Spatiotemporal Variation of Fishy Smell-Causing Algae (Uroglena americana) and Its Correlation with Water Quality Factors in the Source Water of Drinking Water Treatment Plant

The quality of water has a great impact on the life of aquatic species. The frequency of algal proliferation has increased all over the world due to changes in the water quality factors of the water systems. This study determined the correlation between Uroglena americana ( U. americana ) and water quality factors. U. americana mainly proliferated in late April at the surface level of the source water when the water temperature was in the range of 15.8–17.9 °C. Water temperature was negatively correlated with U. americana throughout the sampling period. In spring, the dissolved nitrogen (DN), dissolved organic carbon (DOC), fluorescence substance (peaks 1, 2, 3, 4, and 5), and electrical conductivity (EC) were positively correlated with the U. americana whereas the pH, dissolved oxygen (DO), oxidative reduction potential (ORP), turbidity, color, and dissolved phosphorus (DP) were negatively correlated. The total bacteria (16S rDNA) of source water showed a strong positive correlation ( r = 0.66 at p = 0.05) with U. americana . The proliferation of U. americana also could be influenced by the associated microalgae species of source water . The Peridinium and Asterionella species were negatively correlated with U. americana, whereas the Euglena, Chlamydomonas, and Nitzchia species were positively correlated; among them, Euglena sp showed a significant positive correlation ( r = 0.90, at p = 0.01) with U. americana . The obtained results of this study could be applied to the source water quality management and the optimization of the operating conditions of drinking water treatment plants to ensure the quality of drinking water. Graphical Abstract