Assessing the Effect of Anthropogenic Disturbance on Macroinvertebrates Abundance and Diversity in Selected Streams in Kirinyaga County, Kenya: a Citizen Science Approach

Abstract

Anthropogenic disturbances have negative effects on water quality and biodiversity in riverine ecosystems. Citizen scientists have the capacity to collect data that can be used in management of riverine ecosystems impacted by human-related disturbances. The objective of this study is to evaluate the effect of anthropogenic disturbance on macroinvertebrates abundance and diversity by engaging citizen scientists (i.e., upper primary school children). The study was undertaken at seven study sites with different levels of anthropogenic disturbance in streams located in Kirinyaga County, Kenya. Physico-chemical factors such as temperature, conductivity and oxygen were determined at each study site. Additionally, macroinvertebrates abundance, taxonomic richness and diversity were determined. The low disturbance site (i.e., Nyamindi River) had the highest canopy cover intensity (44.4 %) and total dissolved solids (95.8 mg/L) values. On the other hand, high disturbance sites had the highest mean conductivity values (79-151 µs/cm) and lowest dissolved oxygen (39-72 mg/L) values. A total of 28 macroinvertebrate taxa were recorded across the study sites. The low disturbance site had the highest mean macroinvertebrate taxa richness (14.7 ± 1.5), abundance (121.4 ± 11.7 ind. m-2) and Shannon-wiener diversity (2.5 ± 0.13). Additionally, the low disturbance site had the highest mean abundance (321.1 ± 35.6 ind. m-2) for macroinvertebrates sensitive to pollution such as Ephemeroptera, Plecoptera and Trichoptera when compared to the high disturbance sites (e.g., Murubara and Mukengeria Rivers). Macroinvertebrates abundance and diversity differed significantly (all p < 0.05) across the study sites. The citizen science approach is an important strategy in macroinvertebrate data collection and provides an opportunity for public participation in scientific research, promoting data collection and scientific literacy, strengthening partnerships and informing research and policy decisions