EFFECTS OF COFFEE PROCESSING PLANT EFFLUENT ON BENTHIC MACRO INVERTABRATES DIVERSITY AND WATER QUALITY OF RUKKISA RIVER IN ALETA WONDO WOREDA, SOUTHERN ETHIOPIA

Abstract

The use of benthic macro invertebrates together with physico- chemical parameters was considered as the reliable method for water quality assessment. This study was conducted to assess the level of pollution in the Rukkisa River water using biological and physico chemical parameters. Three sampling sites were selected, one site was not affected by the coffee processing plant effluent used as reference site and two affected sites in the outlet and downstream were used to collect the water samples. A total of three water samples were collected from the three sampling sites. Each water sample was subjected to various physico chemical and biological analyses. Five physico chemical parameters pH, Temperature, Total Alkality Turbidity and BOD were analyzed. In addition, identification and quantification of benthic macro invertebrates was carried out for each sampling sites. There were a significant differences (p<0.05) in the physico-chemical parameters and macro invertebrates. Higher value of temperature, turbidity, total alkality and BOD was recorded at affected sites (outlet &downstream) than reference site (upstream). Most of the physico-chemical parameters were out of World Health Organization and Environmental protection Agency water quality standard. Totally 1149 specimens were identified which were belonged to 26 different species. 334 benthic macro invertebrates were collected from upstream, 431 and 384 benthic macro invertebrates were collected from outlet and downstream, respectively. The numbers of taxa were higher in upstream than impacted sites. 24 different types of species were identified from upstream 20 and 21 species from impacted (outlet & downstream), respectively. Categorical physico chemical parameters associated with benthic macro invertebrates indices. The study showed the effectiveness of the benthic macro invertebrates’ protocol in assessing River pollution condition. Therefore, environmental agencies and researchers have a good option of using macro invertebrates with the objective in assessing and monitoring programs of Rivers.