NOAA is predicting a record-sized “dead zone” in the Gulf of Mexico this summer — stretching from Texas all the way to Alabama — and some scientists are blaming the demand for ethanol, which is made from corn.
The “dead zone” is caused when nitrogen-based fertilizer washes off farm fields in the Midwest Corn Belt and ends up in the Mississippi River, which flows into the Gulf. Just as nitrogen-based fertilizer makes corn grow, it also stimulates the growth of plants in the water, mainly algae. The algae bloom and eventually die and decay. The process removes oxygen from the water, resulting in oxygen-depleted water where marine life can’t live.
Larry McKinney, executive director of the Harte Research Institute for Gulf of Mexico Studies, says ethanol causes the yearly threat to the Gulf. Corn prices are high, so farmers are planting more of the crop, which requires fertilizer. The federal Department of Agriculture estimates that as much as 40 percent of last year’s corn crop was used to make ethanol.
Harte Research Institute chairman and professor Paul Montagna has studied the “dead zones,” or hypoxia zones, for more than 20 years and says they aren’t dangerous to fish. However, because they can’t support bottom dwellers, fish go elsewhere to find food.
“Because fish avoid these areas, commercial shrimp boats and recreational fishermen must go further out, to open water, to make their catch,” Montagna said in a statement.
Last summer was one of the smallest “dead zones” on record, at 2,889 square miles, which scientists at the National Oceanic and Atmospheric Administration attributed to a drought that kept runoff out of the Mississippi River. Conditions this year will be just the opposite because heavy rainfall in the Midwest this spring led to floods, with states such as Minnesota and Illinois experiencing one of the wettest springs on record. All of that flooding, along with bigger corn crops, means more fertilizer flowing into the Gulf.
“Dead zones” normally peak in July and August and start to break up in the fall. The only thing that would fix the situation sooner is a tropical storm or a hurricane to stir up the water and re-oxygenate the area.