Use of voltametric solid-state microelectrode for studying the effect of tidal forcing on biogeochemical processes on mudflat of the arcachon bay (France)
(10/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EDF R&D STEP, EDF R&D, EDF [E.D.F.], LPGN, UN, CNRS, LOBB, OOB, UPMC, CNRS, UPMC, INSU - CNRS, CNRS
Ocean color measurements onboard a jet-ski : consistency for calval exercise of high-resolution satellite imagery?
(. vol. 7150, pp. Vol. 7150, Q1Q10, doi:10.1117/12.805382, 10/04/2026)
CRC, UB, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Last glacial fire regime variability in western France inferred from microcharcoal preserved in core MD04-2845, Bay of Biscay
High resolution multiproxy analysis (microcharcoal, pollen, organic carbon, Neogloboquadrina pachyderma (s) , ice rafted debris) of the deep-sea record MD04-2845 (Bay of Biscay) provides new insights for understanding mechanisms of fire regime variability of the last glacial period in western France. Fire regime of western France closely follows Dansgaard–Oeschger climatic variability and presents the same pattern than that of southwestern Iberia, namely low fire regime associated with open vegetation during stadials including Heinrich events, and high fire regime associated with open forest during interstadials. This supports a regional climatic control on fire regime for western Europe through fuel availability for the last glacial period. Additionally, each of Heinrich events 6, 5 and 4 is characterised by three episodes of fire regime, with a high regime bracketed by lower fire regime episodes, related to vegetational succession and complex environmental condition changes.
(Quaternary Research. vol. 71, n° 0033-5894, pp. 385-396, 10/04/2026)
PACEA, UB, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Imprints of high-salinity water plumes originating from the Red Sea during termination II.
(Palaeogeography, Palaeoclimatology, Palaeoecology. vol. 279, n° 0031-0182, pp. 69-79, 10/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CR2P, MNHN, UPMC, CNRS, IPNO, UP11, IN2P3, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA
Field observations of an evolving rip current on a meso-macrotidal well-developed inner bar and rip morphology
The Aquitanian Coast (France) is a high-energy meso-macrotidal environment exhibiting a highly variable double sandbar system. The inner and the outer bar generally exhibit a bar and rip morphology and persistent crescentic patterns, respectively. In June 2007, an intense five-day field experiment was carried out at Biscarrosse Beach. A large array of sensors was deployed on a well-developed southward-oriented bar and rip morphology. Daily topographic surveys were carried out together with video imaging to investigate beach morphodynamic evolution. During the experiment, offshore significant wave height ranged from 0.5 to 3 m, with a persistent shore-normal angle. This paper identifies two types of behavior of an observed rip current: (1) for low-energy waves, the rip current is active only between low and mid tide with maximum mean rip current velocity reaching 0.8 m/s for an offshore significant wave height (Hs) lower than 1 m; (2) for high-energy waves (Hs≈ 2.5–3 m), the rip current was active over the whole tide cycle with the presence of persistent intense offshore-directed flows between mid and high tide. For both low and high-energy waves, very low-frequency pulsations (15–30 min) of the mean currents are observed on both feeder and rip channels. A persistent slow shoreward migration of the sandbar was observed during the experiment while no significant alongshore migration of the system was measured. Onshore migration during the high-energy waves can be explained by different sediment transport processes such as flow velocity skewness, wave asymmetry or bed ventilation. High-frequency local measurements of the bed evolution show the presence of significant (in the order of 10 cm) fluctuations (in the order of 1 h). These fluctuations, observed for both low- and high-energy waves, are thought to be ripples and megaripples, respectively and may play an important but still poorly understood role in the larger scale morphodynamics. The present dataset improves the knowledge of rip dynamics as well as the morphological response of strongly alongshore non-uniform meso-macrotidal beaches.
(Continental Shelf Research. vol. 29, n° 0278-4343, pp. p. 1650-1662, 10/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM
Spatial heterogeneity in the food web of a heavily modified Mediterranean coastal lagoon: stable isotope evidence
We investigated the food web structure of the Salses-Leucate Lagoon (northwestern Mediterranean) through delta C-13 and delta N-15 analysis of its benthic macrofauna and potential food sources. This lagoon was heavily human-modified during the 1970s, allowing permanent exchange with the open sea and an increase in salinity from that time. As a result, it exhibits a much less marked salinity gradient than the neighbouring lagoon ecosystems, which Suggests a priori that its food web structure is more homogeneous. In this environmental context, we assessed spatial variability in the isotopic composition of non-vagrant macrofauna in Salses-Leucate in relation to degree of connection with the open sea, anthropogenic inputs and the presence of oyster aquaculture. Overall, the main trophic pathway is based on suspended particulate organic matter and sedimented organic matter. However, there were marked spatial differences (at different scales) in both delta C-13 and delta N-15 values of macrofauna, which suggests an important feeding plasticity within each category of primary consumers at a small spatial scale. delta C-13 data showed that the contributions of the different food sources to the diet of primary consumers changed depending on distance from continental inputs, connection with the open sea and local primary producer coverage. Small-scale delta N-15 variability revealed a very localised influence of anthropogenic nitrogen output. Regarding the possible effect of aquaculture, the isotopic ratios of sediment and macrobenthos were not modified underneath the oyster lines with respect to the neighbouring area. Conversely, the isotopic signature of consumers living on the oyster lines contrasted with those living underneath. Therefore, our results suggest that a decoupling exists between the trophic pathways that occur in the water column and on the soft bottom of this shallow water ecosystem.
(Aquatic Biology. vol. 5, n° 1864-7782, pp. 167-179, 10/04/2026)
LEMAR, IRD, IFREMER, UBO EPE, CNRS, LOBB, OOB, UPMC, CNRS, UPMC, INSU - CNRS, CNRS, EFEB, AD2M, SBR, UPMC, CNRS, UPMC, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Treatment of topographic and bathymetric data acquired at the Truc-Vert Beach (SW France) during the ECORS field experiment
(. vol. special issue 56, 10/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM, L3AB, UB, INSU - CNRS, CNRS, OASU, UB, INSU - CNRS, ULR, CNRS, INRAE, LAB, UB, INSU - CNRS, CNRS, UB
Sensory organs of Archaeostraca (Phyllocarida, Crustacea).
(Evolution & Development. vol. 11, n° 1525-142X, pp. 225-232, 10/04/2026)
CR2P, MNHN, UPMC, CNRS, LDO, INSU - CNRS, UBO EPE, CNRS
Benthic geochemistry of manganese in the Bay of Biscay, and sediment mass accumulation rate
Manganese is a major redox reactive element of benthic metabolism. We have built a database of existing knowledge on the benthic geochemistry of Mn in the Bay of Biscay, in order to comprehensively assess the behaviour of Mn in a variety of environments during early diagenesis. The database contains vertical profiles of particulate and dissolved Mn species of 59 cores collected during 17 cruises between 1997 and 2006 at nine stations positioned between 140 and 4,800 m water depths. At all studied stations, Mn species follow the conventional distribution, where Mn(III,IV) species are enriched in the oxic layer, and dissolved Mn is present in the anoxic sediments. A minor part of Mn-oxides originates from sedimenting particles. The major part is of diagenetic origin, and derives from the oxidation of upward-diffusing dissolved Mn(II). Mn-oxide inventories are higher at the deeper stations than at the shallower ones. This difference cannot be attributed to different sources of sedimenting particles, but it must depend on sedimentation rate and diagenetic processes. At depth, dissolved Mn(II) concentrations are constant. This probably reflects equilibrium with an authigenic Mn(II) phase, which is the ultimate phase into which Mn is fossilized. The Mn content of deeper anoxic sediments is similarly low in all the cores studied, associated with corresponding trends of Mn content in sedimenting particles of the Bay of Biscay. Bioturbation, rather than redox oscillations, can convey Mn(III,IV) species downwards into the anoxic sediments where they are reduced, associated with a peak of dissolved Mn. Because dissolved Mn(II) is re-oxidized when it diffuses towards the oxic layer, the inventory of the diagenetic Mn(III,IV) phase remains at steady state, especially at stations where the oxic layer is thick. It then becomes possible to calculate the residence time of diagenetic Mn(III,IV) particles within the oxic layer, using the upward-directed flux of pore water Mn(II). By applying this residence time to the accumulation of sediments within the oxic layer, we obtain the sediment mass accumulation rate. The values calculated for the sediments of the Bay of Biscay fit well with accumulation rates obtained from radionuclides or sediment traps. The method has also been validated with data collected in other marine sedimentary environments.
(Geo-Marine Letters. vol. 29, n° 0276-0460, pp. 133-149, 10/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPGN, UN, CNRS, IPGP - UMR_7154, INSU - CNRS, IGN, UR, IPG Paris, CNRS, UPCité
New core-top Mg/Ca calibration of multiple benthic foraminiferal species: Thermometry of the thermocline water in tropical western Atlantic
(. vol. 11, 10/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UiB, BCCR, BIO / UiB, UiB, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LPGN, UN, CNRS