So why is oxygen disappearing from fishing waters in the Gulf of Mexico? The answer, scientists say, is found hundreds of miles to the north, up the Mississippi River in corn country.
Farmers in Iowa and across the Midwest use tons of nitrogen and phosphorous to make their cornfields more productive, which allows the farmers to take advantage of high corn prices resulting from growing demand from ethanol factories and developing countries.
Response stolen from Mike Rivero of whatreallyhappened.com. because I could not put it better myself:
So, let us recap.
Ethanol is sold to us on the claim that it is "carbon neutral" (which it isn't when you add in the emissions form the processing itself), and therefore a way to deal with the crisis-de-jour, human-caused global warming (at a time when the Earth's temperature is actually in decline). Since ethanol contains less energy than an equivalent amount of gasoline, drivers must buy and burn more of it to drive the same distance, which means it is actually more expensive per mile than gasoline. Plus, Germany has just banned ethanol because they discovered it actually damages the fuel system on cars designed to run on gasoline, thereby driving up the cost of car repairs (and the carbon output from the factories that make those spare hoses and gaskets).
As a side effect of turning corn into ethanol, food prices went through the roof. Crop surpluses vanished, and as a consequence, weather and flood-induced food shortages occurred right here in the United States.
And now we find out that the run-off from all this intensified corn farming is creating oxygen-free dead zones, killing off another source of food, deep ocean fish.
So what we have here is a media hoax used to sell us a product that we did not really need that costs more and does more harm to the world than the non-existent crisis supposedly did.
It sounds good in Al Gore's TV Commercials, but it has not been thought out very well. It may be good public relations, but it is not good science.
But then, snake oil never is.