Nile tilapia and Nile perch are mostly captured from wild capture fisheries while others are imported in frozen form and a substantial proportion is obtained from cages. Knowledge about heavy metal contamination in fish sold is fundamental to guarantee the consumers health.
Safety and quality of fish have become progressively crucial in fish trade because fish is distinctly susceptible to biological and chemical contamination from the environment. This study sought to determine the levels of selected heavy metals including Cadmium (Cd), Lead (Pb) and Mercury (Hg) in the muscles of wild captured fish and caged fish (Oreochromis niloticus). The highest concentration of Hg, Pb and Cd was recorded in wild captured fish as compared to the other groups. Cadmium was significantly lower in wild captured tilapia. Mercury and Cadmium were significantly lower in caged fish than the wild capture fish. Farmed and imported frozen tilapia had significantly lower levels of heavy metal contamination which were well below the permissible limits for fish by European Union/World Health Organization standards and national guidelines. Further, evidence indicates that fish from wild sources have relatively higher levels of heavy metal accumulation, but the levels are still within safe human consumption as recommended by WHO. Therefore, close monitoring of heavy metal loads in Lake Victoria is recommended given the potential risk to consumers’ health. The study recommends further studies to be undertaken to compare the variation of heavy metal concentration in other fish body parts like the gills and liver and to assess the tenable threat linked to their consumption. Future research should focus on assessing heavy metal concentration in small indigenous species (SIS) as they are utilized in feeding fish and commercial fish feeds to identify other sources of heavy metal accumulation in farmed fish and ways to mitigate harmful human impacts. READ MORE