French Research Institute for Exploitation of the Sea
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ICES-FAO Working Group on Fishing Technology and Fish Behaviour (WGFTFB)
No full textThe joint ICES/NAFO Working Group on Deep-water Ecology (WGDEC) deals with the biology and conservation of deep-sea habitats in the North Atlantic. Working Group experts collate new information on the distribution of Vulnerable Marine Ecosystems (VMEs) and fishing activities within ICES ecoregions (including the NEAFC Convention Area) and the NAFO Convention Area for use in ICES advisory processes. This information assists the development of new meth-ods to improve the understanding of deep-sea ecosystems and informs the implementation of management tools to afford the protection of VMEs. During the 2025 meeting, WGDEC reviewed new information on the occurrence and distribution of VMEs, VME indicator taxa and VME elements that were submitted in response to the ICES VME data call (November 2024), including those arising in the NEAFC Convention Area, as well as subareas of the Regulatory Area that are closed to fishing for other purposes than VME pro-tection. New data on VMEs is available from areas within the Barents Sea, Celtic Seas, Greater North Sea, Norwegian Sea and Oceanic Northeast Atlantic ecoregions. A total of 983 new VME indicator presence records and 157 absence (non-detection) records were accepted into the ICES VME da-tabase. There was a total of 50 new VME indicator presence records and 57 absence records re-ported within the 400 – 800 m depth zone of the EU portion (Irish EEZ) of the Celtic Seas ecore-gion. A total of 44 new VME indicator records were reported for the Oceanic Northeast Atlantic ecoregion/NEAFC regulatory area (RA1), of which 5 records were reported from the portion of Rockall Bank that lies within NEAFC RA1. Five new VME indicator records for the NEAFC por-tion of the Barents Sea ecoregion were also received. All new validated data and outputs of the VME weighting algorithm, displaying the likelihood of VME presence (VME Index), were mapped to support ICES in providing advice on the distribution of VMEs in the North Atlantic. New VMS data from NEAFC was analysed by the Working Group on Spatial Fisheries Data (WGSFD), and outputs were used by WGDEC to assess the patterns of fishing activity in the vicinity of VMEs in the NEAFC Convention Area. A further objective of the 2025 meeting was to continue the work addressing the limitations and validation of the VME index. An approach was suggested and agreed where a core group would continue the intersessional work in advance of a workshop to be held in advance of the VME benchmark planned for 2027. Potential workshop ToRs were suggested, and an intersessional meeting organised for autumn 2025. Finally, an additional key activity in 2025 was an analysis correlated the biological traits of VME indicator species with their sensitivity to static fishing gear. Using a traits table developed from literature and expert knowledge, the group scored and mapped species' sensitivity. A main find-ing of the group is that there is a critical distinction between sensitivity (an organism's intrinsic response to pressure) and vulnerability (which also includes exposure and resilience). Therefore, accurately assessing vulnerability requires more detailed data on both VME species (distribu-tion, abundance, and resilience traits) and specific fishing activities (as specific fishing gear con-figurations and effort intensity)
Avis de l'Ifremer sur la surveillance de la zone privée 85.06 "Parcs du Havre de la Gachère"
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Argo data management report 2025, Coriolis DAC & GDAC & A-ARC
No full textThis report covers the activity of Coriolis DAC (Data Assembly Centre) for the one-year period from September 1st 2024 to September 30th 2025
Avis pour le rattachement des tables conchylicoles du lycée de la mer à la zone de production n°34.39.01 « Lotissements conchylicoles de l'Etang de Thau - Zone Bouzigues- Loupian ».
No full textAvis n° 25-056 pour le rattachement des tables conchylicoles du lycée de la mer à la zone de production n°34.39.01 « Lotissements conchylicoles de l'Etang de Thau - Zone Bouzigues-Loupian »
Multigenerational temperature effects on paternal epigenetic inheritance in European sea bass
No full textEnvironmental changes can induce epigenetic modifications, influencing gene expression, phenotype, and species adaptation. This study investigates how temperature affects genome-wide DNA methylation patterns, particularly in genes crucial for sex development and whether these modifications can be transmitted across generations. Using the European sea bass —a fish model with both genetic and environmental sex determination— we analyzed DNA methylation at single nucleotide resolution using reduced representation bisulfite sequencing in 64 individuals from five families across two generations (F0 and F1). Parental fish (F0) were exposed to either control (16 °C, C) or elevated (21 °C, T) temperatures from 12 to 60 days post-fertilization. Their offspring (F1) were then subjected to four thermal regimes: control (CC), ancestral exposure via sires (TC), developmental exposure in offspring (CT), and dual exposure (TT). We determined the length of differentially methylated regions (DMRs) using a conservative, reproducible, and species-specific method adapted from plant epigenetics. To disentangle ancestral and developmental temperature effects, DMRs were classified according to their association with F0, F1, or F0 x F1 interaction effects. This allowed us to quantify the relative contribution of each treatment, separately for testes and ovaries in the F1 generation. While the proportion of additive DMRs showing cumulative temperature effects (e.g., 2.1% in testes, 1.4% in ovaries) was relatively rare, a substantial proportion of DMRs (37% in testes, 31.1% in ovaries), exhibited opposing methylation changes with F0 and F1 treatments, indicative of compensatory epigenetic interactions. These interactions were also reflected at the phenotypic level: TT individuals showed body weights comparable to CC, and the sex ratio in TT approached statistical significance when compared to CC (P = 0.051), suggesting a link between epigenetic regulation and phenotypic plasticity under elevated temperatures. Finally, we also investigated the inheritance of epimarks from sires to offspring. While most epimarks remained stable across generations, ~ 5% of all DMRs were both temperature-induced and inherited, offering direct evidence for environmentally responsive multigenerational epigenetic inheritance. This study demonstrates the role of temperature in shaping the epigenome and highlights the potential of epigenetic plasticity and inheritance in species adaptation and conservation amid global warming
Meridional dipole in eddy activity along Peruvian coast during El Niño events
No full textMesoscale oceanic eddies (O(100)km) play a key role in regulating climate by affecting the transport of heat and water mass properties. However, most climate models struggle to simulate these eddies due to coarse horizontal resolution. Using a 120-year ultra-high-resolution simulation with 1/10° horizontal ocean resolution, conducted with the Community Earth System Model (UHR-CESM), this study examines how eddy activity off Peru changes during strong eastern Pacific El Niño events. The model shows a meridional dipole in eddy activity during El Niño, with increased (decreased) energy north (south) of ~14°S, matching satellite data except for the extreme 1997/98 El Niño. This pattern is caused by baroclinic instabilities linked to El Niño-driven changes in the equatorial undercurrent. The study also finds a nonlinear relationship between the strength of the dipole pattern and El Niño-related equatorial influences, providing new insights into the dynamics of the El Niño-Southern Oscillation
DELMOGES. Rapport sur la cartographie du risque de capture accidentelle de dauphin commun à fine échelle dans le centre du Golfe de Gascogne en février 2023
No full textCe livrable présente une première caractérisation et cartographie du risque de capture accidentelle de dauphin commun à fine échelle dans le centre du golfe de Gascogne en février 2023, à partir des cartes d’observations disponibles : densités des dauphins communs des campagnes Capecet et DriX, indices de proies des dauphins de la campagne DriX, effort de pêche issues de la géolocalisation des fileyeurs, observation des captures accidentelles et de l’effort de pêche issues des programmes Obsmer et OBSCAMe. Ces données permettent d’estimer plusieurs composantes du risque : les chevauchements spatiaux entre la densité des dauphins et des filets d’une part, et d’autre part, les interactions au fond entre les dauphins, leurs proies et les filets.
Le risque de capture accidentelle a été évalué globalement puis caractérisé dans l’espace à échelle fine en fonction de l’effort de pêche et de la densité des différents types de proies, afin de mieux comprendre ses déterminants. Des cartes d’indices de risque potentiel de capture ont ensuite été définis comme la combinaison de 2 à 3 composantes : i) la co-occurrence spatiale entre les dauphins et l’activité de pêche à méso-échelle, ii) la co-occurrence spatiale dans la dimension verticale entre dauphins et engin de pêche à fine échelle, iii) une composante liée au comportement du dauphin en situation à risque à fine échelle. La composante i) a été estimée en combinant les cartes de densité de dauphins et d’effort de pêche, les composantes ii) et iii) ont été estimées à partir d’indicateurs de la distribution, du niveau d’agrégation et de la taille des proies des dauphins. Le pouvoir explicatif et prédictif des indices de risque potentiel a été testé en modélisant la présence et l’absence de captures accidentelles observées dans la zone en fonction des cartes d’indicateurs de risque.
Les captures accidentelles n’étaient pas rares (probabilité par opération pêche : 18%), ni distribuées aléatoirement dans la zone à risque en février 2023. En moyenne autour d’une capture accidentelle, les densités de dauphins commun et l’effort de pêche étaient plus importants et les densités de proies de petite taille plus faibles dans un rayon de 10 à 20 MN. Les deux indices de risque expliquant le mieux les captures accidentelles consistaient en une combinaison des densités de dauphins et d’un indice décrivant la densité, la taille et/ou la distribution de leurs proies. L’ajout de l’effort de pêche des fileyeurs dans l’indice permettait d’améliorer les prédictions après inclusion des autres indices. Ces résultats confirment que la présence, la taille et le niveau d’agrégation des proies semblent jouer un rôle important dans le processus de capture accidentelle de dauphins communs. L’influence des proies pourrait s’exercer à deux échelles : à méso-échelle horizontale, en conditionnant la distribution des dauphins dans certaines zones ; à fine échelle verticale, en attirant les dauphins près du fond dans la zone d’action des filets. Toutefois, le comportement des dauphins à proximité des filets reste un facteur d’erreur dans la prédiction des captures
National Fisheries Profile of France
No full textFrance is a significant maritime nation, with numerous maritime areas within its jurisdiction, particularly in its outermost regions. Coastal areas, though covering only 4% of continental France, host a large population and tourism sector, influencing significantly the economy. Coastal populations including fishers are shifting inland due to high real estate costs. The coastal economy is driven by tourism, fisheries, and other maritime activities, creating both consumer-facing and business-to-business jobs. Socioeconomic disparities exist, with varying incomes and unemployment rates between mainland and outermost regions, contributing to inequalities in education, healthcare, and employment opportunities. It seems that French society has evolved towards more social liberal attitudes, with strong values placed on family, work, friendships, and leisure activities. The fisheries industry in France is structured around diverse fishing activities regulated from the Rural and Fisheries Act of 2010. Fishing is classified based on vessel size, duration of operations, gear types, and target species. The fishing fleet is highly diversified, with over 6,000 vessels operating in different maritime regions, such as the Mediterranean Sea, Atlantic Ocean, North Sea and the outermost regions. Fleet reduction initiatives have been implemented to balance fishing capacity with opportunities, resulting in a 30% reduction in vessels between 2000 and 2023. Despite this reduction, the fleet remains significant, contributing to the economy and representing various social and economic functions. The fleet primarily targets fish, molluscs, and crustaceans, with a wide range of species caught for human consumption. The fishing sector plays a substantial role in France's coastal culture and economy (less than 1% of the GDP), ranking as a major fishing country in Europe. Small-scale and artisanal fishers usually use dedicated auctions for landing, while industrial fleets can land their catches in their registered port or the nearest fishing harbour in their operating area. Fisheries industry involves various stakeholders as such as fishmongers, fish shops, and processors who purchase fish either at auctions or directly from fishers. Direct consumer sales are common in small-scale fisheries, often contacted by fishers’ wives or partners
Trenches apart, yet worm to worm: inter- and intra-trench comparisons reveal divergent and convergent dynamics in hadal nematode biodiversity
No full textThe hadal zone, the deepest part of the global ocean, encompasses several extreme ecosystems with elevated biological activity, contrasting the general trend of declining biomass and biodiversity with increasing water depth. These bathymetrically isolated habitats act as depocenters and are characterized by high hydrostatic pressure and unique environmental conditions that provide an opportunity to fundamentally explore biogeographic patterns and the genetic diversity of deep-sea meiofauna, which remain poorly understood. In this study, we compared nematode communities in two geographically distant trench systems, the Aleutian Trench (North Pacific) and the South Sandwich Trench (South Atlantic), separated by 17 000 km. Environmental DNA (eDNA) sequencing targeting the ribosomal 18S region was combined with a metaphylogeography approach. Comparative analyses were performed for intra- and inter-trench, biodiversity and genetic differentiation across environmentally characterised trench-specific habitats. Our findings reveal evidence for the meiofauna paradox in hadal settings, demonstrating distinct nematode communities that appear to be shaped by availability and quality of food. Furthermore, environmental filtering appeared to contribute to assembly of habitat specific communities according to localised environmental condition. Finally, we observed shared haplotypes among some dominating nematode genera, suggesting potential connectivity between habitats associated within or even across hadal trenches might exist. Overall, this study provides valuable insights on how environmental factors drive nematode biodiversity and genetic diversity in the hadal realm. Environmental heterogeneity plays a pivotal role in shaping nematode communities, influencing their population structure and connectivity by creating spatially variable habitats that drive diversification, local adaptation, and gene flow patterns