Stable isotopes (d13C, d15N and d2H) of fish and basal resources in rivers of Southeastern Mexico

This dataset contains stable isotope ratios (d13C, d15N and d2H) for fish and potential basal resources collected from four rivers within the Grijalva-Usumacinta Basin, Mexico. Data were collected across a gradient of land use and hydrological alteration to assess changes in food web structure and trophic diversity. The dataset includes taxonomic identification for fish and isotopic signatures for both autochthonous and allochthonous resources, used to analyze energy pathways and niche breadth. This data supports the findings published in 'River Flow Regulation and Land Use Changes Shape Food Web Structure and Trophic Diversity of Tropical Fish Communities in Southern Mexico' (River Research and Applications, 2026).