The current state of water quality and benthic invertebrate fauna in Chikke Stream (North-Central Nigeria)

Abstract

The Chikke Stream Bida, Northcentral Nigeria is an important water source for its riparian communities. This study evaluates the impact of habitat structure and anthropogenic activities on Chikke Stream using physicochemical parameters and macroinvertebrate assemblages collected over eight months (January-August 2017) using modified kick sampling techniques. Three sampling stations characterized by various human activities were selected across the stream. The physicochemical parameters examined were the water temperature (24.3-27.6 °C), depth (17.0-28.6 cm), flow velocity (0.301-0.408 m/s), pH (6.0-8.9), conductivity (30-136 μS/cm), alkalinity (10-26.0 mg/L), turbidity (28-152 NTU), dissolved oxygen (2.60-8.0 mg/L), and biochemical oxygen demand (3.0-5.1 mg/L); we also determined the contamination of nitrates (0.99-4.20 mg/L) and phosphates (0.37-0.85 mg/L). A total of 719 individuals from 35 species and 24 families of invertebrates were collected from the sampling stations. The CCA results revealed positive correlation between species abundances and measured environmental variables. benthic invertebrates clustered strongly by stations than by seasons, indicating that water quality differences between the stations were responsible for the observed differences in the macroinvertebratebiotic. High densities of pollution tolerant macroinvertebrate groups and the deteriorating quality of the surface water during the sampling period indicated organic pollution stress caused by different anthropogenic activities, decomposing domestic wastes, and vegetative nature of the stream. Bottom sediment, microhabitat obliteration, and poor water quality were the key factors responsible for the macroinvertebrate assemblage structure in the Chikke Stream.