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.
