Gulf of Mexico could see ‘above average’ summer dead zone

By Nicole Norman | 06/17/2024 01:31 PM EDT

NOAA predicts that larger discharges in the Mississippi-Atchafalaya watershed would result in a bigger area with insufficient oxygen to support marine life.

The confluence of the Mississippi River (left) and Ohio River is visible in Cairo, Illinois.

The confluence of the Mississippi River (left) and Ohio River in Cairo, Illinois. Jeff Roberson/AP

This summer is expected to bring an “above average” dead zone for the Gulf of Mexico, a reversal after scientists last year measured a smaller-than-usual area that lacks the oxygen needed to keep fish and other marine life alive.

Last week, NOAA forecast that there would be low oxygen conditions across around 5,800 square miles, which the agency described as about the size of Connecticut. The average dead zone over the past 37 years has been about 5,200 square miles.

Fertilizer and other nutrients carried downstream from the Mississippi and Atchafalaya rivers cause the low-oxygen conditions that kill or drive out marine life. The hypoxia event occurs every summer, with farm runoff one of the biggest culprits.


The dead zone projected for this summer is more than three times as big as the goal set by the Gulf of Mexico Task Force for 2035.