Overexploitation, Recovery, and Warming of the Barents Sea Ecosystem During 1950–2013
The Barents Sea (BS) is a high-latitude shelf ecosystem with important fisheries, high and historically variable harvesting pressure, and ongoing high variability in climatic conditions. To quantify carbon flow pathways and assess if changes in harvesting intensity and climate variability have affected the BS ecosystem, we modeled the ecosystem for the period 1950–2013 using a highly trophically resolved mass-balanced food web model (Ecopath with Ecosim). Ecosim models were fitted to time series of biomasses and catches, and were forced by environmental variables and fisheries mortality. The effects on ecosystem dynamics by the drivers fishing mortality, primary production proxies related to open-water area and capelin-larvae mortality proxy, were evaluated. During the period 1970–1990, the ecosystem was in a phase of overexploitation with low top-predators’ biomasses and some trophic cascade effects and increases in prey stocks. Despite heavy exploitation of some groups, the basic ecosystem structure seems to have been preserved. After 1990, when the harvesting pressure was relaxed, most exploited boreal groups recovered with increased biomass, well-captured by the fitted Ecosim model. These biomass increases were likely driven by an increase in primary production resulting from warming and a decrease in ice-coverage. During the warm period that started about 1995, some unexploited Arctic groups decreased whereas krill and jellyfish groups increased. Only the latter trend was successfully predicted by the Ecosim model. The krill flow pathway was identified as especially important as it supplied both medium and high trophic level compartments, and this pathway became even more important after ca. 2000. The modeling results revealed complex interplay between fishery and variability of lower trophic level groups that differs between the boreal and arctic functional groups and has importance for ecosystem management.
(Frontiers in Marine Science. vol. 8, n° 2296-7745, 02/09/2026)
UiT, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
A first assessment of organic carbon burial in the West Gironde Mud Patch (Bay of Biscay)
On the Bay of Biscay continental shelf, there are several mid-shelf mud patches including La Grande Vasière to the north, the West Gironde Mud Patch (WGMP) off the Gironde estuary and the Basque Mud Patch close to the Spanish border. In general, these deposits are several meters thick and cover coarser substrate. Questions remain about their storage capability for fine particles and carbon. This work investigates the sedimentation of the WGMP in order to develop a first estimate of organic carbon (OC) burial. Interface sediment cores were collected at nine stations along two cross-shelf transects in October-November 2016. X-radiograph imaging and grain-size analyses were used to characterize sedimentary structures. 210 Pb xs depth profiles were established to calculate sediment (SAR) and mass (MAR) accumulation rates. Sedimentary structures indicate episodic sandy inputs overlying older deposits at proximal sites, and relatively continuous sedimentation at seaward locations. On the outer-central portion of the northern transect, a maximum SAR (0.47 cm yr − 1) was observed, suggesting a depocenter. On the southern transect, excluding two stations where sedimentary inputs appear massive but sporadic, the SARs are lower (<0.3 cm yr − 1). Quantitative estimates of OC burial rates increase seaward with a maximum of 45 gC m − 2 yr − 1. To evaluate carbon loading independent of grain-size variability, OC values were normalized to surface area of sediments (SA). Interestingly, a qualitative comparison of OC burial efficiencies using the OC/SA ratio highlights three groups of sites (low, medium and relatively high OC burial efficiency) which are likely related both to different sedimentary environments and variable deposition conditions linked to local environmental conditions and depth. This work highlights the likely control of hydrodynamic intensity and sedimentary inputs on the amount of OC stored in the WGMP sediments.
(Continental Shelf Research. vol. 221, n° 0278-4343, pp. 104419, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, URI
A Bayesian network approach to modelling rip-current drownings and shore-break wave injuries
Abstract. A Bayesian network (BN) approach is used to model and predict shore-break-related injuries and rip-current drowning incidents based on detailed environmental conditions (wave, tide, weather, beach morphology) on the high-energy Gironde coast, southwest France. Six years (2011–2017) of boreal summer (15 June–15 September) surf zone injuries (SZIs) were analysed, comprising 442 (fatal and non-fatal) drownings caused by rip currents and 715 injuries caused by shore-break waves. Environmental conditions at the time of the SZIs were used to train two separate Bayesian networks (BNs), one for rip-current drownings and the other one for shore-break wave injuries. Each BN included two so-called “hidden” exposure and hazard variables, which are not observed yet interact with several of the observed (environmental) variables, which in turn limit the number of BN edges. Both BNs were tested for varying complexity using K-fold cross-validation based on multiple performance metrics. Results show a poor to fair predictive ability of the models according to the different metrics. Shore-break-related injuries appear more predictable than rip-current drowning incidents using the selected predictors within a BN, as the shore-break BN systematically performed better than the rip-current BN. Sensitivity and scenario analyses were performed to address the influence of environmental data variables and their interactions on exposure, hazard and resulting life risk. Most of our findings are in line with earlier SZI and physical hazard-based work; that is, more SZIs are observed for warm sunny days with light winds; long-period waves, with specifically more shore-break-related injuries at high tide and for steep beach profiles; and more rip-current drownings near low tide with near-shore-normal wave incidence and strongly alongshore non-uniform surf zone morphology. The BNs also provided fresh insight, showing that rip-current drowning risk is approximately equally distributed between exposure (variance reduction Vr=14.4 %) and hazard (Vr=17.4 %), while exposure of water user to shore-break waves is much more important (Vr=23.5 %) than the hazard (Vr=10.9 %). Large surf is found to decrease beachgoer exposure to shore-break hazard, while this is not observed for rip currents. Rapid change in tide elevation during days with large tidal range was also found to result in more drowning incidents. We advocate that such BNs, providing a better understanding of hazard, exposure and life risk, can be developed to improve public safety awareness campaigns, in parallel with the development of more skilful risk predictors to anticipate high-life-risk days.
(Natural Hazards and Earth System Sciences. vol. 21, n° 1561-8633, pp. 2075-2091, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BPH, UB, INSERM
Generational effects of a chronic exposure to a low environmentally relevant concentration of glyphosate on rainbow trout, Oncorhynchus mykiss
In the past few decades, glyphosate became the most used herbicide substance worldwide. As a result, the substance is ubiquitous in surface waters. Concerns have been raised about its ecotoxicological impact, but little is known about its generational toxicity. In this study, we investigate the impact of an environmentally relevant concentration of glyphosate and its co-formulants on an F2 generation issued from exposed generations F0 and F1. Trans, inter and multigenerational toxicity of 1 μg L−1 of the active substance was evaluated on early stages of development and juvenile rainbow trout (Oncorhynchus mykiss) using different molecular, biochemical, immuno-hematologic, and biometric parameters, behavior analysis, and a viral challenge. Reproductive parameters of generation F1 were not affected. However, developmental toxicity in generation F2 due to glyphosate alone or co-formulated was observed with head size changes (e.g. head surface up to +10%), and metabolic disruptions (e.g. 35% reduction in cytochrome-c-oxidase). Moreover, larvae exposed transgenerationally to Viaglif and intergenerationally to glyphosate and Roundup presented a reduced response to light, potentially indicating altered escape behavior. Overall methylation was, however, not altered and further experiments using gene-specific DNA metylation analyses are required. After several months, biochemical parameters measured in juvenile fish were no longer impacted, only intergenerational exposure to glyphosate drastically increased the susceptibility of rainbow trout to hematopoietic necrosis virus. This result might be due to a lower antibody response in exposed fish. In conclusion, our results show that generational exposure to glyphosate induces developmental toxicity and increases viral susceptibility. Co-formulants present in glyphosate-based herbicides can modulate the toxicity of the active substance. Further investigations are required to study the specific mechanisms of transmission but our results suggest that both non-genetic mechanisms and exposure during germinal stage could be involved.
(Science of the Total Environment. vol. 801, n° 0048-9697, pp. 149462, 02/09/2026)
ANSES, UBO EPE, VIMEP, ANSES, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Sorption and desorption kinetics of PFOS to pristine microplastic
The sorption processes of persistent organic pollutants on microplastics particles are poorly understood. Therefore, the present study investigated the sorption processes of perfluorooctanesulfonate (PFOS) on polyethylene (PE) microplastic particles (MPs) which are representing a prominent environmental pollutant and one of the most abundant microplastic polymers in the aquatic environment, respectively. The focus was set on the investigation of the impact of the particle size on PFOS sorption using four different PE MPs size ranges. The sorption kinetics for 6 months was studied with one selected size range of PE MPs. Besides, the desorption of PFOS from PE MPs under simulated digestive conditions was carried out by using artificial gut fluid mimicking the intestinal juice of fish. The investigation of the size effects of particles over 6 months demonstrated a linear increase of PFOS concentration sorbed onto PE with a decrease of the particle size. Thus, our findings implicate efficient sorption of PFOS onto PE MPs of different sizes. The results showed that PFOS desorbed from the PE MPs into the artificial gut fluid with a rate of 70 to 80%. Besides, a longer exposure of PE MPs to PFOS leads to a higher concentration adsorbed by PE MPs, which may favor the ingestion of higher concentration of PFOS, and thus represents a higher risk to transfer relevant concentrations of PFOS during digestion.
(Environmental Science and Pollution Research. vol. 29, n° 0944-1344, pp. 4497-4507, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, NEOLAiA, RWTH Aachen
A Global Ocean Oxygen Database and Atlas for assessing and predicting deoxygenation and ocean health in the open and coastal ocean
In this paper, we outline the need for a coordinated international effort toward the building of an open-access Global Ocean Oxygen Database and ATlas (GO$_2$DAT) complying with the FAIR principles (Findable, Accessible, Interoperable, and Reusable). GO$_2$DAT will combine data from the coastal and open ocean, as measured by the chemical Winkler titration method or by sensors (e.g., optodes, electrodes) from Eulerian and Lagrangian platforms (e.g., ships, moorings, profiling floats, gliders, ships of opportunities, marine mammals, cabled observatories). GO$_2$DAT will further adopt a community-agreed, fully documented metadata format and a consistent quality control (QC) procedure and quality flagging (QF) system. GO$_2$DAT will serve to support the development of advanced data analysis and biogeochemical models for improving our mapping, understanding and forecasting capabilities for ocean O$_2$ changes and deoxygenation trends. It will offer the opportunity to develop quality-controlled data synthesis products with unprecedented spatial (vertical and horizontal) and temporal (sub-seasonal to multi-decadal) resolution. These products will support model assessment, improvement and evaluation as well as the development of climate and ocean health indicators. They will further support the decision-making processes associated with the emerging blue economy, the conservation of marine resources and their associated ecosystem services and the development of management tools required by a diverse community of users (e.g., environmental agencies, aquaculture, and fishing sectors). A better knowledge base of the spatial and temporal variations of marine O$_2$ will improve our understanding of the ocean O$_2$ budget, and allow better quantification of the Earth’s carbon and heat budgets. With the ever-increasing need to protect and sustainably manage ocean services, GO$_2$DAT will allow scientists to fully harness the increasing volumes of O$_2$ data already delivered by the expanding global ocean observing system and enable smooth incorporation of much higher quantities of data from autonomous platforms in the open ocean and coastal areas into comprehensive data products in the years to come. This paper aims at engaging the community (e.g., scientists, data managers, policy makers, service users) toward the development of GO$_2$DAT within the framework of the UN Global Ocean Oxygen Decade (GOOD) program recently endorsed by IOC-UNESCO. A roadmap toward GO$_2$DAT is proposed highlighting the efforts needed (e.g., in terms of human resources).
(Frontiers in Marine Science. vol. 8, n° 2296-7745, pp. 724913, 02/09/2026)
ULiège, CNES, NOAA, SERC, UNESCO, GEOMAR, IO-PAN, PAN, GHER, ULiège, IOW, IRSI, IFREMER, MBARI, LOV, INSU - CNRS, SU, CNRS, IMEV, INSU - CNRS, SU, CNRS, UBC EOAS, UBC, NIWA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRD, CECI, CERFACS, INSU - CNRS, CNRS, UCA, OGS, DMI, IGP, JAMSTEC, MRI, JMA, UP System, RSMAS, NORCE, SIO - UC San Diego, UC San Diego, UC, SUNY, CSIR, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, BCCR, BIO / UiB, UiB, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, OVSQ, UVSQ, INSU - CNRS, CNRS, LSU, UMCES, ARC, USF, UBC, LOPS, IRD, IFREMER, INSU - CNRS, UBO EPE, CNRS, HKU
The silent spring of Sargassum
(Environmental Science and Pollution Research. vol. 28, n° 0944-1344, pp. 15580--15583, 02/09/2026)
CUFR, BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, Migrinter [Poitiers], UP, CNRS, DEAL, LEMAR, IRD, IFREMER, UBO EPE, CNRS, CEVA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Carbon accumulation rates of Holocene peatlands in central–eastern Europe document the driving role of human impact over the past 4000 years
Abstract. Peatlands are one of the largest terrestrial carbon sinks on the planet, yet little is known about the carbon accumulation rates (CARs) of mountainous peatlands. The long-term variability in the size of the associated carbon sink and its drivers remain largely unconstrained, especially when the long-term anthropogenic impact is also considered. Here, we present a composite CAR record of nine peatlands from central–eastern Europe (Romania and Serbia) detailing variability in the rates of carbon accumulation during the Holocene. We show examples of extremely high long-term rates of carbon accumulation (LORCA>120 gCm-2yr-1), indicating that mountain peatlands constitute an efficient regional carbon sink at times. By comparing our data to modelled palaeoclimatic indices and to measures of anthropogenic impact we disentangle the drivers of peat carbon accumulation in the area. Variability in early- and mid-Holocene CARs is linked to hydroclimatic controls, with high CARs occurring during the early Holocene and lower CARs associated with the transition to cooler and moister mid-Holocene conditions. By contrast, after 4000 years (calibrated) before present (years BP), the trends in CARs indicate a divergence from hydroclimate proxies, suggesting that other processes became the dominant drivers of peat CARs. We propose that enhanced erosion following tree cover reduction as well as increased rates of long-distance atmospheric dust fallout might have played a role, as both processes would result in enhanced mineral and nutrient supply to bog surfaces, stimulating peatland productivity. Surprisingly though, for the last 1000 years, reconstructed temperature is significantly correlated with CARs, with rising temperatures linked to higher CARs. Under future climate conditions, which are predicted to be warmer in the region, we predict that peat growth may expand but that this is entirely dependent upon the scale of human impact directly affecting the sensitive hydrological budget of these peatlands.
(Climate of the Past. vol. 17, n° 1814-9324, pp. 2633 - 2652, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, IRD, EPHE, PSL, UM, CNRS, UBB
Contrasting northern and southern European winter climate trends during the Last Interglacial
The Last Interglacial (LIG; 130–115 ka) is an important test bed for climate science as an instance of significantly warmer than preindustrial global temperatures. However, LIG climate patterns remain poorly resolved, especially for winter, affected by a suite of strong feedbacks such as changes in sea-ice cover in the high latitudes. We present a synthesis of winter temperature and precipitation proxy data from the Atlantic seaboard of Europe, spanning from southern Iberia to the Arctic. Our data reveal distinct, opposite latitudinal climate trends, including warming winters seen in the European Arctic while cooling and drying occurred in southwest Europe over the LIG. Climate model simulations for 130 and 120 ka suggest these contrasting climate patterns were affected by a shift toward an atmospheric circulation regime with an enhanced meridional pressure gradient and strengthened midlatitude westerlies, leading to a strong reduction in precipitation across southern Europe.
(Geology. vol. 49, n° 0091-7613, pp. 1220-1224, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, USN
Juvenile growth deficit as an early alert of cockle Cerastoderma edule mortality
In the population dynamics of bi-phasic marine invertebrates, the fitness of one stage in the life of a cohort affects that of the following stage. This effect makes the prediction of the fate of a cohort challenging. We conducted a 22 yr monthly survey of a population of cockles Cerastoderma edule focussed on the juvenile stage. Two types of years were distinguished in terms of cohort longevity: a low-mortality group (‘L’) and a high-mortality group (‘H’). The cockle shell lengths of the 0+ cohorts was higher in the L group, in August and September. A cohort could hereby confidently be assigned to the L or H group as soon as August. Maximum cockle abundance in the cohorts, parasite load, or date of recruitment did not discriminate the groups, while an early date for the peak of the 0+ cohort abundance could be related to the L group. The maximum air temperature and the chl a concentration in July were higher in the H group, whereas the minimum salinity during the month of September was slightly lower in the H group of years. Therefore, a juvenile shell length under a given threshold was identified as an early alert for a short lifespan of the cockle cohort. This long-term analysis contributes to the deeper understanding of the population dynamics of bi-phasic invertebrates. The success of juveniles is not solely related to the intensity of recruitment or mortality by predation, but could also be linked to their fitness, their growth rates appearing as a proxy.
(Marine Ecology Progress Series. vol. 679, n° 0171-8630, pp. 85-99, 02/09/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IMS, UB, CNRS