Annual forecasts and measurements of the Gulf slow zone started in 1985. Because of fertilizer use, agricultural lands contain high amounts of nitrogen and phosphorus, two of the main ingredients in fertilizers. She and her team have been monitoring the Mississippi River discharge and nutrient levels since the first big pulse of flood water in the spring, so they "weren't necessarily surprised" by the results of their models.
ANN ARBOR-University of MI scientists and their colleagues are forecasting that this summer's Gulf of Mexico hypoxic zone or "dead zone"-an area of low to no oxygen that can kill fish and other marine life-will be approximately 7,829 square miles, or roughly the size of MA".
Dead zone may cover, according to various estimates, from 20 to 22 200 560 square kilometers, which is roughly comparable to the area of Slovenia or Israel.
Shrimp boat in Biloxi channel with nets out shrimping while pelicans and sea gulls chase it down the channel.
Both Scheurer and Rabalais, however, say it's too early to say that the gulf's dead zone is already being made worse by climate change.According to the US Geological Survey.
NOAA's forecast assumes normal weather conditions, but large storms could impact the ultimate area of the dead zone. The Gulf supplies 72 percent of US harvested shrimp, 66 percent of harvested oysters, and 16 percent of commercial fish.
The 5-year average is 5,770 square miles - still well above the Hypoxia Task Force's target of shrinking the dead zone to 1,930 square miles. There is another annual dead zone in the mid-Atlantic's Chesapeake Bay.
Those fertilizers contain nitrates and phosphorous, which go into the Mississippi River water and empties into the Gulf.
'While this year's zone will be larger than usual because of the flooding, the long-term trend is still not changing, ' University of MI aquatic ecologist Don Scavia, professor emeritus at the School for Environment and Sustainability, said in a news release.
By posing a significant threat to regional marine life, the pollution that causes the gulf dead zone jeopardizes the tens of billions of dollars generated by commercial fishing in the area.
This map shows how pollution from cities and farms flows down into the Gulf of Mexico.