Valve behavior of the European flat oyster Ostrea edulis and associated underwater sound and temperature data, recorded during a 18-month in situ experiment in Helgoland, Germany
Once widespread across European coasts, the native flat oyster Ostrea edulis has now disappeared from most of its historical range and is officially recognized as threatened. As a key ecological engineer, this species supports biodiversity by filtering water, stabilizing sediments, and providing complex reef habitats. Understanding and evaluating its behavior and biological rhythms in a natural environment before reintroduction, and how it responds to natural geophysical cycles, is essential to support effective restoration strategies. However, current knowledge on O. edulis remains limited, with most studies focusing primarily on reproduction under aquaculture or laboratory conditions. To help fill this gap, we conducted a 18-month in situ study to assess the valve behavior of Ostrea edulis in the field. The experiment took place at the Margate site (54.19°, 7.88°) near the island of Helgoland (Germany) from the 11th of March 2023 to the 31st of August 2024. The experimental setup consisted of 16 oysters disposed on individual cages in a customized oyster basket placed on a lander, a metallic structure immersed at 10m depth. Their valve behavior was continuously measured during 18 months using a High-Frequency Non-Invasive (HFNI) valvometer biosensor (Tran et al. 2023; Le Moal et al. 2023 for further details). Briefly, a pair of lightweight electrodes (<100 mg) was glued on each half-shell of each oyster and was linked to the HFNI valvometer by a flexible wire, allowing undisturbed oyster valve movement. An electromagnetic field was generated between the electrodes, allowing the measurement of the distance between each oyster's valve in continuous mode. In addition to the oyster behavior, environmental parameters were continuously measured underwater by the HFNI valvometer biosensor during the experiment, such as temperature and sound pressure magnitude. This compilation of datasets gives an overview of environmental parameters and behavioral data collected during this experiment.
(11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, AWI, AWI
Valve behavior of the European flat oyster Ostrea edulis and underwater temperature, recorded during a 18-month in situ experiment in Helgoland, Germany
This dataset shows the hourly valve behavioral data of the 16 oysters Ostrea edulis throughout the 18 months of the experiment (11th of May 2023 - 31st of August 2024) in Helgoland (Margate) as well as the temperature recorded by the HFNI valvometer. The oyster valve behavior is characterized by 3 parameters: the Valve Opening Amplitude (VOA, the percentage of the valve opening relative to maximum opening), the Valve Opening Duration (VOD, the percentage of time that an oyster spends with its valves open), and the VOA/VOD. The data are presented for each oyster and as a group average. Missing data corresponds to the death of the oyster number 7 or to the stop of recording due to electrical failure on the oyster's valvometer electrodes.
(11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, AWI, AWI
Hourly irradiance data measured underwater on oyster tables during a one-year semi-controlled experiment
This dataset shows the hourly irradiance data measured underwater on each oyster table (control and ALAN conditions, at the oysters' level) throughout the year of the experiment as well as the temperature recorded by each irradiance sensor.
(11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Hourly sound pressure magnitude data measured underwater on oyster tables during a one-year semi-controlled experiment
This dataset shows the hourly sound pressure magnitude data measured underwater on each oyster table (control and ALAN conditions, at the oyster's level) throughout the year of experiment for different frequencies (10 Hz, 20 Hz, 30 Hz, 40 Hz, 50 Hz, 60 Hz, 70 Hz, 80 Hz, 90 Hz, 100 Hz, 200 Hz, 300Hz, 400 Hz, 500 Hz, 600 Hz, and 700 Hz). The mean sound pressure magnitude is also presented for each condition. In the ALAN condition, data are missing from August 13, 2024, until the end of the experiment due to the failure of the hydrophone used.
(11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Hourly physicochemical parameters measured underwater on oyster tables during a one-year semi-controlled experiment
This dataset shows the hourly physicochemical parameters measured underwater throughout the year of the experiment. The temperature and water depth were measured on each oyster table (control and ALAN conditions, at the oyster's level), while the turbidity was measured only on the ALAN table, and conductivity and salinity were measured only on the control table.
(11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
From fixed to transgressive dunes, the conditions and timing of the transition along the Aquitaine coast, France
Today most of the coastal dunes in temperate latitudes, especially in the northern hemisphere, are relatively stable. However, over the last decade, the Gironde coast, southwest France, has experienced substantial natural dune remobilization following a major marine erosion event. Annual, large-scale and highresolution, airborne LiDAR data and Satellite imagery (Sentinel-2) are combined to address the coastal dune morphological changes and establish relations with forcing and controlling factors (vegetation cover, geomorphological descriptors). Between 2014 and 2023, about 10 out of 85 km of the Gironde dunes have switched from fixed to transgressive state. The analysis showed that in the vast majority of the cases the dominant process involved was dune front cannibalism. However, there is considerable spatial and temporal variability along the coast, depending on the vegetation cover evolution, the amount of sediment remobilized and the morphological characteristics of the dunes (steepness of the front slope, width).
(11/07/2026)
BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
En-échelon Rifting and Origin of the Volcanism in the Comoros
Two volcanic provinces have been recently discovered during the SISMAORE oceanographic cruise in the Comoros archipelago in the North Mozambique Channel between Madagascar and East Africa: N'Droundé, along the North-eastern insular slopes of Grande Comores Island and Mwezi, in the abyssal plain, north-east of Mayotte and Anjouan islands. By combining bathymetry and backscatter data, high-resolution seismic reflection and sub-bottom profiles, we have identified and mapped various tectonic (faults, forced folds) and volcanic structures (lava flows, edifices, sills, dykes) at several spatial scales on the seabed and in crosssection within the sedimentary cover. We have characterized the volcano-tectonic structures (geometry, segmentation, and kinematics) to better understand the link (geometry, chronology) between tectonic and volcanic processes. We show that volcanic and tectonic features are controlled by tectonic processes and viceversa. Ridges, volcanic cones and lava flows are set up along fissures and dikes during main rifting events to accommodate a N40°E regional extension within an E-W right lateral shear transfer zone. The volcano tectonic features are Plio-Pleistocene. This transfer zone lies between the offshore branch of the East African rift system and Malagasy grabens and may have formed when the East African rifts propagated offshore. We evidence a major rifting episode in the last Ma. The estimated volume and flux of extruded lavas show that the volcanism of the Comoros could be related to shallow tectonic processes.
(Geochemistry, Geophysics, Geosystems. vol. 26, pp. e2024GC011576, 11/07/2026)
IPGP - UMR_7154, INSU - CNRS, IGN, UR, IPG Paris, CNRS, UPCité, BRGM, LMV, IRD, INSU - CNRS, CNRS, UCA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, iSTeP, INSU - CNRS, SU, CNRS, CY
Relating estuarine turbidity maxima to tide and river conditions
Tidal rivers and estuaries may experience high levels of suspended particulate matter (SPM), which impacts water quality and ecosystem functioning. The processes controlling the development of estuarine turbidity maxima (ETM) are fairly well understood. However, predicting the maximum SPM concentration in an estuary based on aggregated parameters (estuarine dimensions, river discharge, tidal range) remains, up to now, impossible without extensive in-situ measurements and/or numerical models. This study introduces an approach that links the strength of the ETM to the tidal, river, and morphological characteristics of a system. Using in-situ data from contrasting meso- to macro-tidal estuaries, we found a consistent pattern of maximum SPM concentrations within a two-dimensional parameter space. The resulting turbidity diagram reveals a high SPM hotspot in estuaries with specific forcing conditions, corresponding to intermediate relative tidal amplitudes and freshwater Froude numbers. This multi-site research advances our predictions of ETM intensity in tide-dominated estuaries, offering a straightforward method to explore potential turbidity trajectories under various human pressures.
(Scientific Reports. vol. 16, n° 2045-2322, pp. 3096, 11/07/2026)
DYNECO, IFREMER, IOW, RHITME, Cerema, M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, BAW, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, TU Delft
Non-Stationary Model Free Parameter In Equilibrium Shoreline Modelling
The state-of-the-art equilibrium shoreline model proposed by Davidson et al. (2013) is used to hindcast shoreline evolution. A similar approach to the work of Ibaceta et al. ( 2022) is adopted, where they introduced non-stationary model free parameters to improve long term shoreline change predictions. An Ensemble Kalman Filter (EnKF) is implemented to track the temporal variability in model free parameters and explore if their evolution can be linked to the environmental forcing. A correlation between the winter wave energy and the model free parameter φ (beach memory) is identified where high energetic winters are followed by an increase in the parameter suggesting such time variation in beach memory can be parametrized.
(11/07/2026)
UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM, WRL, UNSW
A new species of Diopatra (Annelida, Onuphidae) from Akanda National Park in Gabon (West Africa)
Several ecological surveys were recently conducted in the Akanda National Park in Gabon. The main objectives of this study were to assess the urban impact on the estuarine ecosystem of Libreville and to document the benthic biodiversity of this ecosystem. Among all the species collected, a new species of Diopatra was discovered in different habitats, including mangroves. This species is described and illustrated in detail, and information on 16S gene is provided. Diopatra ariasi sp. nov. is a medium-sized species and belongs to the D. neapolitana complex, having antennae with long ceratophores and ventral lobes. This species is also characterized by the presence of ceratophores with 9–12 rings on antennae, by sensory buds which are semicircular, by spiraled branchiae from chaetiger 4–5; by bidentate pseudocompound falcigers with moderately long hoods in first four chaetigers; by pectinate chaetae with 11–15 teeth from chaetiger 6–8 and by bidentate subacicular hooks from chaetiger 15–18.
(Marine Biodiversity. vol. 55, n° 1867-1616, pp. 94, 11/07/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR MARBEC, IRD, IFREMER, CNRS, UM