Use of local by-products in fish feed and their effects on physico-chemical and bacteriological parameters of fish ponds in the Guinean forest region

This study evaluates the use of local agricultural by-products and assesses the physical, chemical, and bacteriological parameters of fish ponds in the forested region. Surveys were conducted in four major rural fish farming zones, involving 73 fish farming promoters. Ten fish ponds were randomly sampled across different farms. Results indicate that rice bran is the most widely used feed ingredient (30%), followed by pig waste (25%), fresh cassava leaves (14%), palm oil mill effluent (12%), and corn bran (10%). The most commonly farmed species include Oreochromis niloticus, Heterobranchus isopterus, Clarias gariepinus, and Hemichromis species, typically cultivated in mixed cultures. Analysis of the pond water revealed poor growing conditions characterized by elevated concentrations of phosphates, ammonium, nitrates, iron, manganese, and high turbidity, coupled with low average dissolved oxygen levels. Microbiological evaluation detected significant contamination: total coliforms (1585?±?91.92 cfu/100?mL) and fecal coliforms (1877?±?137.17 CFU/100?mL) were present in all sampled ponds. Correspondingly, fish yields were generally low, with the following averages: C. gariepinus (4.48?±?2.79 kg/ha), O. niloticus (6.00?±?2.83 kg/ha), H. isopterus (8.11?±?5.13 kg/ha), and Hemichromis spp. (13.71?±?6.84 kg/ha). Keywords: Forested region, Local byproducts, physicochemical parameters, bacteriological parameters, ponds.