French Research Institute for Exploitation of the Sea
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Preserving biodiversity from plant protection products demands to make them contaminants of re-emerging concern
No full textKey learnings from the collective scientific assessment on the effects of plant protection products on biodiversity and ecosystem service
Lieux et périodes à risque 2025 pour les toxines lipophiles. Complément aux prescriptions REPHYTOX. Version Finale
No full textCe document met à jour le complément à la Procédure nationale de la surveillance sanitaire des phycotoxines réglementées dans les zones de production de coquillages. Prescriptions du réseau de surveillance des phycotoxines dans les organismes marins (REPHYTOX). Novembre 2020 - ODE/VIGIES/20-11. https://doi.org/10.13155/56600 Il définit les lieux et les périodes à risque concernant les toxines lipohiles produites par les Dinophysis et pouvant être accumulées par les coquillages. Sur ces lieux, en période à risque, le suivi hebdomadaire systématique est mis en oeuvre
Influence of the Advection of Labrador Sea Water on the Decadal Variability of the Eastern Subpolar North Atlantic
No full textThe upper ocean heat content of the eastern subpolar North Atlantic (ESPNA) displays large decadal variations, in particular, a warming starting in the mid‐1990s followed by a cooling trend from the mid‐2000s to the mid‐2010s. Using an eddy permitting ice‐ocean model, we find a relationship between the eastward propagation of dense water formed in the Labrador and Irminger Seas, the barotropic horizontal circulation and the advective heat convergence in the ESPNA. The time evolution of the 3‐year average anomalies of the barotropic streamfunction (BSF) shows a strong resemblance to that of the depth of the deep isopycnals. In particular, the propagation of dense water drives a response of the BSF in the intergyre gyre region. During the warming period, the advection of dense water is associated with a southeastward expansion of the subpolar gyre and a reduction of the supply of cold water from the western subpolar North Atlantic to the upper layers of the ESPNA. Sensitivity experiments suggest that atmospheric forcing can also enhance the trends in the heat content, but the latter cannot be related to trends of the local wind curl. However, circulation changes induced by the wind curl on some specific years can amplify the heat content changes
Large differences in the distribution of pelagic biomass as a result of sonar frequency choice
No full textRecent efforts to understand the global distribution of pelagic fauna have primarily relied on 38 kHz sonar observations, using water-column backscatter as a proxy of biomass. However, backscatter gradients across ocean provinces are not always consistent with biomass observations from net sampling. This mismatch is particularly evident in temperate to polar transition zones due to changes in the resonance of pelagic fauna, which depends not only on the sonar frequency but also on the size of resonant organs such as fish swimbladders. Here, we investigate how sonar frequency choice changes our vision of pelagic ecosystems across latitudes. We analyse sonar observations at 38 and 18 kHz along with size distributions of swimbladdered fish species across the Indian Ocean Subantarctic Front. Our results show a shift from 38 to 18 kHz dominance towards the poles. More interestingly, backscatter differences across the Subantarctic Front are four times larger at 38 kHz compared to 18 kHz. Size distribution of fish suggests an increase of swimbladder volumes in subantarctic waters, which may explain the observed shift in frequency response. This study highlights the need to address swimbladder resonance variability across latitudes in order to correctly interpret large-scale sonar observations of pelagic fauna
Mapping and issues of the “BlueTech” in New Caledonia
No full textThis article was written in the framework of a mission entrusted to the author by the French Tech New Caledonia. The purpose of this mission is, on the one hand, to investigate why the territory of New Caledonia, as an archipelago in the South Pacific, is a territory of blue innovation. On the other hand, it is to draw up a catalogue of innovative Caledonian projects in terms of «Blue Tech». ». The article summarizes the work carried out at the end of May 2025 and focuses on the 34 sheets relating to innovative projects related to the large blue innovation classes, topics and drivers, as well as the prospects for continuation and deployment to French Polynesia as an extension to the South Pacific.Cet article promotionnel a été rédigé dans le cadre d’une mission confiée à l’auteur par la French Tech Nouvelle-Calédonie. Celle-ci a pour objet : d’une part d’instruire les raisons pour lesquelles le territoire de la Nouvelle-Calédonie, en tant qu’archipel du Pacifique Sud, est un territoire d’innovation bleue. D’autre part il est de dresser un catalogue de projets innovants néocalédoniens en matière de « Blue Tech ». L’article résume le travail effectué en date de fin mai 2025 et met l’accent sur les 34 fiches relatives à des projets innovants : grande classes d’innovation bleue, sujets et porteurs, tout comme les perspectives de poursuite et de déploiement, tant vis-à-vis de projets complémentaires calédoniens, que de l’ouverture à la Polynésie française et d’une extension Pacifique Sud
Enhanced deglacial carbon transport by Pacific southern-sourced intermediate and mode water
No full textSouthern-sourced Antarctic Intermediate Water (AAIW) and Subantarctic Mode Water (SAMW) are currently major sinks of atmospheric CO2. During the last deglaciation, atmospheric CO2 levels increased significantly during two specific time periods, Heinrich Stadial 1 (H1) ~18–14.6 ka BP (thousand years ago before present) and the Younger Dryas (YD) ~12.8–11.5 ka BP. Model simulation and proxy data studies suggest that AAIW/SAMW was crucial in explaining these changes during H1 and YD, but its variability and properties in the Southeast Pacific Ocean are still largely unknown. Here, we present records of benthic foraminiferal carbon isotopes, Mg/Ca-based water temperatures, paleosalinity reconstructions, and sortable silt mean grain size variations over the last 30 thousand years from Ocean Drilling Program (ODP) Site 1233, in the Southeast Pacific Ocean, which is bathed in AAIW/SAMW. Our proxy data suggest an increased northward circulation of high pCO2/ nutrient-enriched AAIW/SAMW during H1 and YD. Our data provides support for AAIW/SAMW as one of the important conduits for deglacial oceanic outgassing in the eastern equatorial Pacific upwelling
Integrative taxonomy of two new peltospirid gastropods from Mid-Atlantic Ridge hot vents, including a potentially symbiotic species
No full textDeep-sea hydrothermal vents host lush communities of animals relying on bacterial chemosynthetic primary production, where intimate symbioses often form. Peltospiridae are a family of gastropods endemic to hot vents, whose members exhibit a variety of feeding strategies ranging from bacterial grazing to total reliance on endosymbiosis. Here, we report and describe two new peltospirid snails, Peltospira gargantua sp. nov. and Lirapex pantagruel sp. nov., from two recently discovered vent fields on the Mid-Atlantic Ridge. Peltospira gargantua is clearly distinct from other congeners by its much larger size, differences in the number and arrangement of epipodial tentacles, and notably, a hypertrophied oesophageal gland. Lirapex pantagruel is also the largest known species in the genus, differing from other species also by shell shape and sculpture. Phylogenetic reconstructions using the mitochondrial cytochrome c oxidase subunit I (COI) gene agree with their respective generic placements. An expanded oesophageal gland in peltospirids was known only from the endosymbiotic genera Chrysomallon and Gigantopelta, where it is used to host symbionts, indicating that P. gargantua is probably also endosymbiotic. This would represent another case of likely convergently acquired oesophageal endosymbiosis in the family, and the first record of endosymbiotic gastropod from Mid-Atlantic Ridge vents
Phylogenomic Evidence for Host Specialization and Genetic Divergence in Oshv-1 Infecting Magallana Gigas and Ostrea Edulis
No full textUnderstanding how pathogens adapt to new hosts is critical to elucidating the evolutionary mechanisms driving disease emergence. This study investigates the evolutionary dynamics of Ostreid herpesvirus 1 (OsHV-1) in two host species—the Pacific oyster Magallana gigas and the European flat oyster Ostrea edulis—to address the question of host specificity and cross-species transmission. While OsHV-1 is primarily associated with mortality in M. gigas, its detection in O. edulis raises concerns about its potential host range and evolutionary trajectory. We aimed to determine whether viral populations in these two hosts show genetic differentiation and to identify the evolutionary forces shaping this divergence. Using high-throughput sequencing, we assembled 40 OsHV-1 genomes from both oyster species and applied comparative genomics, population genetics, and phylodynamic approaches. Our results show that host species significantly influence viral genetic structure, with two distinct lineages emerging after a cross-species transmission event likely following the introduction of M. gigas into Europe. Selection signals were detected in viral genes related to host interaction, replication, and membrane-associated functions, suggesting host-driven adaptation. These findings underscore the importance of host-specific evolutionary pressures in shaping viral diversity and provide a framework for future studies on host-virus coevolution in marine ecosystems
Working Group on Beam Trawl Surveys (WGBEAM).
No full textThe Working Group on Beam Trawl Surveys (WGBEAM) coordinates and implements European inshore and offshore beam trawl surveys, including planning, standardization, data transmis-sion and data quality assurance. The group also coordinates the Italian-Slovenian and Croatian beam trawl survey in the Adriatic Sea as there is no other body in the EU coordinating beam trawl surveys, and the EU Data Collection Framework requires survey coordination. In 2024, eleven beam trawl surveys were planned, covering the North Sea, 7d, 7e, 7fg, 7a, 8a, 8b and the Northern Adriatic Sea. Severe weather conditions affected the German offshore beam trawl survey, and the Dutch inshore surveys SNS and DYFS in the North Sea, but the spatial coverage remained intact. The English offshore survey in Q1 was affected by bad weather and by delay of permission for sampling in French waters, leading to incomplete spatial coverage. The Belgian and Italian offshore surveys were carried out on board commercial vessels due to unavailability of the research vessels. In both cases the sampling procedures were amended to be able to collect all information. The Dutch offshore North Sea survey and the SNS, as well as the English offshore survey in the Celtic Sea and Irish Sea faced mechanical issues, which led only for the English survey to incomplete spatial coverage. For the first time, the progress was shown on the monthly survey in the Dutch Wadden Sea, set up to monitor the species year-round. Survey results from the offshore and inshore surveys as well as two industry beam trawl surveys were presented in a joint session with survey data end-users: North Sea and Celtic Sea flatfish, elasmobranch and Crangon working group. Stock coordinators presented relevant results from the benchmark groups on brill, sole, turbot, and one of the chairs of the ICES working group on Crangon fisheries presented the use of survey data in the Crangon stock assessment. R scripts to evaluate the combined offshore and inshore beam trawl survey data by region and cross-regionally have been further developed. Specific analyses have been conducted on elasmo-branchs, patterns in abundance and spatial distribution; species identification consistency in in-shore and offshore surveys; age at length consistency for four flatfish species in the North Sea, Cetlic and Irish Sea: sole Solea solea, lemon sole Microstomus kitt, plaice Pleuronectes platessa and dab Limanda limanda. Length-frequency plots were created for all species, and outliers exported for further checking. A first analysis on the occurrence of whiting and brown shrimp (Crangon) was conducted, and a crude inventory of Cephalopod catches in the surveys was made. Developments in the ICES database on trawl surveys were presented by ICES Data Centre, and feedback was given where requested. The TIMES survey protocol for offshore surveys (published in 2023) was updated where needed, to prepare for publication after mid-2025. The TIMES survey protocol for inshore surveys (pub-lished in 2024) was updated where needed and will be published in approximately two years. The progress in day-ring analysis for plaice in the North Sea was presented, and appointments were made to exchange expertise