June 19th, 2013 by James Ayre
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.
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.
Something to note — “the Gulf estimate is based on the assumption of no significant tropical storms in the two weeks preceding or during the official measurement survey cruise scheduled from July 25-August 3 2013. If a storm does occur the size estimate could drop to a low of 5344 square miles, slightly smaller than the size of Connecticut.”
“This year’s prediction for the Gulf reflect flood conditions in the Midwest that caused large amounts of nutrients to be transported from the Mississippi watershed to the Gulf. Last year’s dead zone in the Gulf of Mexico was the fourth smallest on record due to drought conditions, covering an area of approximately 2,889 square miles, an area slightly larger than the state of Delaware. The overall average between 1995-2012 is 5,960 square miles, an area about the size of Connecticut,” as NOAA reports.
“During May 2013, stream flows in the Mississippi and Atchafalaya rivers were above normal resulting in more nutrients flowing into the Gulf. According to USGS estimates, 153,000 metric tons of nutrients flowed down the rivers to the northern Gulf of Mexico in May, an increase of 94,900 metric tons over last year’s 58,100 metric tons, when the region was suffering through drought. The 2013 input is an increase of 16% above the average nutrient load estimated over the past 34 years.”
“Coastal hypoxia is proliferating around the world,” said Donald Boesch, Ph.D., president of the University of Maryland Center for Environmental Science. “It is important that we have excellent abilities to predict and control the largest dead zones in the United States. The whole world is watching.”
Keep up to date with all the most interesting green news on the planet by subscribing to our (free) Planetsave newsletter.