|Ecology of coastal lagoons in The Netherlands (Veerse Meer and Grevelingen)|
Nienhuis, P.H. (1992). Ecology of coastal lagoons in The Netherlands (Veerse Meer and Grevelingen). Vie Milieu (1980) 42(2): 59-72
In: Vie et Milieu. Observatoire Oceanographique Banyuls: Banyuls-sur-Mer. ISSN 0240-8759
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The Netherlands are for the larger part situated around the estuaries of the rivers Rhine, Meuse and Scheldt. During the period 1960-1980 several estuaries have been closed off from the sea and transformed into artificial lagoons. The hydrography, nutrient dynamics and trophic relations of two large coastal lagoons, mesotrophic Grevelingen and eutrophic Veerse Meer are the subject of this review. Nitrogen and phosphorus loadings on Grevelingen lagoon are only small compared to the loadings on Veerse Meer lagoon. The key-element in the cycling of organic matter in both lagoons is nitrogen, limiting the rates of primary production. Veerse Meer has a relatively high biomass and production of phytoplankton and loose-lying Ulva spp., whereas Grevelingen has a relatively high biomass and production of eelgrass, Zostera marina. In both lagoons large quantities of benthic macrophytes are consumed by herbivorous birds. Veerse Meer is more susceptible to anoxia owing to the high concentrations of labile and refractory organic matter, both in the water column and in the bottom sediments.