Porewater depth profiles of ammonium, nitrate, sulfate, sulfide, dissolved iron, dissolved manganese, methane and oxygen; Solid phase depth profiles of total organic carbon, sequential iron and manganese extraction results of site NB8 in the Ore Estuary in the Bothnian Sea. (data published in doi:10.1021/acs.est.3c02023). Porewater ammonium and nitrate concentrations were determined colorimetrically using the indophenol-blue method and with a Gallery Automated Chemistry Analyzer type, respectively.