Exploration of factors of algal seasonal blooms in a drinking-water source

Context The emergence of cyanobacterial blooms has garnered international concern especially during seasonal transitions. Aims The objective of this study is to investigate the primary correlation factors contributing to algal blooms through an examination of the relationship between nutrient distribution and seasonal algae growth, specifically in the context of low nitrogen and phosphorus concentrations in the source of drinking water. Methods By monitoring water-quality indicators over a 6-month period, including total nitrogen, total phosphorus, ammonia nitrogen, water temperature, pH value and phytoplankton content, the dynamic trend of algal growth was evaluated, and the primary factors contributing to algal outbreaks were analysed. Key results The findings indicated a significant correlation between algae blooms and elevated water temperature and light intensity in Shuangxikou Reservoir. As light intensity and water temperature increased, there was a shift in dominant algae species from Bacillariophyta to cyanobacteria. Conclusions Algal biomass was primarily concentrated at depths between 0 and 4 m, leading to a higher pH value in this specific water area than in the other areas along the vertical axis as a result of the algal outbreak. Implications This study has made a substantial contribution to the identification of safe methods for managing seasonal algae growth.