Dead zone in Gulf of Mexico largest ever, as Georgia awaits ruling on water flow to Florida

By David Pendered

The federal climate agency on Wednesday reported the annual dead zone in the Gulf of Mexico is the largest on record – about the size of New Jersey. The report comes as Georgia awaits a ruling by the U.S. Supreme Court over the amount of water that flows from Georgia into Florida. Florida says the flow is insufficient to support the oyster habitat in the Apalachicola Bay.

dead zone gulf, testing — Water sensors are deployed to collect water samples that are tested for the amount of available oxygen. Credit: noaa.gov

The dead zone and the water war are not directly connected. They are related in the sense that both are manmade situations.

The gulf’s dead zone is caused by nutrient runoff from agriculture and other human activities in the watershed of the Mississippi River, according to NOAA’s statement. The nutrients stimulate an overgrowth of algae in the gulf. The algae bloom consumes oxygen in the water necessary to support other aquatic life.

This year’s dead zone in the Gulf of Mexico is the largest ever measured since mapping began there in 1985, according to the statement from NOAA, the National Oceanic and Atmospheric Administration. NOAA is affiliated with the U.S. Commerce Department.

The dead zone begins at the western edge of the mouth of the Mississippi River, located south of New Orleans. It stretches into Texas, where it almost reaches the waters off Galveston.

dead zone gulf 2017 — This year’s dead zone in the Gulf of Mexico is the largest on record, since mapping began in 1985. Credit: N. Rabalais, via noaa.gov

The zone covers 8,776 square miles, NOAA reported. The largest dead zone previously recorded was 8,497 square miles, recorded in 2002. The average size of the dead zone from 2009 to 2014 has been about 5,806 square miles.

This is how NOAA’s statement describes the situation:

“This large dead zone size shows that nutrient pollution, primarily from agriculture and developed land runoff in the Mississippi River watershed, is continuing to affect the nation’s coastal resources and habitats in the Gulf.
“These nutrients stimulate massive algal growth that eventually decomposes, which uses up the oxygen needed to support life in the Gulf. This loss of oxygen can cause the loss of fish habitat or force them to move to other areas to survive, decreased reproductive capabilities in fish species and a reduction in the average size of shrimp caught.

Tri-state water wars — The U.S. Supreme Court is slated to rule on Florida’s claim that Georgia hogs water in the ACF basin (green) and thus hurts Florida’s shellfish industry. File/Credit: Atlanta Regional Commission

“We expected one of the largest zones ever recorded because the Mississippi River discharge levels, and the May data indicated a high delivery of nutrients during this critical month which stimulates the mid-summer dead zone,” said Nancy Rabalais, Ph.D., research professor at Lousiana State University … who led the survey mission.

In the water war, justices are considering an advisory ruling and may issue their ruling this year. The U.S. Army Corps of Engineers has emerged as a central issue in the debate – even though the corps is not party to the suit and Florida argued vigorously to keep the corps out of the battle.

The court appointed a special master to oversee arguments in the case. The special master issued an advisory ruling that said the corps’ management practices in the Apalachicola-Chattahoochee-Flint river basin determine how much water reaches Florida – regardless of how much water Georgia sends down the river basin. This is due in part to the corps’ control of the water level in dams that line the basin.