East China Sea
Main Contributors:
Other Contributors:
Summary
The East China Sea has faced a huge stress from population growth in the Changjiang river (Yangtze River) drainage basin and the areas along the coasts. Hypoxia was first documented in the early 1980s. In the past two decades, the anthropogenic nutrient load from the Changjiang River has increased over 10-fold and continuous growth is expected in the future. The formation and maintenance of the hypoxia is due to anthropogenic nutrient load through the river and strong stratification. The major source of nutrients is the use of fertilizers in agriculture. It has been suggested that there have been episodic hypoxia for the past 50 years but not every year, and that all events with large size of affected area occurred after the late 1990s.
The East China Sea hypoxia is episodic and sensitive to weather conditions. The Changjiang River is dominated by the East Asia Monsoon causing high flows with large sediment loads (decomposition consumes large quantities of dissolved oxygen) to the sea during summers. Reoccurring typhoons can mix the water and decrease the hypoxic volume. The cold air southward intrusion in the summer can change the wind direction and break the hypoxia. Bottom topography of the East China Sea and inflow of Taiwan Warm Current saline water may also be additional drivers for the hypoxic areas.
East China Sea is one of the world's major fishing grounds.
Type of regime shift
Ecosystem type
- Marine & coastal
Land uses
- Fisheries
Spatial scale of the case study
- Sub-continental/regional (e.g. southern Africa, Amazon basin)
Continent or Ocean
- Asia|-|Pacific Ocean
Region
- East Asia
Countries
- China, People's Republic of
- Japan
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Key References
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Chung-Chi C, Gwo-Ching G, Fuh-Kwo S. 2007. Hypoxia in the East China Sea: One of the largest coastal low-oxygen areas in the world. Marine Environmental Research 64, 399-408.
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Li D, Daler D. 2004. Ocean pollution from land-based sources: East China Sea, China. AMBIO: A Journal of the Human Environment 33, 107-113.
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Wang B. 2009. Hydromorphological mechanisms leading to hypoxia off the Changjiang estuary. Marine Environmental Research 67, 53-58.
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Wei H, He Y, Li Q, Liu Z, Wang H. 2007. Summer hypoxia adjacent to the Changjian estuary. Journal of Marine Systems 67, 292-303.
