The Fragile Fringe - The Mississippi River: Draining a Majority of the United States

Objectives:

1. To establish the role of the Mississippi River in the formation of the coastal wetlands
2. To increase awareness of the problems created by nature (flooding) and those from other sources (pollution) associated with the presence of the Mississippi River

The Mississippi River watershed drains a large portion of the land area between the Appalachian Mountains to the east and the Rocky Mountains to the west and carries that water and its contents through many states before discharging it into the Gulf of Mexico. Long before the Mississippi River was leveed, the sediments carried by the river were dispersed all along the coast of Louisiana as the river changed paths through time. This deposition of material in varying areas, called deltas, formed new areas of land and increased the health of the coastal marshes.

After the flood of 1927, the Corps of Engineers began building levees to contain the flood waters of the Mississippi. The Mississippi River, no longer able to change course, then began depositing all of its sediments into the deeper areas of the Gulf of Mexico where they are of no use to the coastal ecosystems.

Activity: (for upper elementary - middle school students)

1. Provide students with a map of the United States showing the Mississippi Drainage Area.

View Mississippi Drainage Area map.

Have students label the rivers (or you may provide the names of the rivers on the map) and the states associated with the rivers. Some of the major rivers that feed the Mississippi River are the Ohio, Red, Platte, Missouri, Arkansas, Tennessee, and Yellowstone. Have students tally the number of states drained by the Mississippi Watershed.

2. Have students "build" the watershed in a pan using modeling clay or soil. Create indentions for the rivers and have them all connect into the "Mississippi" which in turn should empty into the "Gulf of Mexico."

Use small objects, beads or something similar, to represent things such as pollutants, litter, fertilizers, sediments, etc. that could be transported by the water flowing in the drainage system. Place the objects around the rivers and use a watering can to produce "rainfall" and "floods" that will transport the materials to the Gulf of Mexico.

1. Have students discuss the addition of these various materials into the waters of the Gulf of Mexico. How will they affect the animal life and plant life? What were the effects of sediments deposited in the past and what is happening to the sediments deposited now?
2. Use the activity "Deadly Waters" from the Aquatic Project Wild activity manual to introduce different kinds of pollution and their effects. (pp. 137-141).

Extensions (high school):

1. Research past floods, starting with 1993 and moving back in time, and explore the effects on commercial industries such as fishing, shrimping, and oystering in the Gulf of Mexico.
2. Pollutants added to the water in the rivers in this system are an obvious problem since this water will eventually travel through many states and enter the Gulf of Mexico. Have students explore uses of water taken from the river and how pollution might affect these uses. Introduce the idea of dilution of the pollutants by the water and let the students discuss/research the potential problems or reduction of problems associated with dilution.
3. Have students research and discuss ways that pollution added to rivers in various states has been reduced (if it has) by farmers, industry, and the shipping business. Distinguish between point and nonpoint source pollution and identify examples of each. Develop graphs and charts to show changes in pollution levels, if the information is available.