A Large Step Back

Bryan Walsh of Time writes about The Gulf’s Growing ‘Dead Zone’

The American Midwest is essentially the granary of the world, supplying corn, wheat and other crops to markets from Chile to China. But all that food doesn’t grow by itself. In 2006 U.S. farmers used more than 21 million tons of nitrogen, phosphorus and other fertilizers to boost their crops, and all those chemicals have consequences far beyond the immediate area. When the spring rains come, fertilizer from Midwestern farms drains into the Mississippi river system and down to Louisiana, where the agricultural sewage pours into the Gulf of Mexico. Just as fertilizer speeds the growth of plants on land, the chemicals enhance the rapid development of algae in the water. When the algae die and decompose, the process sucks all the oxygen out of the surrounding waters, leading to a hypoxic event — better known as a “dead zone.” The water becomes as barren as the surface of the moon. What sea life that can flee the zone does so; what can’t, dies.

Thousands of square miles of the Gulf of Mexico around the Mississippi delta have no oxygen in the water. The shellfish and ecosystems that depend on them die. The fish and shrimp die. Those whose living depended on these things go out of business.

My Mother has a small pond in her side yard. I depend on snails and pollywogs to keep the algae under control, but I still have to keep a pump running to aerate the water or the fish will die. When people stop taking care of a swimming pool, it doesn’t take long for it to go from sparkling clear water to a fetid, mosquito-infested swamp. The stench is the algae dying and giving off noxious gases.

The situation was already going to be bad this year, but the flooding will make it worse. Fertilizer-dependent crops are killing coastal waters in the US, and around the world.