Scientists predict largest dead zone ever

By Nikki Buskey
Tuesday, July 15, 2008 at 6:57 p.m.
HOUMA – Louisiana scientists are once again forecasting that this year’s dead zone – an expanse of low-to-no oxygen water resting off the state’s coast – will be the biggest ever recorded.
The LUMCON and Louisiana State University researchers are predicting the area could measure a record 8,800 square miles, roughly the size of New Jersey, and reach into the Texas coastline.
"The prediction of a large dead zone this summer is due to a combination of large influx of nitrogen and exceptionally high flows from the Mississippi and Atchafalaya rivers," said LSU scientist Eugene Turner during a NOAA teleconference Tuesday.
Researchers will leave LUMCON on their annual cruise to begin mapping the dead zone Sunday, and the official measurement of this year’s dead zone is slated to be released in late July.
The forecast was downgraded from estimates last month suggesting the dead zone could grow to about 10,084 square miles — an area the size of the state of Massachusetts. But it still illustrates that the phenomenon is growing, due in part to increased corn farming in the Midwest to meet biofuel demands, scientists said.
In 2007, the dead zone was 7,903 square miles. The largest dead zone on record was in 2002, when it measured 8,481 square miles, and the annual average since 1990 has been annual average has been about 4,800 square miles.
Researchers began taking regular measurements of the dead zone in 1985.
The dead zone is caused when oxygen levels in waters off the Louisiana coast drop too low to support most life in bottom waters.
These low oxygen, or hypoxic, areas are caused when high numbers of nutrients, such as phosphorous and nitrogen, which stimulate an overgrowth of algae that dies off, sinks and decomposes. The decomposition process in turn sucks oxygen out of the Gulf depths.
"When it gets anoxic (meaning there is no oxygen), you wipe out the whole bottom. You change the food web," Turner said.
Check out tomorrow’s edition of the Courier for more on this year’s projected dead zone.