Freshwater marshes as dissolved silica recyclers in an estuarine environment (Schelde estuary, Belgium)
Struyf, E.; Van Damme, S.; Gribsholt, B.; Meire, P. (2005). Freshwater marshes as dissolved silica recyclers in an estuarine environment (Schelde estuary, Belgium). Hydrobiologia 540(1-3): 69-77. https://dx.doi.org/10.1007/s10750-004-7104-0
In: Hydrobiologia. Springer: The Hague. ISSN 0018-8158; e-ISSN 1573-5117, more
Also appears in:Meire, P.; Van Damme, S. (Ed.) (2005). Ecological structures and functions in the Scheldt Estuary: from past to future. Hydrobiologia, 540(1-3). Springer: Dordrecht. 1-278 pp., more
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Keywords |
Chemical compounds > Silicon compounds > Silica Eutrophication Water > Fresh water Water bodies > Coastal waters > Coastal landforms > Coastal inlets > Estuaries Water bodies > Inland waters > Wetlands > Marshes Belgium, Zeeschelde [Marine Regions] Marine/Coastal; Fresh water |
Author keywords |
estuary; dissolved silica recycling; biogenic silica; eutrophication; freshwater marshes |
Abstract |
Compared to knowledge about N and P processing in the aquatic continuum of lakes, wetlands and estuaries, knowledge concerning transport and cycling of Si is only fragmentary. Furthermore, Si research in estuaries has mainly been focused on subtidal benthic sediments and uptake and recycling by diatom communities. The biogeochemical cycling of Si in tidal wetlands, which can contain large amounts of Si, has thus far been neglected. We have conducted several whole ecosystem Si mass-balances on a freshwater marsh located in the Schelde estuary (6 tidal cycles, 2 with BSi included). Our measurements show that the freshwater marsh acts as an important source of dissolved Si to the main river (1–18% more export than import, on average 0.114 g m–2). This export is compensated by import of amorphous silica into the marsh (19–55% more import than export). The marsh was shown to act as silica recycler, resupplying biologically available dissolved Si to the estuarine ecosystem. Extrapolations show that during summer and spring months, when dissolved silica is depleted due to diatom growth, almost half of the total dissolved silica load in the main river channel could result from marsh recycling. |
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