SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

As nutrients are withdrawn from the environment in the proportions required for the growth of primary producers, the C/N ratio known from the literature provides a stoechiometric basis for evaluating the uptake of nitrogen resulting from phytoplankton and phytobenthos activity. This activity has been measured respectively by 14CO2 incorporation and O2 production in in situ and in vitro experiments. The production of the phytoplankton community for the period considered (6 months) amounts to 112 g C/m². That of phytobenthos might well be one third of this amount (37 g C/m²). Therefore, nitrogen uptake would have been 14 g and 4 g C/m². As the yearly...

Ecometabolism of a shallow marine lagoon at Ostend (Belgium): 2. Zooplankton dynamics

Ano: 1974

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3485

The food chain of plankton at the Sluice-Dock is reduced to the simple system "producers-primary consumers". The role of zooplankton is most important only for a short time, namely in May, when it restricts the development of phytoplankton by its grazing activity, and becomes the main source of nutrients due to its excretory activity. After the disappearance of most of the zooplankton biomasses, caused by a mortality that is not due to predation, the phytoplankton can again develop. At other times of the year, the zooplankton activities such as production, grazing, excretion, and respiration only represent 1% of the total plankton activity.

Relation entre des populations successives de phytoplancton et de bactéries hétérotrophes dans le Bassin de Chasse d'Ostende (Belgique), en 1971

Palavras-chave: ANE; Belgium; Oostende Harbour; Sluice Dock.

Ano: 1976

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3537

When the sluices of the "Bassin de Chasse" in Ostend were closed, on the 31th March 1971, we observed an important decrease of the number of heterotrophic marine bacteria in the water: from 5.105 b/ml on 31th March to 103 b/ml on 15th May. This can be interpreted as reflecting the consumption of organic material supporting the growth of the bacteria by the bacteria themselves. The new bacterial populations appearing then were closely related to the phytoplanktonic populations appearing just before them. This relation probably reflects the dependance of the bacteria to the new organic material of the dead phytoplankton cells.

Evolution des populations de bactéries marines hétérotrophes au bassin de chasse d'Ostende (Belgique) en 1971

Palavras-chave: Bacteria Ecological succession Heterotrophic organisms Phytoplankton ANE; Belgium; Oostende Harbour; Sluice Dock.

Ano: 1972

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3465

A bacteriological study of the water of the "Bassin de Chasse" of Ostend (Belgium) has been done from 31 March till 29 July 1971, when the dock has been kept closed. The results show a succession of different populations of heterotrophic marine bacteria. This conclusion appears from different results: <ol><li>total count of bacteria; </li><li>separate count of bacteria forming white and coloured colonies; </li><li>rough determination (morphology and Gram-reaction) of some bacteria. </li></ol>These population-variations could be explained by variations in the organic matter of the water.

Essai de bilan annuel du transfer de l'azote dans le Bassin de Chasse d'Ostende: 3. Recyclage de l'azote dans les sédiments

Palavras-chave: Bacteria Heterotrophic organisms Population dynamics ANE; Belgium; Oostende Harbour; Sluice Dock.

Ano: 1972

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3456

A crude estimation of the fluxes associated with bacterial and physico-chemical transformations of nitrogen in the sediments of the Sluice-dock in Ostend is presented: 1. The annual sedimentation of organic nitrogen is estimated from sedimentation rate and organic nitrogen concentration of top sediments. 2. Ammonification rate is evaluated on the one hand from the shape of organic nitrogen profile in sediment, on the other hand from measurement of bacterial activity by means of HC14O3- incorporation. 3. Diffusion of ammonium towards basin water is calculated from the concentration gradient at the water-sediment interface.4. The shape of the ammonium concentration profile in interstitial...

Ecometabolism of a shallow marine lagoon at Ostend (Belgium): 5. General discussion

Ano: 1974

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3487

The consumption and recycling rates measured at the various trophic levels are used for the assessment of an annual budget of biogenic elements cycling in the ecosystem. Furthermore, an attempt is made in the direction of simulation modeling.

Ecometabolism of a shallow marine lagoon at Ostend (Belgium): 4. The role of microbial activity in sediments in the carbon and nitrogen cycles

Palavras-chave: ANE; Belgium; Oostende Harbour; Sluice Dock.

Ano: 1976

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3540

Nitrogen nutrients being, at least at some periods of the year, a limiting factor of primary production in the Sluice-Dock at Ostend, the production or consumption of ammonium and nitrate by the benthic bacterial communities plays an important role in the dynamics of the ecosystem. A methodology is developed to evaluate the fluxes of carbon and nitrogen associated with the microbiological activity and the physical mass transfer in the sediments. It is based on the analysis of vertical concentration profiles of pertinent substances in the sediment, completed with some direct in situ measurements of microbiological activity. This methodology is applied to denitrification, total heterotrophic activity, and nutrification in the two types...

Essai de bilan du transfer de l'azote dans le Bassin de Chasse d'Ostende: 2. Le rôle du zooplankton dans le cycle de l'azote

Palavras-chave: ANE; Belgium; Oostende Harbour; Sluice Dock.

Ano: 1976

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3539

1.The zooplankton of the Sluice-dock at Ostend consists essentially of calanoid copepods and larvae of benthic animals. 2. The greatest part of the biomass (95 %) consists of 4 species: Eurytemora affinis, Acartia bifilosa and larvae of Polydora ciliata and Crepidula fornicata. 3. All these species are herbivorous; the secondary production has been measured only of these four species; 4. All measurements were expressed as wet weights; the expression of the biomasses, production and excretion in terms of nitrogen, was calculated by means of correction factors found in the literature.

Contribution à l'étude biologique et chimique du port d'Ostende

Ano: 1974

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3486

The harbour of Ostend has been surveyed on the 6th of August 1970 at low water and high water. Samples have been taken at various depths for chemical analysis, bacteriological, phytoplankton and zooplankton investigations. All the results demonstrate an obvious water stratification and a heavy pollution by sewage outfalls and inland water incomes.

Ecometabolism of a shallow marine lagoon at Ostend (Belgium): 3. The role of planktonic heterotrophic bacteria

Palavras-chave: Chemistry Ecology Harbours Phytoplankton Pollution Stratification Zooplankton ANE; Belgium; Oostende Harbour.

Ano: 1972

URL: http://www.vliz.be/imisdocs/publications/327681.pdf

In order to assess the importance of the recycling of organic matter into nutrients in the water column, the bacterial biomass was evaluated by the spread-plate counts method, and the heterotrophic activity by two methods: initial consumption rate of oxygen and anaplerotic bicarbonate fixation. The biomass of aerobic heterotrophic bacteria does not reflect the heterotrophic activity and cannot be used as an index for this activity. This activity is always important as a recycling process for the phytoplanktonic organic matter it is depending on. Different periods can be recognized, with varying importance (relative to other recycling factors) of bacterial activity.

Ecometabolism of a shallow marine lagoon at Ostend (Belgium): 1. Phytoplankton and phytobenthos dynamics

Palavras-chave: ANE; Belgium; Oostende Harbour; Sluice Dock.

Ano: 1976

URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3538

Primary production parameters (numbers and identifications , pigments, photosynthesis, respiration, excretion) have been measured or estimated in a marine lagoon during 4 years. On the seasonal scale, the succession pattern shows a spring bloom in April-May, a depression in May and a summer bloom from June to August. Various nannoplanktonic flagellates are responsible for these fluctuations, which are well paralleled by photosynthetic capacity variations. Primary production was computed using a light-photosynthesis function. Photosynthetic capacities and function parameters have been determined and discussed. On the diel scale, a strong periodicity involving natural mortality was observed and taken into account. Uptake and regeneration rates of inorganic...