The Environmental Problems at the Mississippi Gulf Coast

According to The Economist, the Mississippi picks up a huge amount of chemical fertilizers along its course.

So much so that agriculture’s gift to the gulf is a “dead zone”. The excess nutrients cause algae to bloom, consuming all the available oxygen in the sea, making it hostile to other forms of marine life. Creatures that can swim away, such as shrimp and fish, do so; those that cannot, die. In the four decades since the dead zone was discovered it has grown steadily. Today it covers 6,700 square miles, an area larger than Connecticut.

According to the Union of Concerned Scientists:

The coastal wetlands associated with the Mississippi River delta make up nearly 40 percent of the total coastal salt marsh in the lower 48 states of the U.S. These wetlands are disappearing at an average rate of 25 square miles per year, about 50 acres each day. Already, more than one thousand square miles of freshwater wetlands in Louisiana have been lost or converted to other habitats. Only about 20 percent of the original bottomland hardwood forests and swamps in the lower Mississippi River valley remain today. 

Some of these wetland losses are due to delta subsidence (sinking), which results in relative sea-level rise. Although subsidence is a natural process, human interference with river and sediment flow and withdrawal of groundwater have exacerbated it.