Starved out

The Southern Ocean is losing its oxygen due to global warming

 
Published: Tuesday 30 April 2002

the Southern Ocean, which is considered the lungs of the world's oceans, is being slowly starved of oxygen due to global warming. The ocean swirls around the Antarctic. Research expeditions backed by Australia-based Commonwealth Scientific and Industrial Research Organisation (csiro) show declining oxygen content in the ocean at depths of 500 to 1,500 metres. "The findings are consistent with climate simulations and with change caused by the build up of greenhouse gases," said csiro oceanographer Richard Matear (www.yahoo.com, March 23, 2002).

The readings are important for fine-tuning predictions of severe weather events, including floods and rising sea levels, added Matear. In the much longer term, they have importance for the entire life of the seas. "If you run these models forward for another 3,000-4,000 years you will see significant expansions of regions where there's low oxygen concentration, which will have impacts on marine life," Matear said.

Next to temperature and salinity, oxygen is the most measured element in the ocean and is shown to be sensitive to climate changes. Limited work in the north Pacific also indicates declining oxygen content that is consistent with model simulations. csiro scientists are now collecting further samples south of Tasmania to widen the sample base. Samples so far have been collected from the sea along a line between Tasmania and Antarctica, with most readings taken at 50 to 65 degrees latitude south.

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