Temporal and spatial variation in bacterial communities on uniform substrates in non‐wadeable rivers

Abstract Undertaking environmental assessments on non‐wadeable rivers is challenging due to their size, depth, and water velocity. The cotton strip assay (CSA) a functional indicator used in assessing the ecological health of by measuring cellulose decomposition potential. Enhancing knowledge microbial communities responsible for would assist developing microbial‐based biotic index that could complement CSA. aims this study were explore temporal spatial variability bacterial strips, identify drivers differences, detect potential taxa. Cotton strips deployed at 12 sites, spanning range quality catchment land uses three separate months. Each site was placed into an category (EHC) from A (healthy) D (poor). Metabarcoding (16S rRNA) characterize communities. There significant interaction between month EHC. Higher temperatures pH identified as key differences February (summer) higher levels ammoniacal nitrogen, nitrate/nitrite turbidity August (winter). After removal amplicon sequence variants (ASVs) low abundance, 27 taxa indicative EHCs identified. ASVs associated with EHC‐A generally negatively correlated modified use nitrogen. In contrast, EHC‐D positively temperature. With further validation, molecular be developed aid rivers.