Hurricane Weakened Large ‘Dead Zone’ in Gulf of Mexico

This July 11, 2019, satellite image shows Hurricane Barry as it bears down on Texas, Louisiana, Alabama and the panhandle of Florida as it makes its way through the Gulf of Mexico. (Christina Koch/NASA via AP, File)

(CN) – At the beginning of June, scientists with the National Oceanic and Atmospheric Administration looked at their models and saw sobering news for coastal communities in Louisiana and parts of Texas and Mississippi.

The prediction said the Gulf of Mexico’s annual man-made “dead zone,” where marine life struggles to survive in low oxygen, would be comparable in size to the landmass of Massachusetts.

The dead zone, or hypoxic zone in scientist-speak, occurs when nutrients such as nitrogen make their way into the waterways of the Mississippi River watershed and eventually dump into the Gulf of Mexico. This leads to an explosive growth of algae, which eventually dies and falls to the ocean floor where decomposition eats up the oxygen there.

That’s a death sentence for marine life that doesn’t move to other waters: crabs, young fish and the like. The dead zone near the mouth of the Mississippi River is one of the largest in the world.

As summer rolled on, the signs looked dire. Since last December, the Mississippi has poured a deluge of nutrient-rich freshwater into the Gulf of Mexico. As beaches in Louisiana closed because of toxic algae blooms, lawmakers in Louisiana and Mississippi asked the Commerce Department to issue a federal fisheries disaster declaration.

Louisiana Governor John Bel Edwards said in his June 13 letter to Commerce Secretary Wilbur Ross that all the oysters in some reefs were wiped out because of the low salinity of the water.

Then, on July 23, scientists backed by NOAA funding set out for a week-long research cruise in the 116-foot research vessel R/V Pelican into the dead zone to pick up data from sensors to confirm if the model held true.

The prediction didn’t square with what scientists saw out on the water.

The winds of Hurricane Barry, which had passed through before the researchers began their voyage, churned through the dead zone and lessened its extent.

According to Louisiana State University professor Nancy Rabalais, who led the research cruise, it takes about a week for the dead zone to reform in the summer after a weather event brings wind that disrupts it.

“We found that, despite the storm, the zone reformed and was in the process of rapidly expanding,” she said.

The dead zone, scientists estimated, is about 6,952 square miles large – the eighth largest such zone since they started studying it 34 years ago.

In 2017, scientists witnessed the largest dead zone they had ever seen – 8,776 square miles – and were predicting this year’s zone would have taken up 7,829 square miles.

This year’s area is still well beyond what scientists and the federal government hopes the size of the dead zone will be in the future: 1,900 square miles.

In the early years of a task force formed by states and federal agencies to tackle the issue of nutrients in the Mississippi watershed, many states expected the federal government would expend significant amounts of funding to attack the problem, according to Bill Northey, undersecretary for farm production and conservation at U.S. Department of Agriculture.

Later, the task force realized the 32 states whose land drains to the Mississippi River would have to implement their own nutrient management plans to lessen the amount of fertilizer being washed out of farmers fields, for instance.

“We are seeing some of that,” Northey said in a call with reporters. “It’s going to take a long time at the rate that we’re seeing improvements but I do believe that we’re seeing some momentum that will suggest we’re making more progress now than we were in those early years.”

Other efforts include building up the wetlands that have buffered the ocean and captured nutrients before they head out to sea.

Meanwhile, Kentucky, for instance, is a “little bit behind” when it comes to its strategy for nutrient reduction, said Ward Wilson, executive director for Kentucky Waterways Alliance.

While the state’s waterways contribute to the Mississippi River, its nutrient reduction strategy – formed in March 2014 – focuses on education and monitoring, according to Wilson.

“It’s hard to set up criteria that’s translated to water quality standards,” Wilson said.

Nutrients can enter the Mississippi watershed from many different sources, according to Wilson. Even the Kentucky limestone contains phosphorus, which when confined to the Bluegrass State, is great for horses and bourbon.

U.S. Senator Cindy Hyde-Smith, R-Miss., sent two letters to Commerce Secretary Ross about declaring a federal fisheries disaster.

“Months of record rainfall, spring runoff, and disastrous flooding throughout the Mississippi River Basin has resulted in excess nutrient loading to the Gulf of Mexico… The negative effects on all segments of Mississippi’s fishing and seafood industries are becoming more evident each day,” Hyde-Smith wrote at the end of June.

Congress appropriated $150 million in fishery disaster assistance on June 6. The Commerce Department has yet to make a determination if impacts to the seafood industry on the coast of Louisiana and Mississippi warrant a disaster declaration.

A Commerce Department spokesperson did not return a request for comment Thursday.

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