Saturday, August 16, 2008

The culprit: crop fertilizers

"Dead Zones" in coastal areas of our oceans, that is, areas in which the bottom waters are oxygen starved and hardly able to sustain marine life, have been doubling in size every ten years since the 1960s.

The NY Times reports:
"The main culprit, scientists say, is nitrogen-rich nutrients from crop fertilizers that spill into coastal waters by way of rivers and streams... Scientists attribute dead zones to a process that begins when nitrogen from agricultural runoff and sewage stimulates the growth of photosynthetic plankton on the surface of coastal waters. As the organisms decay and sink to the bottom, they are decomposed by microbes that consume large amounts of oxygen. As oxygen levels drop, most animals that live at the bottom cannot survive."

Apart from the marine life itself, the commercial fishing and shellfish industries are the hardest hit. Not only are these "dead zones" occurring in prime fishing zones (like Baltimore's own Chesapeake Bay), they are very hard to reverse. Population growth, changes in eating habits and of course industrialization - basically human activity - seem to blame. Just saying.

Please read Bina Venkataraman's more eloquent explanation here

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