Book Description

Seasonality is a major factor influencing freshwater ecosystem dynamics in temperate regions. Diatom taxa attain peak populations at different times during a year under different seasonal environmental conditions. This study aimed to track seasonal and environmental changes in diatom abundance and water quality parameters over the course of a year. From June 2015 -- July 2016 monthly samples were collected from Meander Creek Reservoir. Three research questions were investigated: (1) What are the water conditions associated with the most abundant diatoms? (2) In what season are diatoms most abundant? (3) Do diatoms change with seasonal water changes? Results are reported for Secchi disc transparency, temperature, conductivity, pH, and dissolved oxygen profiles collected and analyzed in the lab each month. Results are also reported for vertical tow, van Dorn samples and suspended glass slides that were collected each month and analyzed in the lab. Chlorophyll and biomass measurements were conducted in the lab for diatom productivity. Water samples were analyzed using ion chromatography for anions. Vertical tow, van Dorn and suspended slide methods were used to collect diatom samples. A noticeable shift in relative abundance of diatom taxa occurred in the reservoir (Fragilaria-Asterionella-Aulacoseria). Correspondence of water parameters to relative abundance of diatom tax were assessed in this study. Both positive and negative correlations were found between water parameters and relative abundance of diatom taxa. Correlations were found between temperature and Cyclotella ocellata and Aulacoseria granulata. The results of this study further reveal seasonal diatom dynamics in reservoirs, and ongoing monitoring in this reservoir will also be useful to paleolimnological investigations.