Volcanism in the Comoros Archipelago, Madagascar, and the East African Rift: What is the link?
The Comoros archipelago located in the western Indian Ocean has been a topic of debate for ca. 50 years regarding its origin. Various mechanisms have been proposed to explain its formation, ranging from the impact of a mantle plume to the development of a plate boundary between the Somalia and Lwandle plates. Determining the timing of the volcanic activity is crucial to understanding the archipelago's origin. Despite recent geochronological studies, the age of the initial volcanic eruptions on the islands remains uncertain due to the difficulty of accessing the earliest lavas. This study uses high-quality seismic reflection profiles and regional stratigraphy to identify the first volcanic series that marked the onset of volcanism on each island of the Comoros Archipelago. Our findings reveal that localized volcanic activity began ca. 32 Ma at Zélée and Geyser banks and Mayotte edifice, the eastern portions of the archipelago, much earlier than previously believed. Volcanism spread across the Comoros archipelago ca. 9-8 Ma, from the northern part of the Mayotte edifice to Mohéli Island in the west. Ca. 4 Ma, volcanic activity occurred on Anjouan Island and the Jumelles seamounts, followed by Grande Comore Island ca. 2 Ma. This progression of ages from east to west indicates a chronological sequence over time. The timing of volcanic activity in the Comoros archipelago is similar to the magmatism evolution documented at Madagascar and along the East African Rift System (EARS). Magmatic activity began in the late Oligocene, followed by quiescence during the middle Miocene, and resumed in the late Miocene, coinciding with widespread deformation along the EARS, including its offshore branches and Madagascar. Our study shows that the regional tectonic control of volcanic activity in the Comoros archipelago began during the early Miocene, thereby suggesting that the Comoros archipelago developed as an offshore branch of the EARS south of the Somalian plate at that time.
(Geosphere. vol. 21, pp. 774-796, 11/07/2026)
iSTeP, INSU - CNRS, SU, CNRS, CY, ITES, ENGEES, UNISTRA, INSU - CNRS, CNRS, EOST, UNISTRA, INSU - CNRS, CNRS, LGENS, INSU - CNRS, CNRS, ENS-PSL, PSL, CNRS, ENS-PSL, PSL, BRGM, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], BGR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CSTJF, [Total Energies. Anciennement : Total, TotalFina, TotalFinaElf], CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE
The spread of Aoroides longimerus Ren & Zheng, 1996 across the Mediterranean and the Atlantic: genetic diversity, anthropogenic transport, and ecological implications
Accurate knowledge of the global distribution of non-indigenous species (NIS) is essential for understanding their invasion dynamics and for implementing timely management measures. This study reports the first records of the marine amphipod Aoroides longimerus, putatively native to the East Asian coast, in Italy (2018), Spain (2019) and Tunisia (2022) and provides the earliest documented record of the species in its introduced European range (Portugal, 2011). Furthermore, it expands the species' known distribution in mainland Portugal (including the northernmost record), Macaronesia (with first records in the Canary Islands and Madeira), and confirms its presence along the Atlantic coasts of France and the Netherlands. Aquaculture facilities, particularly those associated with oyster farming, are probably the primary vector of introduction, while recreational boating may have contributed significantly to secondary dispersal. In comparison to other exotic amphipods, A. longimerus remains absent from many marinas, ports and/or aquaculture facilities in the Mediterranean Sea and adjacent regions, such as the Red Sea. This suggests that the species may still be in the early stages of expansion, or that its dispersal ability across marinas and ports is more limited than that of other amphipods. The present study, however, highlights several key ecological traits of A. longimerus: (i) it can survive year-round despite seasonal fluctuations, and reach high local densities, (ii) it exhibits strong colonisation capacity, as shown by its rapid establishment on settlement plates, and (iii) it displays opportunistic feeding behaviour, primarily consuming detritus. These characteristics underscore the importance of continuous surveillance and effective communication with stakeholders to prevent further expansion of this species.
(Mediterranean Marine Science. vol. 26, n° 1108-393X, pp. 842 - 859, 11/07/2026)
M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, IUEM, IRD, INSU - CNRS, UBO EPE, CNRS, LEMAR, IRD, IFREMER, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, AD2M, SU, CNRS, SBR, SU, CNRS, SBR, SU, CNRS, STAMAR, INSU - CNRS, SU, CNRS, FR2424, SBR, SU, CNRS, UMR ISEM, Cirad, IRD, EPHE, PSL, CNRS, UM, ISYEB, MNHN, EPHE, PSL, SU, CNRS, UA
Observations Of Multidecadal Gravel Beach Dynamics From Space
Gravel barrier systems are ubiquitous on mid-and high-latitude coasts and provide vital protection from coastal flooding and coastal erosion. They are highly dynamic systems that exhibit complex responses to hydrodynamic forcing over a range of timescales (hourly-monthly-decadal-centennial). Their dynamics differ greatly from those of sandy beaches yet have received considerably less attention in the literature, particularly at interannual to decadal scales. We use over four decades of satellite-derived shoreline (SDS) data to explore the long-term dynamic of 45 selected gravel systems around the United Kingdom and Ireland. Unlike most large-scale studies, we apply an SDS extraction methodology specifically tailored to gravel beaches to derive the long-term shoreline trends along 1554 shore-normal transects across our sites. Our findings indicate a great variability in shoreline trends, ranging from -4.73 m/year to +10.5 m/year with the majority of transects (62%) remaining stable over the study period (1984 -2023). Overall, 22% of transects showed statistically significant positive trends and 14% negative trends, resulting in an overall +0.36 m/year mean shoreline trend. Large scale climatic forcing seems to have a stronger control on the evolution of gravel nesses with 29% and 26% of transects having an average correlation of -0.36 and -0.34 with North Atlantic Oscillation and Atlantic Oscillation respectively, while open beaches showed the weakest relationship with climate forcing. Importantly, climate forcing did not seem to be a key driver of change in the regions with the highest rates of progradation.
(11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Impacts of neonicotinoids on biodiversity: a critical review
Neonicotinoids are the most widely used class of insecticides in the world but they have raised numerous concerns regarding their effects on biodiversity. Thus, the objective of this work was to do a critical review of the contamination of the environment (soil, water, air, biota) by neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) and of their impacts on terrestrial and aquatic biodiversity. Neonicotinoids are very frequently detected in soils and in freshwater, and they are also found in the air. They have only been recently monitored in coastal and marine environments, but some studies already reported the presence of imidacloprid and thiamethoxam in transitional or semi-enclosed ecosystems (lagoons, bays and estuaries). The contamination of the environment leads to the exposure and to the contamination of non-target organisms, and to negative effects on biodiversity. Direct impacts of neonicotinoids are mainly reported on terrestrial invertebrates (e.g., pollinators, natural enemies, earthworms) and vertebrates (e.g., birds), and on aquatic invertebrates (e.g., arthropods). Impacts on aquatic vertebrate populations and communities, as well as on microorganisms, are less documented. In addition to their toxicity to directly exposed organisms, neonicotinoid induce indirect effects via trophic cascades as demonstrated in several species (terrestrial and aquatic invertebrates). However, more data are needed to reach firmer conclusions and to get a clearer picture of such indirect effects. Finally, we identified specific knowledge gaps that need to be filled to better understand the effects of neonicotinoids on terrestrial, freshwater and marine organisms, as well as on ecosystem services associated with these biotas.
(Environmental Science and Pollution Research. vol. 32, n° 0944-1344, pp. 2794–2829, 11/07/2026)
ECOSYS, INRAE, RiverLy, INRAE, IFREMER, UMR BAGAP, ESA, INRAE, Institut Agro, VAS, ICE, VAS, UCBL, LBBE, UCBL, VAS, CNRS, LBBE, UCBL, VAS, CNRS, LCE, CNRS, UMLP, UBFC, DECOD, IFREMER, INRAE, Institut Agro, Institut Agro, OFB Service Santé Agri, OFB - DRAS, OFB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR Eco&Sols, Cirad, IRD, INRAE, Institut Agro, UMR MARBEC, IRD, IFREMER, CNRS, UM, EMMAH, AU, INRAE, IMBE, AU, AMU, CNRS, UMay, URAFPA, UL, INRAE, UR HYCAR, INRAE, DEPE, INRAE
Main conclusions and perspectives from the collective scientific assessment of the effects of plant protection products on biodiversity and ecosystem services along the land–sea continuum in France and French overseas territories
Preservation of biodiversity and ecosystem services is critical for sustainable development and human well-being. However, an unprecedented erosion of biodiversity is observed and the use of plant protection products (PPP) has been identified as one of its main causes. In this context, at the request of the French Ministries responsible for the Environment, for Agriculture and for Research, a panel of 46 scientific experts ran a nearly 2-year-long (2020-2022) collective scientific assessment (CSA) of international scientific knowledge relating to the impacts of PPP on biodiversity and ecosystem services. The scope of this CSA covered the terrestrial, atmospheric, freshwater, and marine environments (with the exception of groundwater) in their continuity from the site of PPP application to the ocean, in France and French overseas territories, based on international knowledge produced on or transposable to this type of context (climate, PPP used, biodiversity present, etc.). Here, we provide a brief summary of the CSA's main conclusions, which were drawn from about 4500 international publications. Our analysis finds that PPP contaminate all environmental matrices, including biota, and cause direct and indirect ecotoxicological effects that unequivocally contribute to the decline of certain biological groups and alter certain ecosystem functions and services. Levers for action to limit PPP-driven pollution and effects on environmental compartments include local measures from plot to landscape scales and regulatory improvements. However, there are still significant gaps in knowledge regarding environmental contamination by PPPs and its effect on biodiversity and ecosystem functions and services. Perspectives and research needs are proposed to address these gaps.
(Environmental Science and Pollution Research. vol. 32, n° 0944-1344, pp. 2757–2772, 11/07/2026)
RiverLy, INRAE, ECOSYS, INRAE, IFREMER, ISA, UNS, CNRS, INRAE, UniCA, LMGE, CNRS, UCA, UMR BAGAP, ESA, INRAE, Institut Agro, LPED, IRD, AMU, INERIS, EMMAH, AU, INRAE, VAS, ICE, VAS, CRIOBE, UPVD, EPHE, PSL, CNRS, SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS, CNELIAS, AU, AMU, MMSH, AMU, CNRS, CNRS, LBBE, UCBL, VAS, CNRS, LBBE, UCBL, VAS, CNRS, INRAE, Institut Agro, UBE, LCE, CNRS, UMLP, UBFC, UMR SAVE, UB, Bordeaux Sciences Agro, INRAE, DECOD, IFREMER, INRAE, Institut Agro, Institut Agro, OFB Service Santé Agri, OFB - DRAS, OFB, GREDEG, UNS, CNRS, UniCA, ENSFEA, LEREPS, UT Capitole, Comue de Toulouse, UT2J, Comue de Toulouse, ENSFEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR Eco&Sols, Cirad, IRD, INRAE, Institut Agro, IODE, UR, CNRS, UPR HORTSYS, Cirad, Cirad-PERSYST, Cirad, UMR MARBEC, IRD, IFREMER, CNRS, UM, AMURE, IRD, IFREMER, UBO EPE, CNRS, UR EABX, INRAE, IMBE, AU, AMU, CNRS, UdG, PHYTOX, IFREMER, CUFR, URAFPA, UL, INRAE, UR HYCAR, INRAE, DEPE, INRAE
Manila clam (Ruditapes philippinarum) in France: Fishing activity, governance and present knowledge challenges regarding its biology and ecology
Originally introduced to France in the 1970s for aquaculture purposes, the clam Ruditapes philippinarum (Adam and Reeve, 1850) has thrived in favourable conditions across numerous sites along the Bay of Biscay, English Channel and Mediterranean coasts forming neo-naturalized populations. It is harvested by both recreational and professional fishers, with an estimated production ratio of 2.4 for both activities combined. Total French commercial fishing production is roughly estimated at around 2000 to 3000 tons per year. This activity is managed by three types of regulation at different scales: European (Minimum Conservation Reference Size - MCRS), national (licenses), and regional. Regional instruments govern fishing practices by setting spatial and temporal access rules to fishing grounds (also referred to as deposits), prohibiting certain gear types at the local scale, determining the minimum size of clam fishing (above MCRS) and setting fishing quotas. Not all of them are implemented everywhere; most often, they are based on stock assessment results and specific research programs, which are not available in every location. This article first provides a review of available information on current Manila clam production in France, and its regulation. Second, it offers an overview of recent knowledge mobilized for management purposes. This overview covers biological and ecological processes (i.e. population dynamics, reproduction and spawning, habitats considerations, biotic interactions and infectious diseases), and enables us to identify future research prospects of interest.
(Estuarine, Coastal and Shelf Science. vol. 317, n° 0272-7714, pp. 109206, 11/07/2026)
LERAR, COAST, IFREMER, LMAP, UPPA, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR MARBEC, IRD, IFREMER, CNRS, UM, ASIM, IFREMER, DECOD, IFREMER, INRAE, Institut Agro, Institut Agro, SBR, SU, CNRS, AD2M, SU, CNRS, SBR, SU, CNRS, LOV, INSU - CNRS, SU, CNRS, IMEV, INSU - CNRS, SU, CNRS, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, SMEL, LEMAR, IRD, IFREMER, UBO EPE, CNRS, UR ETTIS, INRAE
Biological features for a minimum conservation reference size revision – case of Ruditapes philippinarum in Arcachon Bay (French Atlantic coast)
The Minimum Conservation Reference Size (MCRS) for marine resources ensure that individuals can mature and reproduce at least once before being caught. For management purposes, MCRS should be revised for specific populations in given areas. In Arcachon Bay (southwest France), fishers have repeatedly requested a review of the MCRS for R. philippinarum. In 2020, a joint recommendation, supported by France, was addressed to the European Commission suggesting a possible reduction in the MCRS of R. philippinarum from 35 mm to 32 mm for Arcachon Bay. This paper provides an overview of the biological features that need to be considered to support such a review, primarily focusing on sexual maturity, individual growth and natural mortality. The reproductive cycle and size at first maturity, estimated at 26.7 mm for the Bay, were found to be similar to other locations in France and in Portugal. The greatest length at which growth slowdown occurred ranges between 24.0 and 31.5 mm with few differences among sites and no significant differences within each site (at hypsometric levels). The natural mortality coefficients were high with 0.67 yr−1 and 0.51 yr−1 for juveniles and adults, respectively. Regarding productivity (resulting from growth and mortality processes) and all methods combined, the optimal balance between individual growth and natural mortality above 30 mm was found at a mean length of 32.2 mm for the intra-lagoon sites and at a mean length of 36.8 mm for the oceanic sites. Based on available information, reducing the MCRS to 32 mm would not threaten population viability. However, the European Commission has raised warning points, which are discussed in light of current regulations in Arcachon Bay.
(Estuarine, Coastal and Shelf Science. vol. 320, n° 0272-7714, pp. 109288, 11/07/2026)
LMAP, UPPA, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Machine Learning Beach Attendance Forecast Modelling from Automatic Video-Derived Counting
Accurate predictions of beach user numbers are important for coastal management, resource allocation, and minimising safety risks, especially when considering surf-zone hazards. The present work applies an XGBoost model to predict beach attendance from automatically video-derived data, incorporating input variables such as weather, waves, tide, and time (e.g., day hour, weekday). This approach is applied to data collected from Biscarrosse Beach during the summer of 2023, where beach attendance varied significantly (from 0 to 2031 individuals). Results indicate that the optimal XGBoost model achieved high predictive accuracy, with a coefficient of determination (R2) of 0.97 and an RMSE of 70.4 users, using daily mean weather data, tide and time as input variables, i.e., disregarding wave data. The model skilfully captures both day-to-day and hourly variability in attendance, with time of day (hour) and daily mean air temperature being the most influential variables. An XGBoost model using only daily mean temperature and hour of the day even shows good predictive accuracy (R2 = 0.90). The study emphasises the importance of daily mean weather data over instantaneous measurements, as beach users tend to plan visits based on forecasts. This model offers reliable, computationally inexpensive, and high-frequency (e.g., every 10 min) beach user predictions which, combined with existing surf-zone hazard forecast models, can be used to anticipate life risk at the beach.
(Journal of Marine Science and Engineering. vol. 13, n° 2077-1312, pp. 1181, 11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR ETTIS, INRAE, UR EABX, INRAE, EPOC, SMGBL
Projet IMPEC : IMpact de la PEChe sur les écosystèmes benthiques du large - Evaluation des habitats benthiques du circalittoral du large dans le golfe du Lion au regard des pressions issues des activités de la pêche démersale aux arts traînants : approche multi-indicateurs - Note de synthèse
Ce projet s'inscrit dans le cadre de l'acquisition de connaissance nécessaire au développement et à la consolidation d'indicateurs DCSMM permettant de qualifier l’intégrité des fonds face aux pressions anthropiques sur le plateau continental. Parmi les indicateurs appliqués actuellement pour quantifier le pourcentage de surface impactée et plus précisément l’intensité de l’impact, aucun n’a été spécifiquement développé et/ou testé sur une perturbation physique telle que celle résultant des pêcheries démersales. Or, la pêche aux arts traînants (chaluts et dragues) est la source de perturbation majeure des fonds sur le plateau continental (e.g. Amoroso et al., 2018 ; Brivois et al., 2018 ; Jac et al., 2020). Cette tâche est rendue d’autant plus difficile qu’il est complexe de qualifier des états de référence, au sens « non-impacté » par les pressions d’origine anthropique. Le projet IMPEC propose d’étudier l’impact de la pêche aux arts traînants sur les fonds marins du plateau continental du golfe du Lion en Méditerranée. Le but du projet est de tester plusieurs indicateurs applicables à différentes composantes benthiques (méga-épifaune, macrofaune, méiofaune, foraminifères) pour évaluer l’état des habitats benthiques meubles au regard de l’impact de la pêche de type dragage et chalutage le long d’un gradient de pression d’abrasion.
(pp. 25, 11/07/2026)
LPG-ANGERS, LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, LECOB, SU, CNRS, OOB, SU, CNRS, LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, Nantes Univ, BIAF, UA, NOC, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR MARBEC, IRD, IFREMER, CNRS, UM
Highway runoff and wastewater effluents as drivers of platinum dynamics in an urban river: Insights from a comprehensive monitoring study
The contribution of a single rain event to daily and annual platinum (Pt) transport in an urban river (Jalle River, South-West of France), assessed from high resolution and annual monitoring, is discussed in terms of dissolved (Pt-d) and particulate (Pt-p) partitioning, sources and fluxes. In normal discharge conditions, the Jalle River Pt-d and Pt-p concentrations are respectively 1.90 +/- 1.62 ng L-1 and 19.8 +/- 6.9 mu g kg(-1) and Pt is mostly transported in the dissolved form (similar to 96 %, 110 +/- 123 mgPt(d) d(-1)), due to low sediment yield and urban discharges from a wastewater treatment plant (WWTP). The Pt-d flux in sewage (36-340 mgPt(d) d(-1)) was mainly attributed to excretions from patient undergoing chemotherapy with Pt-drugs (up to 480,000 mgPt(d) yr(-1) at the watershed scale). After a 2-months dry period, an intense rainstorm discharged >= 112 mg of Pt-p in 4 h from the urban highway, resulting in additional 295 mgPt(p) d(-1) exceptionally transported by the Jalle River. In contrast to normal conditions, during the rainstorm up to similar to 95 % of Pt was transported in particulate form during the first flush, and 80 % of the highway Pt-p flux during the first 40 min contributing to similar to one third of the annual Pt-p flux. Short, intense discharge events must be monitored at a high resolution to accurately estimate annual Pt fluxes in urban rivers.
(Applied Geochemistry. vol. 193, n° 0883-2927, 11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, I2M-BX, UB, CNRS, INRAE