“…Most ecosystem models like those of Naranganset Bay (Kremer & Nixon, 1978), the Bristol Channel and Severn Estuary (Radford, 1978), the Ems-Dollard estuary (Colijn et al ., 1987 ;Baretta & Ruardij, 1988 ;De Jonge & De Groot ;, the Cumberland Basin (Keizer et al, 1987), the Western Wadden Sea (Lindeboom et al ., 1989), the stagnant salt water Lake Grevelingen (De Vries et al, 1988), the stagnant brackish Lake Veere (De Vries et al, 1990), the heavily polluted Scheldt estuary (Ouboter, 1988. Van Eck & De Rooij, 1990, and a large number of fresh water systems (Los, 1980 ;Los et al, 1984 ;Bak et al, 1990) simulate ecosystems, which are not exposed to major, actually realized changes in the physical environment . SMOES has to deal with three significantly distinct states of the ecosystem due to the storm-surge barrier construction .…”