Investigative laboratories for high school Ecology courses can be challenging and in some cases prohibitive. To investigate anthropogenic effects of pesticides and fertilizers 2-liter plastic bottles were employed to construct the microcosms. Each student prepares a research proposal with the justification for the chemical being used and a detailed sampling plan of the aquatic community. Chemicals were used based upon student interest, and what was available locally at the garden supply store including but not limited to 2-4 Dichlorophenoxy Acetic Acid, Roundup, Monosodium Methane Arsonate (MSMA), Sevin, hog waste, and commercial fertilizer.
The students compare the microcosms before and after treatment by calculating species diversity using the Simpson Index. These before and after comparisons are tested for significance by a two-tailed Student's T-Test. While each chemical acts differently in the aquatic community, the students are able to observe changes occurring within these communities from the number of individual species to complete changes in the community structure.
