Ecosystem modelling at the NIOZ started in the1980's in the project group BOEDE (Biologisch Onderzoek Eems-Dollard Estuarium) which studied the consequences on the Ems-Dollard ecosystem of the discharge of very large amounts of waste water mainly originating from the patato-processing industry(Baretta and Ruardij, 1988). The experience from this modelling project was used by the NIOZ to initiate and coordinate an EU-project in the Marine Science and Technology program,1990-1995 where a consortium of 9 marine institutes developed the European Regional Seas Ecosystem Model (ERSEM). The specialization of the various institutes within a joint project on a European level was obviously the best way to tackle the formulation of a generic, system-based ecosystem model.
In those days both the modeling approach and the design concept of ERSEM was very innovative in several ways. The ERSEM consortium integrated a team of physicists, chemists and ecologists working closely together to formulate a generic model. Its modular structure, with interlinked modules describing the biological and chemical processes as forced by light and temperature provided the necessary flexibility for incorporating new developments in the understanding of properties, populations and the processes involved in their interactions ERSEM probably was one of the the first European R&D projects where the Internet was crucial for speeding up model development, data exchange and enhancing internal and external communication.