The Gulf of Mexico Dead Zone Is Smaller Than Scientists Expected This Year

Aug 4, 2020

The “dead zone” in the Gulf of Mexico is smaller than average this year, according to scientists at the National Oceanic and Atmospheric Administration.

The Mississippi River/Gulf of Mexico Hypoxia Task Force released its annual forecast today, including a report that the dead zone, formally called a hypoxic area, is about 2,116 square miles, much smaller than the 6,700 square miles scientists predicted. This is the third-smallest in 34 years. The average hypoxic zone over the past five years is 5,408 square-miles.

The hypoxic area in the Gulf is caused by pollution and runoff carried south by the Mississippi River and dumped at its mouth. As a result, the water has less oxygen, which kills fish and other marine life.

Nancy Rabalais, principal investigator and professor at Louisiana State University and Louisiana Universities Marine Consortium, has been on-board the annual research vessel for three decades.

“It didn't take long to figure out that there wasn’t going to be much (hypoxic water) there,” she said of this year.

Researchers said the decrease was largely due to winds from Hurricane Hanna breaking up the polluted water, and also to a decrease in runoff from farms upriver in the Midwest, which they credited to successful environmental programs targeting farmers.

As a result, the crew on the research vessel Pelican spotted much less murky water than predicted.

“The science crew very often are excited when we see hypoxia,” she said, because it’s their job to spot it, “but the goal of course is not to have any anymore, so it’s a very mixed blessing when we have years like this,” Rabalais said.

But she added that much more still needs to be done to clean up the Mississippi in order to fully eliminate the dead zone.