Abstract:
The objective of the present study is to determine the bioaccumulation of heavy metals in various organs. Fish living in polluted waters tend to accumulate heavy metals in their tissues. Generally, accumulation depends on metal concentration, time of exposure, way of metal uptake, environmental conditions and intrinsic factors ( fish age, feeding habits). Various metals show different affinity to fish tissues. Most of them accumulate mainly in stomach, liver, flesh and gills. Fish flesh, comparing to the other
tissues, usually contain the lowest levels of metals. Metal distribution in various organs is time-related. Accumulation of metals in various organs of fish may cause structural lesions and functional disturbances. The result of many field studies of metal accumulation in fish living in polluted water show that considerable amounts of various metals may be deposited in fish tissues without causing mortality. Various metals are accumulated in fish body in different amounts. These different results from the different affinity of metals to tissues, different uptake, deposition and excretion rates. Metal levels in live fish usually follow the ranking : Zn> Fe> Pb >Cu> Cd . Liver accumulated the highest concentration of Fe, Cd, Pb, Zn and Cu compare to stomach, flesh and gill. This probably due to high fat content in this tissue. Body fat contributes the accumulation of heavy metal because the heavy metal usually deposit in body fat (Bryan, G.W. 1976).
