News and Culture Notebook
10:27 am
Mon June 24, 2013

Larger 'dead zone' in Gulf of Mexico predicted

If you're planning a Gulf of Mexico trip this summer, it might be worth the extra drive to visit South Texas instead of Louisiana.

Spring flooding in the Midwest will likely result in a very large and possibly record-setting Gulf of Mexico "dead zone," according to University of Michigan ecologists.

The forecast, one of two announced by the National Oceanic and Atmospheric Administration, predicts an oxygen-depleted, or hypoxic, region of between 7,286 and 8,561 square miles, which would place it among the 10 largest on record.

The reason why has its origins in the fact that what's good for cornfields is bad for the sea.

Runoff containing fertilizers and livestock wastes from the enormous Mississippi River watershed eventually finds its way to the swamps southeast of New Orleans, where the mighty river feeds into the gulf.

Once there, the nutrient-rich waters feed algae such that the little plants grow far beyond their normal numbers. The resulting algal bloom feeds bacteria that then consume the water's oxygen. Deprived of oxygen, marine life either dies or, if it can, escapes for habitable waters.

It's become an annual event for a summertime dead zone to occur along the Southeast Louisiana coast. But in worse-than-usual years, as this is forecast to be, the lifeless waters could extend from Mobile, Ala., to Galveston.

That's bad news for commercial and recreational fishers, as well as anyone who wants the Gulf of Mexico and its creatures to be healthy.

Details are in this National Geographic report.