Researchers say this year's dead zone in the Gulf of Mexico could be one of the largest on record and continue to threaten the over half billion dollar gulf coast seafood industry.
Scientists are predicting the area could measure between 8,000 and 10,000 square miles, or an area roughly the size of Vermont.
The largest hypoxic zone measured to date occurred in 2002 and encompassed more than 8,400 square miles.
The Gulf dead zone forms each spring and summer off the Louisiana and Texas coast when oxygen levels drop too low to support most life in bottom and near-bottom waters.
The zone is caused by nitrates and nitrogen from fertilizer and urban runoff flowing down the Mississippi River.
The amount of nitrogen entering the Gulf of Mexico each spring has increased by about 300 percent since the 1960s, mainly due to increased agricultural runoff.
High water in the Mississippi River and higher-than-average nitrogen concentrations in the waterway this spring are driving the estimate upward.