Gulf of Mexico dead zone predicted to be the size of New Jersey this year

By By Elizabeth Weise, USA Today
Jun 29, 2010

 The Gulf of Mexico‘s ‘dead zone‘ may be larger this year than in recent years, as big as the state of New Jersey, scientists are predicting.

This year’s dead zone could measure between 6,500 and 7,800 square miles. The dead zone has average approximately 6,000 square miles over the past five years. The largest dead zone on record, in 2002, was 8,484 square miles, according to the
National Oceanic and Atmospheric Administration, which funded the team of scientists from the Louisiana Universities Marine Consortium, Louisiana State University, and the University of Michigan.

The dead zone is created by nutrient runoff, mostly from over-application fertilizer on agricultural fields. It flows into streams, then rivers and eventually the Gulf. Once it gets there, the fertilizer stimulates an overgrowth of algae that sinks, decomposes, and consumes most of the life-giving oxygen supply in the water, NOAA says.

NOAA has a video graphic here that describes how it works.This forecast is based on Mississippi River nutrient flows compiled annually by the U.S. Geological Survey.

No one yet knows how the BP Deepwater Horizon oil spill will affect this year’s dead zone.

"The oil spill could enhance the size of the hypoxic [oxygen-free] zone through the microbial breakdown of oil, which consumes oxygen, but the oil could also limit the growth of the hypoxia-fueling algae," R. Eugene Turner, professor of oceanography at Louisiana State University, said in a release. "It is clear, however, that the combination of the hypoxic zone and the oil spill is not good for local fisheries."

Information on the extent of hypoxia will also be available on the NOAA’s Gulf of Mexico Hypoxia Watch Web page, which displays near real-time results of the NOAA Fisheries Service summer fish survey in the northern Gulf of Mexico currently underway and scheduled to be completed by July 18.