ANN ARBOR, Mich.A dry spring in portions of the Midwest is expected to result in the second-smallest Gulf of Mexico "dead zone" on record in 2012, according to a University of Michigan forecast released today.
The U-M prediction calls for a 2012 Gulf of Mexico dead zone of about 1,200 square miles, an area the size of Rhode Island. If the forecast is correct, 2012 would replace 2000 (1,696 square miles) as the year with the second-smallest Gulf dead zone. The smallest Gulf oxygen-starved, or hypoxic, zone was recorded in 1988 (15 square miles).
"While it's encouraging to see that this year's Gulf forecast calls for a significant drop in the extent of the dead zone, we must keep in mind that the anticipated reduction is due mainly to decreased precipitation in the upper Midwest and a subsequent reduced water flow into the Gulf," said aquatic ecologist Donald Scavia, professor at the U-M School of Natural Resources and Environment. "The predicted 2012 dead-zone decline does not result from cutbacks in nitrogen use, which remains one of the key drivers of hypoxia in the Gulf."
The U-M prediction is one of two Gulf dead zone forecasts released today by the National Oceanic and Atmospheric Administration, which funds the research. The other NOAA-supported team, from the Louisiana Universities Marine Consortium and Louisiana State University, predicts a 2012 Gulf dead zone of 6,213 square miles.
The Michigan forecast model is based solely on 2012 spring nutrient inputs from the Mississippi River, which are significantly lower than average due to drought conditions throughout much of the watershed. The Louisiana State University forecast model takes into account last year's above-normal nutrient load, which the Louisiana researchers say can remain in bottom sediments and can result in a "carryover effect" that increases the size of the 2012 dead zone.
Last year, the Gulf dead zone measured 6,765 square miles. The largest Gu
|Contact: Jim Erickson|
University of Michigan