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| Registros recuperados: 50 | |
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| Woillez, Mathieu; Fablet, Ronan; Tran-thanh Ngo,; Lalire, Maxime; Lazure, Pascal; De Pontual, Helene. |
| Numerous methods have been developed to geolocate fish from data storage tags. Whereas demersal species have been tracked using tide-driven geolocation models, pelagic species which undertake extensive migrations have been mainly tracked using light-based models. Here, we present a new HMM-based model that infers pelagic fish positions from the sole use of high-resolution temperature and depth histories. A key contribution of our framework lies in model parameter inference (diffusion coefficient and noise parameters with respect to the reference geophysical fields—satellite SST and temperatures derived from the MARS3D hydrodynamic model), which improves model robustness. As a case study, we consider long time series of data storage tags (DSTs) deployed on... |
| Tipo: Text |
Palavras-chave: Fish movement; Archival tagging; Migration; Population structure; Hidden Markov Model (HMM); State-space model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00300/41097/40270.pdf |
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| Carbini, Sebastien; Chessel, Anatole; Benzinou, Abdesslam; Fablet, Ronan; Mahe, Kelig; De Pontual, Helene. |
| Most of European fish stocks are assessed using age-based models, and otolith interpretation for age estimations costs several million euros annually. In this context, automated ageing systems would provide a mean to 1) standardize ageing, 2) control ageing consistency within and between ageing laboratories 3) build interpreted image data bases ensuring the information conservation and sharing and 4) improve growth studies while reducing the cost of the acquisition of age data. This paper presents a review of different image-based tools for automatic fish ageing from otolith features within the framework of AFISA (EU STREP project on Automated FISh Ageing coordinated by Ifremer). The full automatic ageing process can be divided into three main steps: 1)... |
| Tipo: Text |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00024/13519/10546.pdf |
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| Le Goff, Ronan; Drogou, Mickael; De Pontual, Helene; Talidec, Catherine; Berthou, Patrick; Biseau, Alain. |
| Une réunion technique a été organisée le 21 mai 2013 par la Commission européenne afin de faire le point sur l’état du stock de bar commun (Dicentrarchus labrax) dans les eaux européennes de l’Atlantique du Nord Est. Cette réunion a conclu que le stock de bar peut être considéré comme dans un état « alarmant », et la Commission a demandé aux Etats membres d’identifier les mesures de gestion qu’ils seraient à même de mettre en place dans les meilleurs délais pour obtenir une diminution des captures de 20%. C’est dans ce contexte que la DPMA a adressé à l’Ifremer la présente saisine, en attendant plus particulièrement de l’Institut : - de lister les mesures concrètes applicables aux pêcheries françaises et permettant de réduire les captures et donc la... |
| Tipo: Text |
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| Ano: 2013 |
URL: https://archimer.ifremer.fr/doc/00165/27657/25827.pdf |
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| Mahe, Kelig; Parisi, Vincenc; Carbini, Sebastien; Soria, J.a.; Harbitz, A; De Pontual, Helene; Cotano, U; Songer, S; Millner, R; Lewy, P; Gudmundsson, E.f; Fablet, Ronan; Benzinou, Abdesslam. |
| Most of the fish stocks are assessed using age-based models, however age estimations using otoliths costs several million euros annually. In this context, Automatic Fish Ageing (EU Project) would provide means to standardize ageing among laboratories and build interpreted image databases ensuring the information conservation. Automation improves growth studies while reducing the cost of the acquisition of age data. The whole processing chain from the acquisition of otolith data to the actual ageing issue using pattern recognition or statistical inference has been realised for three case studies : a) Cod (Gadus morhua ; Faeroes, North Sea, North East Arctic) b) Anchovy (Engraulis encrasicolus ; Bay of Biscay) c) Plaice (Pleuronectes platessa, Eastern... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00011/12270/10548.pdf |
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| Dambrine, Chloe; Woillez, Mathieu; Huret, Martin; De Pontual, Helene. |
| Fish habitats sustain essential functions for fish to complete their life cycle, such as feeding, growing and spawning. Conservation is crucial to maintain fish populations and their exploitation. Since 2013, the spawning stock biomass of the northern stock of European seabass (Dicentrarchus labrax) has been in a worrying state. A series of low recruitments with a persistently high level of fishing has been blamed, raising concerns about the processes involved in seabass reproduction and settlement in nurseries. Here, we characterise seabass spawning areas along the French Atlantic coast using vessel monitoring system (VMS) data. A non‐linear geostatistical approach was applied, from 2008 to 2014, to detect locations where seabass aggregate for spawning.... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Bayesian spatio‐temporal modelling; Dicentrarchus labrax; English Channel; European sea bass; Non‐linear geostatistics; Spawning grounds. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00668/77997/80218.pdf |
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| Durieux, Eric D. H.; Labonne, Maylis; Begout, Marie-laure; De Pontual, Helene. |
| The common sole Solea solea (L.) is a commercially important and widely distributed flatfish of the North-East Atlantic. For the Bay of Biscay stock, sole nurseries display differences in terms of quantity and quality. In fine the measure of the quality of a habitat for juveniles of a particular species is expressed by the contribution to the recruitment into the adult population. Understanding this connectivity between juvenile and adult habitats, i.e. evaluating the contribution of each nursery to a single adult stock appears essential in terms of stock management. However, this critical link is still missing for the Bay of Biscay sole stock. Determining if nurseries could be discriminated using otolith elemental composition analysis constitutes the... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00073/18377/15949.pdf |
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| Bertignac, Michel; De Pontual, Helene. |
| The results of a pilot tagging study on hake (Merluccius merluccius), conducted in the northern part of the Bay of Biscay in 2002, indicate that growth rates for this stock may be currently underestimated because of biased estimates of age. The impact that such a bias may have on the stock dynamics and the trends of the key population parameters, recruitment, spawning-stock biomass (SSB), and mortality are investigated. Assuming new growth parameters, a new age-length key is derived and used to produce and catch-at-age data and abundance indices, which are then used to assess the stock. Bias in estimating age affects the absolute levels of fishing mortality and stock biomass estimates, and also impacts the trend in SSB. However, trends in fishing mortality... |
| Tipo: Text |
Palavras-chave: Tagging; Stock assessment; Simulation; Management; Growth; European hake; Age estimation. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2824.pdf |
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| Dambrine, Chloe; Huret, Martin; Woillez, Mathieu; Pecquerie, Laure; Allal, Francois; Servili, Arianna; De Pontual, Helene. |
| The European seabass (Dicentrarchus labrax) is a species of particular ecological and economic importance. Stock assessments have recently revealed the worrying state of the “Northern stock”, probably due to overfishing and a series of poor recruitments. The extent to which these poor recruitments are due to environmental variability is difficult to assess, as the processes driving the seabass life cycle are poorly known. Here we investigate how food availability and temperature may affect the growth and survival of wild seabass at the individual scale. To this end, we developed a bioenergetics model based on the Dynamic Energy Budget (DEB) theory. We applied it to seabass population of the Northeast Atlantic region (Bay of Biscay – English Channel area)... |
| Tipo: Text |
Palavras-chave: Dicentrarchus labrax Northeast Atlantic Dynamic Energy Budget theory Growth; Starvation Early-life stages. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72397/71341.pdf |
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| Heerah, Karine; Woillez, Mathieu; Fablet, Ronan; Garren, Francois; Martin, Stephane; De Pontual, Helene. |
| Background Movement pattern variations are reflective of behavioural switches, likely associated with different life history traits in response to the animals’ abiotic and biotic environment. Detecting these can provide rich information on the underlying processes driving animal movement patterns. However, extracting these signals from movement time series, requires tools that objectively extract, describe and quantify these behaviours. The inference of behavioural modes from movement patterns has been mainly addressed through hidden Markov models. Until now, the metrics implemented in these models did not allow to characterize cyclic patterns directly from the raw time series. To address these challenges, we developed an approach to i) extract new metrics... |
| Tipo: Text |
Palavras-chave: Fourier transform; Non negative matrix factorization; Classification; Animal behaviour; European sea bass; Movement ecology; Diurnal and tidal cycles; Biologging; Data storage tags. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00402/51400/51974.pdf |
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| Borelli, G; Guibbohni, M; Mayer Gostan, N; Priouzeau, France; De Pontual, Helene; Allemand, D; Puverel, S; Tambutte, E; Payan, P. |
| Ionic and organic parameters of the otolith calcification process in the trout Oncorhynchus mykiss were analysed in plasma and endolymph over the day:night cycle. Plasma pH remained constant and total CO2 concentration was significantly lower (by 21%) during the day than at night. Calcifying parameters (total CO2, total calcium concentration) were measured in the proximal and distal endolymphs and were unchanged in the latter during the day:night cycle, but fluctuated in the former. Non-collagenous protein and collagen concentrations in endolymph were higher (1.5- and 10-fold, respectively) during the day than at night. As there was no change in total calcium concentration, we propose that Ca2+ increases during the dark period and was maximal by the end of... |
| Tipo: Text |
Palavras-chave: Endolymph; Day night cycle; Calcification; Otolith. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/2003/publication-418.pdf |
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| Edeyer, Anaick; De Pontual, Helene; Payan, P; Troadec, Herve; Severe, Armelle; Mayer-gostan, N. |
| We studied the circadian variations of the ionic composition ([Na+], [K+], [Cl-]), total CO2 ([tot CO2]), and protein concentration ([protein]) in the plasma and endolymph in the distal and proximal sides of the sacculus in the turbot Psetta maxima. Daily variations in total plasma calcium ([tot Ga]) were also recorded. Significant diurnal fluctuations occurred in most parameters and the spatial heterogeneity of the endolymph composition was maintained throughout a 24 h period. The main parameters implicated in otolith calcification, endolymph [tot CO2] and endolymph [protein], fluctuated diurnally, [tot CO2] was highest and [protein] lowest at night; the relative concentrations were reversed during the day. The inverse, alternating relationship of maximal... |
| Tipo: Text |
Palavras-chave: Daily cycle; Endolymph; Otolith; Chemical composition; Teleost. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10572/7603.pdf |
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| Mille, Tiphaine; Mahe, Kelig; Cachera, Marie; Villanueva, Ching-maria; De Pontual, Helene; Ernande, Bruno. |
| Previous studies have shown that food amount influence fish otolith structure, opacity and shape and that diet composition has an effect on otolith chemical composition. This study investigated the potential correlation between diet and otolith shape in 5 wild marine fish species by addressing 4 complementary questions. First, is there a global relationship between diet and otolith shape? Second, which prey categories are involved in this relationship? Third, what are the respective contributions of food quantity and relative composition to diet–otolith shape co-variation? Fourth, is diet energetic composition related to otolith shape? For each species, we investigated how otolith shape varies with diet. These questions were tackled by describing diet in... |
| Tipo: Text |
Palavras-chave: Fourier analysis; English Channel; Interspecific; Morphometric analysis; Otolith growth; Saccular otolith; Stomach contents. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00345/45639/45269.pdf |
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| Mahe, Kelig; Ider, Djamila; Massaro, Andrea; Hamed, Oussama; Jurado-ruzafa, Alba; Goncalves, Patricia; Anastasopoulou, Aiketerini; Jadaud, Angelique; Mytilineou, Chryssi; Elleboode, Romain; Ramdane, Zohir; Bacha, Mahmoud; Amara, Rachid; De Pontual, Helene; Ernande, Bruno. |
| Otolith shape analysis is an efficient fish stock identification tool. However, most applications used left and right otoliths or only one of them arbitrarily chosen without testing for biases resulting from potential directional bilateral asymmetry (DA) in otolith shape, i.e. a unimodal population-level deviation form bilateral symmetry between right and left otolith shapes. In this study, 560 bogues (Boops boops) were sampled from 11 geographical locations from the Canary Islands to the Aegean Sea and elliptical Fourier descriptors were used to describe their otoliths’ shape. First, a significant otolith DA was observed at the global scale with an average amplitude of 2.77%. However, at the scale of sampling locations, DA was not always significant and... |
| Tipo: Text |
Palavras-chave: Boops boops; Elliptical Fourier analysis; Mediterranean Sea; Side effect; Stock identification. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00468/57967/60418.pdf |
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| Mahé, Kelig; Gourtay, Clemence; Bled--defruit, Geoffrey; Chantre, Celina; De Pontual, Helene; Amara, Rachid; Claireaux, Guy; Audet, C.; Zambonino-infante, Jose-luis; Ernande, Bruno. |
| Otolith shape is an efficient tool for fish stock discrimination. Therefore, it is crucial to identify the environmental parameters that could influence otolith morphogenesis and growth. Current global ocean warming negatively affects the production of polyunsaturated fatty acids (EPA and DHA) by phytoplankton and thus their availability in marine food webs. As EPA and DHA are essential nutrients for most fish species, their deficiency could affect many aspects of fish physiology, notably otolith morphogenesis. The goal of this study was to assess experimentally the combined influences of temperature (T) and dietary polyunsaturated fatty acid (PUFA) content on European seabass (Dicentrarchus labrax) otolith morphogenesis during early life stages. 300... |
| Tipo: Text |
Palavras-chave: N-3 polyunsaturated fatty acids; Otolith shape; Temperature effect; Elliptic Fourier descriptors; Multivariate mixed-effects models; Directional asymmetry. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70054/68017.pdf |
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| Jolivet, Aurelie; De Pontual, Helene; Garren, Francois; Begout, Marie-laure. |
| Controlled experiments were conducted to assess the effects of T-bar and DST tagging on post-release survival and growth of European hake. In this study, two groups of each 30 hake were considered: small fish (SF, average total length: 29.9 cm +/- 2.2 cm) and large fish (LF, average total length: 36.4 cm +/- 2.5 cm). Within each size group, fish were randomly assigned to one of 3 treatment groups: control (C), T-bar tagging referred as conventional tagging (CT) and DST tagging (DST) with dummy tags. After 4 months, the overall survival rate was 35%. Smaller fish were less impacted by the stress induced by handling, anaesthesia and tagging and in the SF group, the survival rates were similar (30%) for CT or DST. Specific growth rates were highly variable... |
| Tipo: Text |
Palavras-chave: Merluccius merluccius; Archival tag; Husbandry; Midterm experiment; Captive hake. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00065/17645/15196.pdf |
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| Registros recuperados: 50 | |
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