Dead Zone (ecology)
Dead zones are hypoxic (low-oxygen) areas in the world's oceans and large lakes, caused by "excessive nutrient pollution from human activities coupled with other factors that deplete the oxygen required to support most marine life in bottom and near-bottom water. (NOAA)." In the 1970s oceanographers began noting increased instances of dead zones. These occur near inhabited coastlines, where aquatic life is most concentrated. (The vast middle portions of the oceans, which naturally have little life, are not considered "dead zones".)
In March 2004, when the recently established UN Environment Programme published its first Global Environment Outlook Year Book (GEO Year Book 2003), it reported 146 dead zones in the world's oceans where marine life could not be supported due to depleted oxygen levels. Some of these were as small as a square kilometre (0.4 mi²), but the largest dead zone covered 70,000 square kilometres (27,000 mi²). A 2008 study counted 405 dead zones worldwide.
Read more about Dead Zone (ecology): Causes, Effects, Locations, Energy Independence and Security Act of 2007, Reversal
Famous quotes containing the words dead and/or zone:
“Every man who has lived for fifty years has buried a whole world or even two; he has grown used to its disappearance and accustomed to the new scenery of another act: but suddenly the names and faces of a time long dead appear more and more often on his way, calling up series of shades and pictures kept somewhere, “just in case” in the endless catacombs of the memory, making him smile or sigh, and sometimes almost weep.”
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“The human race is a zone of living things that should be defined by tracing its confines.”
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