An Assessment of the Condition of Fishes in the Amadi Creek, Rivers State, Nigeria

A five month study was conducted to determine the condition factor of fishes and physico-chemical parameters of the water, of Amadi Creek, aimed at identifying the wellbeing of fishes in this creek, a medium for waste disposal and other anthropogenic activities. Fishery dependent data of length and weight of sampled species, from the creek, served as inputs for determination of the Condition factor (k). Results indicated the creek fauna composed of 12 species, 10 genera and seven families of fin fishes. The families and species, and their condition factor were: Cichlidae (Sarotherodon melanotheron - 2.3; Sarotherodon galilaeus - 2.5; Hemichromis fasciatus – 1.7; Coptodon guineensis – 2.6; Coptodon zilli - 1.0); Mugilidae (Parachelon grandisquamis - 2.4, Mugil cephalus – 1.3); Clupeidae ( Sardinella maderensis – 1.7 ); Claroteidae (Chrysichthys nigrodigitatus – 1.6); Elopidae (Elops lacerta - 0.3); Eleotridae (Eleotris senegalensis – 0.9) and Haemulidae (Pomadasys peroteti - 0.7). Some of the species seemed to be in good condition compared to results of same species obtained from another brackishwater river in the Niger Delta. There was a general reduction in k values in the month of March, fluctuation was observed in K values of S. melanotheron, Coptodon guineensis, Sarotherodon galilaeus and S. maderensis while the values obtained for P. peroteti and Elops lacerta indicated poor condition of the fishes. Estimated Physico-chemical parameters, of the creek water, using standard methods indicated: temperature range of 28.6°C (February) to 35.2°C (March). Dissolved oxygen ranged between 2.1 mg/L (May) and 9.0mg/L (April). The pH ranged from 6.6 (March) to 8.7 (April). Conductivity was: 9.2S/m (April) to 9.9S/m (March), while salinity was: 17.3psu (May) to 24.0psu (February). Most of the  physico-chemical parameters were in line with the dynamic nature of brackishwater systems with the exception of high values of conductivity and very low dissolved oxygen content, both indicative of pollution.