Juvenile growth deficit as an early alert of cockle Cerastoderma edule mortality
In the population dynamics of bi-phasic marine invertebrates, the fitness of one stage in the life of a cohort affects that of the following stage. This effect makes the prediction of the fate of a cohort challenging. We conducted a 22 yr monthly survey of a population of cockles Cerastoderma edule focussed on the juvenile stage. Two types of years were distinguished in terms of cohort longevity: a low-mortality group (‘L’) and a high-mortality group (‘H’). The cockle shell lengths of the 0+ cohorts was higher in the L group, in August and September. A cohort could hereby confidently be assigned to the L or H group as soon as August. Maximum cockle abundance in the cohorts, parasite load, or date of recruitment did not discriminate the groups, while an early date for the peak of the 0+ cohort abundance could be related to the L group. The maximum air temperature and the chl a concentration in July were higher in the H group, whereas the minimum salinity during the month of September was slightly lower in the H group of years. Therefore, a juvenile shell length under a given threshold was identified as an early alert for a short lifespan of the cockle cohort. This long-term analysis contributes to the deeper understanding of the population dynamics of bi-phasic invertebrates. The success of juveniles is not solely related to the intensity of recruitment or mortality by predation, but could also be linked to their fitness, their growth rates appearing as a proxy.
(Marine Ecology Progress Series. vol. 679, n° 0171-8630, pp. 85-99, 21/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IMS, UB, CNRS
Hydrodynamics of a hyper-tidal estuary influenced by the world's second largest tidal power station (Rance estuary, France)
The Rance estuary is a relatively small low-discharge steep-sided ria, located along the Brittany coast in northern France, with a maximum spring tidal range of 13.5 m. Taking advantage of this hyper-tidal regime, the first and currently the second largest operational tidal power station in the world was built at the estuary's mouth and has been in operation since the 1960s. Despite the well-known effect of damping of estuarine water levels, little attention has been given to quantifying the influence of the plant on the propagation and asymmetry of the tidal wave inside the estuary. In this study, hydrodynamics and tidal wave patterns were analyzed in this anthropogenically influenced estuarine system. A two-dimensional depth-averaged numerical model of the Rance estuary was developed. Two scenarios without the tidal power plant involving the dam's pre- and post-construction bathymetry (1957 and 2018 respectively) and present-day conditions scenarios were designed, to highlight the impact of bed evolution and the tidal power station on hydrodynamics and tidal asymmetry. Numerical results showed that, without the structure, bathymetric evolution did not substantially influence estuarine hydrodynamics. Nevertheless, on the estuary-side of the dam, the presence of the tidal power plant induced (i) a decrease in both tidal range and tidal prism, (ii) an increase of low water levels, and (iii) a decrease in both flood and ebb currents. Contrastingly, the region close to the structure reacted differently to plant operating modes, with an increase in flood currents (ebb currents) upstream of the sluice gates (downstream of the turbines). For both the natural condition and the artificially-induced hydrodynamic forcing due to the presence of the plant, numerical results showed that the Rance estuary mainly exhibits flood-dominant behavior, with a longer duration of falling than rising water and stronger peak flood currents than ebb currents. Spanning a period of approximately 60 years, this study presents a quantitative analysis of the influence of the tidal power station on the hydrodynamics in the Rance estuary, and its possible consequences for sediment dynamics. This approach is novel for this particular enclosed water body, characterized by the presence of a dam at its mouth and a lock at its uppermost limit.
(Estuarine, Coastal and Shelf Science. vol. 250, n° 0272-7714, 21/04/2026)
EDF [E.D.F.], EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Last millennium climate variability of the varved Lake Jeinimeni geochemical record from NE Chilean Patagonia
Paleoclimate studies in Patagonia show a high Holocene climate variability, strongly controlled by the intensity and latitudinal position of the Southern Westerly Winds. In this study, environmental and climate variability, and in particular winter precipitation, was reconstructed over the last centuries through sedimentological and geochemical analyses of a core from Lake Jeinimeni in North East Patagonia. Visual description, X-ray radiographies and thin section observations point to finely laminated sediments, made by fine sands and light brown clayey silts forming an annual deposition (varves) occasionally interrupted by two Hudson volcano-related tephras and 15 pluri-millimetre to pluri-centimetre coarser sandy to gravely layers. Varve counting confirmed by 210Pb and 137Cs indicates a detrital sequence of at least 750 yr. Based on a correlation with local meteorological data for the 1930–1988AD interval, varve thickness and statistical treatment of XRF geochemical data give information on transport pathway and sedimentary deposit conditions. The sandy laminae correspond to the deposition of high sedimentary load delivered by austral spring snowmelt whereas the clayey silt laminae result of particle settling in the water column during low hydrodynamical conditions. Thicker varves observed in dry conditions underline the importance of aeolian transport in sedimentary deposition. During locally dry and windy summer, the wind may erode and remobilise the sedimentary deposits along the lake margins. The sandy and gravely layers record massive erosional events due to proximal watershed perturbation driven by climatic or tectonic mechanisms. The clastic varves of Lake Jeinimeni document environmental decadal to multidecadal variability in East Patagonia over the last centuries. The more pronounced sediment transition around 1750 CE is consistent with the inception of the Little Ice Age-type event, in agreement with North Patagonian paleoclimate reconstructions derived from glacier advances, lacustrine varve thickness and tree-ring records.
(Quaternary Science Reviews. vol. 269, n° 0277-3791, pp. 107134, 21/04/2026)
AGEs, ULiège, UdeC, UG, KU Leuven, ULiège, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
High-resolution temperature and precipitation variability of southwest Anatolia since 1730 CE from Lake Gölcük sedimentary records
We report high-resolution multiproxy analyses [lithology, μXRF and magnetic susceptibility (MS)] of two short gravity sediment cores from the crater Lake Gölcük, southwest Turkey. Our results provide a detailed hydroclimatic record for the last ~290 years. Aided with factor analysis of μXRF data and 210Pb and 137Cs dating, our multiproxy data show that the Lake Gölcük records documented a series of wet and dry periods between ~ 1730 (±71) and ~ 2018 (±3) CE. Wet periods are evidenced by dark olive green mixed lithology (sandy, clay, and silts) and high values in MS and log(Sr/Ca). On the other hand, dry periods are associated with light olive green clayey mud lithology and high values in log(Ca/K). We relate the wet periods to negative North Atlantic Oscillation (NAO–) and the dry periods to NAO+. Additionally, all wet periods are related with time of low solar activity and dry periods, except Dalton Minimum, are related with periods of high solar activity. Consequently, we suggest that hydroclimatic changes observed in the Lake Gölcük sedimentary records were caused by the influence of largescale atmospheric circulation and solar activity.
(Turkish Journal of Earth Sciences. vol. 45, n° 1300-0985, 21/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The silent spring of Sargassum
(Environmental Science and Pollution Research. vol. 28, n° 0944-1344, pp. 15580--15583, 21/04/2026)
CUFR, BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, Migrinter [Poitiers], UP, CNRS, DEAL, LEMAR, IRD, IFREMER, UBO EPE, CNRS, CEVA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Contrasting northern and southern European winter climate trends during the Last Interglacial
The Last Interglacial (LIG; 130–115 ka) is an important test bed for climate science as an instance of significantly warmer than preindustrial global temperatures. However, LIG climate patterns remain poorly resolved, especially for winter, affected by a suite of strong feedbacks such as changes in sea-ice cover in the high latitudes. We present a synthesis of winter temperature and precipitation proxy data from the Atlantic seaboard of Europe, spanning from southern Iberia to the Arctic. Our data reveal distinct, opposite latitudinal climate trends, including warming winters seen in the European Arctic while cooling and drying occurred in southwest Europe over the LIG. Climate model simulations for 130 and 120 ka suggest these contrasting climate patterns were affected by a shift toward an atmospheric circulation regime with an enhanced meridional pressure gradient and strengthened midlatitude westerlies, leading to a strong reduction in precipitation across southern Europe.
(Geology. vol. 49, n° 0091-7613, pp. 1220-1224, 21/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, USN
Carbon accumulation rates of Holocene peatlands in central–eastern Europe document the driving role of human impact over the past 4000 years
Abstract. Peatlands are one of the largest terrestrial carbon sinks on the planet, yet little is known about the carbon accumulation rates (CARs) of mountainous peatlands. The long-term variability in the size of the associated carbon sink and its drivers remain largely unconstrained, especially when the long-term anthropogenic impact is also considered. Here, we present a composite CAR record of nine peatlands from central–eastern Europe (Romania and Serbia) detailing variability in the rates of carbon accumulation during the Holocene. We show examples of extremely high long-term rates of carbon accumulation (LORCA>120 gCm-2yr-1), indicating that mountain peatlands constitute an efficient regional carbon sink at times. By comparing our data to modelled palaeoclimatic indices and to measures of anthropogenic impact we disentangle the drivers of peat carbon accumulation in the area. Variability in early- and mid-Holocene CARs is linked to hydroclimatic controls, with high CARs occurring during the early Holocene and lower CARs associated with the transition to cooler and moister mid-Holocene conditions. By contrast, after 4000 years (calibrated) before present (years BP), the trends in CARs indicate a divergence from hydroclimate proxies, suggesting that other processes became the dominant drivers of peat CARs. We propose that enhanced erosion following tree cover reduction as well as increased rates of long-distance atmospheric dust fallout might have played a role, as both processes would result in enhanced mineral and nutrient supply to bog surfaces, stimulating peatland productivity. Surprisingly though, for the last 1000 years, reconstructed temperature is significantly correlated with CARs, with rising temperatures linked to higher CARs. Under future climate conditions, which are predicted to be warmer in the region, we predict that peat growth may expand but that this is entirely dependent upon the scale of human impact directly affecting the sensitive hydrological budget of these peatlands.
(Climate of the Past. vol. 17, n° 1814-9324, pp. 2633 - 2652, 21/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, EPHE, PSL, UM, CNRS, UBB
A Global Ocean Oxygen Database and Atlas for assessing and predicting deoxygenation and ocean health in the open and coastal ocean
In this paper, we outline the need for a coordinated international effort toward the building of an open-access Global Ocean Oxygen Database and ATlas (GO$_2$DAT) complying with the FAIR principles (Findable, Accessible, Interoperable, and Reusable). GO$_2$DAT will combine data from the coastal and open ocean, as measured by the chemical Winkler titration method or by sensors (e.g., optodes, electrodes) from Eulerian and Lagrangian platforms (e.g., ships, moorings, profiling floats, gliders, ships of opportunities, marine mammals, cabled observatories). GO$_2$DAT will further adopt a community-agreed, fully documented metadata format and a consistent quality control (QC) procedure and quality flagging (QF) system. GO$_2$DAT will serve to support the development of advanced data analysis and biogeochemical models for improving our mapping, understanding and forecasting capabilities for ocean O$_2$ changes and deoxygenation trends. It will offer the opportunity to develop quality-controlled data synthesis products with unprecedented spatial (vertical and horizontal) and temporal (sub-seasonal to multi-decadal) resolution. These products will support model assessment, improvement and evaluation as well as the development of climate and ocean health indicators. They will further support the decision-making processes associated with the emerging blue economy, the conservation of marine resources and their associated ecosystem services and the development of management tools required by a diverse community of users (e.g., environmental agencies, aquaculture, and fishing sectors). A better knowledge base of the spatial and temporal variations of marine O$_2$ will improve our understanding of the ocean O$_2$ budget, and allow better quantification of the Earth’s carbon and heat budgets. With the ever-increasing need to protect and sustainably manage ocean services, GO$_2$DAT will allow scientists to fully harness the increasing volumes of O$_2$ data already delivered by the expanding global ocean observing system and enable smooth incorporation of much higher quantities of data from autonomous platforms in the open ocean and coastal areas into comprehensive data products in the years to come. This paper aims at engaging the community (e.g., scientists, data managers, policy makers, service users) toward the development of GO$_2$DAT within the framework of the UN Global Ocean Oxygen Decade (GOOD) program recently endorsed by IOC-UNESCO. A roadmap toward GO$_2$DAT is proposed highlighting the efforts needed (e.g., in terms of human resources).
(Frontiers in Marine Science. vol. 8, n° 2296-7745, pp. 724913, 21/04/2026)
ULiège, CNES, NOAA, SERC, UNESCO, GEOMAR, IO-PAN, PAN, GHER, ULiège, IOW, IRSI, IFREMER, MBARI, LOV, INSU - CNRS, SU, CNRS, IMEV, INSU - CNRS, SU, CNRS, UBC EOAS, UBC, NIWA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IRD, CECI, CERFACS, INSU - CNRS, CNRS, UCA, OGS, DMI, IGP, JAMSTEC, MRI, JMA, UP System, RSMAS, NORCE, SIO - UC San Diego, UC San Diego, UC, SUNY, CSIR, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, BCCR, BIO / UiB, UiB, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, OVSQ, UVSQ, INSU - CNRS, CNRS, LSU, UMCES, ARC, USF, UBC, LOPS, IRD, IFREMER, INSU - CNRS, UBO EPE, CNRS, HKU
I know who you are, but do others know? Why correct scientific names are so important for the biological sciences
Researchers are continuing to identify polychaetes using inappropriate references and failing to appreciate that many if not most species have restricted distributions. Using Marphysa sanguinea (Montagu, 1813) as a case example, we discuss the loss of valuable data by misidentifying a species. We suggest ways in which this problem can be addressed by both taxonomists, ecologists and other researchers. Furthermore, this situation is not unique to polychaetes but applies to many other groups of marine invertebrates.
(Zoosymposia. vol. 19, n° 1178-9905, pp. 151-163, 28/12/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Prolonged interglacial warmth during the Last Glacial in northern Europe
Few fossil‑based environmental and climate records in northern Europe are dated to Marine Isotope Stage (MIS) 5a around 80 ka BP. We here present multiple environmental and climate proxies obtained from a lake sequence of MIS 5a age in the Sokli basin (northern Finland). Pollen/spores, plant macrofossils, NPPs (e.g. green algae), bryozoa, diatoms and chironomids allowed an exceptionally detailed reconstruction of aquatic and telmatic ecosystem successions related to the development of the Sokli Ice Lake and subsequent infilling of a relatively small and shallow lake confined to the Sokli basin. A regional vegetation development typical for the early half of an interglacial is recorded by the pollen, stomata and plant macrofossil data. Reconstructions of July temperatures based on pollen assemblages suffer from a large contribution of local pollen from the lake's littoral zone. Summer temperatures reaching present‑day values, inferred for the upper part of the lake sequence, however, agree with the establishment of pine‑dominated boreal forest indicated by the plant fossil data. Habitat preferences also influence the climate record based on chironomids. Nevertheless, the climate optima of the predominant intermediate‑ to warm‑water chironomid taxa suggest July temperatures exceeding present‑day values by up to several degrees, in line with climate inferences from a variety of aquatic and wetland plant indicator species. The disequilibrium between regional vegetation development and warm, insolation‑forced summers is also reported for Early Holocene records from northern Fennoscandia. The MIS 5a sequence is the last remaining fossil‑bearing deposit in the late Quaternary basin infill at Sokli to be studied using multi‑proxy evidence. A unique detailed climate record for MIS 5 is now available for formerly glaciated northern Europe. Our studies indicate that interglacial conditions persisted into MIS 5a, in agreement with data for large parts of the European mainland, shortening the Last Glacial by some 50 ka to MIS 4‑2.
(Boreas. vol. 50, n° 0300-9483, pp. 331-350, 23/12/2020)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS