Tracing terrestrial nitrogen contributions to the salt marsh food web of the Obitsu River estuary in Tokyo Bay using compound-specific δ15N analysis of amino acids

Abstract Salt marshes, which sustain high productivity, serve as essential living environments for a wide range of organisms. The aquatic food web in salt marshes is basically supported by the high primary production of aquatic algae within the intertidal zone and the organic matter contributed from the terrestrial ecosystems, including the adjacent supratidal zone. As salt marshes facilitate the incorporation of terrestrially fixed energy into estuarine and marine food webs, they represent a ke