A Comparison of the Efficiency of Aquatic Macroinvertebrate Sampling Tools Used in Lotic Environmental Impact Assessment of Human Activities in A Tropical Mountain Stream in Eastern Uganda

Abstract

The study was aimed at comparing the efficiency of three macroinvertebrate sampling tools used in lotic environmental impact assessment of River Sipi including Surber sampler, rock-filled basket and Kick net sampling tools. The efficiency of the sampling tools was based on the data collected by each sampling tool, which was in turn used to calculate the Relative variation (RV) (efficiency), diversity, richness, and relative abundance, time taken to sort macroinvertebrate per sample and taxa assemblage. Data was analysed using a two-way ANOVA that was performed under the R Development Core Team 2010. The results indicated that despite the fact that all the sampling tools were efficient in sampling macroinvertebrates with RV<25%, both kick net and rock-filled basket obtained closely comparable efficiency results with Relative Variation ranging between 0.54-2% for the kick net and 1.4-3.6% for rock filled basket. Of the three sampling tools, the kick net was the most efficient, collecting a greater diversity of macroinvertebrate taxa (1.81±0.04) and a greater number of specimens (1444), abundance (66.4±0.25%), greater taxa richness (11±0.41) but required the biggest amount of time to sort macroinvertebrates (26±0.71minutes). In conclusion, the rock-filled basket served as the next best alternative efficient sampling tool to kick net in sampling macroinvertebrates.