Geomorphology of a modern carbonate slope system and associated sedimentary processes: Example of the giant Great Abaco Canyon, Bahamas
The large acoustic data set acquired during the Carambar cruises is composed of high resolution bathymetry, backscatter data and very-high resolution seismic lines which allow for an overview of the morphology and sediment transfer processes from the shallow upper slope to the abyssal plain of a modern carbonate system: the north-eastern slope of the Little Bahama Bank. Surficial distribution of the acoustic facies and echofacies reflects a wide variety of sedimentary processes along and across the slope. The western sector of the Little Bahama Bank is dominated by depositional processes whereas its eastern sector, which is incised in the lower slope by giant canyons, is affected by erosion and bypass processes. Datasets suggest that currents play an important role both in along-slope sedimentary processes and in the abyssal plain. The Antilles Current appears to affect a large part of the middle and lower slopes. The absence of sizeable present-day channel/levee complexes or lobes at the mouth of the canyon - revealed by the bathymetric map - indicates that the southward flowing Deep Western Boundary Current influences modern abyssal sediment deposition. Based on depositional processes and indicators of canyon maturity observed in facies distribution, the current study proposes that differential subsidence affects the eastern versus western part of the bank. The morphology of the Great Abaco Canyon and Little Abaco Canyon, which extend parallel to the platform, and the Little Bahama Bank slope appears to be related to the Great Abaco Fracture Zone.
(Sedimentology. vol. 68, n° 0037-0746, pp. 266-293, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Response of water-exchange capacity to human interventions in Jiaozhou Bay, China
Intensive anthropogenic activities, land reclamation, a cross-bay bridge construction, and the correction of Red Island have significantly changed the topography of Jiaozhou Bay (JZB) in northern China over the last decades. To quantify the effects of these modifications on the water-exchange capacity of the bay, the Finite Volume Community Ocean Model was used to calculate basin, regional and local residence time (RT) in the years 1935, 1966, 1986, 2000, 2008, and 2013, covering the periods of significant land reclamation. The bridge construction and a government plan to restore Red Island were also included in additional modelling scenarios. The regional RT increased significantly between 1935 and 1986, by 77% in the northeast, 40% in the west and 56% in the north-bridge regions, concurrent with the largest land reclamation. The regional RT continued to increase from 1986 to 2000 in the northeast and north-bridge regions but decreased slightly from 2000. These patterns can be explained by the general decreasing trend of the tidal prism from 1935 to 2000, up to 66% in the northeast region. A significant decrease in residual currents from 1935 to 1966 probably also contributed to explain this trend. The bridge construction had only a limited effect on regional RT. The restoration of Red Island would have reduced the regional RT in the northeast region from 83 to 60 days. The simulation of tracer transport, and therefore calculation of local RT, was found to be sensitive to the scheme used to formulate the horizontal diffusion coefficient, which should be taking into account when comparing results from different model configurations.
(Estuarine, Coastal and Shelf Science. vol. 249, n° 0272-7714, pp. 107088, 22/04/2026)
UNSW, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Fluorescence analysis allows to predict the oxidative capacity of humic quinones in dissolved organic matter: implication for pollutant degradation
Dissolved organic matter (DOM) controls the degradation and sequestration of aquatic pollutants and, in turn, water quality. In particular, pollutant degradation is performed by oxidant species that are generated by exposure of DOM to solar light, yet, since DOM is a very complex mixture of poorly known substances, the relationships between potential oxidant precursors in DOM and their oxydative capacity is poorly known. Here, we hypothesized that production of oxidant species could be predicted using fluorescence analysis. We analysed water samples from an alluvial plain by fluorescence spectroscopy; the three-dimensional spectra were then decomposed into seven individual components using a multi-way algorithm. Components include a protein-like fluorophore, e.g. tryptophan-like and tyrosine-like, three humic fluorophores, 2-naphthoxyacetic acid, and a by-product. We compared component levels with the ability of water samples to generate reactive species under solar light. The results show a strong correlation between reactive species production and the intensity of two humic-like fluorophores assigned to reduced quinones. Monitoring these fluorophores should thus allow to predict the ability of DOM degradation of pollutants in surface waters.
(Environmental Chemistry Letters. vol. 19, n° 1610-3653, pp. 1857-1863, 22/04/2026)
ICCF, SIGMA Clermont, INC-CNRS, UCA [2017-2020], CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GEOLAB, UBP, IR SHS UNILIM, UNILIM, UCA [2017-2020], CNRS, UCA
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, 22/04/2026)
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, 22/04/2026)
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, 22/04/2026)
ANSES, UBO EPE, VIMEP, ANSES, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
A review of the effects of contamination and temperature in Solea solea larvae. Modeling perspectives in the context of climate change
The flatfish species Solea solea has been the subject of research for supporting their management in fisheries, restocking natural populations, domestication in aquaculture, and ecotoxicology research. Soles undergo a metamorphosis with drastic morphological and physiological changes and settlement, processes that make them potentially more vulnerable to pollutants than other fish. Up to date, efforts made to develop its aquaculture production in Europe have been limited. In the context of climate change (CC), this review aims i) to gather research conducted in S. solea larvae that summarizes the effects of increased temperature and contaminant exposures during larval development; and ii) to provide a summarized and synergistic view about its larval development. The review consists of 4 sections. Section 1 justifies the selection of this species from ecological and economic perspectives. Section 2 focuses on larvae ontogenesis, metamorphosis, rearing challenges, and further aquaculture production. Section 3 reviews studies dealing with the effects of temperature change (due to CC) and pollutants on larval development. Finally, section 4 provides a "how to go forward on ecotoxicological research" guideline, in which we highlight the methods that we found promising as tools to study the combined effects of CC and pollution. The section includes a multidisciplinary framework that proposes how existing data coming from different scientific domains can be synthesized to be useful for risk assessors and ecotoxicologists. To benefit from such a framework, it is necessary to reach consensus and nurture team effort from players that operate in different research disciplines.
(Journal of Sea Research (JSR). vol. 176, n° 1385-1101, pp. 102101, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSEA MARBEC, UMR MARBEC, IRD, IFREMER, UM, CNRS, UMR MARBEC, IRD, IFREMER, UM, CNRS, GABI, INRAE, LEMAR, IRD, IFREMER, UBO EPE, 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, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, RWTH Aachen
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, 22/04/2026)
UiT, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The Southern Ocean Radiolarian (SO-RAD) dataset: a new compilation of modern radiolarian census data
Abstract. Radiolarians (holoplanktonic protozoa) preserved in marine sediments are commonly used as palaeoclimate proxies for reconstructing past Southern Ocean environments. Generating reconstructions of past climate based on microfossil abundances, such as radiolarians, requires a spatially and environmentally comprehensive reference dataset of modern census counts. The Southern Ocean Radiolarian (SO-RAD) dataset includes census counts for 238 radiolarian taxa from 228 surface sediment samples located in the Atlantic, Indian, and southwest Pacific sectors of the Southern Ocean. This compilation is the largest radiolarian census dataset derived from surface sediment samples in the Southern Ocean. The SO-RAD dataset may be used as a reference dataset for palaeoceanographic reconstructions, or for studying modern radiolarian biogeography and species diversity. As well as describing the data collection and collation, we include recommendations and guidelines for cleaning and subsetting the data for users unfamiliar with the procedures typically used by the radiolarian community. The SO-RAD dataset is available to download from https://doi.org/10.1594/PANGAEA.929903 (Lawler et al., 2021).
(Earth System Science Data. vol. 13, n° 1866-3508, pp. 5441-5453, 22/04/2026)
RSES, ANU, HU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS