Sediments and nutrients darken the waters of the Gulf of Mexico from the Mississippi River and its distributaries, as seen in this image captured by NASA's Aqua satellite on May 6, 2013. (Image: NASA) This summer's "dead zone" in the Gulf of Mexico measures some 5,840 square miles, or roughly the size of Connecticut, according to the National Oceanic and Atmospheric Administration. A dead zone is an area where oxygen levels in the water drop so low that most forms of life cannot survive. Thanks to huge amounts of nutrients coursing down the Mississippi River from America's agricultural heartland, formation of a dead zone along the Louisiana coast has become an annual occurrence, threatening commercial and recreational fisheries valued in 2011 at $818 million.
This map shows the extent of low oxygen in the Gulf of Mexico along the Louisiana coast this summer. (Source: LUMCON/Rabalais) A wet spring that brought ...
