Asulabha K.S., Sincy V., Jaishanker R. and Ramachandra T.V.
Abstract
Biomonitoring entails monitoring the quality of an ecosystem through representative biota, which responds to environmental changes through alterations in morphological, physiological, biochemical, molecular, and genetic traits. The sustained inflow of untreated wastewater due to point and non-point sources has been putting significant strain on aquatic ecosystems, leading to a decline in aquatic biodiversity, the loss of vital habitats for sensitive biota, and consequent erosion in ecosystem services. Microalgae constitute the primary producers in aquatic ecosystems and serve as pollution indicators as they respond to changes in water quality. This necessitates an understanding of microalgae dynamics in relation to environmental factors for prudent management of aquatic resources. The study examines microalgal composition and water quality in Sankey and Mathikere lakes, Bangalore, revealing pollution from untreated wastewater in Mathikere Lake, which exhibits high physicochemical parameters. The microalgae composition in both lakes varied in response to the water quality and across seasons. Multivariate analyses through nonparametric canonical correspondence analysis (CCA) demonstrate linkages between microalgal composition and water quality parameters in both lakes. Nutrient enrichment leading to eutrophic conditions with the profuse growth of invasive exotic macrophytes has declined microalgal diversity, suggesting immediate interventions to mitigate pollutants to improve the chemical integrity of waterbodies.