Daphnia Lab Report

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The Effect of pH levels on the Motility of Daphnia in Lake Ecosystems
Introduction:
The production, transportation, and use of chemicals by chemical industries can result in chemical pollution. This leads to a harmful effect on ecosystems and their balance of life (Linlin, Chen, 2012). The pH levels of aquatic environments are important because it affects the physiology of animals by changing their behaviors. The ion concentrations associated with the water and the organism’s survival can also be affected (Mahassen, El-Deeb Ghaxy, 2011). This includes increased levels of basicity. The NaOH spills can also contribute to changing pH levels. This is a very popular compound used by chemical industries. NaOH is significantly found in the water
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Zooplankton are an important part of the food chain and their decline can lead to a change of organismal relationships (Mahassen, El-Deeb Ghazy, 2011). Daphnia, a type of zooplankton, are at the bottom of the food chain in freshwater systems. If toxicity of the water is too high, it can affect these organisms, which will then affect others in the food chain (Ebert, 2005). Changes in the pH levels affected motility strength of Daphnia. There was a definite effect after eight hours in pH 5.0 and 5.5, but none of the Daphnia died throughout the experiment (Linlin, Chen, 2012). Daphnia should be able to survive at the optimum condition of pH 7.9-8.3 (Mahassen, El-Deeb Ghazy, 2011). We will be doing an experiment in order to determine the effect of change of pH on the Daphnia’s motility. We hypothesize the motility of the Daphnia would decrease as the pH increases or decreases from the normal pH range for a …show more content…
Previous studies found that even after 24 hours of Daphnia being exposed to an altered pH it did not lead to their death (Chen, 2012). The Daphnia in this experiment were only exposed to the changed conditions for about eight minutes; therefore none of them died, an observation that supports the initial expectation. The Daphnia were not in these altered conditions for a very long time. This may have had an effect on the motility of the Daphnia. Previous research discusses the changes in pH levels to have an effect on motility strength, but the Daphnia had been given more time to react to their conditions. The motility is not completely affected because we analyzed distance over time rather than simply their movement. We were led to believe that an increase of Daphnia motility was due to the extreme levels of pH tested. However, due to the other inconsistent date this cannot be

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