Eutrophication in the Gulf of Mexico
Introduction
Even though the Midwestern United States produces the majority of the country’s agriculture to date, this immense agricultural activity in the Midwest region has not only degraded the land itself but also the water in the regional rivers and tributaries, which is all interconnected in the network known as the Mississippi-Atchafalaya River Basin (also referred to as MARB). The MARB (Figure 1) covers an extensive 1,245,000 square miles and drains out into the Gulf of Mexico, where over the years it has accumulated an increased and dangerous amount of agricultural runoff pollution, namely nitrogen and phosphorus. Over the years, researchers have identified and pointed to several human interactions that have contributed to the degrading and toxic ecological changes occurring in the Gulf of Mexico. However, only 3 human interactions have been chosen as part of the focus for this research project, all of which will be introduced later in the paper. In addition to the human interactions that accelerates the degradation of the water in the GoM, it also important to note that the continual increase and accumulation of excess nutrients resulting from runoff is defined as eutrophication and is a true real world problem that must be reduced before water becomes uninhabitable.
Eutrophication. What is it?
Eutrophication is “the process by which a body of water acquires a high concentration of nutrients, especially phosphates and nitrates. These typically promote excessive growth of algae. As the algae die and decompose, high levels of organic matter and the decomposing organisms deplete the water available oxygen, cause the death of other organisms, such as fish. Eutrophication is a natu...
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...to the MARB, primarily from the application of agricultural fertilizers.
Agriculture has caused an increase in the flow of nutrients from chemical fertilizers into bodies of water. The excess nutrients change the chemical composition of the water, impacting biological life forms in the affected areas. Sewage is another major source of nutrient flow to the Gulf. There are sections of lakes and oceans all over the world affected by eutrophication and hypoxia, and this has not only biological effects but also economic and social problems. The largest hypoxic area in the western Atlantic Ocean is found in the Gulf of Mexico. The biological repercussions of eutrophication, in the form of habitat alteration and entire trophic structure disintegration are devastating to the Gulf; remediation, though costly, must be put into effect in order to bring life back into the area.
Currently, the United State’s Gulf of Mexico experiences an annual, seasonal “dead zone” as a result of hypoxia. Hypoxia is a low level of dissolved oxygen (<2mg/L) in an area of water. Hypoxia is typically temporary and seasonal, but the low oxygen levels can be devastating to aquatic organisms. Hypoxia occurs in many oceanic waters worldwide, but there is a growing area of concern in our Gulf of Mexico coast. Hypoxia is largely caused by nitrogen fertilizer application for agriculture, with heavy concentrations coming from the Midwestern US. Nitrogen mobilizes as nitrate, and is transported via surface water runoff. The runoff enters tile-drain supported ditches, enters streams and joins the Mississippi river, eventually reaching the gulf. Nitrate mobilization is a problem for human health, and ag. runoff is also often attributed to the contamination of surface and well-water sources in rural areas. High levels of nitrates restrict the ability of red blood cells to carry oxygen. This can harm humans, and is the major cause of infant methemoglobinemia, or “blue baby syndrome”. The safe drinking level standard is 10mg/L.
This is representative of how eutrophication works in an aquatic environment. It shows that the greater the number of blue-green algae then the faster the oxygen depletion
It affects the states surrounding the Gulf of Mexico, such as Texas (epa.gov, 2016). It costs a great amount to restore algal blooms and remove Nitrogen nutrients from the water. Sometimes it can cost billions of dollars to clean polluted water. Also, the tourism industry loses about one billion dollars a year from polluted waters, in fishing and boating. (epa.gov, 2016) Nutrient pollution can be harmful to fish and often kills them, losing millions of dollars in commercial fishing. Moreover, people can play a role in nutrient pollution by the way they use their
Nature designed Florida to be one large marine ecosystem. Florida is one big sand peninsula located below the 40th longitudinal North American line. Three bodies of salt water (Gulf of Mexico, Strait of Florida and Atlantic Ocean) surround three out of four directions of Florida. Man-made canals, natural lakes, rivers and estuaries are confined within the State of Florida’s physical boundaries. All of these form an interlocking system of waterways that impact the interconnected marine environment (marine ecosystem). All of Florida’s waterways are connected back to the surrounding bodies of water while passing through Florida’s sub-tropical and temperate zones and impact the delicate marine ecosystem balance. Man and nature are causing a negative impact to this region like never before. Hurricanes, lack of green initiatives, garbage, pollution and the stripping of natural resources for population growth are decimating Florida’s natural ecosystems.
Eutrophication is a concern in the Chesapeake Bay. Eutrophication is caused by excessive amounts of nutrients. Excessive nutrients in the bay have negative affects on the bay's ecosystem. The extra nutrients make the environment unbalanced. The extra nutrients cause a chain reaction that depletes oxygen and kills most of the organisms in that area. This is what is known as a dead zone.
Once that step is determined, scientists will assign that group of species to a trophic level; to either the primary producers, primary consumers, secondary consumers, or the tertiary consumers. The bottom of the chain and the trophic level that depends upon by all others is the primary producers. These primary producers consist of autotrophs, which are capable of deriving their food and energy source without consuming organisms or substances taken from other organisms. In the Arctic lake of Alaska, one of it’s primary producers consists of aquatic plants and algae. These aquatic and algae contain chlorophyll, which means that they can use light energy from the sun to synthesize glucose and other organic compounds, that they can use for cellular respiration and building material for growth.
During the summers the oxygen content atop the water normally has a salinity level consistent with “more than 8 milligrams per liter”; but when oxygen content drops down to “less than 2 milligrams per liter” the water is then known to be in hypoxic state (CENR, 2000; USGS, 2006). Hypoxia is the result of oxygen levels decreasing to the point where aquatic organisms can no longer survive in the water column. Organisms such as fish, shrimps, and crabs are capable to evacuate the area but the fauna that cannot move either become stress and/or die. Due to this, many call the hypoxia zone the “dead zone” (Overview, 2008; USGS, 2006).
Eutrophication is a concern in the Chesapeake Bay. Eutrophication is caused by excessive amounts of nutrients. Excessive nutrients in the bay have negative effects on the bay's ecosystem. The extra nutrients make the environment unbalanced. The extra nutrients cause a chain reaction that eventually kills most of the organisms in that area. This is what is known as a dead zone.
Overall, the Gulf of Mexico dead zone is an area that should be taken very seriously. This is a part of the ocean that is drastically and undeniably affected directly by human activities. The economies surrounding the Gulf are very dependent on the resources they receive from it and would be devastated if economically-important species began dying off due to lack of oxygen. Although the dead zone varies in size from year to year, the area has increase exponentially ever since the birth of intensive farming practices involving nutrient-rich fertilizers. Thankfully, many efforts have been put forth to monitor and manage the dead zone. Revised farming practices along with greater environmental education for the general population with hopefully lead to a reduced risk of hypoxic conditions causing excess economic or ecological damage.
Water pollution has had devastating effects on the environment, which include irreversible effects on the oceans ecosystem. People often underestimate the importance of the ocean. They don’t realize how much damage pollution has caused to the ocean and the thousands of creatures that inhabit it. Earth is a huge place, but resources are actually very limited and will not last forever unless there is a balance. We must protect the resources we have in order for them to last into the next generation.
Ecosystems are the basic biological units of ecology, and consist of biotic organisms and their interactions amongst other living organisms, as well as the surrounding abiotic environment (Putman and Wratten 1984). One facet of ecosystems that is less-often mentioned is the process of decomposition, as it many may view it as an unclean, unpleasant process that occurs after an organism has ceased to exist. To those with an ecological framework, however, decomposition is viewed as the opposite – an interesting, intricate process teeming with biological activity and life (Swan and Kominoski 2012). What is decomposition? Formally, decomposition is defined as the process to which complex organic matter is broken down to its basic constituents (i.e.
Oceans are such so vast that people underestimate the impact their actions —seeming so insignificant— have on them. Humans have by and large taken the oceans for granted; not considering how important a healthy ocean is to our survival. A popular mind-set is that the oceans are a bottomless supply of fish, natural resources, and an infinite waste dump. There are myriad reasons why the oceans should be saved and the most obvious one is marine life. With 71% of the Earth being covered by water, it is obvious that sea creatures are predominant form of life, making up 80% of the species of life on Earth. However, as important as marine life is, that is not the only reason why saving the oceans is crucial. The ocean floor provides natural resources such as, oil, natural gas, petroleum, minerals, medications, and ingredients for foods and products. The economic benefits of the oceans are huge and significant, as well. Fishing and fish products have provided employment to 38 million people and have generated about $124 billion in economic benefits. However, oceans are on the verge of crisis, marine life, natural resources, transportation, the economy, and important ingredients are at risk due to overfishing, pollution, and acidification. Thus, in this essay I will argue that, oceans are not impervious to human activity and threatening the health of the ocean threatens the health of humanity, since oceans key to our survival.
These results agree with the hypothesis that our “untouched and super-productive world” is affecting marine life ecosystems (Vannela, 2012). All of these results combined confirm the overall hypothesis that pollution is getting worse in the ocean and more marine life ecosystems are being affected, but there
I am particularly surprised how the agricultural industry inflicts these problems on themselves, by excessive use of sewage systems and pollutants which find their way to local rivers [Fig 1.]. The trophic state (i.e. the natural nutrition factors) and biodiversity of lakes and rivers are greatly effected by the main nutrients involved, nitrates and phosphates. The transition occurs mainly between a mesotropic state, with an average biological productivity to a eutrophic state where there is a larger production of organisms due to high nutrient concentrations. Tropical reservoirs in particular often become eutrophic.
Different pollutants cause different things to happen to plants. Sometimes, water pollution causes an explosion of new plant growth by providing necessary nutrients and food. If there is too much of one species, this can harm or kill plants by changing their growing conditions, such as raising or lowering the environment’s acidity. Plants must take in nutrients from the surrounding environment in order to grow. Nitrogen and phosphorus, in particular, help a plant’s growth because they are important in photosynthesis. This is why they are common ingredients in plant fertilizers. When runoff from farms pollute waterways with nitrogen and fertilizers rich with phosphorus, the water enriched with nutrients often have stunts of growth. Sometimes too much growth can be harmful, as when plant-like algae bloom in polluted waters and create oxygen-depleted dead zones. One solution to this issue is planting seaweed farms in areas that get alot of runoff from farms. This is because seaweed can soak up the excess nutrients and be harvested for people to eat. Marine debris is garbage that ends up in the ocean. Plastic debris that builds up at or near the water’s surface blocks sunlight from fully reaching plants that rely on sunlight to move along the photosynthesis process. By blocking sunlight, marine debris prevent plants from creating glucose at full capacity, which stunts their growth. When chemical pollutants