The longest river in the USA and third largest in the world, the Mississippi drains 40 percent of the country, including the majority of its farming heartland. At present, there are no federal laws governing pollution being dumped into the Mississippi River, and last year alone some 817,000 tons of nitrogen made its way into the Gulf of Mexico via the river. These agricultural chemicals have led to the largest ever 'deadzone' (an area so starved of oxygen that it cannot sustain life) in the history of the Gulf.
But farmers are in a difficult situation. As many attempt to alter farming techniques to reduce toxic runoff, legislation that richly rewards a handful of commodity crops drives farmers to rotate less and maximize output through the use of nitrogen-based fertilizers. Short- term return on cash crops is destroying the very land and water that produces these crops. Longer-term solutions must be put in place to help farmers balance their need to survive with the health of the environment.
The dead zone at the mouth of Mississippi encompasses an area of roughly 8,0000 square miles. This has had a devastating impact on marine life and fishing grounds. What other dead zones exist around the world and what can be done to prevent more destruction?