Macroinvertebrates Assemblage Study: An attempt to Assess the Impact of Water Quality on Qua Iboe River Estuary, Akwa Ibom State, Nigeria

This study was conducted to access the water quality of Qua River Estuary, Akwa Ibom state, Nigeria by collecting water samples and macroinvertebrates using standard sampling procedures and analytical methods. The mean values of physicochemical parameters assessed in water samples gave the following ranges: DO (2.38 – 4.63 mg/l), water temperature (26.13 – 29.18 oC), turbidity (22.56 – 39.24 NTU),TDS (224.8 – 332.51 mg/l), pH (6.3 – 7.5 mg/l), salinity (3.13 – 4.84 ppt),BOD (1.13 – 3.64 mg/l), nitrate (2.45 – 6.72 mg/l), phosphate (2.12 – 5.93 mg/l) and Flow velocity (0.23 – 0.38 ms-1). ANOVA reveals significant variation in some parameters. A total of 308 individual species, comprising of three phyla and seven taxonomic groups of macro-invertebrate were identified. Arthropoda constituted the highest percentage composition (75.4%), followed by Mollusca (18.8%), and Annelida (5.8%). The dominant group was Decapoda (35.7%) and the least was Odonata accounted only for 1.9%. Station 5 has the highest number of individual’s species (112), station 3 had the least (43). Chironomus plumosus was the most occurring species, accounted for 19.2%. The result reveals that anthropogenic activities in the water system influence the abundance of aquatic biota; based on the macro-invertebrates identified, it shows that the water quality is moderately polluted owing to human activities.