And it’s Pollution

The Mississippi River begins its life in Itasca State park, Minnesota. From here it begins a 2,350 mile journey to the Gulf of Mexico. Along the way this pristine water comes into conjecture with hundreds of other waterways forming the massive river we know here in St. Louis. But as it flows south, the Mississippi is contaminated by man and much of that beauty is lost to those of us who live downstream. The Upper Mississippi flows through Minnesota and then flows south through Wisconsin, Iowa, Illinois and finally to St. Louis where it converges with the Missouri River to form the Middle Mississippi. The Middle Mississippi continues along the Missouri-Illinois border until it converges with the Ohio River in Cairo, Illinois to form the Lower Mississippi.

The headwaters of the Mississippi

Rivers are oftentimes the hearts of thriving ecosystems, providing drinking water for the many animals that live in and around it, and the Mississippi is no exception. The Upper Mississippi is home to as many as 140 species of fish, and which vary from bluegill, largemouth bass, and Channel Catfish to the rather elusive shovelnose sturgeon and the truly ancient American paddlefish. A plethora of other animals rely upon the river for sustenance including the Bald Eagle, North American river otter, and even the massive Common Snapping Turtle.

But on it’s way downstream the water is injected with various contaminants, including pesticides, fertilizers, sediments, and mercury, all of which can be harmful to both people and ecosystems. Pesticides often find their way into waterways that flow into the Mississippi when they are carried by rainwater in the form of runoff into these waterways. Once in the water, pesticides can poison many of the organisms that live in it, as well as those who drink from it. Fertilizers, used in farming much like pesticides, oftentimes end up in waterways in the same way that pesticides do. Fertilizers contain nitrates which can be dangerous if ingested, especially for infants, and can cause methemoglobinemia, which transforms healthy hemoglobin cells into methemoglobin cells, which cannot carry oxygen, unlike hemoglobin. Some research also suggests that nitrates can cause cancer in humans. But fertilizers can also cause algal blooms, which can have a truly catastrophic effects upon ecosystems. An algal bloom is a sudden rapid growth in algae in a body of water. This in itself can have some ill effects upon the wildlife in the area, and in the case of cyanobacteria, a type of algae that can be harmful to the human body, even on contact. But the real danger comes when that mass of algae begins to die. Such a large population of algae dying and then decomposing creates a condition in the water called hypoxia, a depletion of oxygen, as the decomposers consume oxygen in the process of decomposition. A large area of hypoxia can kill large populations of organisms in the water, from microorganisms like phytoplankton to the largest catfish.This can create what is termed a dead-zone- an area where no biological life can survive for days or even months. These dead zones are common throughout the Mississippi.

But not only do bad agricultural practices lead to chemicals ending up in the Mississippi, but they can also lead to erosion, which dumps sediments into waterways. These sediments can make the water very cloudy, thus decreasing the amount of sunlight that aquatic plants can absorb. This causes the population of plants to decline, throwing the whole food chain off balance.

As the Mississippi passes through farmlands it is injected with those ill effects of unsustainable agricultural practices, but industry can also damage the Mississippi. Mercury is particularly harmful to ecosystems and through the burning of coal and trash, is thrown into the atmosphere. Eventually though, some mercury sinks back down to the ground where it ends up in rivers and streams, and in the American Midwest, almost all of those find their way into the Mississippi sooner or later. Mercury is consumed by fish and other riverine organisms and is passed up the food chain, resulting in larger fish containing large amounts of mercury. Mercury is a poisonous substance and in large amounts can harm the health of not only fish, but also humans. Mercury is particularly dangerous to developing fetuses, and can lead to problems involving the central nervous system, even in relatively low amounts. In high amounts, it can have many of the same effects on adults, such as impairment of peripheral vision, motor skills, muscle weakness, and language skills, amongst other things. For this reason it is best to limit the amount of certain, larger fish one consumes.