There probably isn’t a better example of the interconnected relationships that exist on the planet than the effect of nonpoint source pollution on the Mississippi River. Nonpoint source pollution is simply contamination that comes from diffuse sources. Agriculture is the primary culprit that has ultimately lead to the formation of the infamous Gulf of Mexico dead zone.
What Is a Dead Zone?
A dead zone is a worse-case scenario of the environmental impact of water pollution. Just as the name implies, it is an area that is unlivable by any aquatic organisms because of low oxygen levels. It is the result of the accumulated effects of nutrient, pollutants and other contaminants. It is a classic example of when too much of a good thing, namely, nutrients, becomes pollution.
New Predictions for the Gulf of Mexico Dead Zone
The Gulf of Mexico dead zone is the end-product of pollution coming from the Mississippi River watershed. The river passes through 31 states and two Canadian provinces, which includes about 40 percent of the land base of the lower 48 states.
Estimates by NOAA-supported scientists calculated the dead zone for 2012 to be anywhere between 1,197 and 6,213 square miles, depending upon the model used. On average, it is about 6,000 square miles, based on the last five year’s worth of data. This measure is more than the size of the entire state of Connecticut.
What Creates a Dead Zone?
The problem with the Gulf of Mexico dead zone lies farther north. The watershed includes some of the richest agricultural land in the nation. Some states, such as Minnesota and Wisconsin, have increased the amount of pollutants that they contribute, with nitrogen input surging 75 percent in the last 20 years from these two states alone.
While nitrogen is necessary for plant and animal life, it can become toxic at high levels, hence, its role in the dead zone. The issue comes from use of nitrogen-containing fertilizers. Runoff introduces chemicals into tributaries that eventually make it south to Gulf of Mexico.
The Gulf of Mexico dead zone is an excellent example for interstate and international cooperation to develop an environmentally and economically sound solution. It also makes a strong case for best farming practices because literally, what happens north of the Gulf will impact its waters.