Malmgrenia louiseae sp. nov., a new scale worm species (Polychaeta: Polynoidae) from southern Europe with a key to European Malmgrenia species
Malmgrenia louiseae sp. nov. is described from both the Western Mediterranean in the Gulf of Lions, and the Northeast Atlantic from off Portugal and the Bay of Biscay. The species was found in muddy sediments in shallow water and is possibly associated with echiurids or synaptid holothurians. Malmgrenia louiseae sp. nov. can be clearly distinguished from all other known Malmgrenia species by the presence of an infra-acicular process in addition to the supra-acicular process on the acicular lobe of the neuropodia, the lack of microtubercules on the elytra, two kinds of notochaetae (stout with blunt tip and slender with fine pointed tip), and exclusively unidentate neurochaetae. An identification key to the Northeast Atlantic and Mediterranean Malmgrenia species is provided.
(Journal of the Marine Biological Association of the United Kingdom. vol. 95, n° 0025-3154, pp. 947-952, 23/04/2026)
LIENSs, INSU - CNRS, ULR, CNRS, CESAM, Thomson Unicomarine, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LECOB, OOB, UPMC, CNRS, UPMC, CNRS
The region of the Strandja Sill (North Turkey) and the Messinian events
The two sides of the Strandja Sill show a highly discontinuous stratigraphic succession since the Late Oligocene. This area, together with the Sea of Marmara Basin, is usually proposed as the gateway for the Paratethyan freshwaters and organisms that constituted the Lago Mare facies in the Mediterranean Sea during the Messinian Salinity Crisis (MSC). Our investigations involving new field observations and datings, together with previous studies, suggest that the sill has possibly experienced such a connection at around 8 Ma, i.e. significantly before the crisis. The proposal of a sea-level drop of the Black Sea before 7 Ma is not supported by our data on dinoflagellate cysts. Consistency of calcareous nannofossil succession at DSDP Site 380 is reinforced, allowing to reassert that subaerial erosion impacted both the southwestern Black Sea and the central Marmara – Dardanelles area during the peak of the MSC. At that time, this region was crossed by two oppositely directed fluvial networks, further supporting the absence of a marine gateway through the Strandja Sill. It is concluded that none of the Lago Mare events recorded in the Mediterranean during the MSC were the consequence of the passage of Paratethyan waters and organisms through this area. In the Black Sea, the well-dated Messinian fluvial erosion can be followed offshore. The overlying prograding deltaic deposits attest to a fast marine reflooding after the crisis. This constitutes a comprehensive erosion-sedimentation model in an area intensively explored for hydrocarbons.
(Marine and Petroleum Geology. vol. 66, n° 0264-8172, pp. 149-164, 23/04/2026)
iSTeP, UPMC, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ITÜ, IFREMER, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS, GeoEcoMar, CR2P, MNHN, UPMC, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, AYBE, ITÜ, Cerema, NIHWM
Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species
The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood P7PCB concentrations (range: 61e115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood P7PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood P7PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure.
(Environmental Pollution (1970). vol. 197, n° 0013-9327, pp. 173-180, 23/04/2026)
CEBC, INRA, ULR, CNRS, NINA, NINA, NINA, NILU, TOXEN, UQAM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UC
Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation
Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11 weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish.
(Chemosphere. vol. 139, n° 0045-6535, pp. 303--309, 23/04/2026)
BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, IBIS, ULaval, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, µVIS X-ray Imaging Centre, UR EABX, IRSTEA, INRS, LPTC, UB, CNRS, ISM, UB, INC-CNRS, CNRS
Divergent biophysical controls of aquatic CO2 and CH4 in the World's two largest rivers
Carbon emissions to the atmosphere from inland waters are globally significant and mainly occur at tropical latitudes. However, processes controlling the intensity of CO2 and CH4 emissions from tropical inland waters remain poorly understood. Here, we report a data-set of concurrent measurements of the partial pressure of CO2 (pCO2) and dissolved CH4 concentrations in the Amazon (n = 136) and the Congo (n = 280) Rivers. The pCO2 values in the Amazon mainstem were significantly higher than in the Congo, contrasting with CH4 concentrations that were higher in the Congo than in the Amazon. Large-scale patterns in pCO2 across different lowland tropical basins can be apprehended with a relatively simple statistical model related to the extent of wetlands within the basin, showing that, in addition to non-flooded vegetation, wetlands also contribute to CO2 in river channels. On the other hand, dynamics of dissolved CH4 in river channels are less straightforward to predict and are related to the way hydrology modulates the connectivity between wetlands and river channels.
(Scientific Reports. vol. 5, n° 2045-2322, pp. 15614, 23/04/2026)
ULiège, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, KU Leuven, UENF
Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin
(Biogeosciences Discussions. vol. 12, n° 1810-6277, pp. 8747 - 8787, 23/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, EPHE, PSL, UM, CNRS, BOME, MNHN, UPMC, CNRS, IRD [Burkina Faso]
A strong CO2 sink enhanced by eutrophication in a tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)
Abstract. In contrast to its small surface area, the coastal zone plays a disproportionate role in the global carbon cycle. Carbon production, transformation, emission and burial rates at the land–ocean interface are significant at the global scale but still poorly known, especially in tropical regions. Surface water pCO2 and ancillary parameters were monitored during nine field campaigns between April 2013 and April 2014 in Guanabara Bay, a tropical eutrophic to hypertrophic semi-enclosed estuarine embayment surrounded by the city of Rio de Janeiro, southeast Brazil. Water pCO2 varied between 22 and 3715 ppmv in the bay, showing spatial, diurnal and seasonal trends that mirrored those of dissolved oxygen (DO) and chlorophyll a (Chl a). Marked pCO2 undersaturation was prevalent in the shallow, confined and thermally stratified waters of the upper bay, whereas pCO2 oversaturation was restricted to sites close to the small river mouths and small sewage channels, which covered only 10 % of the bay's area. Substantial daily variations in pCO2 (up to 395 ppmv between dawn and dusk) were also registered and could be integrated temporally and spatially for the establishment of net diurnal, seasonal and annual CO2 fluxes. In contrast to other estuaries worldwide, Guanabara Bay behaved as a net sink of atmospheric CO2, a property enhanced by the concomitant effects of strong radiation intensity, thermal stratification, and high availability of nutrients, which promotes phytoplankton development and net autotrophy. The calculated CO2 fluxes for Guanabara Bay ranged between −9.6 and −18.3 mol C m$^{−2}$ yr$^{−1}$, of the same order of magnitude as the organic carbon burial and organic carbon inputs from the watershed. The positive and high net community production (52.1 mol C m$^{−2}$ yr$^{−1}$) confirms the high carbon production in the bay. This autotrophic metabolism is apparently enhanced by eutrophication. Our results show that global CO2 budgetary assertions still lack information on tropical, marine-dominated estuarine systems, which are affected by thermal stratification and eutrophication and behave specifically with respect to atmospheric CO2.
(Biogeosciences. vol. 12, n° 1726-4170, pp. 6125-6146, 23/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UFF
Technical Note: Large overestimation of pCO2 calculated from pH and alkalinity in acidic, organic-rich freshwaters
Inland waters have been recognized as a significant source of carbon dioxide (CO2) to the atmosphere at the global scale. Fluxes of CO2 between aquatic systems and the atmosphere are calculated from the gas transfer velocity and the water–air gradient of the partial pressure of CO2 (pCO2). Currently, direct measurements of water pCO2 remain scarce in freshwaters, and most published pCO2 data are calculated from temperature, pH and total alkalinity (TA). Here, we compare calculated (pH and TA) and measured (equilibrator and headspace) water pCO2 in a large array of temperate and tropical freshwaters. The 761 data points cover a wide range of values for TA (0 to 14 200 μmol L−1), pH (3.94 to 9.17), measured pCO2 (36 to 23 000 ppmv), and dissolved organic carbon (DOC) (29 to 3970 μmol L−1). Calculated pCO2 were >10% higher than measured pCO2 in 60% of the samples (with a median overestimation of calculated pCO2 compared to measured pCO2 of 2560 ppmv) and were >100% higher in the 25% most organic-rich and acidic samples (with a median overestimation of 9080 ppmv). We suggest these large overestimations of calculated pCO2 with respect to measured pCO2 are due to the combination of two cumulative effects: (1) a more significant contribution of organic acids anions to TA in waters with low carbonate alkalinity and high DOC concentrations; (2) a lower buffering capacity of the carbonate system at low pH, which increases the sensitivity of calculated pCO2 to TA in acidic and organic-rich waters. No empirical relationship could be derived from our data set in order to correct calculated pCO2 for this bias. Owing to the widespread distribution of acidic, organic-rich freshwaters, we conclude that regional and global estimates of CO2 outgassing from freshwaters based on pH and TA data only are most likely overestimated, although the magnitude of the overestimation needs further quantitative analysis. Direct measurements of pCO2 are recommended in inland waters in general, and in particular in acidic, poorly buffered freshwaters.
(Biogeosciences. vol. 12, n° 1726-4170, pp. 67–78, 23/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ULiège, KU Leuven
Hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry for acidic herbicides and metabolites analysis in fresh water
Theoretical papers and environmental applications of hydrophilic interaction liquid chromatography (HILIC) have been published for a wide range of analytes, but to our knowledge, no study focused on acidic herbicides (e.g., triketones, phenoxy acids, sulfonylurea, and acidic metabolites of chloroacetanilides). Matrix effects are the main obstacle to natural sample analysis by liquid chromatography coupled with tandem mass spectrometry (MS) via an electrospray ionization (ESI) interface. Therefore, we paid particular attention on limiting interference by (i) adapting the emerging HILIC technique, which is generally considered more sensitive than conventional reversed phase liquid chromatography and (ii) optimizing the solid phase extraction (SPE) step using a design of experiment. A rapid and reliable off line SPE-HILIC-ESI-MS/MS method was thus developed for the quantification of acidic herbicides in fresh water, with limits of quantifications (LOQs) ranging from 5 to 22 ng l1 . Then, the analysis of freshwater samples highlighted the robustness of the method, and the importance of the chloroacetanilides metabolites among the studied analytes.
(Environmental Science and Pollution Research. vol. 22, n° 0944-1344, pp. 3988-3996, 23/04/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Recent changes in north-west Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past-temperature reconstructions
Combined records of snow accumulation rate, δ 18 O and deuterium excess were produced from several shallow ice cores and snow pits at NEEM (North Greenland Eemian Ice Drilling), covering the period from 1724 to 2007. They are used to investigate recent climate variability and characterise the isotope–temperature relationship. We find that NEEM records are only weakly affected by inter-annual changes in the North Atlantic Oscillation. Decadal δ 18 O and accumulation variability is related to North Atlantic sea surface temperature and is enhanced at the beginning of the 19th century. No long-term trend is observed in the accumulation record. By contrast, NEEM δ 18 O shows multidecadal increasing trends in the late 19th century and since the 1980s. The strongest annual positive δ 18 O values are recorded at NEEM in 1928 and 2010, while maximum accumulation occurs in 1933. The last decade is the most enriched in δ 18 O (warmest), while the 11-year periods with the strongest depletion (coldest) are depicted at NEEM in 1815–1825 and 1836–1846, which are also the driest 11-year periods. The NEEM accumulation and δ 18 O records are strongly correlated with outputs from atmospheric models, nudged to atmospheric reanalyses. Best performance is observed for ERA reanalyses. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the multidecadal accumulation–temperature and δ 18 O– temperature relationships for the strong warming period in 1979–2007. The accumulation sensitivity to temperature is estimated at 11 ± 2 % • C −1 and the δ 18 O–temperature slope at 1.1 ± 0.2 ‰ • C −1 , about twice as large as previously used to estimate last interglacial temperature change from the bottom part of the NEEM deep ice core. Published by Copernicus Publications on behalf of the European Geosciences Union. 1482 V. Masson-Delmotte et al.: Recent changes in northwest Greenland climate Figure 1. Map of Greenland showing the position of ice core records (red) and meteorological stations (green) used to establish a SW Greenland instrumental temperature record. The grey/white shading indicates elevation (source: NOAA/GLOBE, http://www. ngdc.noaa.gov/mgg/topo/globe.html).
(The Cryosphere. vol. 9, n° 1994-0424, pp. 1481-1504, 23/04/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GLACCIOS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, NBI, UCPH, GEUS, ULiège, LGGE, OSUG, UJF, Grenoble INP, INSU - CNRS, IRSTEA, USMB [Université de Savoie] [Université de Chambéry], CNRS, INSU - CNRS, CNRS, ULR, ICMCB, UB, INC-CNRS, CNRS, LMD, UPMC, INSU - CNRS, X, IP Paris, ENPC, CNRS, ENS-PSL, PSL, AWI, INSTAAR