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| Registros recuperados: 113 | |
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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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| Herbert, R. |
| Seasonal data and depth profiles using super(15)N-labelled NO sub(3)u- show that denitrification (77-90% of NO sub(3)u- respired) rather than NO sub(3)u- dissimilation to NH sub(4)u+ was the principal route of nitrate reduction in Kingoodie Bay sediments. Populations of both groups of NO sub(3)u- reducing bacteria were highest in the 0-20 mm horizon in those sediments where highest rates of NO sub(3)u- respiration were recorded (28.56 mu g N.d super(-1) dry wt. sediment super(-1)). Autotrophic nitrification rates shared a marked seasonality with highest rates (0.92 mu g N.d super(-1).g dry wt. sediment super(-1)) occurring during the summer. Maximum populations of autotrophic nitrifying bacteria were also found in the 0-20 mm sediment horizon and these... |
| Tipo: Text |
Palavras-chave: Seasonal variations; Bacteria; Estuaries; Sediment chemistry; Biogeochemistry; Ammonia; Nitrates; Nitrogen cycle. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-971.pdf |
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| Portier, R; Meyers, S. |
| The environmental effect and fate of several agricultural and industrial source toxicants were evaluated in controlled laboratory microcosm systems in the presence of the aminopolysaccharide polymer, chitin. Toxicants examined included methyl parathion, phenol, pentachlorophenol, 2,4 dichlorophenol, 1,2 dichloroethane and Kepone. Microcosm operating parameters, including pH/Eh, salinity, temperature, flow rate and sediment/water interface conditions, were based on comparable in situ measurements. Fate analysis predictions were based on mineralization of the parent toxicant compound as measured by chromatographic analysis or super(14)CO sub(2) expiration. Chitin, amended to continuous flow microcosms, promoted either cometabolic or cooxidative... |
| Tipo: Text |
Palavras-chave: Controlled conditions; Chemical pollutants; Industrial wastes; Pesticides; Metabolism; Food webs; Biodegradation; Ecosystems; Microorganisms; Environmental effects; Brackishwater pollution; Estuaries; Toxicants; Chitin. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1011.pdf |
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| Registros recuperados: 113 | |
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