ISSN:
1573-5117
Keywords:
Scheldt estuary
;
description
;
hydrology
;
sedimentation
;
oxygen profiles
;
productivity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract A general description of the Scheldt estuary,including the hydrology, the sediment transport, theproductivity and the biodegradation with respect totheir influence on the trace metal behaviour in theScheldt estuary, is given. The river basin can be divided in several sectionsaccording to their morphological, hydrodynamical andsedimentary properties. The zone from km 78 to 55,which corresponds roughly with the salinity zone from2 to 10 psu, is the zone of high turbidity, highsedimentation and of oxygen depletion, especially inthe summer period. That area is called the geochemicalfilter because the solid/dissolved distribution of thetrace metals is controlled by redox,adsorption/desorption, complexation andprecipitation/coprecipitation processes. Thesedimentation rate in that area is estimated at280 Mkg y-1. In the downstream estuary the phytoplankton activityincreases due to the restoration of oxygen and to themuch lower turbidity values. That area is called thebiological filter because incorporation of tracemetals by the plankton communities lowers the tracemetal concentrations during the productivity period,while transformation of metal species, especiallyobserved with mercury, occurs during that period too.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1003164009031
