Each summer a large "dead zone" devoid of fish and other animals develops where the Mississippi River flows into the Gulf of Mexico. What causes this?

Question

Quizplus · Accepted Answer

The excessive use of fertilizers in midwestern farm fields causes large quantities of nitrogen and phosphorus to run off into the Mississippi River. These nutrients then create an overgrowth of algae, which consumes the oxygen in the water as it decomposes, leading to the formation of a dead zone in the Gulf of Mexico where there is not enough oxygen to support fish and other aquatic life.

Each Summer a Large "Dead Zone" Devoid of Fish and Other