The balance between heterotrophic and autotrophic processes: consequences for the nitrogen cycle. The objective of the Flemisch-Dutch collaboration programme is to assess the balance between production and respiration processes at the scale of an entire estuary and at the level of isolated communities, considering simultaneously the carbon and nitrogen dynamics. Moreover it will (1) assess system and species specific primary production; (2) Assess the assimilation of carbon and nitrogen by algae and bacteria; (3) Study the three major nitrogen cycling processes (denitrification, nitrification and ammonium regeneration).