French Research Institute for Exploitation of the Sea
ArchiMer - Institutional Archive of IfremerNot a member yet
27944 research outputs found
Sort by
June 2025: Nice, capital of the world ocean
No full textWe outline the critical importance of the ocean for planetary health, economic prosperity, and human well-being, while highlighting the urgent threats it faces from climate change, pollution, overfishing, and poor governance. It presents the One Ocean Science Congress (OOSC) and the 3rd United Nations Ocean Conference (UNOC3), scheduled for June 2025 in Nice, France, as pivotal events aimed at promoting ocean sustainability through science-based policy, innovation, and global cooperation. The OOSC will deliver scientific recommendations to Heads of States and Govern-ments, while additional high-level events—the Ocean Rise and Coastal Resilience Summit and the Blue Economy and Finance Forum—will address climate adaptation and sustainable investment. The outcome of these efforts will be the Nice Ocean Action Plan, comprising a political declaration, voluntary commitments, and strategic priorities focused on multilateral processes, financial mobilization, and enhanced scientific knowledge to advance the Sustainable Develop-ment Goal 14 and ensure a resilient, thriving ocean for future generations.Nous soulignons l’importance cruciale de l’océan pour la santé de la planète, la prospérité économique et le bien-être humain, tout en mettant en lumière les menaces urgentes auxquelles il est confronté : changement climatique, pollution, surpêche et gouvernance insuffisante. Il présente le One Ocean Science Congress (OOSC) et la 3e Confé-rence des Nations Unies sur l’Océan (UNOC3), qui se tiendront en juin 2025 à Nice, comme des événements clés pour promouvoir la durabilité de l’océan à travers des politiques fondées sur la science, l’innovation et la coopération interna-tionale. Le congrès OOS formulera des recommandations scientifiques à l’attention des chefs d’États et de gouverne-ments, tandis que deux autres forums de haut niveau — le Sommet sur l’élévation du niveau de la mer et la résilience cô-tière, et le Forum sur l’économie bleue et la finance — aborderont respectivement l’adaptation au des zones littorales et l’investissement durable. L’ensemble de ces efforts aboutira au Plan d’action de Nice pour l’océan, structuré autour d’une déclaration politique, d’engagements volontaires et de priorités stratégiques centrées sur le renforcement des processus multilatéraux, la mobilisation des financements et l’accroissement des connaissances scientifiques afin de faire progres-ser l’Objectif de Développement Durable 14 et garantir un océan résilient et prospère pour les générations futures
Strengthening policy action to tackle social acceptability issues in European aquaculture
No full textDespite the rapid development of aquaculture worldwide, production has stagnated in Europe and North America, notwithstanding the public policies that support the sector. This stagnation may stem from the insufficient integration of social dimensions into aquaculture governance, often characterized by top-down policies and technology-driven approaches. While environmental, economic and social factors significantly influence the social acceptability of aquaculture, environmental impacts, such as habitat degradation and the spread of disease, have historically dominated regulatory frameworks. Today, low social acceptability appears to be the major obstacle to the sector's growth, highlighting shortcomings in terms of stakeholder engagement, transparency and fairness in the distribution of the benefits generated by the sector. This paper reflects the collective insights from the ICES Working Group on Social and Economic Dimensions of Aquaculture, emphasizing that challenges to social acceptability of aquaculture are widespread but context-dependent and remain insufficiently addressed in public policies related to aquaculture development. This paper recommends broadening governance beyond environmental concerns to include social and economic dimensions from the outset, strengthening public participation in decision-making processes and adopting holistic, socially informed marine spatial planning. In addition, it highlights the importance of recognizing the role of informal governance mechanisms and the production of meaningful social data as essential aspects to foster community acceptance and the sustainable development of aquaculture. Adapting aquaculture policies to local contexts through inclusive and adaptive governance is therefore essential to the sustainable growth of the sector
Benthic communities on restored coral reefs confer equivalent aesthetic value to healthy reefs
No full textCoral reefs are valuable ecosystems that provide diverse ecosystem services to people. For example, many reefs have exceptionally high tourism value, attracting visitors to experience their ecologically and visually rich reef habitat. However, human-induced degradation can alter ecosystem services, such as when damaged reefs lose their visual appeal. Coral restoration has become a common response to reef degradation, but restoration success is usually evaluated based on coral cover increases rather than ecosystem service recovery. Here, we quantify the aesthetic value of restored reefs at one of the world’s largest coral restoration projects, compared to nearby healthy and degraded reefs. Using deep learning models trained on people’s visual preferences, we estimated the aesthetic value of coral reef benthic photographs with high prediction accuracy (R2 = 0.95). Restored reefs exhibited aesthetic value that was statistically equivalent to healthy reefs and significantly higher than degraded reefs. High aesthetic value was primarily driven by colour diversity and live coral cover, which were both higher in healthy and restored reefs than degraded reefs. Taken together, these results demonstrate the recovery of aesthetic value towards a healthy state after large-scale restoration, indicating that coral restoration can support vital tourism services and well-being contributions to people
Global tracking of marine megafauna space use reveals how to achieve conservation targets
No full textThe recent Kunming-Montreal Global Biodiversity Framework (GBF) sets ambitious goals but no clear pathway for how zero loss of important biodiversity areas and halting human-induced extinction of threatened species will be achieved. We assembled a multi-taxa tracking dataset (11 million geopositions from 15,845 tracked individuals across 121 species) to provide a global assessment of space use of highly mobile marine megafauna, showing that 63% of the area that they cover is used 80% of the time as important migratory corridors or residence areas. The GBF 30% threshold (Target 3) will be insufficient for marine megafauna's effective conservation, leaving important areas exposed to major anthropogenic threats. Coupling area protection with mitigation strategies (e.g., fishing regulation, wildlife-traffic separation) will be essential to reach international goals and conserve biodiversity. Editor's summary Many large marine animals are threatened with extinction. To address this problem, the Kunming-Montreal Global Biodiversity Framework has set a goal of protecting, conserving, and managing at least 30% of the world's oceans. However, the effectiveness of area-based conservation may be limited for highly mobile marine species, especially when there is limited understanding of the spatial and temporal dynamics of animal movement in the oceans. Sequeira et al. compiled tracking data from thousands of large marine vertebrates representing more than 100 species and identified important migratory corridors and areas where many species reside (see the Perspective by Gerber and Davis). Their findings show hotspots of movement and reveal that 30% protection will be inadequate for effective conservation, particularly considering the distribution of threats to biodiversity. -Bianca Lope
Spatio-Temporal Variability of Flooded Areas in the Ouémé Floodplain (Benin, West Africa) from 2015 to 2023
No full textStudy region
Ouémé floodplain, southern Benin, West Africa.
Study focus
The Ouémé floodplain is a vast hydrological system feeding the Nokoué lagoon via the Sô and Ouémé rivers, crossing an extensive wetland region. Driven by the African monsoon, this area is marked by pronounced seasonal and interannual hydrological variability, leading to recurrent flooding that significantly threatens local communities’ safety and livelihoods. This study aims to assess the spatio-temporal variability of flooded areas in the Ouémé floodplain from 2015 to 2023, using both in-situ measurements and satellite remote sensing.
New hydrological insights for the region
The analysis reveals a clear seasonal cycle of flooding, modulated by interannual variability. Sentinel-1A data show that flood extent fluctuates widely, ranging from 20 to 160 km², and identify the Sô region as the most flood-prone area. Importantly, the study detects a significant upward trend in flood extent over the study period. Flood dynamics are primarily governed by cumulative January–September rainfall, with a critical threshold of 1070 mm beyond which flooding expands rapidly. Altimetry data further indicate that a 6 m rise in water surface elevation north of the Ouémé river results in increased flood expansion. Temporary hydrological connections appear during flood events, adding complexity to floodplain hydrodynamics and enhancing connectivity across the basin. Overall, this study provides new insights into the mechanisms driving floods in the Ouémé floodplain using remote sensing
The AI that thought it was a seabird
No full textKnowing and understanding how marine ecosystems function requires vast quantities of observational data that is often difficult to collect and analyse. Artificial intelligence offers a number of advantages in the face of these difficulties
Characterization of Past Marine Heatwaves around South Pacific Island Countries: What really matters?
No full textMarine heatwaves (MHWs) can have devastating and lasting impacts on marine ecosystems. We investigated past MHW characteristics around 12 southwestern Pacific Island countries and territories (PICTs) using two observed sea surface temperature products and an ocean reanalysis product. PICTs are highly dependent on their marine resources for their livelihoods: a better understanding of MHW characteristics is needed for planning and adaptation to risks associated with MHWs. Our research builds on previous studies where MHWs have been detected and described using a point-based definition. We first revisit past MHW characteristics based on their spatial extent, vertical extent and seasonality. We show that filtering MHWs by size (spatial extent) and seasonality can greatly affect their characterisation and help trace their physical drivers. We then characterise past events inside each EEZ (Economic Exclusive Zone) and at the coast with MHW indices tailored to benefit Pacific Island stakeholders. We consider two types of events: large-scale events, covering a large part of the EEZ, likely to affect pelagic fisheries, and events affecting coastal zones and ecosystems. We distinguish between events occurring in the hot season (November to April), and in the cold season (May to October). We show that all 12 PICTs experienced MHWs in the past 30 years that are getting more frequent with greater spatial extents, longer durations, but with less intensity. New Caledonia, Vanuatu, Fiji and Tonga appear to be more exposed to MHWs with longer duration, higher maximum intensity, and deeper extent compared to other countries
Working Group on Biological Parameters (WGBIOP)
No full textThe Working Group on Biological Parameters (WGBIOP) focuses on reviewing the status, issues, developments, and quality assurance of biological parameters used in stock assessments. In 2024: ToR a addressed age-related stock issues for benchmarks scheduled for 2025 and beyond, up-dated the “WK, Ex, sg History Master Table,” reported on 2023–2024 workshops, followed up on delayed exchanges, prioritized species for validation studies, proposed exchanges for 2025 and beyond, and planned workshop coordination for results in 2025/2026. ToR b clarified SMSF maturity scale misinterpretations, refined substage definitions, and em-phasized stock-specific reproductive strategies. WGBIOP advocated histology and alternative methods, standardized protocols, and enhanced collaboration through national coordinators. Nine steps were proposed for standardization, addressing data gaps, costs, AI applications, and training to improve biological data quality and maturity assessments. ToR c compiled key ICES WG contact points for emerging methods and created a dynamic doc-ument for tracking emerging methods. Standardization needs and recommendations were dis-cussed, and opportunities for transnational infrastructure funding were emphasized. Addition-ally, a dedicated ICES workshop was planned to coincide with the WGBIOP 2025 meeting. To enhance communication with stock assessment EGs, ToR d proposed updates to presenta-tions, planned a November 2024 SID meeting to improve its database, reviewed SmartDots re-porting, and drafted a workshop resolution for integrating age errors in stock assessments. Test cases and sampling design are being developed, with cross-group work addressing reference collections and insights into age errors. ToR e reviewed extensive research highlighting the links between environmental conditions and biological responses in various species and regions. Cases where additional biological or life-history parameters were used to improve the understanding of stock health were compiled. Op-tions were assessed for presenting supplementary biological parameters alongside standard stock assessment output to support ecosystem-based fisheries advice. The accessibility and qual-ity assurance of additional biological parameters were evaluated, including the feasibility of cre-ating time-series. Finally, potential environmental data sources and relevant datasets for integra-tion into stock assessments were identified. ToR f reached a consensus on defining two types of reference collections: Training Reference Collections (TRC) for training and self-testing, and Control Reference Collections (CRC) for con-sistency testing. Overviews of historical CRC and high-consensus SmartDots TRC samples were compiled to support the standardization and testing of age interpretation
On the trail of ocean plastic
No full textPlastic owes its commercial success to its durability. But this quality becomes a flaw when it comes to plastics in the environment, where they pose toxicity problems, among other