Some quantitative data on light penetration in sediments
In: Helgoländer Wissenschaftliche Meeresuntersuchungen. Biologische Anstalt Helgoland: Hamburg. ISSN 0017-9957, meer
Ook verschenen in:Kinne, O.; Aurich, H. (Ed.) (1967). Vorträge und Diskussionen. Erstes Europäisches Symposion über Meeresbiologie = Papers and discussions. First European Symposium on Marine Biology = Rapports et discussions. Premier symposium européen sur biologie marine. European Marine Biology Symposia, 1. Helgoländer Wissenschaftliche Meeresuntersuchungen, 15(1-4). 669 pp., meer
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| Abstract |
1. Light penetration in sediments is a function of sediment granulometry; it decreases with the decrease in grain size.2. Light quantities entering the sediments are a function of substrate depth: At 1 mm depth, light penetration ranges between 80 (at medium quartzy sands from Hel) and 2 (at very fine sands from the Black Sea) percent of the light quantities found at the substrate surface; at 2 mm depth light penetration varies between 52 percent and total darkness (when muds replace sand); at 3 mm depth it varies between 0 and 23 per cent; at 4 mm depth, in most samples the aphotic zone was reached; however, in some sediments (quartzy medium or coarse-medium sands) values up to 9 per cent may occur; at 5 mm depth out of 46 analysed samples only 5 contained up to 5 per cent light; at 6 mm depth the lowest readings of down to 3 per cent were obtained.3. On the basis of these data, the photic zone in sandy sediments is very thin. |
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