Effects of Palm Oil Mill Effluent on the Histology of Gill, Liver, Kidney, Heart and Muscle and its Heamatological Effects on African Cat Fish, Clarias gariepinus

Author(s): Oluniyi A. Afolabi; Solomon O. Adewoye; Folakemi D. Afolabi; Oluwaseun A. Ishola

Palm oil mill effluent (POME) is one of the major sources of pollutant produced during oil palm processing. POME in water significantly affects the ability of fishes to detect and respond to chemical stimulus. The aim of this study isto examine the toxicological effects of POME with emphasis on the histopathology of the gills, liver, kidney, heart and muscle as well as the heamatological effects. African catfish, Clarias gariepinus of mean weight 300g and standard length 18-21cm were exposed to varying concentrations 0.01, 0.03, 0.05, 0.07 and 0.09 ml/l of POME in duplicates for 14 days to determine the toxicity of POME. 110 healthy fishes were randomly placed into eleven rearing tanks of 100 litres capacity (dimension 50 cm x 25 cm x 25 cm) and filled with 40 litres non-chlorinated water at 10 fishes per tank (one tank for control and two tanks each for each concentration) Histopathological examination of the liver after 14 days of exposure revealed lesions which ranged from necrosis, vacuolation and diffused congestion of cells that deteriorate more with increase in POME effluent concentration. Toxic reactions were observed during the experiment. Haematological values of RBC, PCV and Hb decreases with increase in POME concentration while WBC registered an initial increase before declining at concentrations 0.07 and 0.09 ml/l. POME is harmful to aquatic organisms, according to the findings of this study, hence its discharge into bodies of water without sufficient treatment should be avoided.