Dead Zones what are they? By now a lot of people already know what they are. They are parts of the sea or ocean or other water forms which are devoid of dissolved oxygen. They are what we call “choke” points. They can vary from a very small size to hundreds of square meters.
What is a dissolved oxygen? It is the quantity of oxygen diffused in water which is directly absorbed from the atmosphere. . Land beings use oxygen found in the atmosphere to survive but marine animals which include fishes won’t be able to breathe what we can and vice versa. They will drown in open air. So when fishes go up the surface, they can’t stay long and have to dive once more to take a breath of that dissolved oxygen.
Now, there are various water areas that don’t have dissolved oxygen anymore. Once these areas or better still, dead zones travel to one place, yes they move around in whirling water, they will kill all marine life without sparing anything. If we compare it to the land mass, they are the “deserts” of the oceans. While we can still breathe in deserts, dead zones are much more restrictive and lethal.
These dead zones are found in highly populated areas along the coasts of eastern and southern parts of the US and the Baltic Sea. Lately, they have been spotted in open waters like the Atlantic Ocean.
How these dead zones are formed anyway? The team had been monitoring the area for seven years and had their work published in the journal Biogeosciences.
The findings of the scientists showed that there are low-oxygenated waters in the Atlantic Oceans. This is according to Washington Post. They are massive and can measure up to 100 square miles. That would be very scary to say the least. Being seasonal, they go around travelling around without stopping. It’s one of the largest discovered so far and is found in the Gulf of Mexico.
What occurs inside these dead zones? Mixed-up nutrients and microbes are to delivered from several places. Algae eats the nutrients and which in turn are fodder to microorganisms. Wastes are generated and in turn eaten by other microbes. There are a series of breakdown of food from one form to another. These processes use up a lot of oxygen. Small oxygen-free pockets are formed then.
The lack of nutrients here would be fatal to fish or other sea animals which has to move out immediately or may die while inside the area.
Dead zones are mostly found in shallow waters but researchers discovered that they are found in the Atlantic Ocean by now. They form eddies or what is similar to cyclones but it happens underwater . They spin so fast creating s a vortex. This will continue for months creating a watery wall surrounding the core which sucks the oxygen out from the area.
“The fast rotation of the eddies makes it very difficult to exchange oxygen across the boundary between the rotating current and the surrounding ocean. Moreover, the circulation creates a very shallow layer – of a few tens of meters – on top of the swirling water that supports intense plant growth,” study author Johannes Karstensen of the University of Bremen says in the press release of the journal of the European Geosciences Union (EGU).
Dead zones could affect people on land even if they are found in the middle of the Atlantic Ocean especially in Cape Verde, say scientists.
“Given that the few dead zones we observed propagated less than 100 kilometers north of the Cape Verde archipelago, it is not unlikely that an open-ocean dead zone will hit the islands at some point,” Kartsensen explains. “This could cause the coast to be flooded with low-oxygen water, which may put severe stress on the coastal ecosystems and may even provoke fish kills and the die-off of other marine life.”