Mississippi Business Journal
Bonnet Carre Spillway shut down as river falls below flood stage
By Jack Weatherly
The U.S. Army Corps of Engineers over the weekend completed the shutdown of the Bonnet Carre Spillway north of New Orleans, starting a process that will lead to the return of normal saltwater conditions in the Mississippi Sound.
The river at New Orleans fell below flood stage over the weekend.
The return to normalcy in the Sound will take a minimum of two to four weeks, without factoring in winds, which can speed up or slow down the process, depending on direction, according to Dr. Monty Graham, director of the Marine Research Center at the University of Southern Mississippi.
The process may even produce fish kills, said Graham. That may lead some to conclude that the cause is toxicity, but the cause in such cases would be hypoxia, or low oxygen levels, he said.
The influx of fresh water diverted from the swollen Mississippi River through Lake Pontchartrain and into the waters between the Mississippi Coast and the Barrier Islands has devastated commercial and recreational fishing in the Sound as well as tourism, which amounts to about $2 billion annually in the three coastal counties.
The islands, which are managed by the National Park Service, have not been under an advisory.
Record flooding on the river, which has inundated about 250,000 agricultural acres in the Mississippi Delta, led to the unprecedented downstream use of the spillway to protect New Orleans.
All beaches along the Mississippi Coast have been, in effect, closed because the Mississippi Department of Environmental Quality has said the near-shore water can be harmful to humans because of the occurrence of algal bloom, which can cause rashes, vomiting and diarrhea.
The Department of Marine Resources has recently said that testing shows that seafood caught near shore is not harmful to eat, urging, however, that fishermen use caution and not cast their bait in the potentially harmful algal bloom, caused by the freshwater infusion.
Recovery of aspects of the seafood industry is going to take years to recover, Graham said, citing the oysters, whose beds have been virtually destroyed by the fresh water.
He said the shrimp industry, which, according to the Department of Marine Resources, over the past five years have yielded 2 million pounds in June, compared with about 500,000 pounds this June, should recover much quicker.
U.S. Sen. Cindy Hyde-Smith and Gov. Phil Bryant have asked for federal aid for the fish industry in Mississippi waters.