Studies On The Effect Of Produced Water On Juvenile African Catfish (Clarias Gariepinus)

ABSTRACT

This study investigated the effect of produced water from an oil exploration company in Rivers State on the blood, gills and liver of Juvenile African Catfish (Clarias gariepinus). Seventy Juvenile African Catfish were separated into 7 groups (10 per treatment) and used for the study. The juveniles were exposed to three varying concentrations of fresh and stale produced water (2.5ml/l, 5.0ml/l and 10.0ml/l) for a period of 3weeks. At the end of the test period, haematological, biochemical and anti-oxidant activities were carried out on the blood and liver of the juveniles, histopathological examination of the gills and liver were also conducted. The results obtained from the physicochemical analysis of the stale produced water showed that the stale produced water was within DPR and FMENV acceptable levels, while those of the fresh produced water were slightly above the acceptable levels, although statistically not significant, except for the salinity and conductivity parameters. The results obtained showed no difference in the heamatological, biochemical and anti-oxidant parameters. Histopathological examination of the gills exposed to fresh produced water showed lesions, oedema (mucous-filled cavity), displacement of epithelial cells and filament detachment with increasing concentration of the fresh produced water, which according to previous studies indicates reduced oxygen supply, resulting to decrease in respiratory response. The results obtained from the liver showed inflammation, enlarged hepatic area and increased vacoulation of the hepatocyte suggestive of metabolic damages and signal of degenerative process possibly related to exposure to contaminated water. All the juveniles held in the control stock showed no histological degradation. The severity of damage to the gills and liver depends on the concentration of the pollutants and the period of exposure. Conclusively, this study has revealed that exposure of juvenile Clarias gariepinus to even low concentrations of untreated produced water may induce histological degradations in the liver and gill structures of the fish.