The Gulf of Mexico has a "dead zone" within it that is largely devoid of life. It appears every summer before shrinking again in the Fall. That area is predicted to be bigger than ever in 2013, possibly suffocating large areas of the Gulf this year. That zone is predicted to cover between 7,286 to 8,561 square miles, which would be up to the size of New Jersey.
This dead zone forms, ironically, from nutrients which pour into the Gulf from the Mississippi River. This runoff can also include fertilizers including nitrogen and phosphorus from farms. This feeds short-lived algae, which thrive and multiply, and then quickly die. Their remains, in turn, are feasted upon by bacteria. This bacteria, during respiration, drain the surrounding water of free oxygen, creating what is known as as hypoxic (low-oxygen) anoxic (no-oxygen) regions that suffocate any marine life unlucky enough to be in the area. Bottom-dwelling creatures like worms and clams would be affected first, which would reduce the amount of food available for fish as well. In a typical year, around 75,000 tons of worms and clams are killed in the Gulf by this annual event.
Last year, the watershed that feeds the Mississippi River experienced a drought, resulting in few nutrients being transported to the Gulf and a small dead zone in 2012. This year, heavy rains in the area are causing nutrients - 168,650 tons of it - to be carried to the Gulf in large quantities, feeding the quickly-growing dead zone. That amount of runoff is about 16 percent higher than normal, and is made worse by the fertilizer that farmers applied to their lands in 2012, which were not fully consumed by the plants which experienced little growth due to the drought.
The largest dead zone yet recorded in the Gulf was measured at 8,481 square miles in 2002. The National Oceanic and Atmospheric Administration (NOAA) believes that this year's dead zone in the gulf could be one of the top ten largest such zones ever recorded. Researchers from the University of Michigan and Louisiana State University also participated in the research.
A study will be made by boat to measure the actual size of the dead zone in the Gulf between July 25 and August 3. Large storms over the Gulf would help oxygenate the water, reducing the size of the dead zone.
A similar, if much smaller, dead zone exists in the waters between Maryland and Virginia in the Chesapeake Bay. NOAA predicts a smaller-than-normal zone in that area this year.
