237 - Seasonal and Historical Trends of Cyanobacteria Dominance in Conesus Lake

The purpose of this research was three-fold. First, an analysis of long-term data was conducted to determine how the abundance of the cyanobacteria of the genus Dolichospermum changed historically since 1985 in Conesus Lake. Secondly, to look at the seasonality of the Dolichospermum blooms in the Summer of 2022. Third, to determine Dolichospermum's Nitrogen-fixing activity based on analysis of the frequency of Nitrogen-fixing cells in the population (heterocysts). Long-term data shows Dolichospermum has increased in representation in recent years and in 2022 reached a peak biomass that represented 75% of all the cyanobacteria biomass and 56% of all the phytoplankton in Conesus Lake. We predict that we will see an increase in Nitrogen-fixing cells during this peak. This study is important because it shows an increase in the representation of a species of cyanobacteria that has the potential to form harmful algal blooms. A better knowledge of Dolichospermum’s population changes is important for public health and the safety of the public’s drinking water supply.