We surveyed two salt marshes in each of six estuaries (Solway, Morecambe Bay, Ribble, Humber, Blackwater, Chichester) between September and November 2024 to characterise national differences in denitrification rates and their relationship with potential drivers. A key ecosystem service in coastal systems is the remediation of nutrient pollution through sediment burial, vegetative uptake and microbial processing. Denitrification is a facultative anaerobic process where microbial activity transforms nitrate (NO3-), which in high concentrations can be environmentally harmful, into the environmentally benign dinitrogen gas (N2). Denitrification's magnitude is considered particularly important in saltmarsh systems compared to other habitats, although an intermediate product, nitrous oxide (N2O), can also be given off and contribute to climate change. Full details about this dataset can be found at https://doi.org/10.5285/26efc506-a265-4bb1-8296-d6988ab8d714
