10 June, 2019
As a result of the unusually heavy rainfall across the Mississippi River watershed, scientists forecast that the dead zone in the Gulf of Mexico may be 67 percent larger than average this year.
The dead zone, or hypoxic zone, is an area in the Gulf with low to no oxygen that can kill marine life and is one of the largest in the world. This year, the area is expected to span about 7,829 square miles, about the size of Massachusetts, according to a press release from the National Oceanic and Atmospheric Administration.
Scientists from LSU predict the dead zone’s size could range from 7,889 to 9,583 square miles. The five-year average is 5,770 square miles.
“This year’s historic and sustained river flows will test the accuracy of these models in extreme conditions, which are likely to occur more frequently in the future according to the latest national climate Assessment,” said Steve Thur, director of NOAA’s National Centers for Coastal Ocean Science.
Each year, the appearance of the dead zone is primarily caused by excess nutrients discharged into the Gulf by the Mississippi River from agricultural pollution picked up from upstream in the watershed.
The excess nutrients fuel the growth of large blooms of algae, which leads to the low oxygen concentrations and threatens the lives of living resources such as fish and other marine life.
Environmental advocacy groups blame different agricultural companies for the recurring dead zone.
In a press release, Mighty Earth Campaign director Lucia von Reusner pointed to meat processing company JBS USA, claiming it dumped about 80 million tons of manure and slaughterhouse waste into the river. Some of the country’s largest meat companies have placed their facilities along the Mississippi River basin.
“Given the climate-fueled extreme flooding washing more and more pollution downstream, it would not be surprising if this is ultimately the largest-ever dead zone,” von Reusner said.
Healthy Gulf Executive Director Cynthia Sarthou the size of the zone isn’t surprising, criticizing the lack of “significant reduction” to the dead zone under the Hypoxia Task Force, a partnership between 12 states, five federal agencies and a tribal representative that works to reduce nutrient pollution in the river basin.
“Voluntary reduction measures have not worked up to this point, and yet they continue down this path,” she said. “Until Louisiana, Mississippi River states and federal agencies start taking reductions seriously, the dead zone will continue to impact Louisiana’s $2.4 billion fishing industry,”
The true size of the dead zone won’t be confirmed until scientists supported by NOAA conduct their annual monitoring survey in either late July or early August.