Scientists with Louisiana State University and the Louisiana Universities Marine Consortium, supported by NOAA, said this year’s Gulf of Mexico dead zone is approximately 6,705 square miles. It’s the 12th largest zone in 38 years of measurement and is bigger than originally predicted.
The area of low to no oxygen is equal to more than 4 million acres — roughly the size of New Jersey.
The dead-zone survey, conducted July 21-26 informs the collective efforts of the Mississippi River/Gulf of Mexico Hypoxia Task Force, a state/federal partnership with a long-term goal of reducing the five-year average extent of the dead zone to fewer than 1,900 square miles by 2035.
NOAA’s annual survey provides a snapshot of the dead zone, but the five year average captures the changing nature of the area over time. The five year average is 4,298 square miles.
“It’s critical that we measure this region’s hypoxia as an indicator of ocean health, particularly under a changing climate and potential intensification of storms and increases in precipitation and runoff,” Nicole LeBoeuf, assistant administrator of NOAA’s National Ocean Service, said in a statement. “The benefit of this long-term data is that it helps decision makers as they adjust their strategies to reduce the dead zone and manage impacts to coastal resources and communities.”
In June, NOAA predicted a dead zone of 5,827 miles, based primarily on Mississippi River discharge and nutrient runoff data from the U.S. Geological Survey. The measured size fell within the uncertainty range for NOAA’s ensemble forecast.
“The area of bottom-water hypoxia was larger than predicted by the Mississippi River discharge and nitrogen load for 2024 but within the range experience over the nearly four decades that this research cruise has been conducted,” said Nancy Rabalais, a professor at LSU and LUMCON, and co-chief scientist for the survey. “We continue to be surprised each summer at the variability in size and distribution.”
