'Ocean deserts' are growing

Low-oxygen 'underwater deserts' in the tropical oceans have expanded over the past 50 years, according to new measurements. The most likely cause of the change is global warming, and climate models predict that the trend will continue, potentially threatening marine ecosystems.

The discovery concerns a layer of the ocean called the 'oxygen-minimum zone', where concentrations of dissolved oxygen are particularly low. The new study shows that this zone has been expanding both upwards and downwards into the adjacent layers in tropical waters.

Climate models predict that warming of the sea's surface as a result of human activity will hamper the mixing of oceanic waters, preventing dissolved oxygen from mixing evenly through the water column. The new results suggest that this process has already begun

http://www.nature.com/news/2008/080501/full/news.2008.795.html

Man must learn to combat desertification if he wishes to live on an Eden-like planet. Besides learning to move water from abundant areas to parched areas, this also means learning to move oxygen from the atmosphere to depleted ocean waters.