a graph of the budget spent on research compared to that spent for military purposes), because the more we "submerge" in the matter, the more dark and cold turns, in fact the average temperature of the oceans is 2 ° C, but not only that, the pressure also increases. At sea level we are at 1 atmosphere (atm) or 760 millimeters of mercury (mmHg), but if we descend to 10 meters below sea level this pressure is doubled, if we descend to 20 meters it triples ... And so on.
Well, that's a small part of why the sea is so great. So the least we can do for it is take care of it, pollution is a very serious matter and it's sad to see how we end up with the different life forms on Earth.