Updated calibration of the clumped isotope thermometer in planktonic and benthic foraminifera
Accurate reconstruction of past ocean temperatures is of critical importance to paleoclimatology. Carbonate clumped isotope thermometry (“Δ47 ”) is a relatively recent technique based on the strong relationship between calcification temperature and the statistical excess of 13C–18O bonds in carbonates. Its application to foraminifera holds great scientific potential, particularly because Δ47 paleotemperature reconstructions do not require assumptions regarding the 18O composition of seawater. However there are still relatively few published observations investigating the potential influence of parameters such as salinity or foraminiferal size and species. We present a new calibration data set based on 234 replicate analyses of 9 planktonic and 2 benthic species of foraminifera collected from recent core-top sediments, with calcification temperatures ranging from −2 to 25 °C. We observe a strong relationship between Δ47 values and independent, oxygen-18 estimates of calcification temperatures:
Δ47 = 41.63 × 103/T2 + 0.2056
The formal precision of this regression (± 0.7–1.0 °C at 95 % confidence level) is much smaller than typical analytical errors. Our observations confirm the absence of significant species-specific biases or salinity effects. We also investigate potential foraminifer size effects between 200 and > 560 μm in 6 species, and conclude that all size fractions from a given core-top location and species display statistically undistinguishable Δ47 values. These findings provide a robust foundation for future inter-laboratories comparisons and paleoceanographic applications.
(Geochimica et Cosmochimica Acta. vol. 239, n° 0016-7037, pp. 1-16, 29/04/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPG-ANGERS, LPG, UA, UN UFR ST, UN, INSU - CNRS, CNRS, CLIMAG, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
A comparison between water circulation and terrestrially-driven dissolved silica fluxes to the Mediterranean Sea traced using radium isotopes
The circulation of seawater through permeable coastal sediments is increasingly recognized as an important source of nutrients, including dissolved silica (DSi), to the coastal ocean. Here, we utilized a Ra isotope (223 Ra, 224 Ra ex , 228 Ra) mass balance to quantify DSi fluxes driven by water circulation to a small shallow coastal lagoon (La Palme; French Mediter-ranean) during June 2016, as compared to karstic groundwater spring inputs. The DSi flux driven by lagoon water circulation (derived from 224 Ra ex) was approximately one order of magnitude greater (1900 ± 1700 mol d À1) than the DSi load of the karstic groundwater spring (250 ± 50 mol d À1) and greater than molecular diffusion (970 ± 750 mol d À1). Lagoon water circulation was a negligible source of 228 Ra, indicating that circulation-driven DSi inputs occur over a timescale of days. Offshore transects were studied to quantify fluxes of marine-derived submarine groundwater discharge (SGD) from the permeable sandy coastline adjacent to the lagoon, into the Mediterranean Sea. Surface water transects revealed near-shore enrichments of Ra and DSi, attributed to wave-setup and water exchange through the permeable beach between the lagoon and the sea. Upscaling over the 9.5 km stretch of sandy beaches results in a marine SGD-driven DSi flux of 2.3 ± 1.3 Â 10 4 mol d À1 , similar in magnitude to the Têt river during November 2016 (3.3 ± 2.4 Â 10 4 mol d À1), the largest river in the region. A positive relationship between DSi and 224 Ra ex in lagoon water and seawater, but not 228 Ra, suggests that 224 Ra ex and DSi enrichments are derived from a similar source, the sediment (i.e. lithogenic particle dissolution), operating on short timescales. A marine SGD-driven DSi flux to the Gulf of Lions (3.8 ± 2.2 Â 10 5 mol d À1) is likely continuous over time. The relatively constant DSi inputs from water circulation for the shallow lagoons and beaches along the French Mediterranean Sea
(Geochimica et Cosmochimica Acta. vol. 238, n° 0016-7037, pp. 496-515, 29/04/2026)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, UAB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOMIC, INSU - CNRS, SU, CNRS, OOB, SU, CNRS, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, JCU, VUB
Whole-transcriptome response to wastewater treatment plant and stormwater effluents in the Asian clam, Corbicula fluminea
The increase in human population and urbanization are resulting in an increase in the volume of wastewater and urban runoff effluents entering natural ecosystems. These effluents may contain multiple pollutants to which the biological response of aquatic organisms is still poorly understood mainly due to mixture toxicity and interactions with other environmental factors. In this context, RNA sequencing was used to assess the impact of a chronic exposure to wastewater treatment plant and stormwater effluents at the whole-transcriptome level and evaluate the potential physiological outcomes in the Asian clam Corbicula fluminea. We de-novo assembled a transcriptome from C. fluminea digestive gland and identified a set of 3,181 transcripts with altered abundance in response to water quality. The largest differences in transcriptomic profiles were observed between C. fluminea from the reference site and those exposed to wastewater treatment plant effluents. On both anthropogenically impacted sites, most differentially expressed transcripts were involved in signaling pathways in relation to energy metabolism such as mTOR and FoxO, suggesting an energy/nutrient deficit and hypoxic conditions. These conditions were likely responsible for damages to proteins and transcripts in response to wastewater treatment effluents whereas exposure to urban runoff might result in immune and endocrine disruptions. In absence of comprehensive chemical characterization, the RNAseq approach could provide information regarding the mode of action of pollutants and then be useful for the identification of which parameters must be studied at higher integration level in order to diagnose sites where the presence of complex and variable mixtures of chemicals is suspected.
(Ecotoxicology and Environmental Safety. vol. 165, n° 0147-6513, pp. 96-106, 29/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GENOTOUL, UT3, Comue de Toulouse, ENVT, Toulouse INP, INSERM, CNRS, Toulouse INP, Comue de Toulouse, INRAE, MIAT INRAE, INRAE, INRAE
The dinoflagellate cyst genera Achomosphaera Evitt 1963 and Spiniferites Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions
We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus Achomosphaera Evitt 1963 and 33 of the genus Spiniferites Mantell 1850 emend. Sarjeant 1970 occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by workshop participants. In addition, several holotypes and topotypes are reillustrated. Three species previously assigned to Spiniferites are here considered/accepted as belonging to other genera: Impagidinium inaequalis (Wall and Dale in Wall et al. 1973) Londeix et al. 2009, Spiniferites? rubinus (Rossignol 1962 ex Rossignol 1964) Sarjeant 1970, and Thalassiphora balcanica Balteş 1971. This summary forms the basis for a set of papers that follows, where points raised during the workshops are explored in greater detail.
(Palynology. vol. 42, n° 0191-6122, pp. 10-44, 29/04/2026)
DGD.REVE, MNHN, GEOTOP, EPM, UdeM, UQAT, UQAR, UQAM, UCPH, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CR2P, MNHN, SU, CNRS, LGO, UBS, IFREMER, UBO EPE, CNRS, ISMER, UQAR, LSU
Contamination of soils by metals and organic micropollutants: case study of the Parisian conurbation
Soils are playing a central role in the transfer and accumulation of anthropogenic pollutants in urbanized regions. Hence, this study aimed at examining the contamination levels of selected soils collected within and around the Paris conurbation (France). This also evaluated factors controlling contamination. Twenty-three trace and major elements as well as 82 organic micropollutants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), phthalates (PAEs), polybrominated diphenyl ethers (PBDEs), alkylphenols (APs), and perfluoroalkylated substances (PFASs) were analyzed. Results reinforced the concern raised by the occurrence and levels of metals such as Zn, Pb, Cu, and Hg, identified as metallic markers of anthropogenic activities, but also pointed out the ubiquitous contamination of soils by organic micropollutants in the 0.2–55,000-μg/kg dw range. For well-documented compounds like PAHs, PCBs, and to a lesser extent PBDEs, contents were in the range of background levels worldwide. The pollutant stock in tested soil was compared to the annual atmospheric input. For PAHs; Pb; and to a lesser extent Zn, Cu, Cd, Hg, Sb, PAEs, and APs, a significant stock was observed, far more important than the recent annual atmospheric fluxes. This resulted from both (i) the persistence of a fraction of pollutants in surface soils and (ii) the cumulative atmospheric inputs over several decades. Regarding PBDEs and PFASs, stronger atmospheric input contributions were observed, thereby highlighting their recent dispersal into the environment.
(Environmental Science and Pollution Research. vol. 25, n° 0944-1344, pp. 23559–23573, 29/04/2026)
LEESU, ENPC, UPEC UP12, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEDI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, METIS, UPMC, EPHE, PSL, CNRS, EPHE, PSL, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Early back-calculated size-at-age of Atlantic yellow eels sampled along ecological gradients in the Gironde and St. Lawrence hydrographical systems
An international sampling program investigating the causes of the decline of American eels (Anguilla rostrata) and European eels (Anguilla anguilla) in the St. Lawrence (Canada) and Gironde (France) rivers systems provided the opportunity to compare early growth of eels of each species among habitats using back-calculated size
(Canadian Journal of Fisheries and Aquatic Sciences. vol. 75, n° 0706-652X, pp. 1270-1279, 29/04/2026)
INRS, DFO-MPO, UR EABX, IRSTEA, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Migrations néandertaliennes et variations climatiques pendant le Saalien supérieur. Apport des modélisations analogiques en enceintes thermo-regulées
(pp. 23-24, 29/04/2026)
CReAAH, UM, UR, UR2, CNRS, UFR HHAA, UN, MC, NSU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Influence of recent climatic events on the surface water storage of the Tonle Sap Lake
Lakes and reservoirs have been identified as sentinels of climate change. Tonle Sap is the largest lake in both the Mekong Basin and Southeast Asia and because of the importance of its ecosystem, it is has been described as the “heart of the lower Mekong”. Its seasonal cycle depends on the annual flood pulse governed by the flow of the Mekong River. This study provides an impact analysis of recent climatic events from El Niño 1997/1998 to El Niño 2015/2016 on surface storage variations in the Tonle Sap watershed determined by combining remotely sensed observations, multispectral images and radar altimetry from 1993 to 2017. The Lake's surface water volume variations are highly correlated with rainy season rainfall in the whole Mekong River Basin (R = 0.84) at interannual time-scale. Extreme droughts and floods can be observed when precipitation deficit and excess is recorded in both the Tonle Sap watershed and the Mekong River Basin during moderate to very strong El Niño/La Niña events (R = −0.70) enhanced by the Pacific Decadal Oscillation (R = −0.68). Indian and Western North Pacific Monsoons were identified as having almost equal influence. Below normal vegetation activity was observed during the first semester of 2016 due to the extreme drought in 2015.
(Science of the Total Environment. vol. 636, n° 0048-9697, pp. 1520-1533, 29/04/2026)
GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CESBIO, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, INRAE, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], LMTG, UT3, Comue de Toulouse, CNRS
Taxonomy and operational identification of Quaternary species of Spiniferites and related genera
In this article, we are proposing an Identification Key for recognition of Quaternary Spiniferites species and some morphologically close Quaternary taxa of some related genera. We summarize the morphological features of 43 taxa (including three subspecies and one variety) based on the original description of the holotypes and sometimes supplemented by our observations. In addition to the Identification Key, we refer to published illustrations that feature both typical and atypical specimens for each taxon. The compilation of this key gave us the opportunity to reconsider some taxonomic concepts, which resulted in two new combinations and an emendation: Hafniasphaera granulata (Mao 1989) comb. nov., emend. and Hafniasphaera multisphaera (Price and Pospelova 2014) comb. nov. In addition, we recommend that the names Spiniferites nodosus and Spiniferites pseudofurcatus subsp. obliquus be restricted to their holotype.
(Palynology. vol. 42, n° 0191-6122, pp. 45-71, 29/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CR2P, MNHN, SU, CNRS
Distribution and (palaeo)ecological affinities of the mainSpiniferitestaxa in the mid-high latitudes of the Northern Hemisphere
In marine sediments of late Cenozoic age, Spiniferites is a very common genus of dinoflagellate cysts (dinocysts). Despite some taxonomical ambiguities due to large range of morphological variations within given species and convergent morphologies between different species, the establishment of an operational taxonomy permitted to develop a standardized modern database of dinocysts for the mid-high latitudes of the Northern Hemisphere. In the database that includes 1490 surface sediment samples, Spiniferites mirabilis-hyperacanthus, Spiniferites ramosus and Spiniferites elongatus were counted in addition to Spiniferites belerius, Spiniferites bentorii, Spiniferites bulloideus, Spiniferites delicatus, Spiniferites lazus and Spiniferites membranaceus. Among these taxa, Spiniferites mirabilis-hyperacanthus, Spiniferites ramosus, and Spiniferites elongatus are easy to identify and are particularly common. Spiniferites bentorii and Spiniferites delicatus also are morphologically distinct and occur in relatively high percentages in many samples. Spiniferites lazus and Spiniferites membranaceus also bear distinctive features, but occur only in a few samples. The identification of other taxa (Spiniferites belerius, Spiniferites bulloideus, notably) may be equivocal and their reported distribution has to be used with caution. The spatial distribution of Spiniferites species, with emphasis on the five most common taxa, is documented here with reference to hydrography (salinity and temperature in winter and summer, sea ice cover), primary productivity and geographical setting (bathymetry, distance to the coastline). The results demonstrate distinct ecological affinities for Spiniferites elongatus, which has an Arctic-subarctic distribution and appears abundant in low productivity environments characterized by winter sea ice and large temperature contrast between winter and summer. Spiniferites mirabilis-hyperacanthus, which occurs in warm temperate water sites, is more abundant in high salinity environments. It shares its environmental domain with Spiniferites bentorii, which appears to have a narrower distribution towards the warm and high salinity end of the Spiniferites mirabilis-hyperacanthus distribution. In contrast, Spiniferites delicatus, which occurs in warm-temperate to tropical environments, shows preference for relatively low salinity and low seasonal contrasts of temperature. Spiniferites ramosus exhibits a particularly wide distribution that overlaps both cold and warm Spiniferites taxa. Its cosmopolitan occurrence and its long-ranging biostratigraphical distribution suggest a high plasticity of the species and/or co-occurrence of several cryptic species. Hence, whereas Spiniferites elongatus and Spiniferites mirabilis-hyperacanthus are useful palaeoecological indicators despite their large morphological variability, Spiniferites ramosus is a taxon with an unconstrained ecological significance.
(Palynology. vol. 42, n° 0191-6122, pp. 182-202, 29/04/2026)
UQAM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GEUS, AWI, UVIC, ISMER, UQAR