The effects of nutrient pollution are increasingly apparent throughout the Mississippi River basin.

ECONOMIST: Nutrient pollution

Nancy Rabalais, executive director of the Louisiana Universities Marine Consortium and an expert on dead zones who didn't participate in the study, said its findings are consistent with climate change scenarios she projects for the upper Mississippi River basin, where flooding caused high algae concentrations two years ago.

NPR: Report Predicts Ever-Bigger Lake Erie Algae Blooms

Opening the spillway will redirect floodwaters from the Mississippi River through the Atchafalaya River Basin, which runs between Baton Rouge and Lafayette south toward Morgan City.

CNN: STORY HIGHLIGHTS

But the consequence is that as many as 4, 000 people, according to Louisiana Gov. Bobby Jindal, could have their homes submerged as waters are funneled into the Atchafalaya River Basin, between that river and the Mississippi.

CNN: STORY HIGHLIGHTS