|
|
|
| Registros recuperados: 24 | |
|
|
| Herbland, Alain; Le Bouteiller, A; Raimbault, P. |
| A study of the size structure of chlorophyll a (Chla) covering the major part of the equatorial Atlantic Ocean from 5 degree N to 5 degree S leads to the conclusion that seasonal nutrient enrichment in the open eastern equatorial Atlantic does not drastically affect the size distribution of the primary producers: 90% of the total Chla is everywhere contained in the < 20 mu m fraction on the average. In the coastal upwelling near Dakar, this percentage is less than 60%, for the same range of chla concentrations. In the equatorial region the percentage of < 1 mu m Chla is the same in the deep chlorophyll maximum located at the top of the nitracline during the warm season and in the subsuperficial maximum of the upwelling. |
| Tipo: Text |
|
| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00267/37855/35936.pdf |
| |
|
| |
|
|
| Debenay, Jean-pierre; Della Patrona, Luc; Herbland, Alain; Goguenheim, Hemitti; Peignon, Jean-marie. |
| Meiofauna is a functional group made of small benthic metazoans 45 to 500µm in size. Although protista, foraminifera living in this kind of environment are often put in to the meiofauna. Meiofauna has been studied in New Caledonia for its double role as biological indicator for monitoring pond health status and as shrimp forage. Suitability of EOM (easily oxidized material), SOD(sediment oxygen demand),as new biochemical tools for monitoring shrimp pond health was assessed in an environmental survey aiming to assess the role of the water/sediment interface in the occurrence of the summer syndrome vibriosis. EOM, SOD and redox were correlated with shrimp survivals. Lowest meiofauna biomass and abundance were concomitantly found in the most polluted station.... |
| Tipo: Text |
|
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00198/30876/29244.pdf |
| |
|
|
| Bergeron, Jean-pierre; Herbland, Alain. |
| Estimates of carbohydrate assimilation within the mesozooplankton compartment are a fundamental concern in oceanography because they give a general expression of the biologically-regulated incorporation of metabolic fuel produced from inorganic nutrients by phytoplankton in the sea. A new tool is proposed for the assessment of such processes. It is based on the measurement of the activity of an enzyme, pyruvate kinase (PK), on samples of the whole mesozooplankton community. Here, the results are presented of an early attempt at such an implementation in the Bay of Biscay (north-east Atlantic) in springtime. A main area situated in front of an estuary (Gironde) has been extensively studied-the same sampling grid was covered on three occasions (two 20 day... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Zooplankton; Phytoplankton; Pyruvate kinase; Carbohydrate. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-452.pdf |
| |
|
| |
|
|
| Gohin, Francis; Lampert, Luis; Guillaud, Jean-francois; Herbland, Alain; Nezan, Elisabeth. |
| A phytoplankton bloom was observed in late winter 2000, on the continental shelf offshore of southern Brittany, in northwestern Bay of Biscay. This bloom appeared initially along the 120-m isobath, in stratified and clear waters, at the interface between the oceanic water and the plumes of southern Brittany rivers (mainly the Loire and Vilaine). The development of the bloom was triggered by favourable meteorological conditions, characterised by solar irradiance reaching the maximum level expected for that period of the year. Outside of the bloom area, the phytoplankton photosynthesis was irradiance limited: inshore, because of the stronger attenuation of the light; offshore, because of the weak stratification. The hydrological conditions at the onset of... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Coscinodiscus; Algal bloom; Phytoplankton; Ocean colour; Satellite sensing. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-463.pdf |
| |
|
|
| Debenay, J.p.; Della Patrona, Luc; Herbland, Alain; Goguenheim, H. |
| This study was carried out in shrimp ponds from New Caledonia, in order to determine the cause of the exceptional proportion of abnormal tests (FAI) (often >50%, sometimes >80%). FAI was positively correlated to the quantity of easily oxidized material (EOM) deposited on the bottom of the ponds and to the sediment oxygen demand, and negatively correlated to redox. These results suggest that a very high FAI is a potential indicator for great accumulations of native organic matter, leading to a high sediment oxygen demand. When studying ancient sediments in core samples, exceptional abundances of abnormal tests may indicate periods of high accumulation of EOM, and therefore of oxygen depletion. This finding should help in better management of... |
| Tipo: Text |
Palavras-chave: SW Pacific; Bioindicators; Organic matter; Shrimp ponds; Deformations; Foraminifera. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6955.pdf |
| |
|
|
| Koutsikopoulos, Constantin; Herbland, Alain. |
| The studies of the pelagic stages of Sole (Solea vulgaris , Quensel) in the northern part of the Bay of Biscay are strongly influenced by the recent concepts concerning the importance of the physical processes in the evolution of marine populations. The investigations of the linkage between water masses circulation and year-class strength started in 1986 with the deployment of 3 ARGOS satellite tracked drifters at different depths in parallel with the ichthyoplanktonic surveys. The trajectory of the 7 m drifter (tracking the water masses above the pycnocline) is related to the wind. This drifter leaves the sector of the study after 10 days. After 40 days of variable environmental conditions, the 34 m drifter (situated below the density gradient) was only... |
| Tipo: Text |
|
| Ano: 1987 |
URL: https://archimer.ifremer.fr/doc/00482/59344/62138.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 |
| |
|
|
| Della Patrona, Luc; Brun, Pierre; Herbland, Alain. |
| Shrimp culture in New Caledonia has developed according to the "intensified" semi-intensive model which uses ponds that stretch over several hectares. Local shrimp farms are for the most part installed in "tannes", barren, highly saline areas of the back mangrove forest. These areas generally have impermeable silty clay soils that have biogeochemical features particularly appropriate for benthic life and are often immersed by tides. During the six months of the grow-out phase, the "pond ecosystem" undergoes an increase in potential, progressing from an initial state of "natural lagoon" to a "grow-out pond" that is highly enriched with degrading organic matter.... |
| Tipo: Text |
|
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/rapport-4399.pdf |
| |
|
|
| Menkes, Christophe; Kennan, Sc; Flament, Pierre; Dandonneau, Y; Masson, S; Biessy, B; Marchal, E; Eldin, G; Grelet, J; Montel, Y; Morliere, A; Lebourges-dhaussy, A; Moulin, C; Champalbert, G; Herbland, Alain. |
| [1] The equatorial Pacific and Atlantic oceans exhibit remarkable meridional undulations in temperature and chlorophyll fronts visible from space over thousands of kilometers and often referred to as tropical instability waves. Here, we present new observations of an ecosystem ranging through three trophic levels: phytoplankton, zooplankton and small pelagic fish whirling within a tropical vortex of the Atlantic ocean and associated with such undulations. Cold, nutrient and biologically rich equatorial waters are advected northward and downward to form sharp fronts visible in all tracers and trophic levels. The equatorward recirculation experiences upwelling at depth, with the pycnocline and ecosystem progressively moving toward the surface to reconnect... |
| Tipo: Text |
|
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/00000/10049/9584.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 |
| |
|
|
| Lucas, Ronan; Courties, C.; Herbland, Alain; Goulletquer, Philippe; Marteau, Anne-laure; Lemonnier, Hugues. |
| In tropical shrimp ponds, the increasing of feed input, concomitantly with the stocking shrimp biomass, induces an eutrophication of the ecosystem. Although difficult to maintain, its stability is required to guarantee the success of the culture. A 110-day period of phytoplankton and bacterioplankton stock and dynamics in an earthen pond (1.2 ha area, 1 m depth) was monitored using flow cytometry to provide baseline information on community characteristics and ecosystem instability. Seven autotrophic cell types were identified over the whole sampling period. Prokaryotic cells included Synechococcus sp., a group named UNK which presented an atypical new flow cytometric signature and picoeukaryotes (PEUK). Nanophytoplankton cells were represented by 4... |
| Tipo: Text |
Palavras-chave: Tropical shrimp aquaculture; Ecosystem shift; Phytoplankton; Bacterioplankton; Vibrio; Flow cytometry. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00029/14068/11312.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 |
| |
|
|
| Lemonnier, Hugues; Herbland, Alain; Salery, Lucas; Soulard, Benoit. |
| The "Summer Syndrome", a septicemic vibriosis caused by Vibrio nigripulchritudo, is responsible for one of the two main seasonal mortalities which affect shrimp aquaculture in New Caledonia. It was identified for the first time in December 1997 in an intensive shrimp farm (called farm DF) and has been enzootic ever since. The "Summer syndrome" affects shrimp during warm-season growout. Although the geographic area concerned is limited, it is a potential threat for the industry in that the disease could spread. Analysis of grow out data from 1991 to 2002 in this farm was carried out in order to characterize the disease and the environmental conditions in relation to mortality. Results of farm DF were compared to data from farms not affected by the disease... |
| Tipo: Text |
Palavras-chave: Eutrophication; Pond management; Vibriosis; Shrimp culture ponds. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1868.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 |
| |
|
|
| Lemonnier, Hugues; Thomas, Yoann; Legrand, Alexandre; Martin, Jean-louis; Herbland, Alain. |
| In the booming context of shrimp culture in French Caledonia, some research actions need to be considered in order (i) to make sure this production will not impact the quality and biodiversity of the coastal environment it is contingent upon (ii) for the field to highlight, based on objective bases, its good "environmental image", for an efficient commercialization of its products. In the framework of the MOM project, a number of actions have been carried out: Action 1: A bibliographical synthesis of the impact of shrimp culture on coastal environment has been conducted, taking into account the works carried out throughout the world and in French Caledonia in order to draw the main issues the Territory will have to deal with. It seems necessary to start... |
| Tipo: Text |
|
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/rapport-6593.pdf |
| |
|
|
| Michel, Pierre; Boutier, Bernard; Herbland, Alain; Averty, Bernard; Artigas, Lf; Auger, Dominique; Chartier, E. |
| The arsenic (As) cycle in the marine environment is known to be sensitive to biological activity. Within the scope of the National Coastal Oceanography Program, we undertook a specific study of the behaviour of this element in a water column on the continental shelf of the Bay of Biscay off the Gironde estuary during two oceanographic cruises conducted in May 1994 and May 1995. Various chemical forms were measured: arsenite (As3), at-senate (As5), monomethylarsenic (MMA), dimethylarsenic (DMA) and dissolved total As after ultraviolet mineralization. The net flux of total As from the Gironde estuary was evaluated as well as its effect on the concentration in surface marine waters. The vertical profiles in the coastal zone during a period of active primary... |
| Tipo: Text |
Palavras-chave: Arsenic; Phytoplankton; Speciation; Gironde plume; Biscay Bay. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/1998/publication-851.pdf |
| |
| Registros recuperados: 24 | |
|
|
|
