Elevator Speech

We studied the effects of urbanization on periphyton density and species richness in the local Amethyst Brook.  Amethyst Brook is a good site for a study due to it being conservation land where houses butt right up against some points of the river.  This allowed us to chose one site that represented close proximity to urbanization and two other sites farther away from human development.  We constructed a three-slide apparatus to place at each of the three sites, removing them at one and two week intervals. Microscope analysis of the slides provided us with multiple species types and overall density.  We hypothesized that urbanization would have an effect on periphyton in the brook, and predicted that there would be lower densities and less species at the site closest to houses. We also hypothesized that our week two collection would comprise of higher densities of periphyton.  Our data showed no correlation between periphyton density and proximity to urbanization. Interestingly, there was also a decrease in density across sites 1 and 3 after two weeks. This was due to heavy rains during the beginning of the second week that increased turbidity and strength of the water flow.  A more elaborate experiment with multiple sites and longer ‘grow periods’ would be necessary as a follow up to this pilot study.