The influence of temporal variation of some limnological parameters on finfish assemblage in Osun River, Nigeria.

Abstract

Background Anthropogenic activities is a major factor that determines the condition and sustainability of an environment. The nature and type of activities will determine the health, ecosystem services and general well-being of the environment. These activities have increased as a result of industrialization and urbanization, notwithstanding pressure on fish species for balanced nutrition and economic returns. The paucity of documented information about the limnological parameters and finfish assemblage in Osun River nessiciated this study. Results Mean temperature (18.7 ± 2.69 °C) and dissolved oxygen (3.2 ± 0.54 mg/L) values were below the recommended limit for fish survival, pH (7.1 ± 0.25) and ammonia (1.2 ± 0.18 mg/L) were within and above the recommended limits. The river had a total of 4544 finfish belonging to 11 families and 19 species. Chrysichthys nigrodigitatus, sampling zone A and Cichlid family had the highest abundance in the river with 21.00%, 24.20% and 32.50% respectively.Fin fish abundance had a negative relationship between dissolved oxygen (r = − 0.032), ammonia (r = − 0.668), pH (r = − 0.819); temperature and DO with ammonia(r = − 0.668, r = − 0.590) and pH (r = − 0.043, r = − 0.011) respectively. Dissolved oxygen (b = − 137.1), ammonia (b = − 522) and pH (b = − 93.4) had a negative effect on finfish assemblage in the river. Significant correlated values (p < 0.05) were observed between fin fish and temperature (p = 0.008), ammonia (p = 0.017), pH (p = 0.001). dissolved oxygen (b = − 2.14), ammonia (b = − 2.72) and pH (b = − 1.97) had a negative association with fin fish abundance while significance (p < 0.05) were observed with dissolved oxygen (p = 0.048). Conclusion It is worthy to note that human activities principally dictates the quality and quantity of limnological parameters which directly affect finfish assemblage; therefore proper environmental management is essential for sustenance of finfish in the river as elaborated by the United Nations Sustainable Development Goals.