In the special session for ‘Ecosystem Model’ demonstrated that there has been significant advancement in the use of time-dependent multi-dimensional numerical models for coastal environmental studies. In addition to themodel applications, these papers also addressed numerous aspects of numerical modeling of coastal environment, including numerical algorithms, process representation and parameterization, larvae transport, environmental assessment, and computer graphics as a output tool. Depending on the target processes of interest, one should select anumerical model that uses the appropriate numerical algorithms and incorporates the appropriate processes.