Our previous studies shows that the tidal flat in the Tokyo Port Wild Bird Park have a function of sink for nitrogen and source for phosphorus. In the present study, we carried out field measurements to estimate the role of denitrification, anammox and microphyto-benthos in nitrogen cycles at the flat. Results from the study show that (1) the denitrification and anammox rates were 33 to 935μmol N/m2/h and 0 to 0-481μmol N/m2/h, respectively, (2)the uptake rates by microphyto-benthos were 3.6μmol N/m2/h in summer, and 4.5μmol N/m2/h in winter.
