|
|
|
Registros recuperados: 26.605 | |
|
|
Donnet, Sebastien; Lazure, Pascal; Ratsimandresy, Andry; Han, Guoqi. |
While the dynamics of narrow fjords, i.e. narrow with respect to their internal Rossby radius, have been widely studied, it is only recently that interest sparked in studying the physics of broad fjords due to their importance in glacial ice melting (in Greenland, especially). Here, we present a comprehensive set of data collected in Fortune Bay, a broad, mid-latitude fjord located on the Northwest Atlantic shores. Aside from being wide (15–25 km width) and deep (600 m at its deepest), Fortune Bay also has the characteristics of having steep slopes, weak tides and of being strongly stratified from spring to fall. Thus, and since strong along-shore winds also characterise the region, this system is prone to interesting dynamics, generally taking the form of... |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00634/74635/74529.pdf |
| |
|
| |
|
| |
|
|
Mesnil, Benoit; Rochet, Marie-joelle. |
With political commitment to restore stocks to levels where they can produce maximum sustainable yield (MSY), fisheries managers request evaluations of management plans that include options for an FMSY policy. The procedure to estimate FMSY with dynamic-pool, stock assessment models is well established for common stock-recruitment relationships (S-RR). In this paper, we extend this capacity to another S-RR, a piecewise function known as the hockey stick, which is frequently assumed when the data do not support more elaborate functions. However, the hockey stick is not continuous, which makes it problematic for this application, where differentiable functions are required. The bent-hyperbola model proves to be an adequate continuous equivalent to the hockey... |
Tipo: Text |
Palavras-chave: Bent hyperbola; F-MSY; Hockey stick; MSY; Stock-recruitment. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00016/12735/9667.pdf |
| |
|
|
Benoit, Eric; Rochet, Marie-joelle. |
A new time-dependent continuous model of biomass size spectra is developed. In this model, predation is the single process governing the energy flow in the ecosystem, as it causes both growth and mortality. The ratio of predator to prey is assumed to be distributed: predators may feed on a range of prey sizes. Under these assumptions, it is shown that linear size spectra are stationary solutions of the model. Exploited fish communities are simulated by adding fishing mortality to the model: it is found that realistic fishing should affect the curvature and stability of the size spectrum rather than its slope. |
Tipo: Text |
Palavras-chave: Predation; Mortality; Growth; Biomass size spectrum; Allometry. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-665.pdf |
| |
|
| |
|
|
Carayon, Kevin; Leh, Herve; Henry, Etienne; Simon, Francoise; Mouscadet, Jean-francois; Deprez, Eric. |
HIV-1 integrase catalyzes the insertion of the viral genome into chromosomal DNA. We characterized the structural determinants of the 3'-processing reaction specificity-the first reaction of the integration process-at the DNA-binding level. We found that the integrase N-terminal domain, containing a pseudo zinc-finger motif, plays a key role, at least indirectly, in the formation of specific integrase-DNA contacts. This motif mediates a cooperative DNA binding of integrase that occurs only with the cognate/viral DNA sequence and the physiologically relevant Mg(2+) cofactor. The DNA-binding was essentially non-cooperative with Mn(2+) or using non-specific/random sequences, regardless of the metallic cofactor. 2,2'-Dithiobisbenzamide-1 induced zinc ejection... |
Tipo: Text |
|
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00206/31773/30183.pdf |
| |
|
|
Mensah, Vigan; Roquet, Fabien; Siegelman-charbit, Lia; Picard, Baptiste; Pauthenet, Etienne; Guinet, Christophe. |
The effect of thermal mass on the salinity estimate from conductivity-temperature-depth (CTD) tags sensor mounted on marine mammals is documented, and a correction scheme is proposed to mitigate its impact. The algorithm developed here allows for a direct correction of the salinity data, rather than a correction of the sample's conductivity and temperature. The amplitude of the thermal mass-induced error on salinity and its correction are evaluated via comparison between data from CTD tags and from Sea-Bird Scientific CTD used as a reference. Thermal mass error on salinity appears to be generally O(10(-2)) g kg(-1), it may reach O(10(-1)) g kg(-1), and it tends to increase together with the magnitude of the cumulated temperature gradient (T-HP) within the... |
Tipo: Text |
Palavras-chave: Data processing; In situ oceanic observations; Instrumentation; Sensors; Profilers; Oceanic. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00585/69697/67577.pdf |
| |
|
| |
|
|
Bellanger, Manuel; Levrel, Harold. |
The growth of marine recreational activities raises the issues of the current lack of knowledge on these activities and the information required to assess their potential impacts. Indeed, the monitoring of unrecorded activities is a great challenge, especially when basic information, such as the size of the population practicing the different activities, is unknown. In this paper, the experience of the monitoring of marine recreational fishing was used to carry out a diagnosis study to assess the cost-effectiveness of survey methods used in France between 2004 and 2012. Costs of alternative surveys were balanced with data quality, and particular attention was paid to potential biases. Results showed that the involvement of citizens through diary surveys... |
Tipo: Text |
|
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00366/47769/47855.pdf |
| |
|
|
Le Goff, Clement; Lavaud, Romain; Cugier, Philippe; Jean, Fred; Flye-sainte-marie, Jonathan; Foucher, Eric; Desroy, Nicolas; Fifas, Spyros; Foveau, Aurelie. |
In this paper we used a modelling approach integrating both physical and biological constraints to understand the biogeographical distribution of the great scallop Pecten maximus in the English Channel during its whole life cycle. A 3D bio-hydrodynamical model (ECO-MARS3D) providing environmental conditions was coupled to (i) a population dynamics model and (ii) an individual ecophysiological model (Dynamic Energy Budget model). We performed the coupling sequentially, which underlined the respective role of biological and physical factors in defining P. maximus distribution in the English Channel. Results show that larval dispersion by hydrodynamics explains most of the scallop distribution and enlighten the main known hotspots for the population,... |
Tipo: Text |
Palavras-chave: Population dynamic model; Ecophysiological model; English Channel; Pecten maximus; Spatial distribution. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00355/46642/46467.pdf |
| |
|
|
Brandefelt, J.; Kjellstrom, E.; Naslund, J. -o.; Strandberg, G.; Voelker, A. H. L.; Wohlfarth, B.. |
We present a coupled global climate model (CGCM) simulation, integrated for 1500 yr to quasi-equilibrium, of a stadial (cold period) within Marine Isotope Stage 3 (MIS 3). The simulated Greenland stadial 12 (GS12; similar to 44 ka BP) annual global mean surface temperature (T-s) is 5.5 degrees C lower than in the simulated recent past (RP) climate and 1.3 degrees C higher than in the simulated Last Glacial Maximum (LGM; 21 ka BP) climate. The simulated GS12 is evaluated against proxy data and previous modelling studies of MIS3 stadial climate. We show that the simulated MIS 3 climate, and hence conclusions drawn regarding the dynamics of this climate, is highly model-dependent. The main findings are: (i) Proxy sea surface... |
Tipo: Text |
|
Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00228/33898/32218.pdf |
| |
|
| |
|
|
Politikos, Dimitrios; Huret, Martin; Petitgas, Pierre. |
Adult anchovies in the Bay of Biscay perform north to south migration from late winter to early summer for spawning. However, what triggers and drives the geographic shift of the population remains unclear and poorly understood. An individual-based fish model has been implemented to explore the potential mechanisms that control anchovy's movement routes toward its spawning habitats. To achieve this goal, two fish movement behaviors – gradient detection through restricted area search and kinesis – simulated fish response to its dynamic environment. A bioenergetics model was used to represent individual growth and reproduction along the fish trajectory. The environmental forcing (food, temperature) of the model was provided by a coupled... |
Tipo: Text |
Palavras-chave: Individual-based model; Behavioral movement; Dynamic Energy Budget; Anchovy; Bay of Biscay. |
Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00273/38446/36868.pdf |
| |
|
| |
|
|
Albert, Luana; Deschamps, François; Jolivet, Aurélie; Olivier, Frédéric; Chauvaud, Laurent; Chauvaud, Sylvain. |
The goal of clean renewable energy production has promoted the large-scale deployment of marine renewable energy devices, and their associated submarine cable network. Power cables produce both electric and magnetic fields that raise environmental concerns as many marine organisms have magneto and electroreception abilities used for vital purposes. Magnetic and electric fields' intensities decrease with distance away from the cable. Accordingly, the benthic and the sedimentary compartments are exposed to the highest field values. Although marine invertebrate species are the major fauna of these potentially exposed areas, they have so far received little attention. We provide extensive background knowledge on natural and anthropogenic marine sources of... |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00617/72944/71974.pdf |
| |
|
|
Verdy, A.; Mazloff, M. R.. |
A Biogeochemical Southern Ocean State Estimate (B-SOSE) is introduced that includes carbon and oxygen fields as well as nutrient cycles. The state estimate is constrained with observations while maintaining closed budgets and obeying dynamical and thermodynamic balances. Observations from profiling floats, shipboard data, underway measurements, and satellites are used for assimilation. The years 2008-2012 are chosen due to the relative abundance of oxygen observations from Argo floats during this time. The skill of the state estimate at fitting the data is assessed. The agreement is best for fields that are constrained with the most observations, such as surface pCO(2) in Drake Passage (44% of the variance captured) and oxygen profiles (over 60% of the... |
Tipo: Text |
Palavras-chave: Southern Ocean; State estimation; Biogeochemistry. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00662/77394/78995.pdf |
| |
|
| |
|
|
Guimarães, Pedro Veras; Ardhuin, Fabrice; Bergamasco, Filippo; Leckler, Fabien; Filipot, Jean-francois; Shim, Jae-seol; Dulov, Vladimir; Benetazzo, Alvise. |
Stereo imaging of the sea surface elevation provides unique field data to investigate the geometry and dynamics of oceanic waves. Typically, this technique allows retrieving the 4-D ocean topography (3-D space + time) at high frequency (up to 15–20 Hz) over a sea surface region of area ~104 m2. Stereo data fill the existing wide gap between sea surface elevation time-measurements, like the local observation provided by wave-buoys, and large-scale ocean observations by satellites. The analysis of stereo images provides a direct measurement of the wavefield without the need of any linear-wave theory assumption, so it is particularly interesting to investigate the nonlinearities of the surface, wave-current interaction, rogue waves, wave breaking, air-sea... |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00631/74285/73895.pdf |
| |
|
|
Rosland, Rune; Alunno-bruscia, Marianne; Duinker, Arne; Strand, Oivind; Strohmeier, Tore. |
A Dynamic Energy Budget(DEB) model was used to analyse growth and toxin elimination processes in musselsthat had been exposed to Diarrhetic Shellfish Toxins (DST). After DST exposure mussels were placed inan experimentalin-situ setup, expected to have low concentrations of toxic phytoplankton, and DST concentrations in mussel tissueswere regularly monitored along with temperature and seston concentration and composition in the water. A one-compartment model for DST concentrations and elimination rate was integrated with the DEB model, assuming that storage and structural compartments absorb DST. The model was used to simulate growth and toxin elimination rates from mussel tissues. Toxin elimination rate was obtained by a calibration between observed and... |
Tipo: Text |
|
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00148/25936/24001.pdf |
| |
Registros recuperados: 26.605 | |
|
|
|