The Burden of Bacteria Pathogens Associated with Cage-cultured Nile Tilapia, (Oreochromis niloticus) along the Mwanza Gulf of Lake Victoria, Tanzania

The recently intensified aquaculture projects in Mwanza Gulf of Lake Victoria, Tanzania, have brought about incidences of increased pathogenic bacteria in the lake waters. In some instances, there have been reports of disease outbreaks in cage-farmed fish. This study aimed to identify the prevalence of selected pathogenic bacteria in Nile tilapia, (Oreochromis niloticus) cage-cultured along the gulf. A total of 250 fish from the cage farms and control site were sampled. Bacteria were isolated and identified from the samples through standard bacterial techniques. A total of 10 bacteria genera were identified, where, staphylococcus spp. had the highest prevalence with 34.5%, pseudomonas spp. at 25.9%, Streptococcus spp. at 10.5%, then Lactococuss spp. 15.5%. These results suggest intensive cage farming is likely the main risk factor for increased bacterial prevalence in the gulf. Henceforth, biosecurity measures must be intensified for sustainable healthy fish farming in cages along the Mwanza Gulf.