The Mississippi River is the fourth longest river on Earth and the longest river in the United States. It is made up of many smaller tributaries stretching from Minnesota in the North to the Gulf of Mexico in the South. The Mississippi River does not mix with the Gulf largely due to several of the structures that surround and impede it.
The Gulf of Mexico consists of deeper ocean waters than the Mississippi River which further contributes to the two not mixing. The gulf is bounded by the continental shelf which is a shallow area of water that gently slopes away from the shore line. The depth of the continental shelf varies but it averages a few hundred feet deep. The Mississippi River, however, is much shallower. Most of the river is less than thirty feet deep.
These two very different water sources meet at the mouth of the Mississippi where a complex system of water circulation blocks the river from mixing with the gulf. First, the strong outflow from the river is pushed by the prevailing winds away from the shore toward the outer edge of the continental shelf. The shape of the shelf then causes the water to be directed back towards the shore line and also towards the mouth of the river. This creates a counter flow that prevents the Gulf of Mexico from entering into the Mississippi.
In addition to the physical barriers between the river and the gulf, a temperature difference also contributes to their lack of mixing. Water from the Gulf of Mexico is usually warmer than the water from the Mississippi. This temperature difference creates an upward flow of cooler water from the Mississippi, further blocking its mixing with the warmer gulf waters.
In a natural system, this effect is known as stratification and it has significant implications for the ecology of the region. Stratification creates different layers of water, each having their own unique properties. The properties of the water in each layer affects the types of organisms that can live in that layer. As a result, stratification has profound effects on the diversity of life found in the Mississippi delta at its mouth.
Furthermore, a combination of strong artificial levees along the river banks, the naturally occurring processes of stratification, and the rotation of the Earth has created a connection between the Gulf of Mexico and the Gulf Stream. This further impedes any mixing of the waters of the two bodies.
Geographical Effects
Geographically, these processes limit the potential for Mississippi River water to mix with the Gulf of Mexico, with the two flows essentially going “hand over fist”. This allows for the stability of the delta and the preservation of the many wetlands associated with the Mississippi River. In addition, it contributes to the natural land formations that help to protect coastal cities from storms and other forms of extreme weather.
From a conservation standpoint, this process is beneficial in that it helps to control erosion along the banks of the Mississippi River and helps to preserve the unique biodiversity of the area. This includes protecting both aquatic and terrestrial life, particularly endangered species such as the American alligator and the Louisiana black bear.
The diverse number of creatures, the health of the ecosystems, and the naturally occurring topography, are just a few of the reasons that the waters of the Gulf of Mexico and the Mississippi River do not mix.
Economic Effects
From an economic standpoint, stratification between the two different waters sources helps to support the large fisheries and recreation industries that rely on the Gulf of Mexico and the Mississippi River for resources.
Fisheries play an important role in the economy of the region, with the species in the waters of the Mississippi being particularly important, including oysters and sea bass. The stratification of the waters helps to protect the delicate larvae of these fish and provides a safe environment for them to mature.
Recreation is also a major benefactor of the stratification of the two water masses. The Mississippi is rich in swimming, boating, and fishing opportunities, providing jobs and income for local people. The ecosystem’s flourishing species also draw in a number of commercial and recreational fishers, contributing to the local economy. Again, the stratification process helps to ensure the health of these species and the environment in which they live.
Political Effects
The Mississippi River also affects politics in the Gulf of Mexico and North America. The river is a major tributary of the Mississippi Delta, a series of wetlands that stretches from Louisiana and the Gulf of Mexico, up through the southeastern US. These wetlands are a critical component of the US Gulf Coast’s environmental defense system, and a great deal of time and money have been spent on preserving and protecting them. The stratification processes helps to protect the delta from saltwater intrusion, leading to stronger defenses against storms, flooding, and other natural disasters.
The Mississippi River is a major transportation artery too. The US Coast Guard and US Navy rely on the river as a source of supply and as a route for large ships. It is also the lifeline for many businesses and communities along its banks. The stratification process helps to keep the Mississippi River free of ocean water, making it safe to use for shipping, fishing, and other maritime uses.
Concerns
Despite the benefits of the stratification process, some experts are concerned about the potential for long-term damage to the region. Global warming could shift the stratification process, potentially leading to an increase in storm surge and flooding to local populations. In addition, the destruction of wetlands, due to a variety of causes, could also lead to changes in the stratification process and consequences for the environment and the regional economy.
However, despite those concerns, it is clear that the processes of stratification between the Mississippi River and the Gulf of Mexico are beneficial in many ways. They create a natural barrier to protect the areas’ ecosystems and people, as well as providing safe protection for aquatic and terrestrial organisms. In addition, they provide a peaceful, natural environment for leisure and commercial activities, boosting the regional economy above and beyond what it would be without the protection of the stratification processes.
Conclusion of Current Research
At present, research suggests that the process of stratification between the Mississippi River and the Gulf of Mexico is crucial for the protection of the region, both politically and environmentally. However, due to the potential for long-term damage brought about by global warming and wetland destruction, it is important to protect the area and keep a close watch on potential changes that could occur and how they may affect the region.
