Some Physicochemical Parameters and Macrobenthic Invertebrates as Bioindicators of Water Quality in Ajiwa Reservoir, Katsina State.

Abstract

Ajiwa reservoir is a water body in Katsina State, Nigeria and faces quality threat due to anthropogenic activities in and around it. The aim of this study is to examine the water quality using some physicochemical parameters and macrobenthic invertebrates as bioindicators of water quality in Ajiwa Reservoir. The study was carried out from September to December, 2023. The water samples were collected twice a month from four (4) sampling stations (A, B, C and D) and analyzed for physicochemical parameters such as (pH, temperature, transparency, conductivity, DO and BOD) using standard procedures. Benthic macro invertebrate samples were collected with the aid of D-frame sweep sampler net and identified using standard keys. The physicochemical parameters were found to be within the WHO/NESREA standard limits. The mean of physicochemical parameters of Ajiwa reservoir were pH (7.1031±0.4849), Temperature (22.9281±4.0192), Transparency (12.6093±2.4654), Conductivity (113.9700±10.6330), DO (6.7812±1.0908), and BOD (3.5225±0.8854). The following taxa of macrobenthic invertebrates were observed; Hemiptera, Coleoptera, Odonata, Diphtera, Plecoptera and Gastrpoda in all the sampling stations across the sampling period. A Total number of 1505 macrobenthic invertebrates were identified across all the sampling stations. Station A had 454, B 444, C 331 and D 276 respectively. There was less abundance of pollution sensitive bioindicators in station C due to anthropogenic activities compared to other stations. The study concludes that using macrobenthic invertebrates as bio-indicators is effective approach for assessing water quality in Ajiwa reservoir. It is recommended that regular assessments of macrobenthic invertebrates and physicochemical parameters should be conducted to understand ecosystem dynamics.

Keywords: Bioindicator, Macrobenthic, Physicochemical parameters, Anthropogenic activities, Pollution.