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| Registros recuperados: 17 | |
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| Huret, Martin; Petitgas, Pierre; Bourriau, Paul; Grellier, Patrick. |
| The objective of the study is a better understanding of recruitment variability in anchovy population. An Individual Based Model (IBM) is being developed for the full life cycle of anchovy. The early life stages are presented on this poster. The model is tested in a 1D-vertical framework for validation of the vertical distribution of modelled eggs and larvae against in-situ data. The dynamic Energy Budget (DEB) theory is the biological baseline for individual growth. We test its ability to simulate the observed growth curves between years with contrasted temperatures. |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00054/16508/14022.pdf |
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| Gatti, Paul; Cominassi, Louise; Duhamel, Erwan; Grellier, Patrick; Le Delliou, Herve; Le Mestre, Sophie; Petitgas, Pierre; Rabiller, Manuella; Spitz, Jerome; Huret, Martin. |
| There is a growing interest in monitoring body condition of marine organisms in the context of the ecosystem approach to fisheries and global change. Fish condition is under the influence of environmental variability on seasonal scale, but also on longer timescales. It represents a good indicator of habitat quality or individual fitness, and is also a relevant parameter to evaluate energy transfer through the trophic chain. However, the sources of variability in fish condition need to be accurately understood and the significance of existing indices has to be correctly assessed. Here, we measured the energy density, a precise and global indicator of fish bioenergetic condition, for anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) in the... |
| Tipo: Text |
Palavras-chave: Energy density; Calorimetry; Small pelagic fish; Engraulis encrasicolus; Sardina pilchardus; Northeast Atlantic. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52754/53615.pdf |
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| Grellier, Patrick. |
| The downstream part of the Loire river is divided into three regulation zones (marine, fluvial and mixed zones) where a traditional fishery for sea lamprey is practised. More than one hundred professional fishermen (either marine or fluvial statute) are interested in this activity during winter and spring to catch lampreys on their trip to the up stream spawning areas. The fluvial contraints (fluvial discharge, tidal current etc...) generate two types of exploitation : the osier trap and the trammel net. For both studied years 1988 and 1989, total catches are estimated to 37,9 T (88) and 50,2 T (89), indicating the economical value of this fishery, amounting for 2,6 MF (88) and 3,3 MF (89). This species is dedicated to the market of the Aquitaine region... |
| Tipo: Text |
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| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00085/19617/17257.pdf |
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| Doray, Mathieu; Petitgas, Pierre; Romagnan, Jean-baptiste; Huret, Martin; Duhamel, Erwan; Dupuy, Christine; Spitz, Jérôme; Berger, Laurent; Dorémus, Ghislain; Bourriau, Paul; Grellier, Patrick; Massé, Jacques; Sanchez, Florence. |
| The initial objective of the PELGAS integrated survey was to assess the biomass of small pelagic fish in the Bay of Biscay in spring. Sampling has been extended to study the spatial structure and dynamics of the pelagic ecosystem in springtime. The PELGAS survey has produced since 2000 long-term time-series of spatially-explicit data and indices, describing the main pelagic ecosystem components: hydrology, phytoplankton, mesozooplankton, fish and megafauna. In addition to small pelagic fish biomass estimates used for fish stock assessment, the survey now delivers two types of ecosystem products: standard gridded maps of ecosystem parameters, and a time series dataset of indicators of the Bay of Biscay pelagic ecosystem state. The evolution of the PELGAS... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00457/56844/58693.pdf |
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| Doray, Mathieu; Petitgas, Pierre; Romagnan, Jean-baptiste; Huret, Martin; Duhamel, Erwan; Dupuy, Christine; Spitz, Jérôme; Authier, Matthieu; Berger, Laurent; Doremus, Ghislain; Bourriau, Paul; Grellier, Patrick; Masse, Jacques; Sanchez, Florence. |
| The initial focus of the PELGAS integrated survey was to assess the small pelagic fish biomass in the Bay of Biscay in springtime, for fisheries management purposes. Sampling has been extended to produce long-term time-series of spatially-explicit data and indices, describing the main pelagic ecosystem components: hydrology, phytoplankton, mesozooplankton, fish and megafauna. A collaborative analysis of these datasets has brought new insights on the Bay of Biscay pelagic ecosystem summarized here. New results on single ecosystem components include an analysis of water samples to groundtruth the results of an ocean color algorithm aiming at detecting phytoplanktonic coccolithophores. New insights on mesozooplankton spatio-temporal distribution and energy... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00445/55665/57331.pdf |
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| Petitgas, Pierre; Grellier, Patrick; Leseur, Floriane; Lenfant, Philippe. |
| Diversity among individuals in a population is an important feature linking vital rates with behaviour and spatial occupation. We measured the growth increments in the otolith of individual fishes collected on the annual fisheries survey PELGAS from 2001 to 2015. Individuals who grew larger at juvenile stage occupied later in life more off-shore habitats. Further, we analysed the allozymes of 13 different loci from 2001 to 2006. Alleles of the enzyme IDH showed different frequencies in inshore and offshore habitats. The population spatially segregates along a coast to off-shore gradient with individuals showing different early growth and allele frequencies. Results show how individuals in a population segregate spatially in different habitats in relation... |
| Tipo: Text |
Palavras-chave: Allozymes; Otoliths; Habitats; Spatial distribution; Anchovy. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00353/46379/46001.pdf |
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| Grellier, Patrick. |
| Vertebrate Cyclostome, the european sea lamprey is a sea spawning migrator amphihaline species, which is a parasite during its growing phase at sea. After the spawning migration, lampreys couple in the upper reach of water courses, they lay their eggs, then die from physiological misery. The eggs develop sheltered into a nest until hatching of small larvae, the ammocoetes. Morphologically very different from the adults, the ammocoetes spend a several years sedentary life, being burried into the sediment. Then, they metamorphose into young lampreys which undertake their downstream migration. As soon as they enter sea water, they continue growing at the expense of several species of fishes. |
| Tipo: Text |
Palavras-chave: Morphologie; Cycle Biologique; Migrations; Reproduction. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00085/19616/17256.pdf |
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| Guerault, Daniel; Desaunay, Yves; Bellois, Pierre; Grellier, Patrick; Robin, Jean-paul; Robineau, Brigitte. |
| A survey of the glass-eel fishery in the Loire estuary in 1987 (265 boats, 117 tons gasseel, 13733 fishing trips) showed that 16 fishery species constitute the by-catch (49,3 million individuals, mainly juveniles, among which 98 % consist in flounder, sprat and brown shrimp). The analysis of catches in space and time leads to proposaIs for Iimiting the impact during the last fishing weeks. Taking into account the naturai mortality rates of the concerned juveniles, an attempt is made to estimate the actuai impact of the glasseel fishery, after a delay. Only 10 % of the caught brown shrimps wouid have been recruited in the summer shrimp fishery. Up to 85,5 to 97,6 % of juvenile fishes would have disappeared during the following year by natural mortality. |
| Tipo: Text |
Palavras-chave: Anguille; Pêcherie; Prises accessoires; Estuaire; Loire; Eel; Fishery; By catch; Estuary; Loire. |
| Ano: 1989 |
URL: http://archimer.ifremer.fr/doc/00120/23102/20951.pdf |
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| Petitgas, Pierre; Doray, Mathieu; Masse, Jacques; Grellier, Patrick. |
| Fish length frequency histograms from research surveys are of prime importance for identifying habitats of different life stages, as well as for stock assessment. However, no method has thus far been available for mapping these histograms as spatially varying curves. Here, a procedure is applied to map spatially connected curves, and detail is given on how it can be applied to map the length frequency histograms. At each sample location, a fish length frequency histogram is given as a vector of non-independent values. The histogram is first modelled as a polynomial expansion on the basis of orthogonal polynomials. Then, the polynomial coefficients are mapped by co-kriging, after fitting a model of co-regionalization. The length frequency map is finally... |
| Tipo: Text |
Palavras-chave: Co-kriging; European anchovy; Fish length; Functional kriging; Habitat; Mapping curves. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00049/16042/13581.pdf |
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| Mahe, Kelig; Bellail, Robert; Dufour, Jean-louis; Boiron-leroy, Anne; Dimeet, Joel; Duhamel, Erwan; Elleboode, Romain; Felix, Jerome; Grellier, Patrick; Huet, Jerome; Labastie, Jacques; Le Roy, Didier; Lizaud, Oceann; Manten, Marie-line; Martin, Stephane; Metral, Luisa; Nedelec, Daniel; Verin, Yves; Badts, Vincent. |
| This document presents all the techniques used in routine by Ifremer to estimate the age of fish from the calcified piece. The procedure for estimating age describes each technical stage from the taking of the calcified piece through to the supplying of key sizes/ages to the European work groups. This procedure is specific to each species and even each population of fish. |
| Tipo: Text |
Palavras-chave: Poisson; TNPC; Préparation; Procédure; Age; Ecaille; Illicium; Otolithe; Sclérochronologie; Fish; TNPC; Preparation; Procedure; Age; Scale; Illicium; Otolith; Sclerochronology. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/7294/rapport-7294.pdf |
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| Doray, Mathieu; Petitgas, Pierre; Romagnan, Jean-baptiste; Huret, Martin; Duhamel, Erwan; Dupuy, Christine; Spitz, Jerome; Authier, Matthieu; Sanchez, Florence; Berger, Laurent; Doremus, Ghislain; Bourriau, Paul; Grellier, Patrick; Masse, Jacques. |
| The Pélagiques Gascogne (PELGAS) integrated survey has been developed by a multidisciplinary team of Ifremer and La Rochelle University scientists since 2000, joined by commercial fishermen in 2007. Its initial focus was to assess the biomass and predict the recruitment success of anchovy in the Bay of Biscay in spring. Taking advantage of the space and versatility of R/V Thalassa II, sampling has been progressively extended to other ecosystem components. PELGAS therefore further developed the second objective of monitoring and studying the dynamic and diverse Biscay pelagic ecosystem in springtime. The PELGAS survey model has allowed for the establishment of a long-term time-series of spatially-explicit data of the Bay of Biscay pelagic ecosystem since... |
| Tipo: Text |
Palavras-chave: Pelagic ecosystem; Integrated ecosystem monitoring survey; Marine Strategy Framework Directive; Ecosystem variability; Bay of Biscay; Fishing vessels. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00407/51801/52401.pdf |
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| Petitgas, Pierre; Grellier, Patrick; Duhamel, Erwan; Masse, Jacques; Doray, Mathieu. |
| Individual fish growth depends on internal population factors such as phenotypic variability as well as external factors such as past environmental conditions (temperature, food) and selective mortality (predation or fishing). In the anchovy, growth in the first year is key to population dynamics as it determines the potential energy allocated to reproduction as well as the capacity to occupy off-shore habitats. Further, in the recent past, the anchovy in the bay of Biscay has experienced collapse and recovery and the role played by growth in this history is unknown. Since 2001 with the spring acoustic survey series PelGas, we have monitored individual fish growth by measuring in the otolith the increments between annual rings, in addition to age... |
| Tipo: Text |
Palavras-chave: Anchovy; Biscay; Otoliths; Growth; Metapopulation. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00114/22550/20236.pdf |
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| Registros recuperados: 17 | |
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