Gulf of America dead zone shrinks to second smallest size on record

NOAA‑supported scientists announced that the 2026 Gulf of America hypoxic (dead) zone measured about 1,332 square miles, the second smallest extent recorded in four decades of surveys. The annual assessment was led by researchers from Louisiana State University and the Louisiana Universities Marine Consortium (LUMCON) and conducted aboard the LUMCON vessel Pelican from July 24‑30.

The reduced size is attributed to Tropical Storm Bertha, whose strong winds and waves mixed oxygen‑rich surface water down to the seabed just before the cruise. While the survey may not have captured the zone’s full boundary, such weather events help scientists refine models of hypoxia formation and dissolution.

Timothy Petty, NOAA assistant secretary of commerce for oceans and atmosphere, said, “Measuring the hypoxic zone provides more than just a score card of the Gulf's ocean oxygen levels—it helps us better understand the interconnectivity of our nation’s land, waterways and ocean.” The data are intended to improve upstream management strategies and mitigate impacts on commercial and recreational fisheries, tourism, and coastal ecosystems.