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| Registros recuperados: 58 | |
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| Reecht, Yves; Gasche, Loïc; Lehuta, Sigrid; Vaz, Sandrine; Smith, Robert J; Mahevas, Stephanie; Marchal, Paul. |
| In the past decade, systematic conservation planning tools have been increasingly and successfully used to set spatial conservation plans that meet quantitative protection targets while minimizing enforcement and socioeconomic costs. However, when applied to fisheries, systematic conservation planning fails to account for (1) changes in fleet dynamics induced by new conservation constraints and their associated feedbacks on conservation costs or (2) their influence on fish population dynamics and distributions, which may in turn alter the achievement of conservation targets. Such a static approach may therefore lead to short- or medium-term misestimates in forecasted costs and target achievements. In order to circumvent such limitations of systematic... |
| Tipo: Text |
Palavras-chave: MPAs; Systematic conservation planning; Mixed fisheries dynamics; Model coupling; Eastern English Channel; Marxan with Zones; ISIS-Fish. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00293/40421/39077.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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| Amelot, Morgane; Bastleer, Jurgen; Foucher, Eric; Girardin, Raphael; Marchal, Paul; Poos, Jan Jaap; Sys, Klaas. |
| Rajidae stocks (Raja clavata, Raja brachyura, Raja montagui, Raja microocellata, Leucoraja naevus and Raja undulata) in the English Channel and North Sea (ICES divisions 3a, 4 and 7d) are actually managed as a complex (“skates and rays”) and subject to a single TAC. TAC advices from the ICES are based on scientific survey indices trends from each species. Rajidae catches are mainly bycatch from flatfish fisheries such are sole (Solea solea) and plaice (Pleuronectes platessa) fisheries. Furthermore, because of their top predator position as well as their life history, Rajidae are species sensitive to overfishing. These different factors have led to a revision in stock assessment methods. ICES classified Rajidae as category 3 data limited stocks. The lack of... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00620/73220/72433.pdf |
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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... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00223/33377/31802.pdf |
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| Janssen, Holger; Bastardie, Francois; Eero, Margit; Hamon, Katell; Hinrichsen, Hans-harald; Marchal, Paul; Nielsen, J. Rasmus; Le Pape, Olivier; Schulze, Torsten; Simons, Sarah; Teal, Lorna R.; Tidd, Alex. |
| The relationship between fisheries and marine spatial planning (MSP) is still widely unsettled. While several scientific studies highlight the strong relation between fisheries and MSP, as well as ways in which fisheries could be included in MSP, the actual integration of fisheries into MSP often fails. In this article, we review the state of the art and latest progress in research on various challenges in the integration of fisheries into MSP. The reviewed studies address a wide range of integration challenges, starting with techniques to analyse where fishermen actually fish, assessing the drivers for fishermen's behaviour, seasonal dynamics and long-term spatial changes of commercial fish species under various anthropogenic pressures along their... |
| Tipo: Text |
Palavras-chave: Fisheries; Marine space; Maritime spatial planning; MSP; Marine governance; EBM. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00364/47480/47500.pdf |
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| Bourdaud, Pierre; Travers-trolet, Morgane; Vermard, Youen; Marchal, Paul. |
| Managing mixed fisheries requires understanding fishers’ behaviour to allow predicting future fisheries distribution and impact on marine ecosystems. A new approach was developed to compare fine scale fishing effort distribution of Eastern English Channel (EEC) bottom trawlers, to the monthly- and spatially-resolved abundance distributions of commercial species. First, the added-value of using species-specific spatial overlap metric to quantify effective fishing effort and improve the relationship between fishing effort and fishing mortality was assessed. Second, based on the Ideal Free Distribution (IFD) theory, the species-specific weights given by fishers to different species were estimated by maximizing the overlap between target species assemblage and... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00446/55747/57402.pdf |
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| Girardin, Raphael; Fulton, Elizabeth A.; Lehuta, Sigrid; Rolland, Marie; Thebaud, Olivier; Travers-trolet, Morgane; Vermard, Youen; Marchal, Paul. |
| The ecosystem model Atlantis was used to investigate the key dynamics and processes that structure the Eastern English Channel ecosystem, with a particular focus on two commercial flatfish species, sole (Solea solea) and plaice (Pleuronectes platessa). This complex model was parameterized with data collected from diverse sources (a literature review, survey data, as well as landings and stock assessment information) and tuned so both simulated biomass and catch fit 2002–2011 observations. Here, the outputs are mainly presented for the two focus species and for some other vertebrates found to be important in the trophic network. The calibration process revealed the importance of coastal areas in the Eastern English Channel and of nutrient inputs from... |
| Tipo: Text |
Palavras-chave: Ecosystem modelling; Flatfish fisheries; Trophic relationships; Calibration; Atlantis; Eastern English Channel. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00354/46524/46289.pdf |
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| Holley, Jean-francois; Marchal, Paul. |
| A typology is presented for the French offshore fleet fishing in the North Atlantic. The investigation was carried out separately for all years between 1985 and 2002. Two methods were combined: PCA and cluster analysis. In 1985, most vessels targeted saithe off western Scotland (vessels from Lorient) and in the northern North Sea (vessels from Boulogne and Fecamp). Then, probably because of the decline in biomass of saithe, some vessels started to target deepwater species from the early 1990s. In 2002, some vessels fished exclusively for saithe (>80%), while others targeted mainly deepwater species. In all, 12 fisheries are identified for the period 1985-2002. Results are given of a preliminary investigation trying to identify the external factors... |
| Tipo: Text |
Palavras-chave: Saithe; Multivariate analyses; Mixed fisheries; Fishing strategy; Fisheries dynamics; Deepwater species. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-384.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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| Denis, Jeremy; Vallet, Carole; Vincent, Dorothée; Courcot, Lucie; Marchal, Paul; Loots, Christophe. |
| The aim of this study was to characterize the feeding strategy of Downs herring larvae at "critical period" during winter in the English Channel and North Sea was defined to assess whether nutrition is responsible for low recruitment in stocks over the past years. Data collected during the French part of the International Bottom Trawl Survey from 2008 to 2014 were used to analyse fish larvae diet by direct observation using Scanning Electron Microscope (SEM). Gut content methods generally used for copepods was adapted to fish larvae to assess phytoplankton ingestion. The relative importance of small preys (0,5-375µm) observed in gut contents proved the essential role of SEM to better acknowledge Downs herring diet. We demonstrated that Downs herring larvae... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00255/36608/35174.pdf |
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| Vermard, Youen; Rivot, Etienne; Mahevas, Stephanie; Marchal, Paul; Gascuel, Didier. |
| Recent advances in technologies have lead to a vast influx of data on movements, based on discrete recorded position of animals or fishing boats, opening new horizons for future analyses. However, most of the potential interest of tracking data depends on the ability to develop suitable modelling strategies to analyze trajectories from discrete recorded positions. A serious modelling challenge is to infer the evolution of the true position and the associated spatio-temporal distribution of behavioural states using discrete, error-prone and incomplete observations. In this paper, a Bayesian Hierarchical Model (HBM) using Hidden Markov Process (HMP) is proposed as a template for analyzing fishing boats trajectories based on data available from... |
| Tipo: Text |
Palavras-chave: Bayesian Hierarchical Models; Hidden Markov Model; State-space model; VMS; Fleet behaviour; Fishing effort. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00009/11993/9342.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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| Di Pane, Julien; Gendrot, F.; Giraldo, Carolina; Marchal, Paul; Koubbi, Philippe; Loots, Christophe. |
| In the present study, the histological-based condition of common sole (Solea solea) larvae in the English Channel was evaluated to assess the relevance of experimentally-calibrated indices for wild collected specimens. Based on topographical observation of foregut, midgut, hindgut, liver and pancreas, each of the 202 larvae analysed was attributed one of the six grades of a condition index that was developed for sole in the nineties. In parallel, a synthetic table of 20 criteria historically used as condition indicators was created from an extensive review of the literature. These criteria were related to tissular integrity, cells height, nuclei, presence of prey and vacuolisation of the same five target organs. For each larva, each criterion was scored on... |
| Tipo: Text |
Palavras-chave: Condition index; Eastern English Channel; Fish larvae; Histology; Solea solea; Starvation. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00601/71325/69754.pdf |
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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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| Cormon, Xochitl; Kempf, Alexander; Vermard, Youen; Vinther, Morten; Marchal, Paul. |
| During the last 15 years, northern European hake (Merluccius merluccius) has increased in abundance, and its spatial distribution has expanded in the North Sea region in correlation with temperature. In a context of global warming, this spatial shift could impact local trophic interactions: direct impacts may affect forage fish through modified predator–prey interactions, and indirect impacts may materialize through competition with other resident predators. For instance, North Sea saithe (Pollachius virens) spatial overlap with hake has increased while saithe spawning-stock biomass has decreased recently notwithstanding a sustainable exploitation. In this context, we investigated the range of potential impacts resulting from most recent hake emergence in... |
| Tipo: Text |
Palavras-chave: Hake; Interspecific competition; Maximum sustainable yield; Multispecies stock assessment; Norway pout; Predator-prey interactions; Saithe; Simple foodweb; SMS. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00327/43794/45917.pdf |
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| Marchal, Paul; Gasche, Loic; Girardin, Raphael; Le Pape, Olivier; Huret, Martin; Mahevas, Stephanie; Travers-trolet, Morgane; Vaz, Sandrine. |
| Considerable research has been conducted in the past 15 years around the Eastern English Channel ecosystem. Data collected since the 1970s on the biotic and abiotic compartments have been collated and mapped out in the mid-2000. This spatially explicit information formed a sound basis to improve knowledge on, and model, the functioning and dynamics of key ecosystem compartments, with a focus on flatfish species and fisheries and their interactions with other sectors of activity (aggregate extractions, maritime traffic). The more recent ongoing works are dedicated to the integration of those processes into several complementary end-to-end ecosystem models. |
| Tipo: Text |
Palavras-chave: Eastern English Channel; Flatfish; Spatial analyses; Ecosystem modelling. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00293/40420/38946.pdf |
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| Marchal, Paul; Andersen, B; Bromley, D; Iriondo, A; Mahevas, Stephanie; Quirijns, F; Rackham, B; Santurtun, M; Tien, N; Ulrich, Clara. |
| The scope of this paper is to quantify, for a wide selection of European fisheries, fishing tactics and strategies and to evaluate the benefits of adjusting the definition of. fishing effort using these elements. Fishing tactics and strategies were identified by metiers choices and a series of indices. These indices have been derived to reflect shifts in tactics (within a fishing trip) and in strategies (within a year). The Shannon-Wiener spatial diversity indices of fishing tactics (FT_SW) and strategies (YE_SW) had the greatest impact on catch rates. In particular, FT_SW was always negatively correlated to catch rates. One may anticipate that during a fishing trip, vessels with high FT_SW have been searching fish aggregations for a long time, while... |
| Tipo: Text |
Palavras-chave: Fishing effort; Fishing mortality; Catch rates; GLM modeling; Skipper effect. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/2006/publication-1339.pdf |
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| Registros recuperados: 58 | |
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