The bioaccumulation of Cu, Zn, Mn, Cd, Cr, Ni and Pb in Wholefish, Gill, Offal and Carcass samples of Oreochromis niloticus and Hemichromis fasciatus from the upper reaches of Ogba river was monitored for the period January to December, 2000, using standard methods.

An investigation of the helminth parasite of fresh water fish in Ogba River by the bridge (the river length is about 200 km) in Benin City, was carried out from May to October, 2004.  Of the 246 fish examined, 160 were Clarias gariepinus, 61 Clarias senegalensis, 10 Parachanna obscura, 14 Erpetoichytes calabaricus and 1 Helisynodontis