General description of the Scheldt estuary

Abstract

A general description of the Scheldt estuary, including the hydrology, the sediment transport, the productivity and the biodegradation with respect to their influence on the trace metal behaviour in the Scheldt estuary, is given.The river basin can be divided in several sections according to their morphological, hydrodynamical and sedimentary properties. The zone from km 78 to 55, which corresponds roughly with the salinity zone from 2 to 10 psu, is the zone of high turbidity, high sedimentation and of oxygen depletion, especially in the summer period. That area is called the geochemical filter because the solid/dissolved distribution of the trace metals is controlled by redox, adsorption/desorption, complexation and precipitation/coprecipitation processes. The sedimentation rate in that area is estimated at 280 Mkg y ,1 .In the downstream estuary the phytoplankton activity increases due to the restoration of oxygen and to the much lower turbidity values. That area is called the biological filter because incorporation of trace metals by the plankton communities lowers the trace metal concentrations during the productivity period, while transformation of metal species, especially observed with mercury, occurs during that period too.

Role of intertidal wetlands for tidal and storm tide attenuation along a confined estuary: a model study

“…1b) is approximately 5 km wide and flood enters twice a day with an average flood volume of 1.04 Gm 3 (Baeyens et al, 1998). The funnel shape of the estuary amplifies the tidal range, for mean spring and neap tides respectively, from 4.46 and 2.97 m at the mouth to 5.93 and 4.49 m near Schelle (km 103) (Fig.…”

Barium uptake into the shells of the common mussel (Mytilus edulis) and the potential for estuarine paleo-chemistry reconstruction

“…Within the next week (on 24 Oct. 2001), 50 mussels were placed into four stainless steel cages and these were deployed along an estuarine salinity gradient in the Westerschelde estuary ( Fig. 1; see Baeyens et al, 1998 for a general description of the Westerschelde). Cages were attached at the same tidal level as the highest density of 'local' mussels at Ossenisse (OS; the most 220 upstream occurrence of wild Mytilus populations), Griete (GR), Hooftplaat (HF), and Knokke (KN; Fig.…”

Flame retardants, surfactants and organotins in sediment and mysid shrimp of the Scheldt estuary (The Netherlands)

“…It is an important passing, overwintering and feeding area for waterbirds and an important nursery for fish and shrimp. The Scheldt estuary was also ranked among the most polluted estuaries worldwide, based on contaminant concentrations in the dissolved as well as the particulate phase (Bayens et al, 1998). The physical, chemical and biological characteristics of the Scheldt estuary are further discussed in Heip (1988Heip ( , 1989, Herman et al (1991), Van Eck et al (1991) and Bayens et al (1998).…”