A persistent chlorophyll a maximum coinciding with an enriched benthic zone
Creutzberg, F. (1985). A persistent chlorophyll a maximum coinciding with an enriched benthic zone, in: Gibbs, P.E. (Ed.) Proceedings of the 19th European Marine Biology Symposium, Plymouth, Devon, UK, 16-21 September 1984. pp. 97-107
In: Gibbs, P.E. (Ed.) (1985). Proceedings of the Nineteenth European Marine Biology Symposium, Plymouth, Devon, UK, 16-21 September 1984. Cambridge University Press: Cambridge. ISBN 0-521-30294-3. 541 pp., more
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Document type: Conference paper
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| Abstract |
In the southern North Sea, there is an extensive gradient of tidal current velocities, decreasing from south to north. Where the current velocities drop below a critical value, mud and detritus are deposited on the bottom. This area of deposition coincides approximately with a boundary or front between stratified and mixed waters in the summer months of the year. At this boundary the benthic fauna is very rich, showing significantly higher biomass figures than in the south. These figures are comparable to those occurring in the Wadden Sea. The question, discussed in the present paper, is to what extent this increased biomass can be attributed to increased primary production at the frontal zone or whether it is increased by the deposition of organic matter from adjacent, more turbulent areas. Temperature and chlorophyll a sections were measured across the enriched zone through the period July 1982 to July 1984. The most conspicuous phenomenon in this context is the persistence of a chlorophyll a maximum just above the enriched zone irrespective of the presence or absence of a tidally-induced front. This chlorophyll a maximum is, therefore, attributed to the accumulation of organic matter which is mineralized in that enriched zone and mixed with the overlying water masses. |
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