Aldehyde oxidase activity and levels of uric acid in selected tissues of Clarias garienpinus (African catfish) and Oreochromis niloticus (Tilapia) from different sites of Ikpoba River

The major part of the environment and resources are made up of the aquatic environment. The safety of the aquatic environment is directly related to the safety of humans and animals in both the aquatic and non-aquatic (terrestrial) environment. The aquatic environment being the ultimate recipient of contaminants/pollutants from anthropogenic and natural sources is a major environmental and health concerns. This study was carried out to screen some sections of Ikpoba River (Guinness Nigeria Plc, and Abattoir in Iguana village) for metals and to assess some stress enzymes in the gill, heart, liver and muscle of African catfish ( Clarias gariepinus ) and Tilapia (Oreochromis niloticus) . The results show that Ikpoba River has a pH of 6.2, density (1.02) and dissolved salts (0.0018). The recorded nickel (Ni) level was 0.004; while cadmium (Cd) was not detected in Ikpoba River.  Other metals detected in the river water were lead (Pb), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn). The abattoir section of the river has a higher level of these metals than the Guinness area. An investigation into the effects of these metals on antioxidant enzymes, aldehyde oxidase. Lactate dehydrogenase activities in the gills, heart, liver and muscle of African Catfish ( Clarias gariepinus ) and Tilapia (Oreochromis niloticus) show an enhanced level of uric acid and antioxidant enzyme activities, decrease level of aldehyde oxidase and lactate dehydrogenase activities in some tissues/organs of the fish species from the river when compared with the control. Like the river water, the fishes from the abattoir sections contain the highest level of these stress enzymes. This study provides some baseline data for the deterioration of Ikpoba River and the effect of some metals on its aquatic habitants.