Spatial variability and sources of platinum in a contaminated harbor – tracing coastal urban inputs
Biogeochemical cycles that include processes to control platinum (Pt) distribution remain widely unknown in aquatic environments, especially in coastal systems. Dissolved Pt concentrations in coastal seawater (PtD) and in suspended particulate matter (SPM, PtP) were measured, together with master variables comprising dissolved oxygen, dissolved and particulate organic carbon, chlorophyll-a, turbidity, and ammonium levels, along two longitudinal profiles in the industrial Genoa Harbor (north-west Italy). Concentrations and spatial distribution of PtD and PtP levels reflect distinct concentration gradients that were attributed to different Pt sources such as hospital, domestic and industrial wastewater, atmospheric deposition, and/or road runoff. Concentrations reaching up to 0.18 ng L−1 PtD and 14 ng g−1 PtP reflect the impact of Pt urban inputs to coastal sites. These first data highlight considerable anthropogenic contamination in a confined harbor compared with the proposed reference value for the western Mediterranean surface seawater measured at external sites. Identified correlations between Pt levels and human pollution signals suggest the potential use of Pt as a new tracer of anthropogenic inputs that can be applied to other urbanised coastal systems. Biogeochemical processes that induce changes in the partitioning and fate of Pt in coastal seawater reflect a spatial variability and highlight the need for comprehensive environmental monitoring at an appropriate spatial scale.
(Environmental Chemistry. vol. 17, n° 1448-2517, pp. 105-117, 24/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNIGE, UniGe
Coral carbon isotope sensitivity to growth rate and water depth with paleo-sea level implications.
Although reef coral skeletal carbon isotopes (δC) are routinely measured, interpretation remains controversial. Here we show results of a consistent inverse relationship between coral δC and skeletal extension rate over the last several centuries in Porites corals at Fiji, Tonga, Rarotonga and American Samoa in the southwest Pacific. Beginning in the 1950s, this relationship breaks down as the atmospheric C Suess effect shifts skeletal δC > 1.0‰ lower. We also compiled coral δC from a global array of sites and find that mean coral δC decreases by -1.4‰ for every 5 m increase in water depth (R = 0.68, p < 0.01). This highlights the fundamental sensitivity of coral δC to endosymbiotic photosynthesis. Collectively, these results suggest that photosynthetic rate largely determines mean coral δC while changes in extension rate and metabolic effects over time modulate skeletal δC around this mean value. The newly quantified coral δC-water depth relationship may be an effective tool for improving the precision of paleo-sea level reconstruction using corals.
(Nature Communications. vol. 10, n° 2041-1723, pp. 2056, 24/04/2026)
LDEO, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ZMT
Declining maerl vitality and habitat complexity across a dredging gradient: Insights from in situ sediment profile imagery (SPI)
Maerl beds form complex biogenic benthic habitats, characterized by high productivity as well as diverse biological communities. Disturbances associated with extraction and/or fishing activities using mobile bottom-contacting gears such as clam-dredges induce the most severe and long-term effects on these fragile habitats. We here investigated the effects of dredge-fishing on maerl in the bay of Brest (France). We quantified maerl beds structure and vitality across a fine scale quantified dredging intensity gradient through the acquisition of in-situ images of beds cross-section using Sediment Profile Imaging system (SPI). Declines in the proxies of maerl vitality and habitat complexity were measured across the gradient, and were associated with significant changes in the vertical distribution of live and dead maerl as well as of interstitial space. Fishing with dredges caused maerl mortality, substratum compaction, and decreasing habitat complexity. SPI imaging techniques also allowed for an assessment of changes in spatial heterogeneity that dredging created on several aspects of the structure and vitality of maerl beds. It suggests that direct and indirect disturbances induced by dredging are not acting at the same spatial scale, and can thereby differentially affect the ecosystem functions linked to vitality and habitat complexity.
(Scientific Reports. vol. 9, n° 2045-2322, pp. 16463, 24/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Application of the European Water Framework Directive: Identification of reference sites and bioindicator fish species for mercury in tropical freshwater ecosystems (French Guiana)
Mercury (Hg) is a toxic metal subject to several international regulations. The European Water Framework Directive (WFD) established in 2008 an Environmental Quality Standard for biota (EQSbiota) at 0.02 µg.g.
(Ecological Indicators. vol. 106, n° 1470-160X, pp. 14, 24/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRSTEA
Identifying 2010 Xynthia Storm Signature in GNSS-R-Based Tide Records
In this study, three months of records (January-March 2010) that were acquired by a geodetic Global Navigation Satellite Systems (GNSS) station from the permanent network of RGP (Réseau GNSS Permanent), which was deployed by the French Geographic Institute (IGNF), located in Socoa, in the south of the Bay of Biscay, were used to determine the tide components and identify the signature of storms on the signal to noise ratio (SNR) during winter 2010. The Xynthia storm hit the French Atlantic coast on the 28th of February 2010, causing large floods and damages from the Gironde to the Loire estuaries. Blind separation of the tide components and of the storm signature was achieved while using both a singular spectrum analysis (SSA) and a continuous wavelet transform (CWT). A correlation of 0.98/0.97 and root mean square error (RMSE) of 0.21/0.28 m between the tide gauge records of Socoa and our estimates of the sea surface height (SSH) using the SSA and the CWT, respectively, were found. Correlations of 0.76 and 0.7 were also obtained between one of the modes from the SSA and atmospheric pressure from a meteorological station and a mode of the SSA. Particularly, a correlation reaches to 0.76 when using both the tide residual that is associated to surges and atmospheric pressure variation.
(Remote Sensing. vol. 11, n° 2072-4292, pp. 782, 24/04/2026)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, DTP, UT3, Comue de Toulouse, INSU - CNRS, CNRS, BRGM, SIAME, UPPA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Monsoon-driven Saharan dust variability over the past 240,000 years
Reconstructions of past Saharan dust deposition in marine sediments provide foundational records of North African climate over time scales of 10(3) to 10(6) years. Previous dust records show primarily glacial-interglacial variability in the Pleistocene, in contrast to other monsoon records showing strong precessional variability. Here, we present the first Saharan dust record spanning multiple glacial cycles obtained using Th-230 normalization, an improved method of calculating fluxes. Contrary to previous data, our record from the West African margin demonstrates high correlation with summer insolation and limited glacial-interglacial changes, indicating coherent variability in the African monsoon belt throughout the late Pleistocene. Our results demonstrate that low-latitude Saharan dust emissions do not vary synchronously with high-and mid-latitude dust emissions, and they call into question the use of existing Plio-Pleistocene dust records to investigate links between climate and hominid evolution.
(Science Advances. vol. 5, n° 2375-2548, pp. eaav1887, 24/04/2026)
GEOPS, UP11, CNRS, EAPS, MIT, MIT, LDEO, UdeC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Introduction to the Special Issue on Breaking Waves
(European Journal of Mechanics - B/Fluids. vol. 73, n° 0997-7546, pp. 1-5, 24/04/2026)
UiB, CARDAMOM, IMB, UB, Bordeaux INP, CNRS, Inria, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, I2M-BX, UB, CNRS, INRAE
Plant interactions shape pollination networks via nonadditive effects
Plants grow in communities where they interact with other plants and with other living organisms such as pollinators. On the one hand, studies of plant–plant interactions rarely consider how plants interact with other trophic levels such as pollinators. On the other, studies of plant–animal interactions rarely deal with interactions within trophic levels such as plant–plant competition and facilitation. Thus, to what degree plant interactions affect biodiversity and ecological networks across trophic levels is poorly understood. We manipulated plant communities driven by foundation species facilitation and sampled plant–pollinator networks at fine spatial scale in a field experiment in Sierra Nevada, Spain. We found that plant–plant facilitation shaped pollinator diversity and structured pollination networks. Nonadditive effects of plant interactions on pollinator diversity and interaction diversity were synergistic in one foundation species networks while they were additive in another foundation species. Nonadditive effects of plant interactions were due to rewiring of pollination interactions. In addition, plant facilitation had negative effects on the structure of pollination networks likely due to increase in plant competition for pollination. Our results empirically demonstrate how different network types are coupled, revealing pervasive consequences of interaction chains in diverse communities.
(Ecology. vol. 100, n° 0012-9658, pp. e02619, 24/04/2026)
UZH, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UNIROMA, UAL, OUMNH, LSV Angers, LSV, ANSES, UNIBO
Correlating three centuries of historical and geological data for the marine deposit reconstruction of two depositional environments of the French Atlantic coast
This paper details a high-resolution record of French Atlantic coast extreme wave events using a multi-proxy analysis of dated sedimentary deposits. Two lagoons 1) the Petite Mer de Gâvres and 2) the Traicts du Croisic were chosen to identify damaging storm events from the last 300 years with Beeker sampling, 210Pb and 137Cs dating and sedimentary analysis. Using two new geochemical proxies in the French Atlantic coast, Sr/Fe and Ca/Ti, shows that several storminess events are reported in the nine cores drilled. By correlation with historical archives, seven major storms are confirmed: 1924 CE, 1940 CE, 1972 CE, 1977 CE, 1990 CE, 1999 CE, and an 1896 CE highly damaging event. Four other XIXth and XVIIIth century extreme wave event correlations are also proposed from this multi-proxy analysis: 1775 CE, 1811 CE, 1838 CE and 1876 CE. Societal and natural impacts caused by these coastal floods are revealed using our dense and varied historical archives.
(Marine Geology. vol. 407, n° 0025-3227, pp. 181-191, 24/04/2026)
OSUNA, UA, UN UFR ST, UN, IFSTTAR, INSU - CNRS, Cnam, CNRS, IMT Atlantique, IMT, LETG - Nantes, UNICAEN, NU, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
EStimating Contaminants tRansfers Over Complex food webs (ESCROC): An innovative Bayesian method for estimating POP's biomagnification in aquatic food webs
Pollution greatly impacts ecosystems health and associated ecological functions. Persistent Organic Pollutants (POPs) are among the most studied contaminants due to their persistence, bioaccumulation, and toxicity potential. Biomagnification is often described using the estimation of a Trophic Magnification Factor (TMF). This estimate is based on the relationship between contamination levels of the species and their trophic level. However, while the estimation can be significantly biased in relation to multiple sources of uncertainty (e.g. species physiology, measurement errors, food web complexity), usual TMF estimation methods typically do not allow accounting for these potential biases. More accurate and reliable assessment tool of TMFs and their associated uncertainty are therefore needed in order to appropriately guide chemical pollution management. The present work proposes a relevant and innovative TMF estimation method accounting for its many variability sources. The ESCROC model (EStimating Contaminants tRansfers Over Complex food webs), which is implemented in a Bayesian framework, allows for a more reliable and rigorous assessment of contaminants trophic magnification, in addition to accurate estimations of isotopes trophic enrichment factors and their associated uncertainties in food webs. Similar to classical mixing models used in food web investigations, ECSROC computes diet composition matrices using isotopic composition data while accounting for contamination data, leading to more robust food web descriptions. As a demonstration of the practical application of the model, ESCROC was implemented to revisit the trophic biomagnification of 5 polyfluoroalkyl substances (PFAS) in a complex estuarine food web (the Gironde, SW France). In addition to the TMF estimate and 95% confidence intervals, the model provided biomagnification probabilities associated to the investigated contaminants.
(Science of the Total Environment. vol. 658, n° 0048-9697, pp. 638-659, 24/04/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPTC, UB, CNRS, ISM, UB, INC-CNRS, CNRS