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| Registros recuperados: 473 | |
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| Baleux, B.; Caumette, P.; Trousselier, M.. |
| Numeration, biomass, distribution within time, some physiological characters and a taxonomical outline, with a standardized micro method, of aerobic hétérotrophie bacteria isolated from sediments an waters, from fishponds of "Domaine de Certes" (Arcachon) from june 1977 to may 1978 are described. Number of hétérotrophie bacteria evolved in a significant way, according to seasons, and bacterial biomass is higher in the sediments than in the waters. Metabolic or physiological differences (proteolysis, denitrification) appeared among populations due to the origin of sediments. Moreover the qualitative study pointed out taxonomical units as Bacillus associated to seasons, or Agrobacterium associated to vegetable detritical sediments. |
| Tipo: Text |
Palavras-chave: Lagunes; Bactéries hétérotrophes aerobies; Biomasse; Taxonomie; Micro méthode; Enzymatiques; Lagoons; Aerobic heterotrophic bacteria; Biomass; Taxonomy; Enzymatic micro methods. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41677/40886.pdf |
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| Dufour, P.; Cremoux, Jl.; Slepoukha, M.. |
| "In vitro" enrichment experiments on natural populations have been used to determine the nutrients controlling the potential biomass of phytoplancton in the Ebrié coastal lagoon. The limiting nutrients were generally nitrogen, phosphorus and carbon, in this order ; in three cases out of eleven, P and N act simultaneously ; in an extreme eutrophication case, N, P and C were all limiting. No effect was observed following addition of metals, vitamins or chelators. The limitations deduced from the enrichment experiments show a. good agreement with the elementary composition of the external medium ; in waters potentially limited by N alone, the dissolved inorganic nutrients have a N : P ratio lower than 25. The agreement is poorer when the sestonic N : P ratio... |
| Tipo: Text |
Palavras-chave: Lagune; Estuaire; Zone tropicale; Phytoplancton; Biomasse; Eléments limitants; Tests biologiques; Composition chimique; Coastal lagoon; Estuary tropical zone; Phytoplankton; Biomass; Limiting nutrients; Bioassay; Chemlcal composition. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41689/40898.pdf |
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| Gaudy, R.; Guerin, J.p.. |
| Following are results obtained in our laboratory during breeding experiments with an harpacticoid copepod, Tisbe holothuriae. In small size volumes (200 ml), the potential production appears to be higher when an artificial compound food of animal substances is used instead of a vegetal diet. In medium volume experiments (100 l) the production is related to the surface available for animals in breeding tanks, Breeding in complete cycles can be obtained using various foods, but the quality of diet may markedly affect the characteristics of the vital cycle, such as the length of the fertility period and fecundity. Temperature has a crucial effect, chiefly on dynamic preoccesses, that is to say, developmental rate and average generation time. With different... |
| Tipo: Text |
Palavras-chave: Production; Dynamique des populations; Biomasse; Composition chimique élémentaire; Bilan énergétique; Copépodes harparcticoïdes; Production; Population dynamic; Biomass; Chemical elementary composition; Energy balance; Hapacticoïd copepods. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41672/40881.pdf |
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| Maestrini, S; Rochet, M; Legendre, L; Demers, S. |
| Nutrient analyses were done in melted ice, frazil and sea water of the upper part of the water column, where as major constitutive elements of micro-algae were analysed. Measurements of nutrient uptake were carried out with frazil algae incubated at -1.5 degree C in a field incubator. Differential-enrichment bioassays and mean N/P ratio (5.9) demonstrated that actual growth of the cultures was nutrient-limited. Nitrogen governed the algal yield when illumination and grazing allowed the microalgae to grow. It concluded that the epontic dynamics is not only controlled from above, by the seasonal (climatic) changes in light intensity as generally assumed, but also from below, by the short-term (hydrodynamic) events of vertical mixing that replenish the... |
| Tipo: Text |
Palavras-chave: Nutritive value; Growth; Food absorption; Algae; Ice water interface; Biomass; Nutrients (mineral). |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1533.pdf |
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| Meyerreil, L; Graf, G. |
| The seasonal development of benthic communities was followed in a coastal marine sediment of the Kiel Bight (Baltic Sea; FRG). Total benthic biomass, (ATP), bacterial biomass, overall benthic activity (heat production), and enzymatic decomposition rates of carbohydrate (d-amylase activity) followed a seasonal cycle strongly related to certain events in the sediment. Among these, the input of the phytoplankton blooms in autumn and spring, the accumulation of organic material during winter, and changes in the physical characteristics of the sediment turned out to be most important for the development of benthic biomass and activity. Processes within the benthic community occurred in very short time scales (within days). |
| Tipo: Text |
Palavras-chave: Bacteria; Organic matter; Sediments; Bioenergetics; Enzymatic activity; Biomass. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-944.pdf |
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| Hamon, Pierre-yves; Tournier, Henri. |
| Since 1980, the IFREMER research laboratory "Resources Aquacoles", Sete (France), follows during the summer period, the evolution of the commercial stocks of molluscs (mussels and oysters) reared in Thau Lagoon. The data for this estimation are collected, on one hand, by surface observations and, on the other hand, by diving observations. During the years 1980 to 1984, the authors noticed an increase of oyster biomass, during the same period the mussel biomass decreased. The different simulations used to know the total filtration and the biodeposit, have shown that the impact of the increase of the total biomass is not so important as it could be feared. |
| Tipo: Text |
Palavras-chave: Bivalvia; Marine mollusks; Stock assessment; Population density; Biomass. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/publication-1787.pdf |
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| Caumette, P. |
| In the deepest parts of the estuarine region of Ebrie Lagoon (Abidjan Africa, (5 degree N, 4 degree W) stratified conditions have been observed during the rainy season (May to Nov.), owing to salinity differences between oxic and anoxic layers. At the interface, 3-4 m depth, phototrophic bacteria (Chromatium, Chlorobium and Pelodictyon ) developed, forming a brown layer due to their different pigments. Their production has been estimated at 41% of the total photosynthetic production during high stratification (Sep. 1981) and their biomass was used by the copepod population for 40 to 60% of its diet. During the dry season, the water column became homogeneous and oxygen was detected to 6m depth. The brown layer of phototrophic bacteria disappeared, as well... |
| Tipo: Text |
Palavras-chave: Chlorobium; Chromatium; Primary production; Photosynthesis; Estuaries; Seasonal variations; Plankton; Stratification; Vertical distribution; Bacteria; Coastal lagoons; Trophic relationships; Biomass. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-957.pdf |
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| Maestrini, S; Robert, J. |
| Microalgal population of oyster ponds is dominated by several tychobenthic diatoms which provide a very good food to grow oysters. The mechanisms which allow them to dominate have been put under research. H.P.L.C. analysis demonstrated 17 amino acids amounted 10-17% of total DON, i.e. 0.6-11.5 mu g-at/l nitrogen. Serin and glycin were the most abundant. None of the substances was related to the presence of oyster. Glutamic acid, alanin and ornithin concentrations showed the greatest variations; they are suspected to play the major role as nutrient source. Screening of nutritional capabilities of ten local isolates of micro-algae to use 42 organic substances as sole source of nitrogen, demonstrated urea, glutamic acid and hypoxanthin are assimilated by all... |
| Tipo: Text |
Palavras-chave: Bacillariophyceae; Bivalvia; Biomass; Pond culture; Algal settlements; Oyster culture; Nutritive value; Dissolved organic nitrogen. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1531.pdf |
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| Registros recuperados: 473 | |
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