A survey of cyanobacteria and total microcystins in recreational lakes of the Pocono Plateau

Abstract Harmful algal blooms of cyanobacteria (cyanoHABs) are increasingly common in aquatic ecosystems and form in response to eutrophication and water column stagnation. The dominance of toxigenic cyanobacteria can impact water quality and therefore can have a detrimental impact on aquatic organisms. Aquatic conservation efforts must integrate and ultimately disentangle various biotic and abiotic drivers of cyanoHAB formation. A synoptic survey approach was used to analyze phytoplankton community structure, including cyanobacteria and associated toxicity (total microcystins), alongside limnological conditions in 14 recreational lakes across the Pocono Plateau. This approach provided a baseline for small, forested lakes in the region during peak recreational seasons. Total microcystins were only detected in three of the 14 lakes and did not exceed 0.2 μg L-1. The proportion of the phytoplankton community represented by cyanobacteria demonstrated a consistent, negative association with total nitrogen (TN). However, variable relationships with nutrients were observed for that of Dolichospermum and Microcystis, which were positively associated with total phosphorus and TN, respectively. This provides unique insight into phytoplankton community structure, including cyanoHAB-forming taxa, in the absence of excess toxigenicity for small lakes of the Pocono Plateau that aligns with predictions derived from large-scale studies of broad geographic regions.