Part of: GS Prelims and GS Mains III–Environment Conservation
In News
According to the study released by IUCN at Madrid Climate conference, the levels of oxygen in oceans fell by around 2 per cent from 1960 to 2010. Also, the water in some parts of the tropics had experienced a 40 per cent to 50 per cent reduction in oxygen.
The deoxygenation of the oceans occurred due to climate change and other human activities (such as the nutrient runoff from farm fertilizers into waterways)
The loss of oxygen in the oceans can affect the planetary cycling of elements such as nitrogen and phosphorous which are essential for life on Earth
As oceans lose oxygen, they become more acidic, a phenomenon that has resulted in some places in shellfish having their shells degraded or dissolved — the so called “osteoporosis of the sea”.
In many parts of the world,fish have been dying en masse — a clear illustration of the ways in which deoxygenation is choking the oceans.
Apart from their declining oxygen content, oceans have, since the middle of the 20th century, absorbed 93 per cent of the heat associated with human-caused greenhouse gas emissions, leading to mass bleaching of coral reefs.
