The dataset contains measurements of the annual average abundance, biomass and elemental composition (C, N, P) of consumers (fish and invertebrates) in six rivers within sub-catchments of the Hampshire Avon of contrasting geology (clay, sand, chalk). Full details about this dataset can be found at https://doi.org/10.5285/6e9a9a6e-1b42-46db-973b-06c1db2961c0