|North Sea estuaries|
McLusky, D.S. (2001). North Sea estuaries, in: Burning Issues of North Sea Ecology: the 14th International Senckenberg Conference North Sea 2000. Wilhelmshaven, Germany, 8-12 May 2000. Senckenbergiana Maritima: wissenschaftliche Mitteilungen der Senckenbergischen naturforschenden Gesellschaft, 31(2): pp. 177-186
In: (2001). Burning Issues of North Sea Ecology: the 14th International Senckenberg Conference North Sea 2000. Wilhelmshaven, Germany, 8-12 May 2000. Senckenbergiana Maritima: wissenschaftliche Mitteilungen der Senckenbergischen naturforschenden Gesellschaft, 31(2). Schweizerbart: Stuttgart. ISBN 9783510613281. 273 pp., more
In: Senckenbergiana Maritima: wissenschaftliche Mitteilungen der Senckenbergischen naturforschenden Gesellschaft. E. Schweizerbart'sche Verlagsbuchhandlung (Nägele u. Obermiller): Stuttgart. ISSN 0080-889X, more
Ecosystems; Estuaries; Nursery grounds; Nutrients (mineral); ANE, North Sea [Marine Regions]; Marine; Brackish water
North Sea; estuary; ecosystems; contaminants; nutrients; nursery grounds; feeding areas
Studies of the North Sea in the past two decades have shown that its estuaries and associated areas, such as the Wadden Sea, are important as nursery grounds for young fish and as feeding grounds for seabirds. These same areas are also those most likely to be affected by the highest inputs and concentrations of contaminants. The development of agriculture, industry and tourism has imposed severe pressures on the habitats for species that require intertidal, salt marsh or other forms of estuarine habitat.This paper provides a broad overview of our knowledge of the 'ecosystems estuaries' of the North Sea, and considers the implications of this for the entire North Sea ecosystem.Studies of the estuaries of the North Sea have traditionally focussed on a study of three themes, namely: (i) the physiological responses of estuarine organisms, (ii) their ecology, and (iii) their responses to pollution. From this basis of knowledge has developed the study of ecosystem processes and the factors controlling energy flow, either at the species or community level. Initially many studies concentrated on a single species, measuring its consumption, growth and production of energy. In time such studies have been combined in order to build up food webs or trophic diagrams.Recent studies have shown that it is the relationship between the benthic and pelagic environment which critically controls the entire functioning of the estuarine ecosystem, and conclude that estuaries are effectively light-limited systems where excess nutrient input cannot lead to increases in primary production. The estuarine ecosystem can also be described as being a subsidised ecosystem in that it is a net recipient of energy from a number of sources outwith its confines. In turn it exports material, mainly to the sea, in various forms including nutrients and contaminants, as well as juvenile fish and migrating birds.Examples of the ecosystem functioning of North Sea estuaries are considered. The extent to which estuaries are either 'sources' or 'sinks' of materials is reviewed. Three principal interactions between the North Sea and its estuaries emerge, with estuaries acting as: a) a nursery area for fish, b) as a source of land-derived nutrients, and c) as a sink, as well as a source, for metal contaminants. The paper places these interactions within the overall context of the North Sea, in order to judge the magnitude of the ecosystem role of its estuaries, concluding that the estuaries have a major role in the ecosystem of the North Sea, and as a provider of services, far out of all proportion to their apparent size.