Effect of Indomie industrial effluent discharge on fish fauna of New Calabar River, Port Harcourt

Abstract

The effect of Indomie industrial effluent discharge on the fish fauna of New Calabar River was investigated in order to ascertain the influence of BOD, COD, DO, TDS, TSS, pH, salinity, phosphate and temperature on the composition and distribution of fish fauna. The diversity of the fish fauna was found to be poor, only 12 fish species in 6 families were identified. The highest number (10) of fishes was recorded in station 4 while the least number (1) of fishes was observed in station 1. The fish families were: Cichlidae (38.89%), Clupidae (33.33%), Pomadasyidae (16.67%), Bagridae (11.11%) while Genidae and Muglidae had zero percentage of fishes in its abundant. The resident fish species (Ethmalosa fimbriata and Tilapia guinensis) were highly adapted to the changes in the study environment and this was dependent on their trophic relationship within the environment. These species had great affinity for indomie industrial waste, because they feed on waste remains, mud/sediment silts and annelids, juveniles of shrimps and crabs. The deterioration of water quality was evident by the high BOD (12.80mg/L), COD (130mg/L), TDS (37mg/L), TSS (62mg/L), pH (5.2), salinity (50.54mg/L), phosphate (0.14mg/L) and temperature (27 0 C) as well as the low dissolved oxygen (2.8mg/L) values observed. It was recommended that a routine treatment of the effluent before discharge into the water should be carried out so to maintain safe levels of industrial effluent in the immediate and extended environment.