Afr J Ecol. 2024;62:e13274. wileyonlinelibrary.com/journal/aje | 1 of 16 https://doi.org/10.1111/aje.13274 © 2024 John Wiley & Sons Ltd. Received: 18 October 2021 | Revised: 29 March 2024 | Accepted: 1 April 2024 DOI: 10.1111/aje.13274 RESEARCH ARTICLE Linking physico-chemical parameters and macroinvertebrates for water quality assessment of Kakamega and the East Usambara montane ecosystems in Kenya Joseph G. Ndungu 1 | Rose M. Marubu 1 | John B. Ochola 1 | Nixon B. Onyimbo 1 | Subramanian Sevgan 1 | Caroline W. Muriuki 2 | Kalist E. Komu 3 | Mary W. Gikungu 4 1 Environmental Health Division, International Centre of Insect Physiology and Ecology, Nairobi, Kenya 2 Department of Wetlands Management, National Environment Management Authority, Nairobi, Kenya 3 Beekeeping Unit, Mkinga District Council, Tanga, Tanzania 4 Department of Zoology, Centre for Bee Biology and Pollination Ecology, National Museums of Kenya, Nairobi, Kenya Correspondence Joseph G. Ndungu, Environmental Health Division, International Centre of Insect Physiology and Ecology, P.O. Box 30772, 00100 Nairobi, Kenya. Email: jndungu@icipe.org Funding information Biovision Foundation for Ecological Development, Grant/Award Number: BV DPE-005 Abstract Sub-Saharan freshwater biodiversity is impacted by changes in land use and climate change. To evaluate the relationship between physico-chemical variables and macroin- vertebrate community assemblages in Kakamega and the East Usambara Mountains forests, we explored benthic macroinvertebrate community structure in relation to physico-chemical conditions of the water along an anthropogenic stress gradient. Sampling was done in six selected streams during the rainy and dry seasons between April 2017 and November 2019. At Kakamega, 367 macroinvertebrate individuals were identified belonging to 22 families, while at Usambara, 456 individuals belonging to 25 families were identified. Spearman's correlation revealed significant interactions in species diversity, evenness, and richness between macroinvertebrates and several physico-chemical parameters (pH, conductivity, total dissolved substances, salinity and temperature). At Usambara, species richness, evenness and diversity was signifi- cantly negatively correlated with conductivity, tds, salinity, temperature and pH. We demonstrated that macroinvertebrate indices can be used as a quick evaluation tool of water quality in response to stream systems in the region as well as help in pointing out early warnings to help mitigate and reduce threats to stream biodiversity from anthropogenic activities. KEYWORDS aquatic macroinvertebrates, biomonitoring, diversity, ecosystem, freshwater Résumé La biodiversité des eaux douces en Afrique subsaharienne est affectée par les changements dans l’utilisation des terres et le changement climatique. Pour évaluer la relation entre les variables physico-chimiques et les assemblages de communautés de macroinvertébrés dans les forêts de Kakamega et des monts Usambara orientaux, nous avons exploré la structure des communautés de macroinvertébrés benthiques en relation avec les conditions physico-chimiques de l’eau le long d’un gradient de stress anthropogénique. L’échantillonnage a été réalisé dans six cours d’eau sélectionnés pendant les saisons des pluies et les saisons sèches entre avril 2017 et novembre 2019. À Kakamega, 367 macroinvertébrés appartenant à 22 familles ont été identifiés,