Gulf of Mexico Dead Zone

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Nitrogen from fertilizer runoff causes huge dead zones in the oceans where fish and other marine life can't survive.

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

According to a study done by the
Environmental Working Group, much of the
fertilizer runoff comes from heavily subsidized farms in the Corn
Belt, an area that includes Iowa, Illinois and Indiana. Corn
requires the highest fertilizer input of any major crop, and about
45 percent of all commodity support payments in that area go to its
production. The money typically spent on taxpayer-funded farm
subsidies in the area dwarfs the amount spent on efforts to protect
water quality and conservation by a ratio of more than 500 to

To learn more about the dead zone, visit the
Museum of Minnesota’s
interactive site, or the
River Basin Alliance

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