Gulf Dead Zone Smaller This Year

The annual Gulf “dead zone,” an area of low to no oxygen just offshore that can kill fish and marine life, is approximately 4,402 square miles, 21 percent smaller than estimates from early June and the 15th smallest measurement on record, according to scientists supported by the National Oceanographic and Aeronautic Administration.

This equates to roughly 2.8 million acres of habitat potentially unavailable to fish and bottom-dwelling species, a reduction of 30 percent from the previous year. It is caused by nutrients from agricultural runoff that flows down the Mississippi River each year and feeds oxygen-depleting algae and other microorganisms.

Scientists at Louisiana State University and the Louisiana Universities Marine Consortium (LUMCON) led the annual dead zone survey July 20-25 aboard LUMCON research vessel Pelican. This annual measurement is a key metric that informs the collective efforts of the Mississippi River/Gulf of America Hypoxia Task Force, which has set a long-term goal of reducing the five-year average extent of the dead zone to fewer than 1,900 square miles by 2035.

“This year’s significant reduction in the Gulf of America’s ‘dead zone’ is an encouraging sign for the future of this area,” said Laura Grimm, acting administrator of the National Oceanic and Atmospheric Administration. “It highlights the dedication and impactful work of NOAA-supported scientists and partners and serves as a testament to the effectiveness of collaborative efforts in supporting our U.S. fishermen, coastal communities and vital marine ecosystems.”

Data from the survey is available online for the public.