"2021 low oxygen area along Louisiana coast well above the average size for past five years"
"This summer's low-oxygen dead zone in the Gulf of Mexico along the Louisiana coast covered 6,334 square miles - 10 times the size of Lake Pontchartrain and well above the average size for the past five years, researchers said Tuesday.
It encompasses a huge area of Gulf bottom waters that contains fewer than 2 parts per million of oxygen, a condition called hypoxia. Insufficient oxygen kills bottom-living organisms that form the base of the Gulf food chain, and it forces fish, crabs and shrimp to flee, often disrupting or driving up expenses for commercial fishers.
Scientists blame the dead zone on nutrient-rich freshwater that flows to the Gulf of Mexico through the Mississippi River’s vast watershed, which includes parts of 32 states and two Canadian provinces. Freshwater exiting the Mississippi and Atchafalaya rivers creates a layer atop salty Gulf waters until it’s mixed by tropical storms in the summer or frontal systems in the fall."
Mark Schleifstein reports for the New Orleans Times-Picayune August 3, 2021.
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