The significance of sedimentation and sediments to phytoplankton growth in drinking-water reservoirs
Contribuinte(s) |
Sutcliffe, David W. Jones, J. Gwynfryn |
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Data(s) |
1992
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Resumo |
In the mesotrophic-eutrophic Saidenbach Reservoir in Saxony, the nanoplankton and cyanobacteria have increased at the expense of diatom dominance, due to a doubling of the external phosphorus load in the last 15 years. However, the phosphorus sedimentation flux is still very high (up to 80% of the input), corresponding to more than 2 g m2 d-1 in terms of dry weight. There is a strong correlation between the abundance of diatoms in the euphotic zone and their sedimentation flux (with a delay of about 2 weeks). Only about 25% of the deposited material could be clearly attributed to plankton biomass; the remainder resulted from flocculation and precipitation processes or directly from the inflow of clay minerals. The ash content of the deposited material was high (73%). Thus the sedimentation flux can be considered to operate as an internal water-treatment/oligotrophication process within the lake. The neighbouring Neunzehnhain Reservoir still has a very clear water with a transparency up to 18 m depth. Though the sediment was not much lower than Saidenbach sediment in total phosphorus and total numbers of bacteria, sulphide was always absent and the ratio of Fe 2+ to Fe 3+ was very low in the upper (0- 5 cm) layer. Thus the external and internal phosphorus loads do not attain the critical level necessary to induce a ”phosphorus - phytoplankton” feedback loop. |
Formato |
application/pdf |
Identificador |
http://aquaticcommons.org/5290/1/SPEC3j_1992_uhlm_thes.pdf Uhlmajnn, D. and Horn, H. (1992) The significance of sedimentation and sediments to phytoplankton growth in drinking-water reservoirs. In: Sutcliffe, David W. and Jones, J. Gwynfryn (eds.) Eutrophication: research and application to water supply. Ambleside, UK, Freshwater Biological Association, pp. 94-106. (FBA Special Publications,3) |
Idioma(s) |
en |
Publicador |
Freshwater Biological Association |
Relação |
http://aquaticcommons.org/5290/ |
Palavras-Chave | #Ecology #Limnology #Pollution |
Tipo |
Book Section NonPeerReviewed |