Cyanobacterial blooms are becoming a greater concern in freshwater systems due to their increasing frequency and potential to produce of toxic secondary compounds. Microcystis is a common bloom forming cyanobacteria genera that is capable of creating harmful algal blooms (HABs) through the production of the hepatotoxin, microcystin. HABs can cause many negative effects to the surrounding environment that include scums on surface waters, hypoxia, or unsafe drinking water. The goal of my project is to develop quantitative polymerase chain reaction (qPCR) methods that allow for early detection and quantification of toxic or non-toxic Microcystis strains to aid in the management of water resources. Currently, nutrient and environmental samples have been collected and analyzed from our study sites: Muskegon and Bear Lakes in Muskegon, Michigan. This information will be used to assess what factors are driving algal blooms and contributing to microcystin production. Furthermore, standards of our genes of interest have been developed for qPCR, and this will allow us to quantify the abundance and toxicity of Microcystis present in the water. In tandem, this data will provide a spatial and temporal profile of the bloom status in these lakes.
Results/Conclusions
Preliminary results of phytoplankton samples collected during the summer are indicative of a much higher proportion of non-toxic to toxic cells (~5,000:1), which is in accordance with similar findings in the literature. DNA copy numbers of our toxin producing gene were found to be correlated with concentrations of microcystin present in the water column. Ongoing analyses are being performed to confirm if this trend is consistent throughout our sampling period. We are also in the process of obtaining measures of gene expression to detect the frequency of toxin production and what environmental factors may influence this. The development of these qPCR methods will serve as a tool for lake managers to make informed decisions regarding public and environmental health.