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This paper summarizes the lessons learnt for the management of small pelagic fish from the case study of managing the international fishery on the Bay of Biscay anchovy. A constant catch regime ended up with a fishery crash and closure (2005–2009) after a series of recruitment failures. Precautionary advices had been disregarded due to their inability to predict the size of the population during the first half of the year when the major fishery takes place. The crash triggered the EU to develop a long-term management plan in 2008. In the absence of a recruitment indicator, biological risk was minimized through a close coupling between assessment, advice and management, changing the management year to start just after the spring surveys on adults. A major improvement arrived in 2014 by the incorporation of an early recruitment indicator from an autumn acoustic survey on juveniles. This allowed additional exploitation of the resource at similar risk levels. Accordingly, TACs are nowadays set after the recruit survey on a management calendar basis. The interactive collaboration between fishers, scientists, and managers allowed inclusion of the stakeholders’ preferences for a biomass-based catch bounded harvest strategy suitable for these valuable fisheries. This strategy allows catches between a minimum and maximum TAC level, to account for an economically viable minimum activity when approaching a minimum biomass threshold level, and for the limited market absorption capacity when exceeding an upper biomass threshold level, respectively. Such strategy was adopted by consensus and supposed a successful participatory process in fishery management.

This document presents the results of the acoustic biomass estimation of small pelagic fish near sea surface in the Bay of Biscay in spring 2023, based on PELGAS survey data. Estimates were based on lateral echosounder data.

Acoustic and egg-based indices produced by the scientific surveys conducted in the Bay of Biscay (BoB) under the hauspices of the ICES Working Group ACEGG were compared since 2000, to identify potential bias. Potential effects on biomass estimates of changes in daily fecundity are discussed. A workplan was proposed to further investigate discrepancies between acoustic and egg-based biomass estimates.

This paper summarizes the lessons learnt for the management of small pelagic fish from the case study of managing the international fishery on the Bay of Biscay anchovy. A constant catch regime ended up with a fishery crash and closure (2005–2009) after a series of recruitment failures. Precautionary advices had been disregarded due to their inability to predict the size of the population during the first half of the year when the major fishery takes place. The crash triggered the EU to develop a long-term management plan in 2008. In the absence of a recruitment indicator, biological risk was minimized through a close coupling between assessment, advice and management, changing the management year to start just after the spring surveys on adults. A major improvement arrived in 2014 by the incorporation of an early recruitment indicator from an autumn acoustic survey on juveniles. This allowed additional exploitation of the resource at similar risk levels. Accordingly, TACs are nowadays set after the recruit survey on a management calendar basis. The interactive collaboration between fishers, scientists, and managers allowed inclusion of the stakeholders’ preferences for a biomass-based catch bounded harvest strategy suitable for these valuable fisheries. This strategy allows catches between a minimum and maximum TAC level, to account for an economically viable minimum activity when approaching a minimum biomass threshold level, and for the limited market absorption capacity when exceeding an upper biomass threshold level, respectively. Such strategy was adopted by consensus and supposed a successful participatory process in fishery management.

Plusieurs analyses sont proposées dans ce cadre et en réponse à la saisine : 1) un bilan de l’effort de pêche des navires français en zone CIEM VIII aux engins sensibles aux captures accidentelles sur les périodes hivernales de 2019 à 2021 (entre le 1er décembre et le 31 mars), 2) une cartographie de l’effort de pêche aux engins sensibles sur ces mêmes périodes, 3) une analyse de l’évolution de l’activité halieutique française et étrangère entre 2010 et 2020 avec une attention particulière portée aux périodes hivernales et aux engins sensibles, 4) des premiers éléments sur la problématiques de l’estimation des métriques d’effort de pêche des engins sensibles en particulier des filets, 5) une actualisation de la typologie des navires pratiquant le filet dans la zone CIEM VIII durant les périodes hivernales étendue 2019 et 2020 (entre le 1er décembre et le 31 mai) et enfin 6) une analyse de l’évolution de l’abondance des espèces – proies des cétacés. Selon le niveau de précision disponible dans les données. Par exemple en l’absence de géolocalisation généralisée des navires de pêche, la cartographie des activités de pêche des navires français de moins de 12 mètre n’a pu être réalisée qu’au niveau des rectangles statistiques ICES, niveau insuffisant pour une bonne représentation de l’activité de pêche de ces navires.

Uncommon fish records may reflect local or global changes of fish composition resulting from environmental changes or anthropogenic activities. Significant records of uncommon marine fishes, including migrant, non-native, cryptic, rare and threatened species, collected in French waters or by French vessels in European waters, observed by scuba divers or beachgoers, are reported for the year 2019. They include first, new, rare and unusual records for the following 33 species: Tetronarce nobiliana, Gymnothorax unicolor, Maulisia mauli, Salmo trutta, Grammonus ater, Photostomias guernei, Ijimaia loppei, Echiodon drummondii, Holocen- trus adscensionis, Nerophis lumbriciformis, Scorpaena scrofa, Lepidotrigla dieuzeidei, Eutelichthys leptochirus, Liparis montagui, Mycteroperca rubra, Serranus cabrilla, Remora remora, Caranx crysos, Naucrates ductor, Trachurus picturatus, Seriola rivoliana, Argyrosomus regius, Parablennius pilicornis, Pseudoscopelus astro- nesthidens, Deltentosteus collonianus, Didogobius schlieweni, Didogobius splechtnai, Gobius couchi, Gobius gasteveni, Lebetus guilleti, Synapturichthys kleinii, Lagocephalus lagocephalus and Mola mola, among which I. loppei, H. adscensionis and P. astronesthidens represent first records for the French waters and additions to the Checklist of the marine fishes from metropolitan France. Photostomias guernei is a first record for the Bay of Biscay, found close the French EEZ., Les signalements inhabituels de poissons peuvent témoigner de changements locaux ou globaux résultants de modifications environnementales ou d’activités anthropiques. Des signalements remarquables de poissons marins, comprenant des espèces migrantes, non natives, cryptiques, rares et menacées, collectés dans les eaux françaises ou bien par des navires français dans les eaux européennes, observées par des plongeurs sous-marins ou des promeneurs, sont mentionnés pour l’année 2019. Ils comprennent des premiers et nouveaux signalements ainsi que des signalements rares et inhabituels pour les 33 espèces suivantes : Tetronarce nobiliana, Gymnothorax unicolor, Maulisia mauli, Salmo trutta, Grammonus ater, Photostomias guernei, Ijimaia loppei, Echiodon drummondii, Holocentrus adscensionis, Nerophis lumbriciformis, Scorpaena scrofa, Lepidotrigla dieuzeidei, Eutelichthys leptochirus, Liparis montagui, Mycteroperca rubra, Serranus cabrilla, Remora remora, Caranx crysos, Naucrates ductor, Trachurus picturatus, Seriola rivoliana, Argyrosomus regius, Parablennius pilicornis, Pseudoscopelus astronesthidens, Deltentosteus collonianus, Didogobius schlieweni, Didogobius splechtnai, Gobius couchi, Gobius gasteveni, Lebetus guilleti, Synapturichthys kleinii, Lagocephalus lagocephalus et Mola mola, parmi lesquelles I. loppei, H. adscensionis et P. astronesthidens représentent des premiers signalements pour les eaux françaises et des additions à la Liste des poissons marins de France métropolitaine. Photostomias guernei est un premier signalement pour le golfe de Gascogne, trouvé proche de la ZEE française.

This year the group changed its name to Working Group on Acoustic and Egg Surveys for small pelagic fish in NE Atlantic (WGACEGG). WGACEGG coordinates, assesses and quality controls acoustic and daily egg production (DEPM) surveys of several pelagic stocks in ICES areas 6-9. During three 2020 WGACEGG meetings, results of three DEPM surveys, three spring/summer acoustic surveys and all six autumn surveys were presented. Implications of the cancellation of three surveys (SAREVA and PELACUS (Spain)) and PELGAS (France) were also discussed, as were possible mitigations to minimize the effects on the relevant stock assessments. No concerns were raised about the surveys that took place. The results from the DEPM survey for sardine in 9a could not be provided until December, as COVID-19 had restricted laboratory access. WGACEGG also met with members of the Working Group on Southern Horse Mackerel, Anchovy, and Sardine (WGHANSA) to present the results from the 2020 Portuguese (PELAGO) acoustic survey in advance of the June assessment meeting. The working groups discussed the implications of PELAGO using a different vessel and of the earlier timing (compared to the timeseries) on the sardine and anchovy indices. The joint meeting also identified which surveys were at risk of being cancelled because of COVID-19 and discussed possible mitigations. Biomass estimates for both sardine and anchovy in division 9a were higher than observed in recent years as confirmed by both acoustic and DEPM surveys; DEPM derived Bay of Biscay anchovy spawning stock biomass was the highest on record although the number of recruits in the Bay of Biscay observed later in autumn did not reflect this increase. However, this was at least partly due to a northwards expansion into the English Channel where Bay of Biscay juveniles were found for the first time; sardine biomass in the Bay of Biscay from all available surveys suggested slightly lower values than the long-term average; in the English Channel

The goal of a benchmark is consensus agreement on an assessment methodology that is to be used in future update assessments. This assessment methodology can be an analytical assessment, but can also be non-analytical, for instance based on trends in an assessment or in a selected set of (survey) indicators, with or without forecasts. The result will be the 'best available' method that ICES advice will be based on. WKWEST 2021 dealt with the following stocks: Sardine (Sardina pilchardus) in Subarea 7 (southern Celtic Seas, and the English Channel); Pollack (Pollachius pollachius) in subareas 6-7 (Celtic Seas and the English Channel); Red gurnard (Chelidonichthys cuculus) in subareas 3–8 (Northeast Atlantic); Plaice (Pleuronectes platessa) in divisions 7.h–k (Celtic Sea South, southwest of Ireland); Sole (Solea solea) in divisions 8.c and 9.a (Cantabrian Sea and Atlantic Iberian waters).

Based on a long-term analysis of more than a century of sardine production on the French coast, this article raises the question of the adaptive behavior of fishing communities in the face of variabilities in the abundance of the resource. A time-series segmentation method identifies turning points by looking for stationary phases. The results show three periods, the first beginning in 1900 with a turning point in 1971. The next two segments run over the periods 1972 to 1998 and 1999 to 2017. The concentration of the sardine industry accelerated precisely around the first turning point. In addition to the segmentation method, the article uses the conceptual framework of socio-systems and of the resilience of stakeholders in the face of major disturbances. While the sardine fishing ports were able to maintain their specialization through their ability to adapt to minor changes, before the first turning point this ability became insufficient when confronted with major disruptions. The literature on socio-systems considers that adaptability is therefore required to maintain economic activity. This is illustrated in the paper. JEL classification: Q22, N54, C22, L23., A partir de séries longues, sur plus d’un siècle de production de sardine sur les côtes françaises, l’article pose la question du comportement d’adaptation des communautés de pêcheurs face aux variabilités dans l’abondance de la ressource. Une méthode de segmentation de la série chronologique permet d’identifier des points de rupture en recherchant des phases stationnaires. Le résultat aboutit à trois périodes, la première débutant en 1900 avec un point de rupture en 1971. Les deux segments suivants courent sur les périodes 1972 à 1998 et de 1999 à 2017. Le mouvement de concentration de l’industrie de la sardine s’accélère précisément sur le premier point de rupture. Le cadre conceptuel retenu, en complément de la méthode de segmentation, est celui des socio-systèmes et de la résilience des acteurs face à de fortes perturbations. Si les ports de pêche sardiniers ont pu maintenir leur spécialisation par une capacité d’adaptation à des changements mineurs, avant le premier point de rupture, elle devient insuffisante face à des perturbations majeures. La littérature sur les socio-systèmes considère que la capacité d’adaptabilité est alors requise pour maintenir une activité économique. C’est un fait illustré dans cet article. Classification JEL : Q22, N54, C22, L23.

he Working Group on Acoustic and Egg Surveys (WGACEGG) coordinates pelagic surveys for a number of stocks and provides monitoring for the two major sardine and anchovy stocks in ICES areas 6, 7, 8, and 9. The group evaluated small pelagic fish biomass indices derived from acoustic and Daily Egg Production Method (DEPM) surveys in ICES areas 6, 7, 8 and 9. These indices have been provided to the ICES Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA), the Working Group on Widely Distributed Stocks (WGWIDE) and the Herring Assessment Working Group for the Area South of 62ºN (HAWG) stock assessment group, to serve as fishery-independent input for analytical assessment purposes. DEPM and acoustic indices were derived based on data collected using independent methods. Acoustic- and DEPM-derived biomass indices from quasi-synoptic surveys conducted in the Bay of Biscay in spring were compared, to assess the presence of potential bias and to improve the precision of fish stock biomass estimates. The DEPM-based anchovy biomass index was 22% higher than the acoustic index in 2019. Unusual concentrations of anchovy in Eastern Cantabrian Sea, an area not covered by the acoustic survey, and the presence near the sea surface of actively spawning individuals possibly under-sampled by acoustics in central Bay of Bay had been postulated as potential causes of this discrepancy. No significant difference was found between sardine biomass indices derived from DEPM and acoustics in 2019. The group has updated its database of standard gridded maps covering the European Atlantic area. This initiative continues to inform on the spatial dynamics of various parameters collected during the surveys coordinated under the auspices of the group (fish acoustic densities, anchovy and sardine egg abundance, surface temperature and salinity). Results of an analysis of the time series of gridded maps (anchovy and sardine acoustic density, surface salinity and temperature) showed

Le projet FFP Captain visait à l’amélioration des connaissances biologiques et sur la connectivité des stocks de sardine et d’anchois sur la façade Atlantique française (Manche et golfe de Gascogne). Il a reposé sur la collecte de données au travers d’une collaboration avec les professionnels de la pêche (organisations de producteurs et pêcheurs) et de l’exploitation opportuniste des pêches sur l’ensemble des campagnes halieutiques de la zone (PELGAS, EVHOE, CGFS). Ceci a permis une couverture spatiale et saisonnière optimale. Nous avons ainsi affiné la description spatio-temporelle de la reproduction pour les deux espèces, et montré une plus forte croissance ainsi qu’une densité énergétique plus élevées en Manche que dans le golfe de Gascogne. Cette densité énergétique varie fortement saisonnièrement, avec des niveaux élevés à l’automne suite à l’accumulation de réserves, et des niveaux très bas en mars à la sortie de l’hiver. Ces données ont par ailleurs permis de calibrer un modèle bioénergétique pour chacune des espèces. Finalement, une analyse de génétique des populations d’anchois a révélé la structuration spatiale forte sur la zone d’étude, avec une limite entre un stock Gascogne et un stock nord (Manche, mer du Nord, mer d’Irlande) localisée à la pointe bretonne, et a mis en évidence la présence d’anchois appartenant à un écotype estuarien en Loire comme en Gironde.

The negative impacts that scientific monitoring may have on marine ecosystems has been a neglected topic, mainly on the basis that its magnitude is minor compared to commercial fisheries, even though this raises ethical and, in certain cases, conservation issues. We argue that ethical principles should lead us to reconsider marine wildlife resource monitoring such as the fish and shellfish trawl surveys providing the science-based evidence needed for fisheries management and assessment of how environmental change impacts marine shelf communities worldwide. Recent scientific and technological progress has provided methods and tools which might now be harnessed to reduce the impact of marine monitoring. We review these alternative methods, consider modifications to current practices and identify areas requiring further research.

The Working Group on Southern Horse Mackerel, Anchovy and Sardine (WGHANSA1) met by correspondence from 3 to 7 June 2019, and in Madrid from the 25 to the 28 of November 2019, and was chaired by Alexandra Silva (Portugal). There were 13 participants from France, Portugal, Spain and UK. The main task of WGHANSA was to assess the status the stocks of sardine in the Celtic Seas and English Channel (pil.27.7), sardine in the Bay of Biscay (pil.27.8abd), sardine in the Cantabrian Sea and Atlantic Iberian waters (pil.27.8c9a), anchovy in the Bay of Biscay (ane.27.8), anchovy in Atlantic Iberian waters (ane.27.9a; components west and south), horse mackerel in Atlantic Iberian waters (hom.27.9a) and jack mackerel in the Azores (jaa.27.10). Assessments and short-term forecasts were updated according to the stock annexes. There is no assessment method adopted for pil.27.7 due to the lack of data. The stock of pil.27.8abd was assessed as category 1 for the first time, following an interbenchmark. Recruitment has been above the average, the spawning–stock biomass declined and fishing mortality steeply increased in 2010–2012. SSB is fluctuating above MSY Btrigger and F2018 is above FMSY and below Fpa. This year, the DEPM datapoint for 2017 was included in the pil.27.9a assessment for the first time, following a revision of the survey data. The stock has decreased since 2006 and stabilized to a historical low since 2012. The biomass of age 1 and older fish has been decreasing since 2006 and reached the lowest historical value in 2015. It has since increased slightly but is below Blim since 2011. Recruitment has been below the time-series average since 2005. Recruitment in 2018 was around the geometric mean of the last five years. Fishing mortality has been decreasing from a peak in 2011. In 2018, it was the lowest in the time-series and below Fpa and Flim. The stock size indicator for anchovy in 9a.west decreased 90% from 2018 to 2019 (4129 t), after a period of an increasing tre

An acoustic survey (PELGAS) is carried out every year in the Bay of Biscay in spring onboard the French research vessel Thalassa. The objective of PELGAS survey is to study the abundance and distribution of pelagic fish in the Bay of Biscay. The main target species are anchovy and sardine but they are considered in a multi-specific context and within an ecosystemic approach as they are located in the centre of pelagic ecosystem.

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 survey and sampling sampling designs are presented and discussed, to highlight their impact on the survey ecosystem products. The potential of PELGAS survey products for ecosystem assessment is demonstrated with two case studies. Series of multivariate maps are first analysed to assess the pelagic ecosystem spatial structure. A map of consistent ecosystem seascapes boundaries and of their inter-annual variability in time is presented. Second, time series of potential ecosystem indices derived from the survey are jointly analysed to select the most continuous indicators within, and across, several ecosystem components. Trends in the selected time series are interpreted to derive information on marine ecosystem status and dynamics. Challenges and future directions are discussed, with a focus on the new big data flows that could be provided by the survey in a near future.

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 content have been derived from the analysis of net samples. Adult anchovy and sardine energy content have been studied along a latitudinal gradient, and across different age stages. Changing patterns in the relative abundance of marine megafauna have been evidenced at a community level. Cross-ecosystem component studies are also presented. Actual dates of the annual survey have been corrected, with respect to a surface temperature climatology, allowing for an improved interpretation of anchovy and sardine spawning. Spring habitats of small pelagic fish communities in the Bay of Biscay have been characterised. Fluctuations in habitat preferences of five mobile top predators species have been assessed. Predation of cetaceans on small pelagic fish has been investigated, based on stomach contents. The spatial structure of the ecosystem has been characterised, to map consistent ecosystem seascapes and study their variability in time. Dominant ecological processes in the Bay of Biscay have been identified based on series of potential pelagic ecosystem indicators derived from the survey, and the effects of external forcing on the ecosystem dynamics tested. Perspectives for the survey are discussed in the context of the Euro

Cet atelier 2018 a été mis en place pour intercalibrer les estimations d'âge des anchois et des sardines en Atlantique entre Erwan Duhamel qui est le lecteur de ces espèces du golfe de Gascogne et Célina Chantre et Geoffrey Bled Defruit du pôle national de Sclérochronologie du laboratoire Ressources Halieutiques de Boulogne sur mer qui vont commencer à estimer l'âge de ces petits pélagiques dans le golfe de Gascogne. L'objectif est d'abord de calibrer les estimations d’âge pour ces 2 espèces de petits pélagiques dans le golfe de Gascogne et de revoir les moyens pour réaliser les images en mer lors de la campagne Pelgas et à terre en laboratoire. Cette intercalibration est basée sur la lecture d’images : 136 otolithes d'anchois et 140 otolithes de sardine par 3 lecteurs. Cet atelier a permis de calibrer les lectures entre Erwan Duhamel (lecteur d'anchois et de sardines du golfe de Gascogne) et Geoffrey Bled Defruit et Célina Chantre (lecteurs du pôle de Sclérochronologie). Les discussions ont permis d'identifier les problèmes d'estimation d'âge et de corriger les écarts entre lecteurs. En comparant les résultats des 3 lecteurs à partir des images de sardines, la précision a fortement augmentée entre la première lecture lors de l’échange et la deuxième lecture lors du workshop passant d’un pourcentage d’agrément de 71.7% à 89% et un CV de 36% à 9%. Ceci se traduit par des estimations d’âge pour la sardine réalisées par Erwan et Geoffrey sans biais dû au lecteur. En ce qui concerne l’anchois, les résultats des lectures dès la première lecture lors de l’échange ne montrent pas de différences significatives entre lecteurs avec un pourcentage d'agrément total de 83.5% et un coefficient de variation de 16.9%. Ainsi, il n’y a pas de biais entre les 3 lectures. Ce rapport d'atelier se veut être un support pour l'interprétation des otolithes de ces deux espèces.

This paper describes a methodology that combines meta-population theory and stock assessment models to gain insights about spatial heterogeneity of the meta-population in an operational time frame. The methodology was tested with stochastic simulations for different degrees of connectivity between sub-populations and applied to two case studies, North Sea cod (Gadus morua) and Northeast Atlantic sardine (Sardina pilchardus). Considering that the biological components of a population can be partitioned into discrete spatial units, we extended this idea into a property of additivity of sub-population abundances. If the additivity results hold true for putative sub-populations, then assessment results based on sub-populations will provide information to develop and monitor the implementation of finer scale/local management. The simulation study confirmed that when sub-populations are independent and not too heterogeneous with regards to productivity, the sum of stock assessment model estimates of sub-populations’ SSB is similar to the SSB estimates of the meta-population. It also showed that a strong diffusion process can be detected and that the stronger the connection between SSB and recruitment, the better the diffusion process will be detected. On the other hand it showed that weak to moderate diffusion processes are not easy to identify and large differences between sub-populations productivities may be confounded with weak diffusion processes. The application to North Sea cod and Atlantic sardine exemplified how much insight can be gained. In both cases the results obtained were sufficiently robust to support the regional analysis

Peu de modèles d'évaluation de stock intègrent une description fine des processus biologiques régissant les populations exploitées par la pêche au sein des écosystèmes. Ce manque est particulièrement regrettable dans le cas des petits pélagiques dont la dynamique est fortement influencée par les conditions environnementales. En effet, la pêche et les fluctuations environnementales et climatiques impactent fortement la dynamique de population de la sardine du golfe de Gascogne. Pour comprendre la dynamique de cette population au sein de l'écosystème et les effets des pêcheries, il est donc nécessaire d'identifier et de caractériser cet ensemble de pressions. Afin d'améliorer la gestion et le suivi de la dynamique de ce stock, le développement d'un modèle d'évaluation écosystémique a été initié. Sa formalisation nécessite notamment la prise en compte de facteurs endogènes et exogènes structurant la croissance et la condition de cette espèce. Les indices de condition, notamment l'indice de condition relative de Le Cren, permettent notamment de comparer l'état physiologique individuel des poissons et donc par extrapolation de caractériser l'état de la population. Les études précédentes chez les sardines (mais également chez d'autres espèces de poissons) montrent qu'il existe d'importantes variations spatiotemporelles dans la condition, la croissance et la structure en taille et en âge. En nous basant sur les données récoltés lors de la campagne PELGAS, nous mesurons dans un premier temps les variations de ces paramètres clés dans le temps et dans l'espace (gradient latitudinal) afin d'identifier les facteurs environnementaux régissant l'expression de ces caractères morphologiques qui sont liés à la croissance et la reproduction des individus. Dans un second temps, pour aborder ces mécanismes d'un point de vue quantitatif, une approche bioénergétique individuelle à l'aide du DEB (Dynamic Energy Budget) sera développée pour analyser les processus bottom-up. Son

Demographic connectivity in sardine population