August 9, 2021 — A “dead zone,” or an area of low to no oxygen, in the Gulf of Mexico has grown larger than Connecticut, creating an uninhabitable environment for some commercial marine life, and scientists are saying the sparse amount of tropical activity has played a role.
An hypoxic zone, also referred to as a dead zone, is formed when excess nutrients such as nitrogen and phosphorus from agriculture and sewage from cities and farms upstream wash into the Gulf. Algae then feeds on these nutrients during the warmer months, and when that algae dies and sinks to the Gulf’s floor, the bacteria that then eats away at the large tangled masses depletes the oxygen in the surrounding water.
The resulting area of low oxygen is called a hypoxic zone, or a dead zone as it becomes unable to support marine life, and it forms in the Gulf every year. Not only can it harm local wildlife, but it can also financially impact fisheries.
Hypoxic waters have been found to alter fish diets, growth rates, reproduction, habitat use and availability of commercially harvested species such as shrimp, according to the National Oceanic and Atmospheric Administration (NOAA).
Now, fisheries along the coast of Louisiana will have to deal with a larger-than-average dead zone.
“Basically half of the Louisiana coast for several miles, many miles off shore, the oxygen was too low to support the occurrence of penaeid shrimp, which is one of our biggest economic fisheries in that area,” Dr. Nancy Rabalais, professor at Louisiana State University and LUMCON, and also the principal investigator, told AccuWeather. “So that area was basically lost as available and suitable habitat to those shrimp. How that’s going to convert to catches in money in the next month or so, I can’t really say.”