Conservation Matters June 2013

The Texas Land, Water and Wildlife Connection

NOAA, partners predict possible record-setting dead zone for Gulf of Mexico

NOAA, partners predict possible record-setting dead zone for Gulf of MexicoScientists are expecting a very large “dead zone” in the Gulf of Mexico this year, based on several NOAA-supported forecast models.

NOAA-supported modelers at the University of Michigan, Louisiana State University, and the Louisiana Universities Marine Consortium are forecasting that this year’s Gulf of Mexico hypoxic “dead” zone will be between 7,286 and 8,561 square miles, which could place it among the ten largest recorded. That zone would range from an area the size of Connecticut, Rhode Island and the District of Columbia combined on the low end to the size of New Jersey on the upper end. The high estimate would exceed the largest ever-reported in 2002 of 8,481 square miles, researchers said.

Hypoxic or very low oxygen and anoxic or no oxygen zones are caused by excessive nutrient pollution, often from human activities such as agriculture, which results in insufficient oxygen to support most marine life in near-bottom waters. Aspects of weather, including wind speed, wind direction, precipitation and temperature, also impact the size of dead zones.

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–Aug. 3. If a storm does occur, the size estimate could drop to a low of 5,344 square miles, slightly smaller than the size of Connecticut.

This year’s prediction for the Gulf reflects 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. The forecast is based on nutrient run-off and river stream data from the U.S. Geological Survey (USGS).

"Monitoring the health and vitality of our nation’s oceans, waterways and watersheds is critical as we work to preserve and protect coastal ecosystems,” said Dr. Kathryn D. Sullivan, acting under secretary of commerce for oceans and atmosphere and acting NOAA administrator. “These ecological forecasts are good examples of the critical environmental intelligence products and tools that help shape a healthier coast, one that is so inextricably linked to the vitality of our communities and our livelihoods.”

The dead zone in the Gulf of Mexico affects nationally important commercial and recreational fisheries, and threatens the region’s economy, according to officials. For more information, see NOAA’s news release.

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