Fish under influence: a macroecological analysis of relations between fish species richness and environmental gradients among European tidal estuaries
Estuarine fish assemblages are subject to a great environmental variability that largely depends on both upstream fluvial and downstream marine influences. From this ecohydrological view, our study introduces a macroecological approach aiming to identify the main environmental factors that structure fish assemblages among European tidal estuaries. The present paper focuses on the influence of large scale environmental gradients on estuarine fish species richness. The environment of 135 North-eastern Atlantic estuaries from Portugal to Scotland was characterized by various descriptors especially related to hydromorphology. Major environmental trends among estuaries were underlined using multivariate techniques and cluster analyses applied to abiotic data. In particular, an integrative system size covariate was derived from a principal component analysis. Factors explaining patterns of species richness at different scales from local habitat to regional features were highlighted. Based on generalised linear models, the estuarine system size, and more particularly the entrance width, and also the continental shelf width were identified as the best explanatory variables of estuarine fish species richness at a large scale. Our approach provides a standardized method to estimate the relationship between fish assemblages and environmental factors. This constitutes a first step in assessing estuarine ecological status and studying the effects of additional factors such as anthropogenic disturbances.
(Estuarine, Coastal and Shelf Science. vol. 86, n° 0272-7714, pp. p. 137 - p. 147, 27/08/2026)
UR EPBX, CEMAGREF, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ESE, INRA, ULISBOA
Trace Element Concentrations (Mercury, Cadmium, Copper, Zinc, Lead, Aluminium, Nickel, Arsenic, and Selenium) in Some Aquatic Birds of the Southwest Atlantic Coast of France
Trace elements (mercury [Hg], cadmium [Cd], copper [Cu], zinc [Zn], lead [Pb], aluminium [Al], nickel [Ni], arsenic [As], and selenium [Se]) were investigated using inductively coupled plasma–mass spectrometry in liver, kidney, muscle, and feather of aquatic birds wintering or inhabiting the wetlands situated on the Southwest Atlantic coast of France. A majority of greylag geese, red knots, and grey plovers were collected from among hunter-shot animals. The relation between residue concentrations, age (juvenile vs. adult), and sex was investigated. Trace elements were lower than threshold levels of toxicity, except for Pb. Greylag geese sampled could be considered Pb-poisoned. These consequential levels of contamination could be the result of the ingestion of Pb-shot from ammunition used in hunting areas they crossed during migration. Cd accumulation increased with age, whereas Pb levels in feathers were lower in adult birds in connection with moulting. As was influenced by sex. Female birds displayed higher concentrations in liver and feathers than did male birds.
(Archives of Environmental Contamination and Toxicology. vol. 58, n° 0090-4341, pp. 844 - 853, 27/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IPREM, UPPA, INC-CNRS, CNRS
Experimental study of cadmium interaction with periphytic biofilms
This study addresses the interaction of Cd with natural biofilms of periphytic diatoms grown during different seasons in metal-contaminated and metal-non-contaminated streams, along a tributary of the Lot River, France. Specifically, it aims to test whether the biofilms from contaminated sites have developed a protective mechanism due to high Cd exposure. Towards this goal, reversible adsorption experiments on untreated biofilms were performed in 0.01 M NaNO3 with a pH ranging from 2 to 8, Cd concentration from 0.5 to 10,000 μg/L and exposure time from 1 to 24 h. Two types of experiments, pH-dependent adsorption edge and constant-pH Langmuirian-type isotherms were conducted. Results were adequately modeled using a Linear Programming Model. It was found that the adsorption capacities of natural biofilm consortia with respect to Cd do not depend on season and are not directly linked to the growth environment. The biofilms grown in non-contaminated (4.6 ppb Cd in solid) and contaminated (570 ppb Cd in solid) settings exhibit similar adsorption capacities in the Cd concentration range in solution of 10010,000 μg/L but quite different capacities at low Cd concentration (0.5100 μg/L); unexpectedly, the non-contaminated biofilm adsorbs approximately 10 times more Cd than the contaminated one. It is therefore possible that the strong low-abundant ligands (for example, phosphoryl or sulfhydryls) are already metal-saturated on surfaces of biofilm grown in the contaminated site whereas these sites are still available for metal adsorption in samples grown in non-contaminated sites.
(Applied Geochemistry. vol. 25, n° 0883-2927, pp. 418-427, 27/08/2026)
CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR REBX, CEMAGREF, VAST
Effects of dietary cadmium contamination on bird Anas platyrhynchos—Comparison with species Cairina moschata
This study aimed to assess the effect of two dietary cadmium (Cd) levels (C1: 1 mg kg−1; C10: 10 mg kg−1) on bird Anas platyrhynchos exposed for 10, 20 and 40 days (5 animals per experimental condition). Ducks were able to accumulate high amounts of Cd, especially in kidneys (after 40 days: C1 8.1±1 mg kg−1, C10 37.7±4.3 mg kg−1). After 40 days, the lowest Cd level triggered oxidative stress and stimulated mitochondrial metabolism. At the same time, highest amounts of Cd (C10 group) only triggered repression of genes encoding for catalase and acetyl-CoA carboxylase, with repression factors of 1/50 and 1/5, respectively. High dose exposures were then associated with the repression of genes encoding for antioxidant, whereas low dose exposure triggered their induction. In contrast, the onset of MT gene expression appeared quickly for the C10 group even if a time delay was observed between gene expression and protein accumulation. Through the comparison of A. platyrhynchos and Cairina moschata, the response to Cd toxicity appeared species-dependent. Discrepancies between species could be explained by differential utilization of MT. This pathway of detoxification seemed sufficient to counter Cd toxicity.
(Ecotoxicology and Environmental Safety. vol. 73, n° 0147-6513, pp. 2010-2016, 27/08/2026)
IPREM, UPPA, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UEPFG, INRA, URA, INRA
The European carbon balance. Part 3: forests
(Global Change Biology. vol. 16, n° 1354-1013, pp. 1429-1450, 27/08/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, ICOS-ATC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, MPIB, UNITUS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EPHYSE, INRA, CNR, UNIBO, EFI, TKK, VU, ICOS-RAMCES, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, MOSAIC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
Formation of Thetis Deep metal-rich sediments in the absence of brines, Red Sea
Almost all Red Sea deeps contain metal-rich sediments covered by brine pools. It is generally agreed that these metal-rich deposits precipitated from overlying metal-rich brines that originated from migrating hydrothermal fluids. No brine pool has ever been reported in Thetis Deep, inciting us to evaluate if such a brine layer ever occurred in the deep during the past. In order to address that questioning, a study combining mineralogical, geochemical (major-, minor-, rare-earth elements) and isotopic (Sr. Nd. Pb) approaches was completed on cored sediments and extracted interstitial waters from inside and outside the deep.;The sediments have an overall hydrothermal origin, as shown by the REE concentrations and patterns, metal contents, and Pb-Nd isotopic data, all pointing to a mantle signature. The intensity of the hydrothermal activity varied with time in the deep; the most intense episode resulting in an almost pure Fe-oxi-hydroxide layer. Varied chemical arguments, especially the Zr and REE data of the sediments, favor the fact that the whole sedimentation in Thetis Deep occurred in the absence of a stable, salt-rich and mineralized brine pool, and that no brine layer ever existed. This conclusion is supported by the constant Sr isotope composition of the sediment and its interstitial waters that are almost identical to that of the Red Sea seawater. The study also suggests that hydrothermal activity monitored fluid supplies that interacted differently with seawater in the different Red Sea deeps, resulting in an overall formation of metal-rich sediments, but along varied local conditions. (C) 2009 Elsevier B.V. All rights reserved.
(Journal of Geochemical Exploration. vol. 104, n° 0375-6742, pp. 12-26, 27/08/2026)
LHyGeS, ENGEES, UNISTRA, INSU - CNRS, CNRS, UAG, INSU - CNRS, UM, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Relationships between sinking particulate matter, early diagenesis, and sedimentary recording in the Bay of Biscay margin)
(27/08/2026)
LPGN, UN, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Sedimentary archives of the French Atlantic coast (inner bay of Vilaine, south Brittany) : depositional history and late Holocene climatic signals.
(Continental Shelf Research. vol. 30 (10–11), n° 0278-4343, pp. 1250–1266, 27/08/2026)
PEPS, UCBL, INSU - CNRS, CNRS, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, CEREGE, IRD, INRA, AMU, CdF (institution), INSU - CNRS, CNRS, LETG, UNICAEN, NU, UA, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, LDO, INSU - CNRS, UBO EPE, CNRS, GEOARCHI, UBS, UBO EPE, IBSHS, UBO EPE
Estimating turbidity and total suspended matter in the Adour River plume (South Bay of Biscay) using MODIS 250-m imagery
The Basque coastal waters (South Bay of Biscay) are directly influenced by the Adour River freshwater plume. The Adour outflow leads to important variations of suspended matter concentrations and turbidity, which in turn may affect biological productivity and water quality. This study aims at both developing specific algorithms and testing the efficiency of atmospherically corrected MODIS-Aqua 250-m surface reflectance product (MYD09) to map total suspended matter concentrations and turbidity within the Adour coastal region. First, regional empirical algorithms based on in-situ data were tested to retrieve the concentration of total suspended matter and turbidity from the remote sensing reflectance. Then, the respective sensitivity of MODIS surface reflectance bands 1 and 2 for water quality application was investigated as well as the quality of atmospheric corrections. Finally, selected algorithms were applied to the MYD09 product. The resulting 250-m resolution maps were then compared to 1000-m maps produced by IFREMER and comparisons between satellite measurements and in-situ sampling points were performed. Results show that MODIS-Aqua band 1 (620-670 nm) is appropriate for predicting turbidity and total suspended matter concentrations using polynomial regression models, whilst band 2 is unadapted. Comparison between total suspended matter concentration 250-m resolution maps and mineral suspended matter 1000-m maps (generated by IFREMER) produced consistent results. A high correlation was obtained between turbidity measured in-situ and turbidity retrieved from MODIS-Aqua satellite data. (C) 2009 Elsevier Ltd. All rights reserved.
(Continental Shelf Research. vol. 30, n° 0278-4343, pp. 379-392, 27/08/2026)
IFREMER, DYNECO, IFREMER, LOV, INSU - CNRS, SU, CNRS, IMEV, INSU - CNRS, SU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Deglacial environments in eastern Prydz Bay, East Antarctica
A high-resolution continuous record of diatom census counts and diatom specific biomarkers in sediment core NBP0101-JPC24 allows assessment of oceanographic and environmental conditions in eastern Prydz Bay during the deglaciation (11 100e9000 cal yr BP) at decadal timescale. Our study improves previous snapshots investigations based on resin-embedded thin sections and presents a new proxy that compliments the diatom census counts. Our results suggest that the ice sheet retreat over the core site is dated ate11 100 cal yr BP, setting the onset of local deglaciation and subsequent open marine conditions. The glacial retreat in Prydz Bay is due to global warming initiated at 18 cal ka BP and the regional development of the Prydz Bay cyclonic gyre. Our results further demonstrate that the deglaciation in eastern Prydz Bay can be separated in four phases: the first between 11 100 and 10 900 cal yr BP when the ice shelf was proximal and sea ice was almost perennial; the second and the third phases between 10 900e10 400 cal yr BP and 10 400e9900 cal yr BP, respectively, when the ice shelf retreated and seasonal sea ice cycle consequently developed promoting warmer water to pump into the bay within the gyre, which in turn forced the ice shelf recession and the yearly sea ice cycle establishment; and the fourth between 9900 and 9000 cal yr BP when Holocene condition were set with a recurrent seasonal sea ice cycle and a well established Prydz Bay gyre.
(Quaternary Science Reviews. vol. 29, n° 0277-3791, pp. 2731-2740, 27/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOCEAN, IPSL, ENS-PSL, PSL, UVSQ, UPMC, CEA, INSU - CNRS, X, IP Paris, CNES, CNRS, MNHN, IRD, UPMC, INSU - CNRS, CNRS