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Registros recuperados: 14 | |
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Pethybridge, Heidi; Weijerman, Mariska; Perrymann, Holly; Audzijonyte, Asta; Porobic, Javier; Mcgregor, Vidette; Girardin, Raphael; Bulman, Cathy; Ortega-cisneros, Kelly; Sinerchia, Matteo; Hutton, Trevor; Lozano-montes, Hector; Mori, Mao; Novaglio, Camilla; Fay, Gavin; Gorton, Rebecca; Fulton, Elizabeth. |
Calibration of complex, process-based ecosystem models is a timely task with modellers challenged by many parameters, multiple outputs of interest and often a scarcity of empirical data. Incorrect calibration can lead to unrealistic ecological and socio-economic predictions with the modeller’s experience and available knowledge of the modelled system largely determining the success of model calibration. Here we provide an overview of best practices when calibrating an Atlantis marine ecosystem model, a widely adopted framework that includes the parameters and processes comprised in many different ecosystem models. We highlight the importance of understanding the model structure and data sources of the modelled system. We then focus on several model outputs... |
Tipo: Text |
Palavras-chave: Best practices; Model diagnostics; Food web; Pedigree; Parameter estimation. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00516/62723/67160.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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Amelot, Morgane; Batsleer, Jurgen; Foucher, Eric; Girardin, Raphael; Marchal, Paul; Poos, Jan Jaap; Sys, Klaas. |
Six Rajidae stocks (Raja clavata, Raja brachyura, Raja montagui, Raja microocellata, Leucoraja naevus and Raja undulata) are currently exploited in the English Channel and North Sea area (ICES divisions 3a, 4 and 7d) and subject to a TAC regulation. This TAC is set based on monospecific approaches (abundance indices) when mangement is complex based. However, stock status disparities exist between these species. In this context a multispecific MSE (Management Strategy evaluation) framework has been developped based on DLMTool package from R. The main objective was to estimate the complex management impact at the different steps of stocks management (data collect, assessment, management measures implementation). The species species assessement and ... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76423/77495.pdf |
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Kaplan, Isaac C.; Hansen, Cecilie; Morzaria-luna, Hem Nalini; Girardin, Raphael; Marshall, Kristin N.. |
Management strategy evaluation (MSE) provides a simulation framework to test the performance of living marine resource management. MSE has now been adopted broadly for use in single-species fishery management, often using a relatively simple “operating model” that projects population dynamics of one species forward in time. However, many challenges in ecosystem-based management involve tradeoffs between multiple species and interactions of multiple stressors. Here we use complex operating models, multi-species ecosystem models of the California Current and Nordic and Barents Seas, to test threshold harvest control rules that explicitly address the linkage between predators and prey, and between the forage needs of predators and fisheries. Specifically,... |
Tipo: Text |
Palavras-chave: Harvest control rules; California Current; Nordic and Barents Seas; Pacific hake; Atlantic mackerel; Management strategy evaluation. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00645/75702/76609.pdf |
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Piroddi, Chiara; Akoglu, Ekin; Andonegi, Eider; Bentley, Jacob W.; Celić, Igor; Coll, Marta; Dimarchopoulou, Donna; Friedland, René; De Mutsert, Kim; Girardin, Raphael; Garcia-gorriz, Elisa; Grizzetti, Bruna; Hernvann, P.-y.; Heymans, Johanna J.; Müller-karulis, Bärbel; Libralato, Simone; Lynam, Christopher P.; Macias, Diego; Miladinova, Svetla; Moullec, Fabien; Palialexis, Andreas; Parn, Ove; Serpetti, Natalia; Solidoro, Cosimo; Steenbeek, Jeroen; Stips, Adolf; Tomczak, Maciej T.; Travers-trolet, Morgane; Tsikliras, Athanassios C.. |
Eutrophication is one of the most important anthropogenic pressures impacting coastal seas. In Europe, several legislations and management measures have been implemented to halt nutrient overloading in marine ecosystems. This study evaluates the impact of freshwater nutrient control measures on higher trophic levels (HTL) in European marine ecosystems following descriptors and criteria as defined by the Marine Strategy Framework Directive (MSFD). We used a novel pan-European marine modeling ensemble of fourteen HTL models, covering almost all the EU seas, under two nutrient management scenarios. Results from our projections suggest that the proposed nutrient reduction measures may not have a significant impact on the structure and function of European... |
Tipo: Text |
Palavras-chave: Ecological modeling; Hydrological modeling; Hydrodynamic and biogeochemical modeling; Higher trophic level modeling; Ecological indicators; Criteria; Policy support. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00685/79746/82520.pdf |
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Vigneau, Joel; Girardin, Raphael. |
During the flatfish benchmark held in ICES in 2020 (WKFlatNSCS), questions arose on the modifications made recently on two key fields of fisheries data processed by France for providing data to stock assessment groups. These two fields are: • the gap filling method in Age Length Keys • the effort aggregates in support of discards raising procedure Updates of procedures, improvements of R scripts and coding are done permanently, and some of the modifications made in 2019 at the demand of WGNSSK experts had unraveled issues that went undetected until data submission of sol.27.7d full time series for WKFlatNSCS benchmark. These issues may have also impacted the Celtic Sea benchmark (WKCELTIC) and to a lesser extent the WKDEM earlier in the year. The document... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72482/71448.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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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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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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Olsen, Erik; Kaplan, Isaac C.; Ainsworth, Cameron; Fay, Gavin; Gaichas, Sarah; Gamble, Robert; Girardin, Raphael; Eide, Cecilie H.; Ihde, Thomas F.; Morzaria-luna, Hem Nalini; Johnson, Kelli F.; Savina-rolland, Marie; Townsend, Howard; Weijerman, Mariska; Fulton, Elizabeth A.; Link, Jason S.. |
Ecosystem-based management (EBM) of the ocean considers all impacts on and uses of marine and coastal systems. In recent years, there has been a heightened interest in EBM tools that allow testing of alternative management options and help identify tradeoffs among human uses. End-to-end ecosystem modeling frameworks that consider a wide range of management options are a means to provide integrated solutions to the complex ocean management problems encountered in EBM. Here, we leverage the global advances in ecosystem modeling to explore common opportunities and challenges for ecosystem-based management, including changes in ocean acidification, spatial management, and fishing pressure across eight Atlantis (atlantis.cmar.csiro.au) end-to-end ecosystem... |
Tipo: Text |
Palavras-chave: Ecosystem-based management; Fisheries management; Ocean acidification; Marine protected areas; Atlantis ecosystem model. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/53948/55094.pdf |
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Depestele, Jochen; Feekings, Jordan; Reid, David G; Cook, Robin; Gascuel, Didier; Girardin, Raphael; Heath, Michael; Hernvann, Pierre-yves; Morato, Telmo; Soszynski, Ambre; Savina-rolland, Marie. |
A scavenger is an animal that feeds on dead animals (carrion) that it has not killed itself. Fisheries discards are often seen as an important food source for marine scavengers so the reduction of discards due to the Landing Obligation may affect their populations. The literature on scavenging in marine ecosystems is considerable, due to its importance in the trophic ecology of many species. Although discards undoubtedly contribute to these species’ food sources, few can be seen to be solely dependent on carrion (including discards). Ecosystem models predicted that discards contributed very little to the diet of scavengers at a regional scale. A reduction in discards through the Landing Obligation may therefore affect populations for a few species in some... |
Tipo: Text |
Palavras-chave: Carrion; Discard consumption; Food subsidies; Food web models; Scavengers. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00473/58436/61011.pdf |
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Girardin, Raphael; Hamon, Katell; Pinnegar, John; Poos, Jan Jaap; Thebaud, Olivier; Tidd, Alex; Vermard, Youen; Marchal, Paul. |
Anticipating fisher behaviour is necessary for successful fisheries management. Of the different concepts that have been developed to understand individual fisher behaviour, random utility models (RUMs) have attracted considerable attention in the past three decades, and more particularly so since the 2000s. This study aimed at summarizing and analysing the information gathered from RUMs used during the last three decades around the globe. A methodology has been developed to standardize information across different studies and compare RUM results. The studies selected focused on fishing effort allocation. Six types of fisher behaviour drivers were considered: the presence of other vessels in the same fishing area, tradition, expected revenue, species... |
Tipo: Text |
Palavras-chave: Fisher behaviour; Meta-analysis; Random utility model. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00357/46834/47127.pdf |
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Registros recuperados: 14 | |
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