Effect of Habitat Locations on the Bacteriological and Physicochemical Assessment of Aquaculture Freshwater Catfish (Clarias gariepinus) Using Small Scale Depuration System

Abstract

Aim: The aim of the study was to investigate the effect of habitat locations on the bacteriological and physicochemical assessment of aquaculture freshwater fish (Clarias gariepinus) using a small scale depuration system. Catfish samples were harvested from two different locations, Michael Okpara University of Agriculture (MOUAU) and Umugbalu fish farm. Methodology: The fish samples were subjected to depuration for a period of 48 h. The total bacteria count of the fish samples was determined and the isolates characterized before and after depuration time. The total bacteria count (TBC) and other selected pathogenic bacteria in water and the fish organs recorded significant difference (p < 0.05) with TBC having the highest (1.90 x 106cfuml-1) in water sample from Umugbalu habitat. The TBC and other pathogenic bacteria from different fish organs (gill, muscle and gut) differed, which recorded 1.52 x 106, 1.41 x 106, 1.60 x 106cfug-1 (TBC); 9.9 x 105, 9.0 x 105, 9.5 x 105cfug-1 (Coliform); 2.0 x 105, <101, 1.5 x 105cfug-1 (Listeria spp); 3.5 x 105, 2.7 x 105, 4.0 x 106cfug-1 (Salmonella spp) respectively as typically observed in samples from MOUAU habitat. For pH, temperature, salinity and turbidity, water sample from MOUAU had the lowest values of 5.45, 30.0oC, 4.10ppt and 20.0NTU and 7.60mg/l respectively. Conclusion: Small scale depuration system was adequate for the assessment of bacterial quality of the water and the freshwater fish organs. The results obtained in this study have underscored the importance of adequate processing and cooking prior to consumption of freshwater fish. The Physicochemical parameters of the ecosystem investigated, differed from one location to the other.