Heavy Metals Impact on Fisheries of Mithilanchal

The fish reflects the water quality directly and indirectly fish communities reflect present and past conditions and are useful in the biological assessment of water quality as a result the water quality fish productivity has been effected in order to maintain the potential of fisheries,physico chemical characteristic, PH acidity, alkalinity, temperature and biological characteristic of the aquaculture has made. The effect of cadmium,lead, chromium etcs exposure were analyzed in fresh water ponds of these areas.The deposition of these heavy metals were analyzed in gills, liver, kidney & muscles. The deposition of lead was maximum followed by cadmium and chromium.The pH was found to be highest in january ranged from 7.5 to 8.00 temperature of pond water followed by the same course that of air temperature.Total hardiness,ca,Mg was also found to be highest in january especially in mithila region the population of fish was highest in July and August and minimum in September to January.The fish fauna belong to family Clupeidae , Notopteridae, cyprinidae ,Bagridae Siluridae, Heteropneustiedae, Ophiocephalidae,Amphinoida,Anabentidae, mastecembelidae etc.water pollution due to heavy metals is a matter of global concern during recent years.Heavy metals constitute a care group of water pollutants due to their bio accumulative and non-biodegreadable properties. The rate of bioaccumulation of heavy metals in fishes dopends on the ability of the metals in water,it has to do with the concentration of the heavy matel in the surrounding soil sediments,and as well the feeding habits of the organism.Age of fish ,lipid content in the tissue and mode of feeding are significant factors that the accumulation of heavy metals in fishes.