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| Registros recuperados: 31 | |
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| De Verdelhan, Claude; Gros, Philippe; Catanzano, Joseph. |
| (i) La pertinence du thème est attestée par la richesse de la littérature internationale qui lui est consacrée. 11 convient au demeurant de noter la présence de publications de l'IFREMER dans ce même domaine. Les principaux acquis procèdent généralement d'approches descriptives, permettant de disposer à ce jour d'un inventaire quasi exhaustif des différents outils de gestion classiquement mis en oeuvre. D'ores et déjà il apparaît que la question de la transférabilité de mesures de gestion (e.g QIT, Licence, PME...) soulève plusieurs interrogations: cohérence juridique, acceptabilité, contrôle, coûts, efficience... Mais surtout, poser l'étude de la régulation en termes d'analyse du comportement d'un système élargit le champ des investigations au delà du... |
| Tipo: Text |
Palavras-chave: SEM. |
| Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/rapport-4235.pdf |
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| Blanchard, Michel; Gros, Philippe. |
| Three main intertidal macrofauna communities are identified in Saint-Brieuc Bay: a Macoma balthica community, a Tellina tenuis community; and a third community with Cerastroderma and Tellina tenuis. Physiological parameters such as filtration, respiration and excretion are examined, for the filter-feeding molluscs with the highest biomass (the cockle Cerastoderma edule, the tellinid Tellina tenuis, and the blue mussel Mytilus edulis), either through laboratory experiments, or through previous literature. These results are used together to build up an annual energy budget for the complete soft bottom community, and to observe trophic relations. Results show that the mussel population has a negative influence on the cockle beds that lie just above. |
| Tipo: Text |
Palavras-chave: ENERGY BUDGET; FLUXES; CERASTODERMA-EDULE; TELLINA-TENUIS; SAINT-BRIEUC BAY. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21132/18752.pdf |
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| Guarini, Jean-marc; Blanchard, Gerard; Bacher, Cedric; Gros, Philippe; Riera, Pascal; Richard, Pierre; Gouleau, Dominique; Galois, Robert; Prou, Jean; Sauriau, Pierre-guy. |
| Microphytobenthos plays an important role as primary producer in shallow embayments subject to a tidal regime. The present paper aims to characterize the spatial patterns of sedimentary chlorophyll a (chl a) biomass in 2 seasons in the wide intertidal mudflats of the Marennes-Oleron Bay (France); furthermore, it provides estimates of total microphytobenthic biomass. Accordingly, a systematic sampling scheme was performed in June 1995 and in January 1996. On average, biomass was higher in June (ca 120 mg chl a m-2) than in January (ca 85 mg chl a m-2). Moreover, the geostatistical analysis revealed that spatial similarities were propagated over larger distances in June (6 km) than in January (2.2 km). In order to account for this result , we suggest that... |
| Tipo: Text |
Palavras-chave: Marennes Oleron; Intertidal mudflat; Geostatistics; Spatial distribution; Chrlorophyll a; Microphytobenthos. |
| Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/1998/publication-3820.pdf |
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| Gros, Philippe. |
| Fisheries and aquaculture provide at least 15% of their animal protein diet to 4.3 billion persons. The rise of aquaculture dates back to the end of the 1980s, when fisheries’ production rate was beginning to decline, sounding the end of its post World War II growth phase. The volume of official landings culminated 25 years ago, without outlook for any further increase. About 60% of fish stocks are currently exploited at the maximum sustainable yield (MSY) level, most of the other ones being overexploited because of the chronic overcapacity of the fleets and of poorly regulated access to fishing. The ecosystem approach to fisheries (EAF) emerged as paradigm shift in the 1990s, underpinning the renewal of management objectives and governance along with... |
| Tipo: Text |
Palavras-chave: Common fishery policy; Ecological footprint; Ecosystem approach to fisheries; Fisheries; Global change; Good ecological status. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00183/29414/27775.pdf |
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| Gros, Philippe. |
| Linear regression modelling is one of the most widely used statistical tools: usual applications of this "core technique" encompass description and analysis of experimental data, interpolation, help in recognizing causal relationships, and forecasting. It is thus necessary for the practicioner to obtain an understanding of the basic principles necessary to apply regression methods in a variety of settings. Accordingly, the first two chapters provide the standard results for the simple linear regression (only one controlled variable, or regressor). Since the emphasis is on practical applications, theoretical results are stated without proof, and the major guidelines are building models, assessing fit and reliability, and drawing conclusions. Chapter 1... |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00013/12405/9191.pdf |
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| Santarelli, L; Gros, Philippe. |
| The totality of French landings of whelk (Buccinum undatum L.) is assignable to the fisheries of the Normand-Breton Gulf, western Channel. The aim of this paper is to forecast economic rent of the potters of the harbour of Granville, as a function of the two main variates open to supervision: the size of the fishing fleet, and the number of whelk-pots per ship. In order to assess the biological and financial consequences of a prospective development, a deterministic model of the fleet-resource system is proposed. Results of simulations emphasize the sharpness of the rent-dissipation problem under existing tendencies. Therefore some recommendations are put forward to derive a fishery policy that would enable the system to be maintained near optimal... |
| Tipo: Text |
Palavras-chave: Gastropoda; Marine mollusks; Fishery management; Economic models; Fishery economics. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/publication-1786.pdf |
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| Gros, Philippe. |
| Toward Sustainable Fisheries and Aquaculture in a Changing World Outline · World fish supply: key figures · Global estimates hide marked differences Linkages and dissimilarities between capture and aquaculture A global production sharply unbalanced between geographical areas Bulk of harvest: based on greater diversity of captured species than of farmed ones A globalized fish trade, an uneven food fish consumption between countries · Main causes of bias in official statistics Discards IUU (illegal, unreported, unregulated) fishing · Interactions between fisheries, aquaculture and marine ecosystems Global impacts of marine aquaculture Impacts of fishing on marine biodiversity Implementation of the ecosystem approach to fisheries and... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00027/13845/10991.pdf |
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| Chardy, Pierre; Gros, Philippe; Mercier, Herle; Monbet, Yves. |
| A steady-state energy flow model is proposed for the benthic fine sand community of the Bay of Saint-Brieuc. The main objective is to assess the relative importance of benthic processes associated with the carbon cycle in an eutrophicated bay. Available data include biomass estimates of the major trophic groups and measurements of the most critical fluxes : particulate organic carbon sedimentation, community respiration, microbial production. A balanced annual carbon budget is estimated using an inverse method, particularly appropriate in food web research where the number of unknowns is far higher than the number of independent observations. The method offers the possibility of taking dynamical constraints into account, by introducing global flow... |
| Tipo: Text |
Palavras-chave: CARBON CYCLE; BENTHIC COMMUNITY; FINE SANDS; SUBTIDAL AREA; INVERSE METHOD. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21131/18751.pdf |
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| Gros, Philippe; Laurec, A.; Dupouy, Herve. |
| This paper is devoted to statistical problems associated to the estimation of the parameters of a Von Bertalanffy growth curve. A first part corresponds to theoretical considerations, first within the classical regression point of view, corresponding to residuals normaly and independently distributed, then to resampling techniques (Jackknife/Bootstrap). The possibility of using not only the arithmetic mean of observed lengths for a given age, but also medians and modes is discussed. A software has been written in Fortran, which makes it possible to fit by (Weighted) least squares either mean, median or modal length at age, and provides estimates of variances/covariances using the classical approximation within regression theory or resampling techniques. An... |
| Tipo: Text |
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| Ano: 1987 |
URL: http://archimer.ifremer.fr/doc/00394/50575/51267.pdf |
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| Gros, Philippe. |
| The objective of this report is to characterize the evolution of the pelagie coastal ecosystem (studied by sampling hydrobiological parameters, phytoplankton and zooplankton) off the Gravelines' nuclear power plant (french coast of the North Sea). The sampling program (contractually defined by the Centre National pour l'Exploitation des Océans and Electricité de France) is composed of several successive phases. The results obtained for the first three of them (september 1974 - december 1975 ; august 1976 - july 1977 ; january 1978- june 1979) are presented in this report, with special emphasis on the third one realized just before the power plant's activity started (march 1980). It is shown that, from 1974 to 1979, some subsets of the ecosystem (such as... |
| Tipo: Text |
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| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/00101/21213/18828.pdf |
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| Gros, Philippe. |
| First analytic approaches in population dynamics modelling did not really begin until the 1920s and 1930s. By the 1950s, models that described how fish populations respond to fishing were developed, and provided useful tools in the management of living resources. These early studies, as well as the bulk of existing theoretical ecology, are usually in spatially homogeneous settings: they deal with temporal processes, and ask specifically about steady-state solutions to nonspatial systems. However, several lines of inquiry have stressed the critical role of spatial complexity when thinking about populations and communities as dynamical systems varying in response to natural or human-created disturbance. The introduction of this report is designed to... |
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| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00013/12409/9196.pdf |
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| Gros, Philippe; Biseau, Alain; Fromentin, Jean-marc; Thebaud, Olivier. |
| The report is focused on the research priorities pertaining to the implementation of the ‘maximum sustainable yield’ (MSY) and of the ‘ecosystem approach to fisheries’ (EAF). The MSY is first examined, taking account of its relevance as a management objective, of its link with maximum economic yield (MEY), and of its close relationship with ecosystem productivity and fishing capacity. Related research priorities are identified. In the second part, emphasis is put on EAF, a very challenge for fishery scientists. The extension of fisheries science towards an ecosystem dimension (including human activities) and the integration of uncertainty have opened up large fields of research. Priorities are presented by domain. Five principal areas of knowledge and... |
| Tipo: Text |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00013/12408/9194.pdf |
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| Gros, Philippe; Santarelli, Leonardo. |
| The experimental design of the capture field area of baited whelk-pots involves, as a controlled factor, four different spacings between pots (6, 12, 24 and 36m), randomly distributed along a ground line. This spectrum of values is sufficiently broad to preclude overlap of capturing fields of sorne pots. Taking account of the patterns of the M2 tidal currents in the area studied, an ellipse was chosen as a geometrical model of the shape of the capture field. Semimajor and semiminor axes were estimated by least squares, the expected catch per pot being defined as a decreasing function of the area of overlap with adjacent capture fields. · Experimental fishing of Buccinum undatum L. was carried out in the Channel Isles region (Western Channel), and provided... |
| Tipo: Text |
Palavras-chave: Échantillonnage quantitatif; Estimation de densité; Casier appâté; Gestion de stocks; Buccin; Quantitative sampling; Density estimate; Baited pot; Stock assessment; Whelk. |
| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00112/22279/19954.pdf |
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| Guarini, Jean-marc; Blanchard, Gerard F.; Gros, Philippe; Harrison, S.j.. |
| The mud surface temperature (MST) of an intertidal mudflat in Marennes-Oléron Bay (France) and the biomass-specific photosynthetic capacity (PBmax) of benthic microalgae were modelled to investigate their spatio-temporal dynamics. Simulations were performed over 2 different periods during and after the microphytobenthos spring bloom (April and June, respectively) and under 2 different tidal conditions (spring and neap tides). The deterministic MST model is based on thermodynamic processes. Comparison at different periods between measured data series and simulations clearly establishes the reliability of the model, thus allowing extrapolations over time and space. The spatio-temporal dynamics of MST is primarily controlled by the immersion-emersion... |
| Tipo: Text |
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| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00013/12398/9184.pdf |
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| Registros recuperados: 31 | |
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