Dead Zone in Gulf of Mexico Biggest Ever

Solenn Plantier
Août 7, 2017

Scientists have found a polluted "dead zone" of ocean that is larger than Wales and the biggest ever recorded in the Gulf of Mexico.

The National Oceanic and Atmospheric Administration announced this week that the Gulf dead zone measured in at more than 8,700 square miles - an area roughly the size of New Jersey.

Nitrogen and phosphorus pollution enters the MS throughout its watershed, which includes runoff from Midwest crop farms and meat producers that stimulate massive algal growth that eventually decomposes, which uses up the oxygen needed to support life in the Gulf.

"So in years like this with a lot of precipitation and higher than normal flows", Magnien says, "that carries more nutrients into the Gulf of Mexico to fuel the algal bloom, which will eventually decompose and rob the water of oxygen".

This loss of oxygen in the water can cause the loss of fish habitat or force them to move to other areas to survive.

According to an NOAA funded study led by Duke University, the dead zone may slow shrimp growth, leading to fewer large shrimp.

Another team of researchers at Louisiana State University (LSU) and the Louisiana Universities Marine Consortium (LUMCON) collected data to determine the size of the dead zone during a survey from July 24 to July 31. The dead zone forms annually, mainly because of farm fertilizer pollutants washing into the Atlantic from the Mississippi River, but this year's affected area was the largest since recording began in 1985.

Every spring, a "dead zone" appears in the Gulf of Mexico.

The average size of the dead zone over the past five years has been 5,806 square miles, which is three times larger than the Gulf Hypoxia Task Force target of 1,900 square miles.

These findings suggest that efforts to reduce nutrient pollution in the Mississippi River basin aren't working. The Runoff Risk Advisory Forecast, an initiative to help farmers apply fertilizers at optimum times, is either ineffective or being ignored.

D'autres rapports CampDesrEcrues

Discuter de cet article