Yangtze and Pearl River estuaries now “dead zones”

China's Yangtze River and Pearl River estuaries have been newly listed as oxygen-deficient "dead zones", according to a study released by the United Nations Environment Programme (UNEP).
Oxygen-deficient areas in the world’s seas and oceans are places where nutrients from fertiliser runoff, sewage, animal waste and the burning of fossil fuels trigger algae blooms. The algae blooms use up oxygen in the water, endangering other marine life.
The number and size of deoxygenated areas in China has risen each decade since the 1970s. Experts warn that these areas are fast becoming major threats to fish stocks, and to people who depend upon fisheries for food and livelihoods.
As well as the two areas in China, other dead zones were found off Finland, Ghana, Greece,Peru, Portugal and Uruguay, as well as the western Indian Ocean Shelf.