Effect of Different Heavy Metal Pollution on Fish

The purpose of this review was to check the levels and the accumulation of heavy metals in the various organs of the fresh water fish that comes in contact with the water contaminated with the heavy metals. The subjected fish were exposed to Cd, Zn, Cr and Pb at sublethal levels. Heavy metals entered in fish bodies by three possible ways: by gills, by body surface and digestive track. The estimated accumulation of heavy metals in the liver and gills were in order of Pb > Cd > Ni > Cr and Cd > Pb > Ni > Cr. correspondingly, the order in case of flesh tissues and kidneys wasPb > Cr > Cd > Ni and Pb > Cd > Cr > Ni. InCyprinus carpio (Common carp) the concentrations of cadmium and lead was deliberately raised in tissues as compared to the other heavy metals. Heavy metals accumulate in fresh water and elevate through food chain and fishes are badly affected because they are top consumer in aquatic systems. Humans are also affected by intake of fishes for mostly people of those areas where main food is fish. Keywords–accumulation, bio-magnification , digestive track, gills,pollution, Received 11.01. 2014 Accepted 10.03. 2014 © 2014 AELS, INDIA INTRODUCTION The universal problem is the environmental pollution and most important pollutants are the heavy metals in aquatic network because of their toxicity, accumulation and bio-magnification by marine creatures. Domestic, industrial and anthropogenic activities may broadly become the source of natural aquatic systems contamination of heavy metals[1,2]. The pollution caused by heavy metals might have Heavy metal pollution may have dreadful effects on the ecological equilibrium and a variety of aquatic entities[3,4]. In the list of animal species, detrimental effects of these pollutants, can never be negligible forfishes [5,6,7]. Fishing is a also general pastime [8,9,10] including in urban areas [11]. The pollutants such as heavy metals bioaccumulate in the food chain and cause the adverse effects, even death so fish among other animals are used to determine the health condition of aquatic ecosystem [12,13]. Accumulation patterns are more in some fish species than othersbecause of the ability of fish to bioaccumulate metals [14]. Heavy metals in fish come mainly from their diet, and levels of bioaccumulation of contaminants are higher in fish which comes higher in food chain [15]. In this study, the levels of five heavy metalsi.e. zinc, nickel, cadmium, lead and chromium has been determined from the fishes, sediments and water.Heavy metals accumulate in fresh water and elevate through the food chain. The patterns of bioaccumulation of heavy metals are determined by the absorbance and excretion rates of fish.Different factors such as physical and chemical properties of water as well as seasonal changes are the reason of significant augmentation of metals in different fish tissues [16, 17]. Metal residual problems in the fish epithelium are stern, because ofthe presence of higher metal concentrations in water and sediments [18]. On the contrary, heavy metals are of serious concern in this respect because they can be easily elevated in the food chain due to their bioaccumulation processes [19]. The pattern of heavy metal uptake in fish is different in different species according to various factors i.e.the developmental and psychological factors and also the age of the fish. Fish can transport major dietary sources of arsenic and mercury to humans because of their higher uptake mechanism in their tissues towards these elements. Processed water from the, detergent, textile and cosmetic industries present near the river water have high concentrations of heavy metals, which cause the disruption of the ecological balance of river water if present in much higher concentrations. The order of heavy metal accumulation in the gills and liver was Pb > Cd > Ni > Cr and Cd > Pb > Ni > Cr. Similarly, in case of kidney and flesh tissues, the order was Pb > Cr Research Journal of Chemical and Environmental Sciences Res J. Chem. Environ. Sci. Vol 2 [2] April 2014: 35-40 Online ISSN 2321-1040 CODEN: RJCEA2 [USA] ©Academy for Environment and Life Sciences, INDIA Website: www.aelsindia. com/rjces.htm RJCES