Comparative study of water quality and phytoplankton composition across distinct sites of Srinagar Garhwal, Uttarakhand, India

บทคัดย่อ

Freshwater ecosystems are dynamic and susceptible to human effects; therefore, conducting a quality analysis in these ecosystems is essential. The article highlights the evaluation of the quality of the water as well as phytoplankton diversity of four different areas in Srinagar Garhwal: Madhi Chauras, Sri Yantra Tapu, Chauras Bridge, and Billkedar from February to July 2025. The physical parameters used in the determination of the variation include temperature, turbidity, pH, alkalinity, hardness, nitrates, calcium, magnesium, chlorides, and total dissolved solids. On the same note, phytoplankton collection was performed. A total of 47 phytoplankton species belonging to the classes of Bacillariophyceae, Chlorophyceae and Cyanophyceae were found. Ecological metrics such as Shannon-Wiener index, Simpson Diversity index and Pielou evenness calculated by using PAST software revealed heterogeneity in the spatial distribution of algal abundance dominated by diatoms. Canonical Correspondence Analysis (CCA) also showed strong relationships of nutrient enrichment, turbidity and phytoplankton composition. Use of the Algal Genus Pollution Index (AGPI) showed high organic pollution in Sri Yantra Tapu and Chauras Bridge, but Madhi Chauras and Billkedar indicated non-polluted or less-polluted conditions. Thus, the study emphasises the potential of phytoplankton as biological indicators of water quality status and marks a first attempt to record a set of basic data on the algal composition of a particular Alaknanda River segment in Srinagar, Garhwal.