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Eutrophication is defined by Oxford Languages as “excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.” Run-off or outflow containing fertilizer and various chemicals from cities, industries, or farms travels into ponds, lakes, rivers, and oceans. This causes water acidification and superfluous plant growth due to newly deposited nutrients in the water system, especially in the form of algae blooms. As the plants grow and overtake the ecosystem, they take up more oxygen, sunshine, and nutrients than can be provided for all organisms in the ecosystem.

 

 

 

 

 

 

 

 

 

 

 

Because of the lack of oxygen, aquatic life is suffocated and land-dwelling animals are forced to relocate. This death is evident on the beaches of Florida, as the red tide seasonally surges and lifeless marine animals are washed ashore by the thousands. As described by the NOAA, the red tide is an informal description of harmful algal blooms, or HABs. “HABs have been reported in every U.S. coastal state, and their occurrence may be on the rise. HABs are a national concern because they affect not only the health of people and marine ecosystems, but also the 'health' of local and regional economies” (NOAA). These blooms are made up of phytoplankton and dinoflagellates, but not always of a harmful variety. Phytoplankton and dinoflagellates are microscopic marine and freshwater organisms. Phytoplankton are plankton composed of microscopic plants, while dinoflagellates are a type of phytoplankton, existing as single-celled eukaryotes with two flagella. In the oceans, these microorganisms can provide a food source for fish and other mammals. However, the harmful variety of phytoplankton can produce toxins, in addition to their suffocating and sunlight-shielding properties. The red tide, in particular, is formed by diatom dinoflagellates and three other species, which makes it lethal both to humans and marine animals, and allows the algae to produce a red hue in the tide. The mixture of dinoflagellates produces neurotoxins and exorbitant quantities of brevetoxin. The neurotoxins make fish ill, whose sickness is then transmitted throughout the food chain as they are consumed by predators. The brevetoxins, when released into the air and carried by the wind, can be detrimental to the human lungs and immune system. The red tide in Florida and the states surrounding the Gulf of Mexico is caused in part by the emptying of Lake Okeechobee - a large, polluted freshwater lake - into the rivers and tributaries of Southwest Florida which empty into the gulf. If the outflow of the eutrophic lake into the Gulf of Mexico should continue, it could potentially disrupt the food chain, cause the changing of and possible removal of species and habitats, and promote the overall disruption of the internal homeostasis due to aquatic organisms’ responses to the malignant and toxic algal blooms.

 

 

Bibliography

Howard, Jenny. “Red Tides, Explained.” Red Tides and Algal Blooms, Facts and Information, 5

July 2019, www.nationalgeographic.com/environment/oceans/reference/red-tides/. 

“How Does Eutrophication Work? Causes, Process and Examples.” Earth How, 17 May

2020, earthhow.com/eutrophication-causes-process-examples/. 

US Department of Commerce, National Oceanic and Atmospheric Administration. “What Is a

Red Tide?” NOAA's National Ocean Service, 1 June 2013, oceanservice.noaa.gov/facts/redtide.html.