δ15N of estuarine fishes as a quantitative indicator of urbanization

- We report a quantitative linear relationship between fish δ15N values and % urbanization in the lower catchment for estuaries in Southeast Queensland, Australia.
- The quantitative relationship is maintained when data from other Australian estuaries are included in the analysis.
- Further improvement of the relationship occurs when the trophic level of fish species was included in the model.
- This relationship may be applicable to a wide range of species and geographic locations.
- This finding improves the applicability of fish δ15N values as an indicator of urban influence in estuaries.