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In Colorado, waterbodies are being increasingly threatened by cyanobacteria harmful algal blooms (cHABs), which can cause a host of ecosystem and public health problems. Effective management of these waterbodies requires rapid detection of any potentially dangerous algal blooms. We used drones to collect water samples from Wonderland Lake in west Boulder, CO on 5 dates from May to September of 2022 to rapidly capture the spatial and temporal variability in algal growth. Each sample was studied using flow through imaging microscopy within a day of collection for the abundance of different algal species. We found that water quality parameters (e.g. temperature, pH, conductivity, and dissolved oxygen) were consistent at each sample site across the lake, indicating limited stratification, but changed throughout the summer season. Algal community composition changed throughout the summer, and algal biomass increased from May through September. Potential cyanobacteria growth also increased throughout the summer, with nutrient data suggesting that groundwater upwelling through the lake sediment may serve as a vector for nutrient transport into the lake. The results of this study have clear implications for the future management of Wonderland Lake and urban Front Range waterbodies in general.

Graduate Student Civil, Environmental And Architectural Engineering, CU Boulder