The Mysterious Hypoxic Gulf Dead Zone

The Mysterious Hypoxic Gulf Dead Zone



October 2007

 Off the coast of Louisiana and 
Texas this summer, an area of deep water covering 7,900 square miles in 
the Gulf of Mexico was declared hypoxic. This area of low oxygen water 
called the dead zone was about the size of the state of New Jersey. 
It is the third largest Gulf of Mexico dead zone on record since 
measurements began in 1985. The largest dead zone ever recorded covered 
8,494 square miles in 2002. 
To develop a better understanding of how nutrient pollution from the 
Mississippi River affects Gulf dead zone, researchers at the University of 
Texas at Austin Marine Science Institute have been awarded funding for the 
first year of a three year project. 
The grant from the National Oceanic and Atmospheric Administration, NOAA, 
amounts to $284,000, as part of the total $781,000 project. Funds were 
awarded through NOAA's Northern Gulf of Mexico Hypoxia and Ecosystems 
Research Program. 
"A better understanding of the underlying causes of the dead zone is 
essential for predicting its effect on the Gulf fisheries and the region," 
said NOAA AdministratorConrad Lautenbacher. 
"The goal of this research is to help develop a range of options that 
coastal and upriver resource managers can use to prevent and reduce 
nutrient pollution that contributes to the dead zone," he said. 
Scientists already know that nutrient over-enrichment can lead to 
excessive production of algae. When this organic material sinks and 
becomes decomposed, dissolved oxygen in bottom waters is reduced, 
resulting in seasonal hypoxia - very low oxygen water - over the Louisiana 
continental shelf. 
The northern portion of the Gulf of Mexico ecosystem contains almost half 
of the nation's coastal wetlands and supports commercial and recreational 
fisheries which generate $2.8 billion annually. 
The Marine Science Institute will investigate how the dead zone affects 
commercially and recreationally important fish and shellfish. 
Every summer, large areas of hypoxic bottom water form in the Gulf. 
Hypoxic waters can cause habitat loss, stress and death to marine 
organisms; affecting commercial harvests and ecosystem health. 
This project will provide data to verify water quality models and help 
resource managers determine the quantitative relationships between 
nutrient pollution and development, magnitude, longevity, and distribution 
of the dead zone. 
Findings are expected to support the development of more accurate 
predictions of hypoxia development on the Louisiana continental shelf. 

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