This Summer's Gulf Dead Zone Smaller Than Feared

Jul 30, 2013

2013 Gulf of Mexico dead zone map.
Credit Louisiana Universities Marine Consortium

The low-oxygen dead zone this summer in the Gulf of Mexico is smaller than scientists had predicted. But the area where marine life can’t live is still about the size of Connecticut.

Nancy Rabalais of the Louisiana Universities Marine Consortium — called LUMCON — expected the gulf dead zone to be bigger, based on the level of nutrients measured in the Mississippi River.

Those nutrients come from fertilizer, used on crops upriver, that is carried downstream.

But choppy weather churned up the water, so the dead zone wasn’t as big as feared.

“There was a lot of wind mixing at the water column on the eastern part of the study area, and when you mix up the water column you mix oxygen down to the bottom, so the bottom wasn’t as low as we expected," Rabalais said. "And then, on the western end, there were a lot of winds from the west that pushed the whole thing to the east, and so the bottom boundary was not as large as it would have been if that hadn’t happened.”  

It’s still about 5800 square miles.

Rabalais says samples are taken from various depths of the Gulf — as far as 200 miles off the Louisiana coast west of the Mississippi River to Texas.

She says it’s unclear how the condition will track in the future.

“Federal funding for the work has been cut substantially," she said. "We used to do monthly or bimonthly cruises through the spring and into the early fall during the period of the hypoxia. But this year we only went out once.”    

She says it will be up to Congress to restore funding to federal agencies that pay academics for research projects.