ENVIRONMENTAL PARAMETER AND PROXIMATE COMPOSITION OF DIFFERENT SPECIES OF FISH IN THE GREAT KWA RIVER, CALABAR NIGERIA

Abstract

Environmental variation plays a critical role in shaping aquatic ecosystems and influencing the nutritional quality of fish. This study assessed the impact of physicochemical differences on the proximate composition of five commercially important fish species—Polydactylus quadrifilis, Chrysichthys nigrodigitatus, Oreochromis niloticus, Mugil cephalus, and Heterotis niloticus— from the Great Kwa River, sampled at Idundu and Esuk Atu stations. Standard analytical methods were used to determine protein, lipid, carbohydrate, fiber, ash, and moisture contents, with statistical analysis performed using one-way ANOVA at p < 0.05 in the Statistical Package for the Social Sciences (SPSS) version 25. Results revealed significant interspecies differences, with P. quadrifilis showing the highest protein (21.25 ± 0.09%) and lipid (8.12 ± 0.11%) values, while H. niloticus exhibited the lowest protein (17.10 ± 0.18%) and highest moisture (74.85 ± 0.30%). Ash and fiber contents ranged between 1.22–1.61% and 0.24–0.52%, respectively. Carbohydrate content varied from 0.73 ± 0.01% in P. quadrifilis to 1.17 ± 0.04% in O. niloticus. Environmental parameters such as dissolved oxygen and temperature showed notable correlations with protein and lipid concentrations, suggesting that shifts in water quality can influence fish biochemical composition. These findings provide essential baseline data for fisheries management and underscore the need for sustained monitoring of freshwater ecosystems to safeguard fish nutritional integrity.