www.scholarsresearchlibrary.com t Available online a Scholars Research Library Annals of Biological Research, 2015, 6 (11):68-71 (http://scholarsresearchlibrary.com/archive.html) ISSN 0976-1233 CODEN (USA): ABRNBW 68 Scholars Research Library Heavy metal concentration in some organs of Clarias gariepinus (African Catfish) from Okilo Creek, Rivers State, Nigeria Faye-ofori G. Bob-Manuel, Okorinama A. F. Wokoma and Upadhi Friday Dept. of Biology, Ignatius Ajuru University of Education, Rumuolumeni, Port Harcourt, Rivers State, Nigeria _____________________________________________________________________________________________ ABSTRACT The concentration of some heavy metals (Cd, Fe, Pb, Cu, Ni and Cr) in the different organs (Liver, Gills, Muscle and Kidney) was determined in the African Catfish – Clariasgariepinus from Okilo creek, in Rivers State, Nigeria. The concentration of cadmium (0.001mg/kg) was uniform in all the organs studied, however, that of iron and lead ranged from 28.665 – 58.817 and 0.039 – 0.577 respectively. Similarly, the concentration of Copper, Nickel and Chromium in the different organs under investigation fluctuated from 0.934 – 3.702; 1.243 – 3.689 and 0.09 – 2.859 respectively. The order of metal concentration in the organs concerned are as follows – Liver – Fe > Ni > Cu > Cr >Pb> Cd; Gills – Fe > Ni > Cu > Cr >Pb> Cd; Muscle – Fe > Cu > Ni > Cr >Pb> Cd and kidney- Fe > Cu > Ni > Cr >Pb> Cd. The accumulation of heavy metals by the different organs in the investigation showed that the kidney is the highest accumulator followed by the liver, muscle and gills. The concentration of lead and copper in the kidney and chromium in the muscle, liver and kidney are above the stated limits of different authorities thus making the consumption of catfish from the study area a potential health hazard. Key words: Accumulator, Heavy metal, Okilo creek,Cat fish, kidney _____________________________________________________________________________________________ INTRODUCTION Increased human activities through industrialization, urbanization, population growth and overall man’s greed to overexploit Mother Nature have created a serious threat to all kinds of life in the form of pollution which has now become a global problem[1]. Because all other life forms depend directly or indirectly on water, aquatic pollution is often regarded as one of greater concern. Most environmental problems arise when production of goods and services leads to the release of pollutants which eventually accumulates in water. Humanand industrial activities result in the release of different typesof pollutants into the aquatic environment, which threatens the health of the population and damage the quality of the environment by rendering water environments unsuitable [2]. One of such persistent and potentially harmful pollutant is heavy metal. Heavy metals on reaching the aquatic ecosystem deteriorate the life sustaining quality of water and cause damages to both Flora and Fauna[3]. It can affect aquatic organisms and pose a risk to fish consumers, such as human and other wildlife.In fresh water body’s fish are the most suitable indicative factors for the estimation of trace metal pollution [4], and therefore serves as an early warning indicator of water quality problem and or sediment contamination [5]. Fish have been shown to accumulate and retain heavy metals from the environment [6], and the rate of accumulation in different fish tissues is dependent upon concentration of exposure media, duration, salinity, temperature, hardness and metabolism of the fish [7].