How do Beaver Dams Effect Water Quality?

The North American beaver is second only to man in its ability to change its habitat. By digging canals, cutting down trees, and constructing dams and lodges, beavers engineer new ecosystems that are conducive to their aquatic lifestyles. The lentic habitats that they create trap sediments and nutrients, increase water temperature and fundamentally change the substrate. Because beavers change lotic habitats to lentic systems, the effect on biogeochemical cycling and community composition can be profound. However, little effort has been directed towards quantifying shifts in these bottom-up ecosystem controls to date. We hypothesize that increases in temperature and nutrient availability will increase primary productivity above beaver dams as compared to nearby stream counterpArts. Preliminary work revealed statistically significant differences in dissolved oxygen, pH and temperature between ponds and stream reaches that align with our overall hypothesis. Building off this work, I have analyzed chlorophyll-a concentrations in samples collected from the water column and periphyton as well as Ash Free Dry Mass (AFDM) to estimate biomass production. Statistical analyses (ANCOVA) on data including, pH, temperature, turbidity, dissolved oxygen (DO), dissolved organic carbon (DOC), particulate organic carbon (POC), Chl-a, and AFDM will quantify the effects beaver dams have on water quality here in Cache Valley and provide insight into their utility as a restoration tool