Gulf of Mexico Dead Zone Arrives Early

Scientists from Texas A&M, NASA, and Louisiana State University surveyed 120 sites in the Gulf during March. They recorded data to help them track the dead zone this summer. The scientists found 19 spots of oxygen-depleted water, or hypoxia. They didn't expect to find any, and said that because it has come so early this year, the area could become a severely hypoxic region.

Researchers believe the dead zone is caused by an influx of polluted freshwater from the Mississippi and Atchafalaya rivers. Fresh water floats over salt water and acts as a barrier to oxygen. Meanwhile, pollution also flows from the rivers in to the Gulf, creating algae plumes that further choke off the oxygen.