dead zone, Arabian sea, gulf of oman, oxygen minimum zones

Oceans are insanely suffocating of oxygen, investigators have warned about the world’s biggest danger zone without any marine life. A huge ‘dead zone’ in the Gulf of Oman is growing in size, according to research scientists who predict the oxygen-scarce area is dangerous than previously thought and warn the dead zone as a disaster holding up to happen. Back in the 1960s, researchers for the first time, discovered the Dead Zone in the Arabian Sea, found in the Gulf of Oman, a water area which is essentially lacking oxygen, entirely.

As of today, the dead zone in the Arabian Sea is the world’s largest Oxygen Minimum Zone (OMZ). Almost the size of Scotland or Florida, the dead zone roughly covers the complete Gulf of Oman, which shares the borderline with Iran, Oman, Pakistan and the United Arab Emirates.

A dead zone is a segment of the sea or a wide body of water that’s almost fully empty of oxygen. These low-oxygen areas are known as dead zones as they can’t support life anymore. Fish, animals and plant life in the zones throttle as a result of depressed oxygen levels, while some capable marine life succeeds to swim away from the area, leaving it blank.

Aquatic and marine dead zones can be created by an expansion in chemical nutrients (certainly nitrogen and phosphorus) in the water, scientifically termed as eutrophication. These chemicals are the primary building pieces of single-celled, plant-like organisms that exist in the water column, and whose growth is restricted in part by the accessibility of these materials.

It was in the 1970s that scientists began to notice some rapid increase in the dead zones. In 2008, 405 dead zones throughout the world were registered by Sweden’s Göteborg University. The occurrence of the Gulf of Oman dead zone has been known for about 50 years, but only recently have investigators managed to measure how its perimeters have changed over the past few decades, thanks to the use of marine robots, called Seagliders.

The data collected unveiled that in the regions where it was expected that there would be some significant amount of oxygen, the levels are now almost ceasing to zero. Scientists exposed an area of about 165,000 square kilometers, which is about twice the area of Scotland or as big as Florida.

“The Arabian Sea is the biggest and thickest dead zone in the world. But till date, no-one truly knew how serious the condition was because piracy and disputes in the area have made it too risky to collect information,” Dr. Bastien Queste from UEA’s School of Environmental Sciences said. “We hardly have any data obtained for almost half a century because of how challenging it is to send ships there.”

The remote-controlled submarines are the size of a small man and can work for months underwater at 1km. They were brought in use by research scientists from the University of East Anglia to the Gulf of Oman for eight months.

The team’s conclusions have now been published in Geophysical Research Letters. They received a strong drop of oxygen in the concerned zone compared to pre-1990 levels and also mapped how the oxygen is dispersed around the area over several seasons.

“Our research shows that the situation is actually worse than feared and that the area of the dead zone is vast and growing. The ocean is suffocating,” Queste said.

It is obvious and acceptable for dead zones to be created by natural means. But they can also develop as a result of extreme nutrient pollution from human exercises, the National Oceanic and Atmospheric Administration reveals. Many chemical, physical and biological constituents connect to form dead zones, but nutrient pollutions are the leading culprit. Nitrogen and phosphorus in fertilizers drain into the water resources and then act as nutrients which feed algae.

The algae ultimately die and decompose in the water. Here starts the troubling mechanism. This decomposed algae then serves bacteria which absorb oxygen nearby them, exhausting the supply. Climate change has amplified the issue, as hotter waters hold less oxygen.

The Gulf of Mexico is base to one of the greatest dead zones, which befalls each spring when farmers fertilize their land and the rain cleanses the fertilizer into rivers and the giant oceans. An area in the Baltic Sea is another massive dead zone.

Dead zones are “a real environmental dilemma, with terrible outcomes for humans too who rely on the oceans for food and work.” Guete said. More stressing is the fact that dead zones generate nitrous oxide, which is more hurting to the atmosphere if compared to carbon dioxide emissions.

Limnologist Dr. David Schindler, whose research at the Experimental Lakes Area went for the banning of dangerous phosphates in detergents, reminded about algal blooms and dead zones.

“The fish-killing blossoms that destroyed the Great Lakes in the 1960s and 1970s haven’t gone beyond; they’ve traveled west into a dry world in which people, industry, and agriculture are frequently taxing the quality of what little freshwater there is to be had here….This isn’t merely a field problem. The global development of dead zones generated by algal blooms is increasing rapidly.”

Scientists make a note that computer simulations reveal that the ocean oxygen levels in the Gulf of Oman will shorten over the next 100 years, with oxygen minimum zones growing rapidly. The next step for research scientists is to further examine to learn all of the contributory reasons of the expanding dead zone. Large Dead Zones in the Arabian Sea are taking place at many places and researchers have to find a way out. The ocean is home to a wide range of plants and animals which require oxygen to survive.

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