DETERMINATION OF METALS AND TOTAL HYDROCARBON CONCENTRATIONS IN FIVE COMMERCIALLY IMPORTANT DRY FISHES AVAILABLE IN MARIAN MARKET, CALABAR, NIGERIA

The concentrations of metals such as cadmium (Cd), lead (Pb), iron (Fe), nickel (Ni), copper (Cu), mercury(Hg), manganese (Mn), chromium (Cr), cobalt (Co), zinc (Zn) and total hydrocarbon (THC) in five commercially important dry fishes: Liza falcipinnis (stickle fin mullet), Oreochromis niloticus (Nile tilapia), Ethmalosa fimbriata (Bonga shad), Cynoglossus senegalensis (sole) and Clarias gariepinus (catfish) from Marian market, Calabar, Nigeria, from June to August, 2013 was investigated. The analysis was done through the buck scientific atomic absorption spectrophotometer model VGP210 after digestion of the samples while the level of total hydrocarbon was analysed using the UV-V spectrophotometer at a wavelength of 460 nm. Results showed that Fe was slightly above the permissible limits set by Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO) for metals in fish. The results also revealed that total hydrocarbon in four different species such as Liza falcipinnis, Oreochromis niloticus, Cynoglossus senegalensis and Clarias gariepinus was above the FAO/WHO permissible limits. Only Ethmalosa fimbriata had the concentration of total hydrocarbon below the permissible limits. The concentrations of all other metals were below the permissible limits. Amongst the metals analysed, Hg and Co were not detected in any of the samples. The level of metals and total hydrocarbon in the fish species may be due to industrial effluents and some anthropogenic activities that lead to input of metals into the water bodies where these fishes were caught. Total hydrocarbon concentration in the fish species could also be attributed to oil spillage in the water bodies where the fishes were caught. The concentration of Cd, Pb, Ni, Cu, Hg, Mn, Cr, Co and Zn in all the species were below the permissible limits. Total hydrocarbon (THC) in Ethmalosa fimbriata was below the tolerance limits. Therefore, it can be concluded that no problems on human health would be raised at present from the consumption of this commercial fishes from Marian Market, Calabar, Nigeria. To avoid escalation of concentrations of metals in fish and other aquatic organisms, untreated effluents should not be channeled into water bodies. Efforts should be made to reduce oil spillage and anthropogenic activities that can result to increase in the level of metals and total hydrocarbon in the aquatic environments.