French Research Institute for Exploitation of the Sea
ArchiMer - Institutional Archive of IfremerNot a member yet
27944 research outputs found
Sort by
(Revised) Opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) on the risks to human health associated with the proliferation of Ostreopsis spp. on the Basque coast
No full textAbstract In France, the presence of marine microalgae of the genus Ostreopsis has been identified repeatedly on the Mediterranean coast for several years, whereas on the French Basque coasts its presence is much more recent. In the summers of 2021 and 2022, major Ostreopsis flowering episodes were reported on the Basque coast, resulting in several hundred cases of intoxication among holidaymakers and residents. The main route of human exposure is inhalation of aerosols, although it is not yet known whether the agents responsible for poisoning are Ostreopsis cells, cell debris, known toxins produced by Ostreopsis, or other as yet unidentified compounds. Other routes of exposure (dermal contact, eye contact, ingestion of contaminated water or seafood) are also possible. Poisoning is manifested through various signs and symptoms, occurring within 48 hours of exposure (Neurosensory and neurological, respiratory, dermal and digestive). This document presents the opinion of the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), established from the work of its WATER and ERCA Expert Committees. ANSES received a request from the Directorate General for Health (DGS) and the Directorate General for Food (DGAL) to update knowledge about Ostreopsis that had been reported in the Agency's opinions from 2007 and 2008 (ANSES, 2007 and 2008), and draw up specific recommendations for managing Ostreopsis proliferation on the Basque coast. The literature review conducted as part of this expert appraisal revealed that knowledge about the genus Ostreopsis (diversity, biology, ecology, toxins produced) is still too fragmentary to characterise the hazard and risk to human health. Nevertheless to help local authorities affected by Ostreopsis blooms, Agency proposes a surveillance and quality monitoring strategy based on collaboration between site managers and the regional health agencies (ARSs), applicable to sites currently subject to bathing water quality monitoring and water sports sites that meet the conditions below
Drivers of Water Mass Volume Changes in the Nordic Seas (2005–2020)
No full textThe Nordic Seas are integral parts of the Atlantic meridional overturning circulation and a key region for the global climate. In this study, we combine observational products, largely derived from the Argo array, to examine the changes affecting ocean conditions in the different regions of the Nordic Seas from 2005 to 2020. Significant warming and deepening of isopycnal surfaces have been found across all regions since 2013, resulting in a volume increase of the surface layer above the σ0 < 27.8 kg m−3 isopycnal. A volume budget over three isopycnal layers is built to disentangle the relative roles played by the atmospheric forcing that results in local water mass transformation and large‐scale advection. In eastern basins, an increase in both the advection of Atlantic water and surface water mass transformation led to an expansion of the surface layer after 2012. In contrast, changes found in the Greenland Sea result primarily from a decrease in transport convergence and changes in the surface forcing that ventilates all layers of the region. Our analysis also highlights that an improved sampling of the region, including toward greater depths and on the East Greenland shelves, is required to reduce uncertainties in the water mass transformation budget of the Nordic Seas and to better understand the mechanisms at play
Temporal and spatial scales of Near-Intertial Oscillations inferred from surface drifters
No full textThe study investigates near-inertial oscillations (NIOs) in ocean surface currents, which are important for understanding air-sea interactions and improving satellite measurements of ocean currents, such as those planned by the ODYSEA mission. Traditional methods for measuring near-surface currents, like drifters and HF radars, have limited spatial coverage, while satellite altimetry only captures geostrophic currents, missing high-frequency components like NIOs. Using a decade-long hourly drifter dataset (2010–2021) and outputs from the high-resolution coupled Ocean/Atmosphere model LLC2160, the study estimates the global spatial decorrelation length scales of NIOs. Drifter pairs were analyzed by latitude and distance, isolating the inertial frequency band. The LLC2160 model, which includes tidal and wind-driven forcing, was validated against the drifter data, showing good agreement in spectral characteristics and correlation scales. Results show that NIO signals have larger decorrelation scales (~105–110 km) compared to low-frequency currents (~70–75 km), with variations by latitude (down to 50 km at high latitudes and near 20° N). These findings suggest that NIO energy is spread over larger spatial scales, linked to atmospheric forcing patterns. The LLC2160 simulation reliably reproduces these spatial characteristics and thus serves as a realistic tool for supporting ODYSEA mission planning. The study shows that understanding NIO spatial coherency is critical for interpreting satellite Doppler measurements and mitigating aliasing effects, thereby improving ocean current observation capabilities
AI at the service of marine environmental law
No full textEnvironmental law plays a crucial role in protecting and preserving marine ecosystems. Yet its impact on marine ecosystems remains little studied and poorly documente
Making assessments for more effective steering
No full textCurrent public policies fail to meet the challenges posed by climate change and biodiversity loss. This raises questions about the relevance of the Sustainable Development Goals proposed to governments
Gabon proactive in protecting biodiversity
No full textThe Gulf of Guinea is one of the least studied regions in the world, yet according to the Intergovernmental Panel on Climate Change (IPCC) scenarios, the area will be heavily impacted by climate change. Its biological productivity is expected to plummet by 2050, and numbers of fish caught could fall by almost 30%
Towards a sustainable mangrove crab industry in Madagascar
No full textMangrove crab fishing has long been a secondary economic sector in Madagascar. But the situation has changed dramatically since 2014 with the expansion of live crab exports to the Asian market, which have boosted fishing effort and production
The end of the reign of the anchovy?
No full textThe Peruvian anchovy, one of the most heavily fished species in the world, accounts for up to 10% of the total catch in the best years and plays a key role in aquaculture and animal feed, thus indirectly contributing to global food security
Rapport d’expertise sur le rapport d’étude préliminaire pour l’état initial de l’environnement de la zone du parc éolien en mer AO10 « Fécamp Grand Large »
No full textCe rapport d’expertise présente les observations de l’Ifremer sur le rapport d’étude préliminaire pour l’état initial de l’environnement de la zone du parc éolien en mer de l’AO10 « Fécamp Grand Large » réalisé par les bureaux d’études Sinay et Biotope, sur les compartiments « qualité de l’eau », « qualité des sédiments », « habitats et peuplements benthiques, « communautés planctoniques » et « poissons et méga-invertébrés
Introduction of epigenetic variation contribute to resistance against the human parasite Schistosoma mansoni
No full textBackground
Waddington-type kick-start of adaptive evolution is assumed to be possible based on epigenetic variation alone. We tested this hypothesis in the snail Biomphalaria glabrata, vector of Schistosoma mansoni, the causative agent of the human disease schistosomiasis. Epilines and epigenetic recombinant inbred lines (epiRILs) were used to propagate DNA methylation variants over 3 generations.
Results
The fecundity and susceptibility to infection by S. mansoni were measured. Average parasite prevalence has a higher variance in epiRILs than in controls and decreased from 84 ± 5% in controls to 68 ± 21% in epiRILs. The increase in fertility in epiRILs was 12%, with an average heritability of 0.55. The introduction of 1% epimutant offspring snail into resident susceptible populations was simulated by a model. If genetic assimilation of the resistance occurred in 0.3% of the introduced epimutants, susceptibility would be replaced by resistance after less than one hundred generations.
Conclusions
Environmental management can therefore be envisaged by introducing epigenetically modified organisms to prevent parasite infections from spreading to the intermediate host and, ultimately, the human population