The Negative Effects Of Cultural Eutrophication

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.

Back in the 1960’s, Lake Erie was declared “dead” because, ironically, it was full of life – just not the right kind (GLIN, n.d.). The algal blooms that formed due to high concentrations of nutrient-loaded city street run off invaded the freshwater lake, killing native species, reducing oxygen quantities, and smothering beaches with its slime (GLIN, n.d.).

Even though, fertilizers are needed to supply essential nutrients to the growth of plants; an excess of them is one of the major issues contributing to pollution in the Chesapeake Bay Watershed. Fertilizers are mainly composed of two elements: nitrogen and phosphorus.(4) Throughout the years, millions of pounds of this nutrients are applied all around the Chesapeake Bay Watershed; everything not absorbed by the soil or taken up by plants eventually reaches the Chesapeake Bay through storm-water runoff. This nutrients end up creating algae blooms in the water, which reduce the amount of sunlight available to underwater grasses; not allowing plants to photosynthesize and produce the food they need to survive. Algae then decomposes creating dead zones killing fish and other species since oxygen is needed for any organism to live. (5)

Phosphorus, “...the primary algae-feeding nutrient in Lake Erie, and contributed to the largest algae bloom in history last year” (McCarty, para. 3), is a key factor in how

Did you ever wonder how things you do everyday effect the Chesapeake Bay watershed and Its tributaries? Well, It turns out to be not so good. One of the main causes for the Bay’s bad health are nutrients which are caused by excess nitrogen and phosphorus in the air and water. Plants and animals need nutrients to survive but when too many nutrients are in the water they fuel the growth of algae blooms and create conditions that are harmful for aquatic creatures.

Algae blooms have been an issue in the Chesapeake Bay, especially in the Baltimore Inner Harbor. Algae is a natural and critical part of the ecosystem, however in large doses it is harmful to the plants and organisms within the ecosystem. Algae blooms can block out sunlight and kill other plants in the water. Algae depends on various factors such as water, nutrients and carbon dioxide to grow. Eutrophication of the Inner Harbor has lead to algae blooms that have caused large fish kills in the past. When there is an over abundance of certain chemical nutrients eutrophication can occur. Runoff from land and farms is the main cause of excess nutrients into the water. The most common nutrients that are related to algae outbreaks are nitrate nitrogen and phosphate. In addition, a lack of dissolved oxygen can also be an indicator for the process of eutrophication and risk of an algae outbreak. A particular type of algae commonly found in Maryland is known as Prorocentrum minimum. Prorocentrum tends to cause “mahogany tides” causing water to be brown and have an odor. There has been a campaign launched by the Healthy Harbor

The Conodoguinet Creek is a one-hundred mile long body of water running through central Pennsylvania. This area has many pollution issues, such as Eutrophication and many others. Eutrophication is when there is too much nutrients in the water. Some people might not understand why too much nutrients in the water is a problem, but it is a very serious one. The higher amounts of nutrients in the water allows a larger amount of algae to grow on the surface of the water, absorbing all the dissolved oxygen in the water, leaving no oxygen left for the fish, and they die.

As humanity continues to prosper agriculturally, industrially, and in population, companies, as well as local communities, have obsessively used the Ocean to toss their waste without consequences. The formation of dead zones has been intensified by the increase runoff of fertilizers and the burning of fossil fuels. Enhanced primary production causes algae to bloom at a constant rate creating a layer near the surface. This layer acts as a roof to vegetation below resulting in a lack of oxygen which organisms use to live. According to Robert Diaz and Rutger Rosenberg, “Dead zones have now been reported from more than 400 systems, affecting a total area of more than 245,000 square kilometers, and are probably a key stressor on marine ecosystems.” Specifically, the Chesapeake Bay has been polluted to the point where areas have now been uninhabitable to marine life. Although waste disposal is a difficult issue to solve, polluting bodies of water endangers the marine life, environment, and health of organisms.

Back to the history, the eutrophication problem was first time concerned by public on Great lakes at the 1960s, the Lake Erie was covered by algae as a result of over dumped phosphorus from the sewage and other waste water, at that time, the Lake Erie was known as the “Dead Sea of North America”(Fitzpatrick, J. J., and Di Toro 1999). The reason cause this problem can be concluded in 2 points, 1. the stresses of overfishing, 2. development of phosphorus-based detergents. At the end of 1960, the Canada and the United States have realized the penetrance of this problem and finally sit on the table to sign an agreement that limiting phosphorus dumps to the Lake Erie, and plan to control existing unstoppable algal growth. Because of the awareness of Canada and US government, the concentration of phosphorus got a significant success. And this problem happened again during the 1990s, but this time the reason why this happen is more complexly.

There are innumerable sources of pollution to the Chesapeake Bay creating serious water quality issues. Run-off and discharge from natural, industrial and municipal sources causes nutrient overload, resulting in algae blooms. The algae blocks out the sun, which prevents native aquatic grasses from surviving. As the blooms die, they deplete the water of oxygen which is essential to the survival of all aquatic animals.

The purpose of this experiment is to understand the effects of nutrient enrichment and eutrophication, using samples of water from Rio Salado and Encanto Park. The samples will contain different concentration levels of nitrogen, phosphorous and nitrogen and phosphorous combined and the impact it has on algae growth. The results recorded showed that the nitrogen concentration levels had a little change, phosphorous levels had a higher change and phosphorous and nitrogen combined had a significantly higher change, resulting in higher algae growth. The results showed that phosphorous indeed is a limiting nutrient in algae growth, but to achieve the highest growth rate, both nitrogen and phosphorous need to be combined.

The water in brooks, streams and creeks from Michigan to Puerto Rico carries a heavy load of pollutants particularly nitrates from fertilizers. These nitrogen and oxygen molecules that crops need to grow eventually make their way into rivers, lakes and oceans, fertilizing blooms of algae that deplete oxygen and leave vast "dead zones" in their wake. Therefore no fish or typical sea life can survive. And scientists warn that a federal mandate to produce more biofuel may make the situation even worse.

In Lake Erie, there is out-of-control algae growth that created dead zones. The problem has become critical in the western Lake because of harmful chemicals. Contaminants in fish certainly are causing health problems. At present, the solution is to make

Eutrophication is the slow process that occurs naturally in aquatic ecosystems, such as lakes and ponds. It is a result of an aging body of water gradually increasing its concentration of nutrients. This happens because the intervaling death and growth of organisms that, for whatever given reason, don’t cancel each other out, and modify the fertility of the ecosystem. Eutrophication is not inherently bad, but the hastening of this process through artificial means can be very harmful to the ecosystem, and ultimately end in failure.

Harmful algal blooms (HAB’s) form when regular plants that live in freshwater grow out of control and produce dangerous toxins that hurt humans, animals and marine life living in the water as well. What causes this algae to grow out of control is “overfeeding” as stated on NOAA’s official website. “Overfeeding” happens when high amounts nutrition like phosphorus and nitrogen runoff into to freshwater or oceans. These high amounts usually come from farmland near by. These overgrown plants result in the closing of beaches, lakes and rivers; this results in a decline in tourism in not just our community. HAB’s cost the US about eighty-two million dollars a year. Although this is such a prevalent problem scientists and marine researchers still do not know all causes of this growing issue. (“Why Do Harmful Algal Blooms Occur?”)