Brendan Smialowski/Getty When it rains in the Midwest, runoff from fertilizers laced with nitrogen and phosphorus leak into streams and creeks, many of them eventually dumping into the Mississippi River. The chemicals float hundreds of miles south into the Gulf of Mexico, then out to sea where they begin to spur algae and microbe growth. As the algae decomposes, oxygen disappears.
The federal government just came a step closer to regulating fertilizer runoff in the Mississippi River -- runoff that feeds Gulf of Mexico dead zones.
Shrinking the annual Gulf of Mexico "dead zone" down to the size of Delaware will require a 59-percent reduction in the amount of nitrogen runoff that flows down the Mississippi River from as far away as the Corn Belt.
Chemical runoff from farms along the Mississippi create “dead zones” each year in the Gulf of Mexico—areas where nitrogen, phosphorus, and animal manure settle, feeding the algae that steals the oxygen from all other living things. ...
New research from the University of Minnesota points to lawn fertilizers and pet waste as the dominant sources of nitrogen and phosphorus pollutants in seven sub-watersheds of the Mississippi River in Saint Paul, Minnesota.