Accumulation of heavy metals by freshwater zooplankton - a toxicological study

So far many toxicologic studies are made earlier; we studied the acute toxicity estimation related to some specific identified freshwater zooplanktons of Paradip (Harbour City) area of Jagatsingpur District, Orissa, India which is situated on the bank of Mahanadi River. The study area is prone to heavy metal pollution because mineral based industries in relation to zinc, lead and cadmium are common in and around. Heavy metal pollutants are affecting aquatic life in their surrounding waters. Water quality analysis of sampling location has shown concentration of lead as 0.06-0.55 ppm, zinc 0.04-0.35 ppm and cadmium 0.00-0.01 ppm which are beyond the BIS permissible limit for drinking water. As many people depend upon the fisheries from this area and public health is concerned, acute toxicity to zooplankton was estimated as it is in the middle of food chain. So, after conducting static bioassay, acute toxicity of zinc, lead and cadmium to fresh water zooplanktons was estimated. Whole zooplankton communities were exposed to different heavy metal stresses. Zooplankton community included nine planktonic forms i.e. Heliodiaptomus viduus, Mesocyclops hyalinus, Cyclocypris globosa, Diaphanosoma sarsi, Moina brachiata, Stenocypris malcolmsoni, Alona quadrangularis, Asplanchna brightwelli, Ceriodaphnia were exposed to different heavy metal stresses. Cadmium was found to be most toxic and lead was least toxic to zooplankton. Ostracods and Cyclops were in resistant forms and Rotifers were in sensitive forms in relation to metallic exposure. Sensitivity pattern observed during laboratory experiments was found to be in accordance with biodiversity variation of zooplankton in different sampling locations of Mahanadi River System in Paradip (Harbour City) area of Jagatsingpur District, Orissa.