|
|
|
| Registros recuperados: 35 | |
|
|
| Delmas, Daniel. |
| Carbohydrates have been analysed in arder to establish the state of organic matter in sediment. Samples were collected bath in neritic and oceanic (Orgon croises) areas. Reported data demonstrate that the insoluble-carbohydratesfsoluble-carbohydrates ratio (1/S) is a good indicator of organic matter evolution. In sediments, 1/S values ranging from 6 to 8 are associated with slightly-degraded organic matter, whereas values higher than 10 and eyen up to 30 relate to highly-degraded material. Furthermore, 1/S and CjN ratios generally show the same profile in sediments. The balance betweeh soluble (S) and insoluble (1) carbohydrates depends on the early stages of organic matter evolution, the soluble fraction being more easily degraded; such factors as... |
| Tipo: Text |
|
| Ano: 1983 |
URL: http://archimer.ifremer.fr/doc/00120/23143/20988.pdf |
| |
|
| |
|
|
| Crottereau, C; Delmas, Daniel. |
| In order to estimate in situ bacterial exoproteolysis and its contribution to bacterial secondary production (BSP), we studied microbial activities (BSP and kinetics of exoproteolytic activity) in relation to dissolved combined amino acids (DCAA) during the survey of an Atlantic marine pond. In this pond, high concentrations of DCAA (mean = 4.27 mu M), probably generated by zooplankton grazing, allowed large bacterial biomass development and high production (max = 10(11) cells l(-1) and 18.8 x 10(9) cells l(-1) d(-1) respectively). Exoproteolytic enzyme activity (mean V-m = 55.9 mu M d(-1)) was tightly cou pled to bacterial production, suggesting that protein utilization was essential for bacterial growth. Calculation, according to the Michaelis-Menten... |
| Tipo: Text |
Palavras-chave: Bacterioplankton; In situ exoproteolytic hydrolysis rate; Kinetic parameters; DCAA; Marine pond. |
| Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/00446/55803/62288.pdf |
| |
|
|
| Devez, Aurelie; Delmas, Daniel. |
| Domoic acid (DA), a toxin produced worldwide by some species of the genus Pseudo-nitzschia, is responsible for contamination of marine molluscs, mammals, birds, and for human intoxication, and when detected in high levels results in closures of shellfish farms, thus causing severe economic losses to aquaculture. Studies on algal production of DA in cultures and field samples require sensitive methods capable of measuring trace concentrations of domoic acid. Measuring domoic acid concentrations at trace levels is still a significant challenge. A sensitive and reliable double derivatization using o-phthaldialdehyde-mercaptoethanol/9-fluorenylmethylchloroformate (OPA-MeSH/FMOC-Cl) followed by high-performance liquid chromatography with fluorescence detection... |
| Tipo: Text |
|
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00151/26234/24438.pdf |
| |
|
|
| Lassalle, G.; Lobry, J.; Le Loc'H, F.; Bustamante, Paco; Certain, Gregoire; Delmas, Daniel; Dupuy, C.; Hily, Christian; Labry, Claire; Le Pape, O.; Marquis, Elise; Petitgas, Pierre; Pusineri, Claire; Ridoux, Vincent; Spitz, J.; Niquil, Nathalie. |
| The Bay of Biscay (North-East Atlantic) has long been subjected to intense direct and indirect human activities that lead to the excessive degradation and sometimes overexploitation of natural resources. Fisheries management is gradually moving away from single-species assessments to more holistic, multi-species approaches that better respond to the reality of ecosystem processes. Quantitative modelling methods such as Ecopath with Ecosim can be useful tools for planning, implementing and evaluating ecosystem-based fisheries management strategies. The aim of this study was therefore to model the energy fluxes within the food web of this highly pressured ecosystem and to extract practical information required in the diagnosis of ecosystem state/health. A... |
| Tipo: Text |
|
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00057/16851/14329.pdf |
| |
|
| |
|
| |
|
| |
|
|
| Labry, Claire; Delmas, Daniel; Herbland, Alain. |
| Previous studies conducted on the continental shelf in the Southeast Bay of Biscay influenced by Gironde waters (one of the two largest rivers on the French Atlantic coast) showed the occurrence of late winter phytoplankton blooms and phosphorus limitation of algal growth thereafter. In this context, the importance of dissolved organic phosphorus (DOP) for both algae and bacteria was investigated in 1998 and 1999 in terms of stocks and fluxes. Within the mixed layer, although phosphate decreased until exhaustion from winter to spring, DOP remained high and phosphate monoesters made up between I I to 65% of this pool. Total alkaline phosphatase activity (APA, V-max) rose gradually from winter (2-8 nM h(-1)) to late spring (100-400 nM h-1), which was mainly... |
| Tipo: Text |
Palavras-chave: Phytoplankton; Phosphate; Gironde; DOP; Bacteria; Alkaline phosphatases. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-608.pdf |
| |
|
| |
|
| |
|
|
| Delmas, Daniel; Herbland, Alain; Maestrini, Serge; Mornet, Francoise; Morand, Philippe; Spano, Anna-maria; Burgeot, Thierry; Margat, Sylvie; Charpentier, Gabriel; Fillon, Alain; Leguay, Didier; Thomas, Gerard; Bacher, Cedric; Heral, Maurice; Prou, Jean. |
| Environmental and species features which lead to increases in cell density of the D.S.P. Dinoflagellate Dinophysis in inshore and offshore waters of the île de Ré - île d'Oléron area, France (cruises "Dinopertuis89"). Four weekly sampling series have been carried out, within 10 May – 31 May 1989, at 24 stations located from inshore to offshore waters of the "île de Ré" - "île d’Oléron" area, with the aim to investigate (i) whether Dinophysis increases in cell density occur first in offshore waters and then, eventually, are pushed to the coast, or develop simultaneously in the whole area, and (ii) whether there are some environmental conditions which are related to Dinophysis blooms. Depths of sampling have been stated on the bas is of STD profiles. All... |
| Tipo: Text |
|
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00174/28532/26916.pdf |
| |
|
|
| Gohin, Francis; Loyer, S; Lunven, Michel; Labry, Claire; Froidefond, J; Delmas, Daniel; Huret, Martin; Herbland, Alain. |
| In biological modelling of the coastal phytoplankton dynamics, the light attenuation coefficient is often expressed as a function of the concentrations of chlorophyll and mineral suspended particulate matter (SPM). In order to estimate the relationship between these parameters over the continental shelf of the northern Bay of Biscay, a set of in situ data has been gathered for the period 1998-2003 when SeaWiFS imagery is available. These data comprise surface measurements of the concentrations of total SPM, chlorophyll, and irradiance profiles from which is derived the attenuation coefficient of the photosynthetically available radiation, K-PAR. The performance of the IFREMER look-up table used to retrieve the chlorophyll concentration from the SeaWiFS... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; SeaWiFS; Sediment; Chlorophyll; Ocean color. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1172.pdf |
| |
|
|
| Delmas, Daniel. |
| The étang de Berre, near Marseilles (France), is an inland brackish basin with a high primary rate of production. In 1966, the diversion of the Durance River introduced important hydrological changes. A study of organic matter mineralization and ionie exchanges at the water-sediment interface has made it possible to distinguish two areas, according to the composition of organic matter, mineralization mechanism and ionie transfers. In the North, the high rate of mineral sedimentation leads to a low content of organic matter in the sediment. This organic matter of detrital origin is little affected by mineralization; there is, however, high production of ammonium nitrogen, which is released to overlying waters. Nitrates and nitrites undergo denitrification... |
| Tipo: Text |
Palavras-chave: Interface eau-sédiment; Matière organique; Eau interstitielle; Minèralisation; Milieu saumâtre; Water-sediment interface; Organic matter; Lnterstitial water; Mineralization; Brackish basin. |
| Ano: 1980 |
URL: http://archimer.ifremer.fr/doc/00122/23317/21142.pdf |
| |
|
|
| Delmas, Daniel; Herbland, Alain; Maestrini, Serge. |
| From 22 April to 19 June 1990, 7 stations located off La Rochelle, France, from near-shore ('bassin Marennes-Oleron') to offshore waters (50 m depth contour) were visited 8 times, with the aim of determining whether the toxic dinoflagellates Dinophysis spp. increase in cell density in nutrient-poor offshore water, in nutrient-rich inshore waters, or both, and to determine their vertical distribution in relation to stratification. Temperature stratification developed offshore, but not inshore. In April, few Dinophysis spp. were present offshore and none inshore. In late May, up to 15 X 10(3) cells l(-1) were recorded in the 10 to 15 m layer offshore, whereas inshore waters contained only a few cells l(-1). In late May, a short period of wind partly modified... |
| Tipo: Text |
|
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/00190/30141/28772.pdf |
| |
|
|
| Martin, Jean-louis; Sornin, Jean-marc; Delmas, Daniel; El Sayed, Mohamed A.; Berthet, Brigitte. |
| Au cours de cette étude, nous avons étudié l'impact de la biodéposition sur les bassins conchylicoles. La biodéposition constitue un "concentrateur" de particules fines au niveau du sédiment. Cet impact est particulièrement évident sur les sédiments sableux et concerne la granulométrie, les taux de matière organique, la concentration des métaux et des hydrocarbures. Une étude comparée est faite entre estran sableux et bassin de type "claire" à sédiment argileux. L'impact de la biodéposition sur les sédiments sableux n'est pas irréversible. Le bassin fermé avec un sédiment argileux agit comme un concentrateur-rétenteur de particules et des contaminants potentiels. Ceci souligne le rôle "tampon" des marais maritimes entre milieu continental et milieu marin. |
| Tipo: Text |
|
| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00076/18757/16327.pdf |
| |
|
| |
|
|
| Petitgas, Pierre; Masse, Jacques; Bourriau, Paul; Beillois, Pierre; Bergeron, Jean-pierre; Delmas, Daniel; Herbland, Alain; Koueta, Noussithe; Froidefond, Jean-marie; Santos, Maria. |
| The spatial pattern in hydro-plankton and fish distributions and their relationship were analysed based on the spring 2000 fisheries acoustic survey. The importance of this survey was that it was a multi-disciplinary platform which collected an extensive set of parameters in the hydro-plankton leading to a potentially finer description of hydro-plankton conditions and fish habitats. More than 50 variables were measured on a grid of stations, in four compartments of the ecosystem: hydrology, nutrients, primary producers and meso-zooplankton. First, a joint analysis of all hydro-plankton compartments was performed using multiple factor analysis (MFA). The method was used to estimate a compromise factorial space common to all compartments in which the... |
| Tipo: Text |
Palavras-chave: Fish environment relationship; Hydro plankton; Habitats; Multiple factor analysis; Spatial pattern. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3961.pdf |
| |
|
|
| Labry, Claire; Youenou, Agnes; Delmas, Daniel; Michelon, Pascale. |
| The speciation of particulate phosphorus (TPP) into inorganic (PIP) and organic phosphorus (POP), has been scarcely investigated in suspended particulate matter (SPM), contrary to numerous sediment studies. This work evaluates the actual capacity of methods for TPP, POP and PIP determination in SPM to measure efficiently and specifically each pool. Methods were tested on a range of plankton-associated organic and inorganic P compounds, on microalgal cultures and estuarine samples. Then results are specifically discussed reviewing P speciation in phytoplankton. For TPP analysis, the method of Solorzano and Sharp (1980) is recommended compared with that of Aspila et al. (1976), originally dedicated to sediment, as there is one step less, the protocol is more... |
| Tipo: Text |
Palavras-chave: Phosphorus; Speciation; Waters; Phytoplankton; HTC; CWO. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00149/26046/26385.pdf |
| |
| Registros recuperados: 35 | |
|
|
|
