The Gulf Of Mexico's Dead Zone

More bad news, water lovers:

The Gulf Of Mexico's Dead Zone Is The Biggest Ever Seen

The teal blue area along the Louisiana coastline represents a "dead zone" of oxygen-depleted water.
Resulting from nitrogen and phosphorus pollution in the Mississippi River, it can potentially hurt fisheries.

NASA/Getty Images

Quoting the NPR article:

It has become a rite of summer. Every year, a "dead zone" appears in the Gulf of Mexico. It's an area where water doesn't have enough oxygen for fish to survive. And every year, the National Oceanic and Atmospheric Administration commissions scientists to venture out into the Gulf to measure it.

This week, NOAA announced that this year's dead zone is the biggest one ever measured. It covers 8,776 square miles — an area the size of New Jersey. And it's adding fuel to a debate over whether state and federal governments are doing enough to cut pollution that comes from farms.

The debate actually goes back many years, at least to 1985, when Don Scavia was a scientist at the NOAA. He and his colleagues asked some scientists, for the first time, to go look for a dead zone in the Gulf.

"We expected it to be there," Scavia recalls. They expected to find it because they knew that the Mississippi River delivers a heavy load of nutrient pollution, specifically nitrogen and phosphorus, into the Gulf.

Farmers use those nutrients on fields as fertilizer. Rain washes them into nearby streams and rivers. And when they reach the Gulf of Mexico, those nutrients unleash blooms of algae, which then die and decompose. That is what uses up the oxygen in a thick layer of water at the bottom of the Gulf, in a band that follows the coastline.

The record-breaking dead zone this year is the result of unusually heavy rains in the Midwest, which flushed a lot of nutrients into the Gulf.

The dead zone is invisible from the surface of the ocean. Scientists lower instruments into the water to measure oxygen levels near the bottom. But Scavia describes it as a kind of hidden environmental disaster. "You know, it's 8,000 square miles of no oxygen. That can't be good!" he says. Potentially, it could have huge economic costs as well, because it imperils Louisiana's shrimp industry.



Read full article from NPR here: http://www.npr.org/sections/thesalt/2017/08/03/541222717/the-gulf-of-mexicos-dead-zone-is-the-biggest-ever-seen