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| Registros recuperados: 1.500 | |
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| Hemminga, M.A.; Cattrijsse, A.; Wielemaker, A.. |
| Bedload and nearbed transport of coarse (>1mm) detritus particles were investigated in a tidal creek of a salt marsh in the Westerschelde estuary (south-west Netherlands). Using a fyke net positioned on the creek bottom, hourly transport through the creek was measured during 14 flood-ebb cycles in 1990 and 1991. Transport was bi-directional with flood imports varying between 32 and 2601 g dry weight (DW), and ebb exports varying between 0 and 4737 g DW. In nine of 14 tidal cycles, the creek was functioning as a net exporting system. The material that was exported with the ebb consisted mainly of macrophyte material. The annual loss of coarse organic matter by bedload plus nearbed transport through the creek was estimated to be less than 0-2% of the... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1996 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=308 |
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| Baeyens, W.F.J.; Meuleman, C.; Muhaya, B.; Leermakers, M.. |
| Surface waters, sediments and the polychaete <i>Nereis diversicolor</i> were sampled in the Scheldt Estuary between 1990 and 1994. In surface waters particulate Hg (Hg<sub>p</sub>) concentrations ranged from 350-1610 ng g-¹. They are essentially controlled by physical mixing of polluted fluvial particulates with relatively unpolluted marine particulates, but unaffected by seasonal changes. Dissolved Hg species, on the other hand, show large seasonal variations essentially controlled by the redox conditions in the estuary, as well as by bacterial and phytoplankton activity. Total dissolved (Hg<sub>TD</sub>) concentrations ranged from 0.5 to 3.0 ng l-¹ with 10 to 90% as reactive Hg. High concentrations of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7047 |
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| Panutrakul, S.; Baeyens, W.F.J.. |
| The Ballasplaat intertidal mud flat in the Scheldt estuary has been polluted by Cd and Pb and also high amounts of organic matter as a result of suspended matter deposition. The degree of pollution is, however, not uniform over the mud flat due to varying physico-chemical conditions (essentially variable redox profiles). Measurements of the redox profile, and the metal concentrations in the pore water, the total sediment and the fraction <63 µm combined with sequential extraction results and enrichment factors can explain the behaviour of Cd, Pb, Fe and Mn in the sediments. In a strong anoxic sediment, where sulphate reducing bacteria are active, the heavy metals are trapped as poorly soluble metal complexes while in an oxic or suboxic sediment metals... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cadmium Chemical reactions Estuaries Iron Lead Manganese Marine pollution Mud flats Physicochemical properties Sediment chemistry Sediment pollution Sediments ANE; Netherlands; Westerschelde; Ballastplaat. |
| Ano: 1991 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3112 |
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| De Clerck, R.; Redant, F.. |
| In 1973 the commercial shrimp catches reached the very high level of 1615 tons. This represented the highest catch since 1956 and twice the landings of 1971 or 1972. The average engine-power of the vessels was 147.3 hp and the average catch per hour fishing was 23.6 kg. The catch curve shows the same pattern as the previous years, with a marked peak in October. This peak however was in 1973 (51 kg/ hour fishing) clearly much higher than in 1971 (33 kg/hour fishing) or in 1972 (30 kg/hour fishing). The experimental shrimp fishery was carried out by the <i>RV Hinders</i>. On the fishing ground of the Westdiep five stations were monthly sampled with an otter trawl. The shrimp catches were divided into two length classes (smaller or larger than 54... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1975 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3520 |
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| de Haan, W.; Van den Bergh, E.; Jacobusse, C.. |
| The ecological quality ofthe Scheldt has been strongly affected by deepening, reclaiming and polluting the water of the river. The use of national instruments of protection has unsufficiently contributed to the recovery of the estuarium. Field managers of nature-areas have succesfully taken the negative effects of the other functions as starting point into their management. The program for compensation of lost nature on behalf of the recent deepening will be evaluated next year, and adapted if necessary. The European directives for nature, water and fishery become more and more important. They play a big role in the long term vision for the Scheldt-estuarium. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ecosystem management; Water policy. |
| Ano: 2001 |
URL: http://www.vliz.be/imisdocs/publications/280711.pdf |
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| Polk, P.. |
| The Tunicate <i>Botryllus schlosseri</i> (Pallas) was observed for the first time in the sluice-dock (Bassin de Chasse) of Ostend during the year 1960. This species was probably imported into Belgium together with spat from Zealand (Holland). During the year the species has spread and multiplied extensively. This species can therefore be considered as belonging to the Belgian marine fauna. The sexual reproduction and settling of new colonies took place during the months of August, September, October and November. During those months a settling of 98% was observed on the test surfaces in the immediate vicinity of the infected oysters. About 1 km from this locality in the Bassin de Chasse, where no infected oysters were found, a settling of only... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oyster culture Parasites Botryllus schlosseri (Pallas; 1766) ANE; Belgium. |
| Ano: 1962 |
URL: http://www.vliz.be/imisdocs/publications/241948.pdf |
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| Polk, P.. |
| 1. For the first time, <i>Crepidula fornicata</i> was observed in Belgium on 28-9-1911; in 1959, it became an oyster pest. 2. It was first introduced into Belgium with seed oysters from Great Britain. Later on, with seed oysters from the Netherlands. 3. Probably, the geographical spreading is caused by the adult animals attached to oysters. Larval propagation is responsible for local extension. 4. In the sluice-dock at Ostend, larvae occur from the middle of May till the end of November; they swim freely for a period of about 12 days. The first massive emission of larvae is observed during May and June, a second one in September. 5. The larvae settle preferentially at a depth of 65 cm. 6. Maximum settling takes place in May. It then decreases... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Introduced species Crepidula fornicata (Linnaeus; 1758) ANE; Belgium; Oostende Harbour; Sluice Dock. |
| Ano: 1962 |
URL: http://www.vliz.be/imisdocs/publications/256254.pdf |
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| García-Ortega, A.; Verreth, J.A.J.; Coutteau, P.; Segner, H.; Huisman, E.A.; Sorgeloos, P.. |
| Decapsulated <i>Artemia</i> cysts were used to study the factors which induce the superior performance of live organisms as food for fish larvae. The biochemical composition, the in vitro protein digestibility, and the total proteolytic and trypsin activities in cysts and nauplii of <i>Artemia</i> were determined at different developmental stages as a function of incubation time. Six different incubation times were studied: 1, 6, 11, 16, 21 and 25h of development, which cover cyst and early nauplii stages. The individual dry weight of <i>Artemia</i> decreased through development. The individual protein and lipid content (µg ind<sup>-1</sup> remained constant during development until the time of hatching after... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Artemia. |
| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=305 |
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| Registros recuperados: 1.500 | |
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