A recent survey of the Gulf of Mexico by the Louisiana Universities Marine Consortium found the fourth smallest “dead zone” in the history of NOAA-supported surveys. Unlike past surveys, however, researchers also found a patchy distribution of hypoxia across the Gulf.
“The smaller area was expected because of drought conditions and the fact that nutrient output into the Gulf this spring approached near the 80-year record low,” said Nancy Rabalais, executive director of the consortium. “What wasn’t expected was how the scattered distribution of hypoxia areas differed from any others documented in the past.”
Hypoxia is fueled by nutrient runoff in the Mississippi River watershed, which stimulates an overgrowth of algae that sinks, decomposes and consumes most of the oxygen supply in bottom waters. Hypoxic zones threaten valuable commercial and recreational fisheries in Texas and Louisiana.