Parasites are the second most abundant microorganisms that infect and cause disease in wild and cultured fish after bacteria. The study investigated the parasite prevalence, abundance, mean intensity and dominance in some fresh water fish from Akomoje, Ogun River, Nigeria from February to May, 2016. Eight fish species were collected and identified to the species level. Experimental fish were measured and weighed. Endo-and ectoparasites were examined for; from Skin/scale, dorsal and caudal fins, gills, intestine and stomach of fish. Water sample was collected from shore, mid and extreme of the landing site and also analysed for parasite abundance. Prevalence of parasite in all fish species varied slightly with size. Myxozoan group revealed the highest dominance of ecto-and endo-parasites in virtually all fish species while mean intensity and abundance of Myxozoan spp. was highest in Oreochromis niloticus and Hemichromis fasciatus. Highest case of a single species of ectoand endo-parasite in a fish sample was that of Nematode larva in Chrysicthys nigrodigitatus (41.43 %) and Trichocerca sp. (Rotifera) in Mormyrus rume (52.9 %).Water analysis revealed three parasite groups that were present in the sampled fish. Conclusively, Akomoje landing site of Ogun River has a rich burden of parasites.

Heavy metals load in fish environment and fish products had been an issue of public concern. The burden of some heavy metals in fresh tilapia (Oreochromis niloticus), frozen Herring (Clupea harengus), smoked herring, and associated risk to man was investigated. Atomic absorption spectrometry was used to determine metal concentrations. Standard risk measurement indices [daily metal intake (DMI), hazard quotient (HQ), and health risk index (HRI)] were used. Levels of Mn and Fe were significantly different (p<0.05) among the fish species, while the burden of other metals was low to not detected in the samples. The level of Cu (0.11±0.04), Zn (2.51±0.82), and Fe (8.72±4.41) were recorded in the bones of smoked herrings, while the highest levels of Mg were recorded in fresh tilapia. Gills recorded significantly (p<0.05) high levels of Mg (1.16±0.02), Fe (14.92±0.53), Cu (0.10±0.00), and Zn (1.35±0.04). The muscle of the frozen herring records the highest burden of these metals. Mn, Fe, Cu, and Cd revealed the highest HRI in all fish samples and age categories, especially for nine years old and below children. In conclusion, health fish indicators revealed that Mn, Fe, Cu, and Cd pose a risk to the populace and, with long time consumption, can do more damage to consumers, especially frozen herring.