Researchers have discovered a huge dead zone in the Bay of Bengal. The area, estimated at 60,000 square km, reported to contain little or no oxygen.
The area is hosting microorganisms which remove a large amount of nitrogen from the ocean.
Though dead zones were found in other oceanic bodies as well, this also marks the first time there is indication of nitrogen loss.
Researchers from the CSIR National Institute of Oceanography reported though some amount of oxygen does exist in the Bay of Bengal, the concentrations are lesser than could be detected by standard techniques.
Oxygen levels are stated to be around 10000 times lesser than the amount discovered in air saturated surface waters.
Microbes present in the Bay of Bengal were capable of removing the nitrogen from the water, but traces of oxygen stop them from doing so.
Though there is some evidence of nitrogen removing microorganisms exist in well known dead zones as well, they are reported to work at a slower, more gradual rate.
Wajih Naqvi, the former director of the National Institute of Oceanography said that if the last amount of oxygen is removed from the ocean, then the bay would become the cause of nitrogen removal from oceans across the world.
Complete removal of nitrogen could affect the nitrogen balance in marine life and the rate of their productivity.
Dead zones are created when excess nutrients (nitrogen and phosphorous) result in the overgrowth of algae which later decomposes in the water consuming excess oxygen, lowering the supply available to marine life.
Global warming triggered by climate change will expand the dead zones.
It is not clear whether climate change would lead to removal of all oxygen from the bay.
What Are Dead Zones?- Large areas in the ocean with low oxygen concentration(hypoxic) in the lower part.
- Marine life in such areas suffocates and dies or moves away.
- Dead zones can occur due to natural or manmade reasons.
- Main cause of zones created by humans is nutrient pollution.
Other dead zones:
- Baltic sea bottom.
- Gulf of Mexico
- North, South America west coasts
- Namibia coast
- Indian western coast
