The Effects of Motor Oil in A Controlled Freshwater Jar Ecosystem
“An ecosystem is an environment where plants, animals, and micro-organisms all interact and reside together in a setting” (Simon, Reece, and Dickey, 2010). There are two main types of aquatic ecosystems, freshwater and marine. The main difference between them is that marine ecosystems contain salt, which causes them to be undrinkable without substantial alterations. Freshwater systems contain nearly no salt and provide a majority of the Earths’ drinking water, with little alterations. Freshwater ecosystems are aquatic systems that include both abiotic and biotic components. Abiotic components are the non-living chemical and physical factors in the environment including; radiation, temperature, water, atmospheric gases, and soil. Biotic components include all of the living elements of a community (Simon, Reece, and Dickey, 2010). Motor oil is a contaminant that affects many freshwater ecosystems around the world. It contains a base ingredient of crude oil, with additives to improve certain properties (Green, 1989). Therefore, though the majority of our research for this experiment reflects studies conducted on crude oil contamination of freshwater ecosystems, we expect similar results from the motor oil contamination in our experimental freshwater jar ecosystem. The successful conduction and application of this and similar experiments can be applied towards the successful monitoring and maintaining of freshwater ecosystems’ health. Our hypothesis states that the freshwater ecosystem containing the motor oil will show signs of a shift from heterotrophic to autotrophic domination (Werner, 1985). We will test this variable by observing and recording the various numbers of biotic components (Protozoa and Cynobacteria) and levels of dissolved oxygen in both our controlled freshwater jar ecosystem and our experimental freshwater jar ecosystems and by comparing the results of each over a period of 4 weeks. If we notice both a significant decrease in Protozoa and an increase in Cyanobacteria in our experimental freshwater jar ecosystem, we can conclude that the experimental jar has shifted from heterotrophic to autotrophic domination (Werner, 1985). Autotrophic components are self-feeding organisms that use photosynthesis and other substances from the environment to thrive (Sa, n.d.). They are the basis of the ecosystem, in the form of algae and other plant-like organisms that are the provider food source of the ecosystem. Heterotrophic components are components that cannot self-feed and rely on the autotroph’s organic compounds to supply their food source (Sa, n.d.). Dissolved oxygen is necessary to maintain aerobic conditions in surface waters and is considered a primary indicator when assessing the suitability of surface waters to support aquatic life (Vandermeulen, 1995). “Concentrations below 5 mg/l may adversely affect function and survival of biological communities and below 2 mg/l can lead to death of most fishes” (Water Quality Assessments, 1996). Methods:
In both the controlled and the experimental jar ecosystems, we mimicked a pond by using still standing water with a combination of sand and rocks as a base in a 3.78 liter jar. On Monday, August 27, 2012 we placed 20 ounces of sand, 4 ounces each of both small and big rocks, 3000 mL of well water, and 1 mL of Bristol’s solution. We waited two days for the environment to settle then added both abiotic and biotic factors into each jar on Wednesday August 29, 2012. We added 20 drops of Cyanobacteria (blue-green bacteria), and 5 drops each of Blepharisma, vitachrome, Volvox, Stentor, Spirostomum and mixed flagellates. In our experimental jar we also added 2.5 mL of used motor oil to test the effects of oil contamination on a pond with a similar ecosystem to that of our controlled freshwater jar ecosystem. On Wednesday September 12,...
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