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Billiones, R.G.; Tackx, M.L.M.; Flachier, A.T.; Zhu, L.; Daro, M.H.. |
The performance of image analysis in measuring suspended particulate matter concentrations was compared with that of the Coulter counter in different samples including latex spheres, diatoms and natural estuarine waters. The two techniques gave comparable numerical concentrations. Image analysis results also correlated positively with dry weight measurements of estuarine suspended particulate matter samples. The conversion of particle areas measured by image analysis into volumes was addressed by trying to determine the average height of the particles. This was done by plotting volume concentrations from the Coulter counter against area concentrations from image analysis. The resulting linear relationships were found to be significant in homogeneous... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Image analysis; Image analysis; Image analysis. |
Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3992 |
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Tackx, M.L.M.; Zhu, L.; De Coster, W.; Billones, R.G.; Daro, M.H.. |
Although estuarine zooplankters are generally believed to be detritivorous, high clearance rates by the estuarine copepods <i>Eurytemora affinis</i> and <i>Acartia tonsa</i> on natural estuarine microplankton have been reported in the literature. In order to enable detection of possible selectivity for these microplankton organisms over detritus, a method that measures clearance rates on total particulate matter is proposed. Image analysis is used to measure copepod gut contents, and combined with Coulter counter measurements of total particulate matter concentration, allows one to calculate clearance rates on the latter. The first results indicate that, in the Westerschelde estuary (SW Netherlands), both <i>E.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Estuarine organisms; Feeding behaviour; Image processing; Selective feeding; Acartia tonsa; Copepoda [copepods]; Eurytemora affinis. |
Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2632 |
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Tackx, M.L.M.; Herman, P.M.J.; Van Rijswijk, P.; Vink, M.; Bakker, C.. |
Phytoplankton and zooplankton biomass distributions were calculated on a carbon basis for the inland part of the Oosterschelde, in the period before (1983), during (1984, 1986) and after (1987, 1988) the construction of the storm-surge barrier. In all years studied, both phytoplankton and zooplankton distributions are very irregular, and little consistent patterns emerge. The data were used to test the model of Sheldon et al. (1977). The observed standing stock ratios of zooplankton to phytoplankton agree with the model predictions in 1983, and are slightly higher during the period 1984-1987. In 1988, the model predictions are very different from the observed values, because of important changes in the zooplankton species abundance occurring in this year. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Particles; Particles; Particles; Plankton; Size distribution; Spectra; Zooplankton; Netherlands. |
Ano: 1994 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2675 |
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Tackx, M.L.M.; Bakker, C.; Francke, J.W.; Vink, M.. |
Grazing of adults of the copepods <i>Acartia</i> spp., <i>Temora longicornis, Centropages hamatus</i> and nauplii of <i>Balanus</i> spp. on natural particulate matter from the Oosterschelde was studied using a Coulter counter. Two types of particulate matter distributions were found to occur in the Oosterschelde: 1. distributions with distinct peaks in the >20 µm size range (A) and 2. more flattened distributions which were bell-shapened or contained multiple small peaks spread over the entire 4-100 µm size range (B). In A-type distributions, peak tracking was performed in all species studied, especially in <i>Acartia</i> spp. and <i>T. longicornis</i>. In B-type distributions, the animals... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zooplankton ANE; Netherlands; Oosterschelde. |
Ano: 1989 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3190 |
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