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| Registros recuperados: 64 | |
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| Marchal, Paul; Bartelings, Heleen; Bastardie, François; Batsleer, Jurgen; Delaney, Alyne; Girardin, Raphael; Gloaguen, Pierre; Hamon, Katell; Hoefnagel, Ellen; Jouanneau, Charlène; Mahevas, Stephanie; Nielsen, Rasmus; Piwowarczyk, Joanna; Poos, Jan-jaap; Schulze, Torsten; Rivot, Etienne; Simons, Sarah; Tidd, Alex; Vermard, Youen; Woillez, Mathieu. |
| The scope of this report is to present the science developed within the VECTORS project to improve the understanding of the key processes driving the behaviour of human agents utilising a variety of EU maritime domains. While particular attention has been paid to the spatial interactions between fishing activities and other human uses (e.g., maritime traffic, offshore wind parks, aggregate extractions), the behaviour of non-fishing sectors of activity has also been considered. Various quantitative and semi-qualitative approaches have been pursued to gain better insight into behavioural drivers based on past data, and also forecast how human agents would react if access was constrained by either management (e.g. Marine Protected Areas – MPA), or the... |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00223/33377/31802.pdf |
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| Lehodey, Patrick; Marchal, Paul; Grandperrin, René. |
| Commercial and scientific bottom longline catches of alfonsino, #Beryx splendens$, from seamounts of New Caledonia were sampled to study length-frequency distributions. A total of 14,674 fish were measured. CPUE of #Beryx splendens$ on two seamounts is modelled in terms of length and depth. The data show that mean length increases with depth ; this is well described by a bivariate normal model that estimates catch for a given seamount. In addition, the data show that mean length also varies with the depth of the top of seamounts ; this is described by a recursive model that is designed to predict approximate catch for any seamount. The limitations of both models are discussed, particularly with regard to temporal variation. (Résumé d'auteur) |
| Tipo: Text |
Palavras-chave: POISSON MARIN; ECHANTILLONNAGE; LONGUE LIGNE; CROISSANCE; PROFONDEUR; ANALYSE STATISTIQUE; MODELE MATHEMATIQUE. |
| Ano: 1994 |
URL: http://www.documentation.ird.fr/hor/fdi:010006413 |
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| Cormon, Xochitl; Ernande, Bruno; Kempf, Alexander; Vermard, Youen; Marchal, Paul. |
| North Sea saithe Pollachius virens, a major top predator in the area, supports the fishery economy of several European countries. However, recent stock assessments suggested a decrease in spawning stock biomass along with a decline in saithe mean weight-at-ages. In this context, we investigated North Sea saithe growth characteristics at the population level. First, saithe annual weight increments and age-length relationships were studied. Modelling of saithe age-length relationships was carried out using (1) the traditional von Bertalanffy growth function model, (2) the Verhulst logistic model and (3) an empirical linear model. Second, the effects of environmental factors on saithe growth were investigated. Explanatory environmental factors included food... |
| Tipo: Text |
Palavras-chave: Bottom-up processes; Von Bertalanffy growth function; Logistic growth; Norway pout; Prey availability effects; Density-dependence; Predator-prey interactions; Resource limitation; Competition. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00314/42499/41875.pdf |
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| Di Pane, Julien; Joly, Lea; Koubbi, Philippe; Giraldo, Carolina; Monchy, Sébastien; Tavernier, Eric; Marchal, Paul; Loots, Christophe. |
| Condition indices aim to evaluate the physiological status of fish larvae by estimating both the level of starvation and potential of survival. Histological indices reveal direct effects of starvation whereas biochemical indices such as lipid classes or RNA:DNA ratios are used as proxies of condition, giving information on the amount of energy reserves and growth rate, respectively. We combined these three indices to evaluate ontogenetic variations of growth performance, lipid dynamics and nutritional condition of plaice larvae caught in the field during winter 2017 in the eastern English Channel and the Southern Bight of the North Sea. RNA:DNA ratios showed that larvae at the beginning of metamorphosis (stage 4) had a lower growth rate than younger... |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00514/62610/66974.pdf |
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| Peck, Myron A.; Arvanitidis, Christos; Butenschon, Momme; Canu, Donata Melaku; Chatzinikolaou, Eva; Cucco, Andrea; Domenici, Paolo; Fernandes, Jose A.; Gasche, Loic; Huebert, Klaus B.; Hufnagl, Marc; Jones, Miranda C.; Kempf, Alexander; Keyl, Friedemann; Maar, Marie; Mahevas, Stephanie; Marchal, Paul; Nicolas, Delphine; Pinnegar, John K.; Rivot, Etienne; Rochette, Sebastien; Sell, Anne F.; Sinerchia, Matteo; Solidoro, Cosimo; Somerfield, Paul J.; Teal, Lorna R.; Travers-trolet, Morgane; Van De Wolfshaar, Karen E.. |
| We review and compare four broad categories of spatially-explicit modelling approaches currently used to understand and project changes in the distribution and productivity of living marine resources including: 1) statistical species distribution models, 2) physiology-based, biophysical models of single life stages or the whole life cycle of species, 3) food web models, and 4) end-to-end models. Single pressures are rare and, in the future, models must be able to examine multiple factors affecting living marine resources such as interactions between: i) climate-driven changes in temperature regimes and acidification, ii) reductions in water quality due to eutrophication, iii) the introduction of alien invasive species, and/or iv) (over-)exploitation by... |
| Tipo: Text |
Palavras-chave: Distribution; Modelling; Habitat; Resources; Man-induced effects. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00337/44845/44436.pdf |
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| Di Pane, Julien; Koubbi, Philippe; Giraldo, Carolina; Lefebvre, Valerie; Caboche, Josselin; Marchal, Paul; Loots, Christophe. |
| ish assemblages vary through time in both abundance and diversity, often due to changes in climate. The potential consequences of these changes on the larval phase need to be considered. In the Eastern English Channel, fish larvae of 30 taxa, from surveys conducted during spring in the nineties and in 2017 with bongo nets, were used to investigate seasonal and interannual changes in larval assemblages with different statistical tests and multivariate analyses (Outlying Mean Index, Principal Coordinate Analysis and variance partitioning). The major change observed was significant lower abundances in 2017 (in April and May) compared to the nineties. Most of the dominant taxa were two to three-fold less abundant in 2017 than the 1990s. We suggest that the... |
| Tipo: Text |
Palavras-chave: Fish larvae; Temporal variations; Atlantic Multidecadal Oscillation; Outlying Mean Index; Variance partitioning; English Channel. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00604/71631/70078.pdf |
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| Timmerman, Charles-andre; Marchal, Paul; Denamiel, Margaux; Couvreur, Clemence; Cresson, Pierre. |
| An accurate description of trophic interactions is crucial to understand ecosystem functioning and sustainably manage marine ecosystems exploitation. Carbon and nitrogen stable isotopes were coupled with stomach content analyses to investigate whiting (Merlangius merlangus, Linnaeus, 1758) feeding behavior in the Eastern English Channel and Southern North Sea. Whiting juveniles and adults were sampled in autumn and winter to investigate both ontogenetic and seasonal changes. In addition, queen scallops (Aequipecten opercularis) samples were collected along with fish to be used as isotopic benthic baseline. Results indicated an ontogenetic diet change from crustaceans to fish and cephalopods. In autumn, δ15N values generally increased with fish size while... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00651/76359/77350.pdf |
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| Queiros, Ana M.; Huebert, Klaus B.; Keyl, Friedemann; Fernandes, Jose A.; Stolte, Willem; Maar, Marie; Kay, Susan; Jones, Miranda C.; Hamon, Katell; Hendriksen, Gerrit; Vermard, Youen; Marchal, Paul; Teal, Lorna R.; Somerfield, Paul J.; Austen, Melanie C.; Barange, Manuel; Sell, Anne F.; Allen, Icarus; Peck, Myron A.. |
| The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate change, creating the space for solutions for conservation of the ocean addressing two of its largest threats: climate change and ocean acidification (CCOA). Recent arguments that ocean policies disregard a mature conservation research field and that protected areas cannot address climate change may be oversimplistic at this time when dynamic solutions for the management of changing oceans are needed. We propose a novel approach, based on spatial meta-analysis of climate impact models, to improve the positioning of marine protected areas to limit CCOA impacts. We do this by estimating the vulnerability of ocean ecosystems to CCOA in a spatially explicit manner and... |
| Tipo: Text |
Palavras-chave: Climate change; Conservation; COP21; Ecosystem model; Habitat; Marine spatial planning; Ocean; Ocean acidification; Species distribution; Warming. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00360/47089/48566.pdf |
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| Large, Philip A.; Agnew, David J.; Alvarez Perez, Jose Angel; Barrio Frojan, Christopher; Cloete, Rudi; Damalas, Dimitrios; Dransfeld, Leonie; Edwards, Charles T. T.; Feist, Stephen; Figueiredo, Ivone; Gonzalez, Fernando; Gil Herrera, Juan; Kenny, Andrew; Jakobsdottir, Klara; Longshaw, Matt; Lorance, Pascal; Marchal, Paul; Mytilineou, Chryssi; Planque, Benjamin; Politou, Chrissi-yianna. |
| Scientific interest in deep-water marine resources has increased dramatically over the last 10-20 years as management bodies have sought advice on how to manage deep-water fisheries and protect deep-water ecosystems. The strengths and weaknesses of the management and monitoring of deep-water stocks, fisheries, and ecosystems in various areas of the world are described, with the objective of informing the EU FP7 DEEPFISHMAN project so that it can fulfill its primary aim, which is to develop strategic options for a short-and long-term management and monitoring ecosystem-based framework for the northeast Atlantic. To provide a baseline, the current monitoring and management regime in the northeast Atlantic is reviewed, followed by a brief description of the... |
| Tipo: Text |
Palavras-chave: Deep-water; Fisheries; Ecosystem; Monitoring; Management. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00142/25321/24803.pdf |
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| Gasche, Loic; Mahevas, Stephanie; Marchal, Paul. |
| Ecosystems are usually complex, nonlinear and strongly influenced by poorly known environmental variables. Among these systems, marine ecosystems have high uncertainties: marine populations in general are known to exhibit large levels of natural variability and the intensity of fishing efforts can change rapidly. These uncertainties are a source of risks that threaten the sustainability of both fish populations and fishing fleets targeting them. Appropriate management measures have to be found in order to reduce these risks and decrease sensitivity to uncertainties. Methods have been developed within decision theory that aim at allowing decision making under severe uncertainty. One of these methods is the information-gap decision theory. The info-gap... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00166/27746/25947.pdf |
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| Eigaard, Ole Ritzau; Marchal, Paul; Gislason, Henrik; Rijnsdorp, Adriaan D.. |
| Many marine fish stocks are overexploited and considerable overcapacity exists in fishing fleets worldwide. One of the reasons for the imbalance between resource availability and fishing capacity is technological development, which continuously increases the efficiency of the vessels—a mechanism referred to as “technological creep.” We review how the introduction of new and more efficient electronic equipment, gear design, engines, deck equipment, and catch-handling procedures influences the capture efficiency (catchability) of commercial fishing vessels. On average, we estimate that catchability increases by 3.2% per year due to technological developments, an increase often ignored in fisheries management. The documentation and quantification of... |
| Tipo: Text |
Palavras-chave: Catchability; Fishing mortality; Fishing power; Fisheries management; Fleet capacity; Technological development. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00222/33368/35784.pdf |
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| Le Floc'H, Pascal; Murillas, Arantza; Aranda, Martin; Daures, Fabienne; Fitzpatrick, Mike; Guyader, Olivier; Hatcher, Aaron; Macher, Claire; Marchal, Paul. |
| A survey of past and existing management measures applied to different fisheries in European Western Waters is analyzed as a typology of co-management between governments and stakeholders. Faced with increasing constraints on accessing fish stocks, management measures have evolved toward fishing rights individualization, limited access and various other specific measures. Restrictions on access have changed fishermen’s behaviour in several significant ways. A comparative analysis, based on qualitative data collected through interviews and focus groups, is developed for fisheries from the following European countries: France, Ireland, Spain and the United Kingdom. Past and existing individual harvesting rights in the four countries are reviewed and compared. |
| Tipo: Text |
Palavras-chave: Management; Fishery governance; Common Fishery Policy (CFP). |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00248/35912/34455.pdf |
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| Registros recuperados: 64 | |
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