Daphnia Magna Case

This project was conducted to test the toxicity of sediment in a local pond using Daphnia magna in order to assess the affects on wildlife in the pond ecosystem. This study tested to see if sediment found in close proximity to the pond in a parking lot contained toxic compounds that could contaminate the water and then flow into the pond. A bioassay was used to test for the presence of toxic compounds in a water sample that contains sediment from a parking lot. Daphnia magna, a fresh water crustacean, was used in the bioassay to monitor water quality. The number of organisms present at the beginning of the research was recorded, then the organisms were exposed to different concentrations of the suspected toxin, and then the number of organisms that remained viable were recorded. After I had estimated the LC50 of my research I was able to use this number to make a statement about the toxicity of the sediment I was testing. The results were however inconclusive, as my concentrations did not allow an accurate representation of the LC50.

As human developments continue to grow, watersheds are becoming increasingly affected by the existence of industries, buildings, roadways and parking lots in today’s world. Watersheds are “the area of land that catches rain and snow and drains or sweeps into a marsh, stream, river, lake or groundwater.” Watersheds don't just drain the water; they pass along any contaminants and chemicals that have been dumped into them. Construction of roads and buildings have resulted in creating "fast lanes" where rainwater, and the chemicals that can be passed along with it, drain quickly into streams and lakes instead of being absorbed by soil and plants. A fast lane created by rushing rain water over sediment running into a large pond is a small example of the large scale environmental issue of unhealthy watersheds. These toxins can be detrimental to the plant and wildlife in the water. “Aquatic life quickly suffers

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