Fig. 4: Wastewater nitrogen in global estuaries.

a Distribution of wastewater nitrogen input in global estuaries. b Zoomed-in view of estuarine wastewater nitrogen in China. c Zoomed-in view of estuarine wastewater nitrogen in the PRE. Wastewater nitrogen input is shown in log10(g N). Green circles in (a) represent the 83 estuaries covered in the meta-analysis. Zoomed-in view of different continents are shown in Supplementary Fig. 6.