The increasing use of heavy metals in various industries has lead to an increase in their environmental burden. Nickel represents a good example of a metal which is being widely used in modern technologies, such as nickel plating, ceramics, production of electrodes for making nickel-cadmium batteries, oil refining, and production of wrought stainless steel, nickel based alloys and also in large power units. The accelerated consumption of nickel-containing products, nickel compounds are being continuously released into the environment at all stages of production and utilization. Nickel is added to aquatic environment from these and other sources and is a cause of stress on aquatic life including fish. The fish exposed to stress due to nickel chloride showed statistically a highly significant decrease in amount of haemoglobin, total plasma proteins and serum albumins. The biochemical parameters, such as blood sugar, blood urea, S.G.O.T., S.G.P.T., and lactic dehydrogenase show highly significant increase due to stress of nickel chloride.
