209 -- Increasing Dominance of Cyanobacteria in Conesus Lake
Sponsored by Isidro Bosch
Abstract
Cyanobacteria are the leading cause of harmful algae blooms (HABs) in lakes, often producing toxins that damage the equilibrium of the native community structure. Phytoplankton community data collected during the summer season since 1972 indicate that cyanobacteria populations have been increasing in Conesus Lake. There is less evidence on whether these trends extend into the late summer and autumn. Microscopic analysis was performed on samples collected in September and October 2021, to identify the species of phytoplankton present in each sample and their relative abundance. Results of this evaluation indicated an increase in the presence of cyanobacteria in September of 2021 even compared to the same time period in 2020. With the blue-green algae comprising 55.9% of the phytoplankton community on September 5th and 39.6% on September 19th, more than a 25.0% increase from 2020. The dominant species of cyanobacteria were Anabaena and Lyngbya. Cyanobacteria decreased by October as waters cooled, with their abundance declining to 10.3% on 10/28/21. Diatoms became the dominant group in late September and October samples with the relative abundance of colonies ranging from 35.4% to 88.0%. The dominant species of diatoms were Aulacoseira and Fragillaria. Diatoms (another major group of phytoplankton) have higher success rates in cooler waters, explaining why they may be more prevalent in cooler months preceding fall turnover. The findings of our study supported that cyanobacteria dominance persisted into Summer 2021.
209 -- Increasing Dominance of Cyanobacteria in Conesus Lake
Cyanobacteria are the leading cause of harmful algae blooms (HABs) in lakes, often producing toxins that damage the equilibrium of the native community structure. Phytoplankton community data collected during the summer season since 1972 indicate that cyanobacteria populations have been increasing in Conesus Lake. There is less evidence on whether these trends extend into the late summer and autumn. Microscopic analysis was performed on samples collected in September and October 2021, to identify the species of phytoplankton present in each sample and their relative abundance. Results of this evaluation indicated an increase in the presence of cyanobacteria in September of 2021 even compared to the same time period in 2020. With the blue-green algae comprising 55.9% of the phytoplankton community on September 5th and 39.6% on September 19th, more than a 25.0% increase from 2020. The dominant species of cyanobacteria were Anabaena and Lyngbya. Cyanobacteria decreased by October as waters cooled, with their abundance declining to 10.3% on 10/28/21. Diatoms became the dominant group in late September and October samples with the relative abundance of colonies ranging from 35.4% to 88.0%. The dominant species of diatoms were Aulacoseira and Fragillaria. Diatoms (another major group of phytoplankton) have higher success rates in cooler waters, explaining why they may be more prevalent in cooler months preceding fall turnover. The findings of our study supported that cyanobacteria dominance persisted into Summer 2021.