The 2013 Gulf of Mexico dead zone may very likely be the largest one ever, according to new predictions based on several different NOAA-supported forecast models. The hypoxic dead zone is forecast to cover somewhere between 7,286 and 8,561 square miles of the Gulf of Mexico. The largest dead zone on record was the 2002 one, which covered 8,481 square miles.

“Less oxygen dissolved in the water is often referred to as a ‘dead zone’ (in red above) because most marine life either dies, or, if they are mobile such as fish, leave the area. Habitats that would normally be teeming with life become, essentially, biological deserts.”
Image Credit: NOAA

Dead zones — whether hypoxic (very low oxygen) or anoxic (no oxygen) — are caused primarily by high-levels of nutrient pollution. This nutrient pollution — mostly the fertilizers used in industrial agriculture — causes large algal blooms which use up all of the oxygen in a given environment. As a result, the environment becomes devoid of life — a “dead zone”. These deadzones have been increasing in frequency and scale since at least the 1970s. More than 1.7 million tons of potassium and nitrogen make their way into the Gulf of Mexico every year as a result of agricultural runoff — via the Mississippi river.

If the 2013 Gulf of Mexico dead zone becomes as large as is being predicted it will cover an area the size of New Jersey. The 2013 predictions were made by modelers at the University of Michigan, Louisiana State University, and the Louisiana Universities Marine Consortium.