Major Biological Processes in European Tidal Estuaries : Springer : 9780792336990 : 0792336992 : 30 Nov 1995 : Table 1. State variables modeled in MOSES. State variable Units Estuaries are characterized by a strong diversity in car­ bon sources. This is because of the existence of an 3 Fast-decay detritus g- intertidal habitat, the supply of nutrients and organic 3 Slow-decay detritus g- material from the river and from the sea and the input of 3 gCm- Freshwater diatoms matter from human origin. If turbidity remains limited, 3 Freshwater flagellates g- estuaries can also support a high primary production 3 Brackish and marine diatoms g- as nutrients are abundant. Nevertheless, estuaries are 3 Cm- Brackish and marine flagellates usually heterotrophic ecosystems (Billen et aI. , 1991; 3 gCm- Micro-zooplankton Smith & Hollibaugh, 1993) where respiratory process­ 3 Brackish meso-zooplankton gCm- 3 es exceed in situ production. Marine meso-zooplankton gCm- 2 3 gCm- The Westerschelde estuary