The Gulf of Mexico's "dead zone" — the area where there's too little oxygen to support marine life — is the biggest ever measured this year.
The low-oxygen dead zone along the Louisiana and Texas Gulf Coast measured 22,720 square kilometers (8,776 square miles), about the size of the U.S. state of New Jersey.
Scientist Nancy Rabalais found a solid band of water along the Gulf bottom with oxygen levels of less than 2 parts per million stretching from just west of the mouth of the Mississippi River in Louisiana well into the Texas coast area near Houston. Rabalais said the area was likely even larger, but the mapping cruise had to stop before reaching the western edge.
She and the National Oceanic and Atmospheric Administration released the latest measurement Wednesday.
"The number of dead zones throughout the world has been increasing in the last several decades and currently totals 500," the news release said. "The dead zone off the Louisiana coast is the second-largest human-caused coastal hypoxic area in the global ocean and stretches from the mouth of the Mississippi River into Texas waters and less often, but increasingly more frequent, east of the Mississippi River."
Nitrogen and phosphorus pollution enters the Mississippi 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.