Studies on Metal Contamination Levels in Plankton and Their Role as Biological Indicator of Water Pollution in the River Ravi

The fate of plankton as biological indicator of metal`s pollution in the stretch of river Ravi from Baloki headworks to Sidhnai barrage has been studied. This investigation reveals that effluents from three main tributaries viz. Degh nulla, Sammundri and Sukhrawa main drains have adversely affected the planktonic biota in the river. Among the three tributaries, Degh nulla exhibited significantly higher contaminated plankton, showing the reason due to uptake and accumulation of heavy metals from water and sediments. This caused significant impact of metallic ions in water body on its accumulation in plankton. Therefore, in an aquatic ecosystem plankton showed a great tendency to accumulate metals in their bodies from water and sediments. Among phytoplankton, Aphanocapsa, Bumilleria, Bacillaria, Cladophora, Closterium, Cocconeis, Cosmarium, Eudorina, Microcystis, Oscillatoria, Pandorina, Scenadesmus, Spyrogyra, Volvox and Zygnema indicated direct relationships with the intensity of pollution as these genera were almost absent in highly polluted tributaries. However, the genera viz. Aphanothece, Anabaena, Arthrospira, Cyclotella, Denticulla, Dinobryon, Euglena, Navicula, Peridinium, Phacus and Synedra showed considerable tolerance against heavy metals pollution. Among the zooplankton, Asplanchna, Brachionus, Canthocamptus, Cyclops, Diaptomus, Moina and Polyarthra were almost absent at highly polluted sites. The genera viz. Bosmina, Filinia, Keratella and Monnstyla showed considerable tolerance against metallic ion pollution. Daphnia appeared to be a sensitive form against metallic pollution in water. Therefore, present investigation reveals that plankton are the best indicators of metal pollution in the river Ravi aquatic habitat.