Abstract
Owing to the high flexibility of tidal estuaries and the unknown extent of the coupling between the chemical and the
biological processes there, there is a need for a conspicuous set of data enabling description of the dynamics of bio-elements（e. g., C, N, P and Si）. As such, a long-term and multidisciplinary approach is appropriate. The chemical characters of water and sediments were examined from May 1993 to March 2002, monthly, in both an intertidal flat and a subtidal zone. Laboratory experiments were performed on the nutrient excretion rate of the dominant macrozoobenthos species. These works were carried out in the context of a long-term project planned to quantify the dynamics of bio-elements, to evaluate the roles played by the macrozoobenthos on the above processes and to propose a final budget on the dynamics of bio-elements for the sustainable use of tidal estuaries.
