Dead zone discovered in Bay of Bengal:
Scientists including those from India have found a huge ‘dead zone’ of an estimated 60,000 square kilometres in Bay of Bengal. This area is said to supports microbial processes that remove vast amount of nitrogen from the ocean.
What is Dead zone?
Dead Zone is an area in water body that contains little or no oxygen (or they are hypoxic) in bottom and near-bottom water. Mostly they occur naturally but it can be caused by excessive nutrient pollution from human activities coupled with other factors.
They are well-known off western coasts of North and South America, off coast of Namibia and off west coast of India in Arabian Sea.
What has led to the expansion of dead zones?
In recent times, warming of the atmosphere through climate change is predicted to lead expansion of ‘dead zones’ in the ocean.
Key Findings Researchers, demonstrated that some oxygen does exists in the Bay of Bengal waters. But the concentration of oxygen is much less than standard techniques could detect and some 10,000 times less than that found in the air-saturated surface waters.
The researchers also discovered that the Bay of Bengal hosts microbial communities that can remove nitrogen but at really slow rates. Removing more nitrogen from the oceans could affect the marine nitrogen balance and rates of marine productivity.