Trophic Status and Water Quality Study Based On Diatoms from the Coastal Lakes of Palghar District, Maharashtra

Abstract

The physicochemical characters and diatoms of two coastal lakes i.e. the Khajuri Lake and the Babule Lake from the Palghar District Maharashtra were studied to ascertain the relationship between water quality and diatom diversity. The prevalent diatom assemblage from the Khajuri Lake indicates fresh to brackish, alkaliphilous water with mild pollution and mesotrophic to eutrophic status. Similarly, dominant diatom assemblage from the Babule Lake indicates alkalibiontic, eutrophic water with the impact of anthropogenic pollution. The pH values clearly indicate alkaline nature of both the lakes, but very high values of pH were noted for the Khajuri Lake (9.6). Thus, these pH values clearly point moderate to high alkaline nature of water. However, higher values of the pH for the Khajuri Lake suggest increased decomposition of organic matter in addition to elevated photosynthetic activities. The conductivity of these lakes varies from minimum at the Khajuri Lake (255ps/cm) to a maximum at the Babule Lake (620ps/cm). The highest conductivity in the Babule Lake may be due to release of ions from the decomposed organic matter during summer. The total dissolved solids (TDS) content was higher in the Babule Lake (326 mg/l), followed by the Khajuri Lake (125 mg/l), respectively. The low- medium levels of TDS in these lakes may be due to the presence of low to moderate content of potassium, chloride and sodium. The higher values of the total hardness in both these lakes may be due to the usages of excessive fertilizers from the adjoining agriculture fields. The Calcium hardness of both the lake may be categorized as rich lakes. The phosphorous and total nitrogen content suggest fair to poor, eutrophic to hyper-eutrophic water quality for both the lakes.