Gulf of Mexico Dead Zone

In the Gulf of Mexico, several miles off the Louisiana coast, lies one of the world’s largest “dead zones" — oxygen-deprived areas devoid of all marine life. Researchers predict that this summer, the dead zone will grow to cover nearly 6,700 square miles, an area roughly half the size of Maryland, and far larger than its size in recent years of 4,800 square miles.

Worst of all, the dead zone is human-made: runoff from farms in the Midwest adds as much as 7.8 million pounds of nitrate fertilizer to the Mississippi River and its tributaries each day during peak loading periods, which then runs downriver and empties into the Gulf. As it does with plants grown on land, the nitrogen causes algae and plankton in the area to flourish, using all available oxygen in the water. The result is hypoxia, an oxygen depleted dead zone in which fish and other marine life simply cannot survive.

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