In this study, we adapted copper quantification to the CHEMINI instrumentation [1] using the colorimetric method based on reverse flow analysis (rFIA) with liquid core wavelength (GOF) detection, as recently described [2]. This method relies on the reduction of ferricyanide by L-glutathione in acidic media, with copper acting as the reaction catalyst. Various parameters (flow rates, reaction, injection loop and GOF length) were optimized using chemometric experimental designs. By adapting the method to seawater (salinity effect, metal and organic matter interferences), we achieved high-performance analytical limits in the subnanomolar range (detection limit = 0.03 nmol.L^-1, GOF 1 m). The first application of the method was conducted along the land-sea continuum from the Aulne estuary towards the Iroise Sea, measuring both soluble and dissolved copper concentrations (FeLINE project, [3]). The average copper concentrations obtained were comparable (5-20 nmol.L^-1) to those reported earlier in this system [4]. Concentrations decreased almost conservatively from the Aulne freshwaters (22.0 nM at S=0) towards the Bay of Brest (8.1 nM at S=34). and slightly increased toward the Iroise Sea (11.2 nM at S=35.2). The soluble copper fraction represented between 72% and 100% of the dissolved copper fraction, indicating a low contribution of high molecular weight colloidal Cu species (0.02-0.45 µm) in the Aulne estuary.

Figure : Evolution of dissolved copper DCu (<0.45µm) as a function of salinity along the Aulne estuary

[1]         R. Vuillemin et al., “CHEMINI: A new in situ CHEmical MINIaturized analyzer,” Deep. Res. Part I Oceanogr. Res. Pap., vol. 56, no. 8, pp. 1391–1399, 2009.

[2]         T. Wang et al., “A shipboard method for catalytic kinetic spectrophotometric determination of trace Cu(II) concentrations in seawater using reverse flow injection analysis coupled with a long path length liquid waveguide capillary cell,” Microchem. J., vol. 179, no. April, p. 107441, 2022.

[3]         A. Laes-Huon et al., “Rapid and simple determination of iron-porphyrin-like complexes ( Fe-Py ) in estuarine and marine waters,” vol. 244, no. May, 2022.

[4]         G. Bordin, “Distribution et évolution saisonnière du cuivre dissous dans un écosystème estuarien macrotidal d’Europe occidentale (estuaire de l’Aule, France),” Oceanol. Acta, vol. 14, no. 5, pp. 445–457, 1991.

How to cite: Laes, A., Mordant, C., Davy, R., El Rakwe, M., Waeles, M., Devesa, J., and Dulaquais, G.: Adaptation of a rFIA-GOF method for measuring Cu concentrations in estuarine waters , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-114, https://doi.org/10.5194/oos2025-114, 2025.

Over the past two decades, interest in the study of floating breakwaters has increased owing to the advantage of lower investment and being environment friendly. The use of a simple, inexpensive, and effective type of floating breakwater is increasingly becoming a necessity in shoreline and marine structure protection. This study concerns the hydrodynamic behaviour of a new type of free surface inclined porous floating breakwater in the purpose of wave attenuating, allow the sediment to pass through and to increase the aeration near onshore. The surface will be rough, porous and partially permeable with the purpose of disturbing the flow over the volume as well as creating an aerated turbulence in, and around, the structure and inclination of the structure is to induce the wave breaking. The inclined structure supported by two ballast floating box which uses several configurations of rocks and artificial concrete units for wave attenuation mechanisms. A series of experiments were carried out on the new floating breakwater model with six different types of porous configuration with different porosity and surface roughness to compare their performances. The hydrodynamic effectiveness which is presented as a function of the wave transmission coefficient, reflection coefficient is investigated experimentally. The action of 2D regular and irregular waves with wide ranges of wave heights and periods were considered. The motion responses of the floating breakwater with directional mooring line have also been measured. Emphasis is given on the effect of the incident wave characteristics; the inclined angle of the floating breakwater was kept at 15 degrees for all the set of experiments. A two-dimensional wave flume was used in the experiment; the incident and transmitted waves, the tensions on the mooring lines and the motion responses of the floating breakwaters were measured. Results showed that the new floating breakwater had a better performance for mid-level porosity and roughness in long and short-wave cases. The free body movement was significantly reduced, especially for short waves. However, the potential to implement bio enhancing features will be discussed and tested to investigate whether the breakwater can act as an artificial floating reef.

How to cite: Rasenthiram, A., Mouaze, D., and Lubbad, P. R.: Experimental Investigation of An Inclined, Floating Breakwater – A Case Study With Porous Design And Bio Enhancing Features, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-145, https://doi.org/10.5194/oos2025-145, 2025.

This presentation draws on key scientific and policy recommendations from the EMB Position Paper on ‘Building Coastal Resilience in Europe’, Future Science Brief ‘Marine Habitat Mapping’, Policy Brief ‘Blue Carbon: Challenges and Opportunities to Mitigate the Climate and Biodiversity Crises’, and Position Paper ‘Navigating the Future VI’ towards meeting the conservation and restoration targets of the Global Biodiversity Framework.

The protection and restoration of marine and coastal ecosystems are important Nature-based Solutions to build climate resilience through coastal protection, and blue carbon sequestration and storage. However, these must be planned and managed effectively, be able to persist in the face of sea-level rise and storms, and enough space and time must be allocated. In addition, critical knowledge gaps must be filled on their feasibility and benefits including site-specific research on which coastal habitats and species provide coastal protection and under which conditions, the amount of Blue Carbon removed and stored by Blue Carbon ecosystems, and on technological improvements to scale-up restoration efforts. Co-benefits, including for biodiversity and the creation of space for recreation and tourism, need to be better described, promoted and monetised so that they can be taken into account within management. It is important to consider the cost-effectiveness of restoration initiatives compared to taking no action and the future costs of losing natural resources from overexploitation to help justify investments.

Scaling-up the protection and restoration of coastal ecosystems requires effective marine spatial planning which must take a holistic approach that considers the land and sea as a single, dynamic socio-ecological system, and with policies that are coherent across all economic sectors. Links between marine- and land-based policies need to be improved, including the inclusion of all aspects of the land-sea interface in the EU’s Integrated Maritime Policy. Holistic, adaptive coastal management plans are needed that should consider the ongoing liveability of coastal areas in the face of ongoing changes, moving away from a focus on singular issues such as erosion or flooding. The participation of local communities in coastal management and the implementation of Nature-based Solutions should be improved as these are key actors in the success of protection and restoration initiatives.

In addition, accurate and extensive marine habitat maps that include more information on biodiversity are important tools for the effective design of protection and restoration initiatives. They enable identification of where habitats are, how big they are, their connectivity, and their ecological status so that marine protected areas can accurately represent ecological processes. They are also needed to be able to plan and spatially prioritize active restoration interventions, and to document and monitor the location and extent of degraded habitats in need of restoration.

How to cite: Alexander, B. E., Heymans, J. J., Villasante, S., Richter, K., Fraschetti, S., and Strong, J.: Science and policy needs for effective ecosystem protection and restoration in Europe to build climate resilience, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-149, https://doi.org/10.5194/oos2025-149, 2025.

The Celtic Sea, located between France, Ireland and England, is an area of high biodiversity due to the diversity of its habitats and its geographical location between the Lusitanian and Boreal provinces. This North-East Atlantic ecosystem provides significant catches, taken by many European fleets

The presentation will summarise multi-disciplinary research projects carried out at local, national and international scales in the area over the last two decades. We combined taxon-based, trait-based and trophic network approaches to assess the relative effects of environmental variables and fishing activities on spatio-temporal distribution of species, community dynamics and ecosystem functioning. More recently, modelling work has explored the cumulative effects of fishing and climate change scenarios on ecosystem resilience by 2100. Results suggest that slight reductions in fishing effort could be enough to compensate the impact of climate change in the area.

From a management point of view, we highlight the benefits, for slow-living species, of temporary closures of fishing zones, initially designated to protect the spawning grounds of exploited species such as cod. Several applied projects on minimising the impact of fishing by improving the selectivity of fishing gears in order to reduce discards practices at sea were carried out. This work will be illustrated by an example of a practical low-cost technical solution that has been tested and approved and then implemented on certain fleets.

How to cite: Robert, M., Kopp, D., Mouchet, M., Mérillet, L., Potier, M., Amelot, M., Gascuel, D., and Méhault, S.: Dynamic and durability of exploited marine ecosystems: The case of the Celtic sea , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-151, https://doi.org/10.5194/oos2025-151, 2025.

Blue carbon ecosystems in southeast Asia present substantial opportunities for both carbon market development and biodiversity conservation. Recognizing this potential, countries throughout this region have initiated coastal restoration projects with blue carbon conservation objectives. However, continued uncertainties in the natural science foundation, slow political mobilization, and notable community hesitancy and exclusion often constrain the benefits of these efforts, leading to land-use conflicts, social inequalities, and missed opportunities for local development. In the SCOPE project, we address these challenges, particularly focusing on Cambodia and Vietnam whilst maintaining a wider southeast Asia perspective. By evaluating emerging blue carbon financing mechanisms, restoration effort outcomes, agent relationships, and the policy implications of these initiatives we elucidate the top-down standpoint. Through community engagement across demographics, we reveal the ‘grassroots’ perception and implementation of blue carbon policy and conservation at the local level. Integrating these perspectives allows us to assess the opportunities and challenges of blue carbon policy. Working together, we aim to co-create actionable steps for a sustainable blue carbon management plan with community acceptance. Our multi-actor approach helps to harmonize local and national priorities, providing a framework for future blue carbon policies that foster social inclusion, environmental resilience, and economic viability across southeast Asia.

How to cite: Long, V. H., Joshi, S., Cuc, N. T. K., Sandström, C., Hien, H. T., Chi, V. K., Kamenos, N. A., and Burdett, H. L.: Developing a framework for co-creating blue carbon policy in southeast Asia, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-253, https://doi.org/10.5194/oos2025-253, 2025.

Seaweeds and their associated habitats are vital for the health of the planet and are increasingly recognised for their significant ecological and economic importance. Seaweed habitats are diverse, ranging from kelp forests to rhodolith beds, and efforts to study, manage and protect them tend to occur in isolation, despite their interconnectivity and reliance on each other. Therefore, there have been no comprehensive assessments on the status of seaweeds globally and no global unified conservation goals exist to protect seaweeds to date. This is in direct contrast with other marine habitats, such as mangroves or coral reefs. The State of the World’s Seaweeds Report brings together our current understanding of the diversity, distribution, importance, threats, status, and current protection measures surrounding seaweed habitats globally. This document will form the knowledge base for the Seaweed Breakthrough, an initiative to set measurable and science-based targets to rally public and private actors in a shared vision to ensure the survival and prosperity of seaweed habitats and the seaweed industry for generations to come. This presentation will describe the contents of the State of the World’s Seaweeds report and highlight its key take home messages, including the major knowledge gaps that need to be urgently addressed in relation to seaweeds. This presentation will also outline how this report is being used to inform the targets of the Seaweed Breakthrough.

How to cite: Corrigan, S. and Brodie, J.: Understanding the State of the World’s Seaweeds and what must be done to protect them, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-467, https://doi.org/10.5194/oos2025-467, 2025.

The North Pacific coast of Costa Rica has had the largest infrastructure growth for the commercial, urban and tourism sectors in the country. This development has contributed to the economic progress of the region with higher incomes and employment generation, but has caused social and environmental problems in recent decades. The shortage of water sources, salinization of aquifers, problems of contamination of the estuaries and beaches mainly due to nutrients and microbiological pollutants from poor wastewater management have generated conflicts between different sectors, mainly between investors and the local population. The Water Resources Centre for Central America and the Caribbean (HIDROCEC-
UNA) has developed a research process in recent years in this area, where 10 sampling points were evaluated in seven tours from 2022 to 2024 to analyze nutrients, measurement of in situ parameters, microbiological and physicochemical parameters. During the process, different forms and types of pollution that are reaching the water bodies and the coast were identified, their spatial location and their vulnerability with respect to drinking water
sources. The analysis of the quality of coastal waters and effluents reaching the sea showed that 3 of the 10 points exceed the presence of microbiological pollutants for recreational uses and that a decrease in water quality in 5 of the parameters analyzed (fecal coliforms, Enterococci, turbidity, dissolved oxygen and saturation, ammonium) is foreseen in the future. The results were presented to the social actors in the area in order to strengthen advocacy and environmental management. The construction of a participatory work agenda was achieved through inclusive strategies, the search for the involvement of government institutions and the promotion of citizen science to improve the protection of environmental and coastal resources.

How to cite: Golcher-Benavides, C., Baldioceda Garro, A., Suárez Serrano, A., Lopez Maietta, M. T., Guillén Watson, A., and Rojas Conejo, J.: Water quality monitoring in tourist coastal areas to enhance community participatorymanagement of marine-coastal resources, Guanacaste, Costa Rica., One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-665, https://doi.org/10.5194/oos2025-665, 2025.

Difficult to define and deeply damaging: the huge cost of non-selective fisheries for marine biodiversity

Non-selective fishing practices represent a critical threat to marine biodiversity, driving widespread degradation of marine ecosystems with profound consequences. Our presentation examines the extensive impacts of non-selective fisheries—both artisanal and commercial—on marine species, with a focus on biodiversity conservation. Through in-depth consultation with taxon experts from the marine-focused Specialist Groups of the IUCN Species Survival Commission (SSC), we reveal the vast taxonomic range of species (from polychaetes to marine mammals) affected by non-selective fishing, with pressures coming from a great diversity in gear types, scales, and modes of impact across fisheries.

Non-selective methods lead to both lethal and sublethal consequences, affecting individual organisms, entire populations, and community structures. Our analysis addresses direct mortality rates and sublethal effects—such as injury, stress, and reduced reproductive success—that collectively degrade ecological integrity. These impacts impose huge costs not only on marine species but also on food security, ecological justice, and the livelihoods of communities dependent on marine resources.

We will discuss the ecological and socio-economic ramifications of these practices, underscoring the urgent need for selective and sustainable fisheries management. This presentation seeks to build understanding of the scale of damage inflicted by non-selective fishing and advocate for policies centered on preserving marine biodiversity for future generations. We offer ideas on how to reduce pressures from non-selective fishing methods and propose means of making just and equitable transitions to less damaging fisheries.

Dr Amanda Vincent, Professor of Marine Conservation, The University of British Columbia, a.vincent@oceans.ubc.ca. Chair, IUCN SSC Marine Conservation Committee; Chair, IUCN SSC Seahorse, Pipefish & Seadragon Specialist Group.

Dr Gianna Minton, Co-Chair, IUCN SSC Cetacean Specialist Group; Member, IUCN SSC Marine Conservation Committee.

Coralie Palmer, Marine Conservation Coordinator, Global Center for Species Survival, Indianapolis Zoological Society; IUCN SSC. Member, IUCN SSC Marine Conservation Committee.

How to cite: Palmer, C., Vincent, A., and Minton, G.: Difficult to define and deeply damaging: the huge cost of non-selective fisheries for marine biodiversity, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-871, https://doi.org/10.5194/oos2025-871, 2025.

The Science Based Targets Network (SBTN) Ocean Hub, co-led by WWF and Conservation International, has launched Version 1 of Science Based-Targets for Seafood Value Chains and is expanding targets to address corporate pressures on nature and biodiversity across the Blue Economy.

SBTN methodology is a new tool that supports the seafood industry’s journey to create and meet robust environmental responsibility targets. By empowering businesses to operate within Earth's limits while meeting society's needs, science-based targets give companies a clear pathway to competitiveness and resilience, using science to define their role in monitoring, protecting, and restoring nature and biodiversity while creating consistency across corporate  commitments.

The current methodology covers wild capture and farmed seafood and includes several key drivers of nature and biodiversity loss.

• Target 1: Avoid and Reduce Overexploitation
• Target 2: Protect Structural Marine Habitats
• Target 3: Reduce Risks to Endangered, Threatened, and Protected Marine Wildlife

Moving forward, the SBTN Ocean Hub will cover pressures placed on nature and biodiversity beyond seafood, in sectors such as coastal development, tourism, offshore renewable energy, and shipping. And it will further align with global frameworks to address these pressures to conserve nature and biodiversity. The Ocean Hub is considering targets to address the key drivers of biodiversity loss in the ocean including sea use change, pollution, and invasive species, while developing robust science for how companies can monitor, act on, and track their progress toward target outcomes that address the state of marine biodiversity. 

The SBTN Ocean Hub will introduce the above V1 methodology for the seafood industry to address pressures on nature and biodiversity in the ocean first, then share the exciting work to expand the methodology to address further pressures, monitor biodiversity, and expand to more key Blue Economy sectors for greater reach and impact on marine biodiversity outcomes.

How to cite: Thomas-Smyth, A. and Witkin, T.: Corporate Targets to Address Biodiversity Loss and Protection: The Science Based Targets Network Ocean Hub, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-875, https://doi.org/10.5194/oos2025-875, 2025.

While marine conservation strategies are intended to support long-term sustainability and human wellbeing, past research has shown that in some cases they can cause negative impacts for coastal communities, exclude them from decision-making, and neglect their contributions to conservation. The Kunming-Montreal Global Biodiversity Framework specifies that marine protected areas (MPAs) and other effective conservation measures (OECMs) must be both effectively managed and equitably governed. Yet, much work remains to ensure that marine conservation is inclusive and equitable. Clear guidance is needed on how to evaluate equity and improve marine conservation interventions to improve equity. To help fill this gap, we convened an international group of conservation researchers and practitioners to collaboratively develop several approaches for assessing social equity in different types of marine conservation initiatives (e.g., MPAs, OECMs, LMMAs). This includes a rapid, a stakeholder, and a participatory approach to assessing social in marine conservation. Next, we are field testing the assessment approaches in several marine conservation initiatives around the world. Finally, the assessment approaches will be published as an IUCN guidebook in time for the upcoming World Conservation Congress. The guide is intended for managers, practitioners, researchers, and representatives of government at different levels. Ultimately, users of the guide are encouraged to focus on collaboration with local actors, share and deliberate on the results of equity assessments, and to identify actions for improving equity in marine conservation. In this talk, we will present the approach, results of early testing from several case studies, and an early draft of the guide for discussion and feedback.

How to cite: Bennett, N. and Andrachuk, M. and the The Assessing and Improving Social Equity in Marine Conservation Working Group: Assessing and Improving Social Equity in Marine Conservation, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-914, https://doi.org/10.5194/oos2025-914, 2025.

How to cite: Harris, B., Fischer, M., and Williams, T.: Enhancing Blue Carbon Conservation: The Role of Muddy Seabed Sediments in Climate Mitigation and Marine Protected Areas, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-953, https://doi.org/10.5194/oos2025-953, 2025.

Sharks, rays, and chimaeras (hereafter ‘sharks’) face a high risk of extinction. Populations of many species of sharks and rays have declined by over 70–90% in last few decades. Immediate action is required to halt population declines and allow for species recovery. Area-based measures are key for biodiversity conservation but commonly do not focus on sharks, and existing ones often fail to provide them adequate protection. Target 3 of the Kunming-Montreal Global Biodiversity Framework commits nations to conserving 30% of coastal and marine areas, “especially areas of particular importance for biodiversity”. With that in mind, the Important Shark and Ray Areas (ISRA) approach was developed to ensure sharks are considered and represented in conservation planning approaches. Since 2022, over 600 ISRAs have been delineated across six regions of the world. Analysis have now been undertaken to understand overlap with existing marine protected areas (MPAs), how ISRAs can be integrated into Key Biodiversity Areas (KBAs), and what fisheries management tools can be used at the site level. In several regions (e.g., Central and South American Pacific and Western Indian Ocean), existing MPAs overlap by less than 7% with ISRAs, highlighting poor MPA coverage for these species. Without management measures to reduce fisheries mortality, preventing further losses and species recovery will not be possible. As nations move towards achieving the 30x30 targets by expanding MPA coverage, it is critical that sharks and their important habitats are considered and incorporated in national marine spatial planning processes, guided by robust scientific data.

How to cite: Jabado, R., Bettcher, V., Charles, R., García-Rodríguez, E., Palacios, M., Armstrong, A., Battle-Morera, A., Rohner, C., Gonzalez-Pestana, A., Kyne, P., and Notarbartolo di Sciara, G.:  Important Shark and Ray Areas (ISRAs) – Identifying key habitats for sharks, rays, and chimaeras, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-994, https://doi.org/10.5194/oos2025-994, 2025.

Remote sensing has emerged as a powerful tool for mapping and monitoring marine and coastal ecosystems, as it allows for the repeated collection of large-scale and consistent data on their extent and health. In addition to primary measurements (e.g., spatial coverage, species composition, biomass estimation), remote sensing can be used to acquire information of environmental variables influencing those ecosystems (e.g. temperature, salinity, sea-level, currents, waves, wind etc), but much more advanced study and monitoring is now possible. The objective of this presentation is to give an overview of the objectives and main results of the current projects relevant to marine and coastal ecosystem monitoring funded within the EO4Society programme element of the European Space Agency (ESA). This includes projects dedicated to the improved understanding and monitoring of coastal Blue Carbon ecosystems (mangroves, seagrass, tidal marshes), or to the development of global seascapes as a tool for for guiding conservation and management strategies, including for mapping Marine Protected Areas or Ecologically or Biologically Significant Marine Areas. Other projects focus on developing improved satellite products of the pressures threatening these precious ecosystems, as marine heatwaves, acidification, deoxygenation, extreme winds events, or even a combination of those occurring simultaneously (compound events e.g., combined heatwave and acidification) and investigate their impact on marine life. These products, which are all freely and openly available to the community, offer a unique dataset for  monitoring and quantifying marine and coastal ecosystem health in a changing environment.

How to cite: Rio, M.-H., Sabia, R., Landolfi, A., Martinez Vicente, V., Santoleri, R., Sechaud, A., Shutler, J., Alonso Concha, J., and Fernandez, D.: Monitoring marine and coastal ecosystems from space: on-going activities at the European Space Agency, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1157, https://doi.org/10.5194/oos2025-1157, 2025.

Human activities and climate change increasingly threaten biodiversity and marine resources, demanding effective management programs that can adapt over time. A critical aspect of this effort is understanding population connectivity, i.e. the exchange of individuals among fragmented subpopulations. Population connectivity is a crucial process supporting the persistence, regeneration, and evolution of species distribution, with significant implications for ecosystem function and biodiversity. Connectivity data are essential for setting, implementing, and monitoring conservation goals, especially in marine spatial planning. In coastal ecosystems, connectivity is primarily driven by the dispersal of pelagic larvae, influenced by ocean currents and species-specific life-history traits (e.g., spawning periods, larval duration). These factors are environmentally sensitive and vary over short timescales, due to meteorological and life-history stochasticities, and on longer timescales because of climate-driven changes. Yet, the extent of the resulting connectivity variations on different timescales and our ability to anticipate them are largely unknown. Indeed, connectivity assessments often rely on snapshot studies that may not capture temporal variability.

Our study investigates the robustness of empirical and simulated population connectivity estimates in the face of a shifting climate. Using Mediterranean gorgonians as models, we integrate connectivity estimated from (1) the genetic analysis of hundreds of samples collected following a time-structured sampling strategy (historical samples and per-cohort samples from 2022) and (2) biophysical larval dispersal simulations based on a very-high-resolution (~500m) hydrodynamical model and including non-sampled populations. We compare the inter-annual variability of connectivity over the recent past (estimated between 2001 and today) and its amplitude with a longer-term trend (measured on an interdecadal scale). This approach enables the distinction between the impact of ongoing climate-driven changes and the natural variability arising from the stochasticity of the influencing parameters. Overall, this work aims to establish a baseline for predicting how frequently connectivity estimates should be updated. By sharing these results with French and Italian policymakers, we will directly contribute to the objectives of the EU Biodiversity Strategy for 2030.

How to cite: Sant, C., Fleury, A., Guizien, K., Bramanti, L., Costantini, F., Dos Santos, J., Estournel, C., Forcioli, D., Marsaleix, P., Parras-Berrocal, I. M., Sevault, F., Somot, S., Irisson, J.-O., and Fauvelot, C.: From connection to conservation: temporal trends in coastal populations connectivity and implications for marine spatial planning, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1289, https://doi.org/10.5194/oos2025-1289, 2025.

The Mediterranean Sea is one of the most biodiverse yet ecologically fragile marine regions, and currently faces multiple interacting pressures, including overfishing, habitat degradation and pollution, and climate change. As these challenges intensify, conserving biodiversity has become paramount for sustaining healthy ecosystems and fisheries resources while safeguarding the livelihoods of coastal communities. The General Fisheries Commission for the Mediterranean (GFCM) of the Food and Agriculture Organization of the United Nations (FAO), as regional fisheries management organization (RFMO), through its 2030 Strategy for sustainable fisheries and aquaculture, offers a framework that aligns fisheries management with broader conservation goals. This contribution seeks to examine the GFCM’s evolving role in biodiversity conservation, exploring how its strategic initiatives and adaptive governance for fisheries management can also contribute to mitigating threats to biodiversity and to global conservation targets. It will highlight specific measures within the GFCM management process, offering insights into how governance, science, and stakeholder involvement can converge to secure a sustainable future for Mediterranean biodiversity. Through these actions, the GFCM is positioned to make a critical contribution toward maintaining balanced Mediterranean ecosystems where biodiversity thrives alongside sustainable fisheries.

How to cite: Nastasi, A. and Morello, E. B.: Biodiversity conservation in the Mediterranean: how can an RFMO contribute?, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1314, https://doi.org/10.5194/oos2025-1314, 2025.

Coastal regions are among the most vulnerable areas to climate change drivers, extreme events, and human impacts. At the same time, they host marine habitats essential for ecosystem services. In this context, the development of coastal infrastructure can potentially create direct or indirect impacts on marine ecosystems, which may be exacerbated by extreme events. The implementation of a coastal Digital Twin of the Ocean (cDTO) is therefore crucial to develop Nature-Based Solutions (NBS) that provide effective and environmentally sustainable alternatives. This work represents a pioneering effort to create a cDTO by developing an ecosystem-based approach to manage and implement restoration measures in coastal marine environments. It involves establishing a multipurpose observation system combined with a very high-resolution coastal operational modeling framework, featuring an AI-based interface into the large-scale regional model. The system is designed to simulate what-if scenarios to guide the restoration of seagrass meadows and coral habitats, ultimately supporting critical ecosystem services. This system was applied in the coastal areas of Civitavecchia (Latium, Central Tyrrhenian Sea), where the expansion of a large harbor and the increase in extreme events could affect existing Posidonia oceanica seagrass meadows, rocky habitats, and algal reefs.

How to cite: Piermattei, V., Federico, I., Bonamano, S., Causio, S., Shirinov, S., piazzolla, D., Scanu, S., Mentaschi, L., Alessandri, J., Sarà, G., Coppini, G., Pinardi, N., and Marcelli, M.: Integration of observing systems and operational modelling toward seagrass Nature Based Solutions, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1498, https://doi.org/10.5194/oos2025-1498, 2025.

The discourse surrounding marine conservation policy has long been dominated by spatial considerations, particularly within the framework of Marine Protected Areas (MPAs). However, this paper contends that an exclusive focus on spatial dynamics overlooks the crucial temporal dimensions inherent in effective marine management. While permanent closures are often heralded as the cornerstone of marine conservation efforts, this paper advocates for a paradigm shift towards embracing temporary marine closures, particularly in regions such as the Global South where traditional practices like the rahui persist. Drawing upon interdisciplinary perspectives from social, cultural, and ecological domains, this paper delves into the implications of temporary management regimes on marine conservation. It argues that temporary closures represent an underexplored yet invaluable tool for sustainable fisheries management, offering insights into their effectiveness and socio-cultural significance. Through a comprehensive review of literature and case studies, this paper highlights the efficacy and socio-cultural relevance of temporary closures, challenging the prevailing narrative of permanence in marine conservation discourse. Furthermore, this paper addresses the conceptual ambiguities surrounding temporary management regimes, advocating for a nuanced understanding that acknowledges the diverse forms and motivations behind such closures. By elucidating the multifaceted benefits and tradeoffs associated with temporary closures, this research aims to inform policy-making in the face of global environmental challenges

How to cite: Aceves, E.: exploring temporary marine spatial management , One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1555, https://doi.org/10.5194/oos2025-1555, 2025.

Marine resources of the Atlantic coast of Galicia (NW Spain) are controlled by the efficient transport of nutrients through upwelling processes across multiple coastal inlets known as Rias. In the shallow regions of these Rias, estuaries are dominated by tide and fluvial forcings, creating sand sediment accumulations with a profitable substrate for shellfish ecosystem. These resources are heavily harvested by locals, playing a significant role in the economy of the region. Over the last decade, these coastal ecosystems have degraded, as observed by the lower production of commercial shellfish species. Among multiple factors, changes in suspended particulate matter trends and sediment stability, both driven by local hydrodynamic conditions, emerge as potential contributors. However, these factors have been barely studied, despite their susceptibility to be affected by climate change and anthropogenic interferences. 

In this study, we aim to enhance our knowledge of hydrodynamic processes in Ria’s estuarine regions by actual in situ measurements, with the final goal of contributing to an efficient resilience of the local shellfish community. For this purpose, we deployed a set of mooring stations measuring turbidity, current velocities, water level, and temperature, in three traditionally exploited estuaries with varying fluvial-ocean influence on the southern margin of Ría de Arousa. The obtained dataset spans a spring timeframe with changing weather conditions and is combined with measurements from meteorological and oceanographic permanent stations in the area from public institutions. The ongoing data analysis focuses on the role of tidal and fluvial processes on suspended particulate matter dynamics, examining how it varies over tide cycles and specific events, and identifying discrepancies between locations that may impact shellfish habitat quality. The acquired dataset will also help to validate a hydrodynamic model, which will be essential to explore suspended particle matter behaviour and biogeochemical cycles in the region under the projected climate change scenarios.

How to cite: Guitián, J., Jalón-Rojas, I., Sottolichio, A., Bienzobas, N., and Bernabeu, A.: Exploring hydrodynamics and suspended particulate matter at shallow shellfish estuaries of Galicia, NW Spain, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1125, https://doi.org/10.5194/oos2025-1125, 2025.

Abstract

Coastal ecosystems, including mangroves, salt marshes, and coral reefs, perform vital functions such as flood mitigation, erosion prevention, habitat conservation, and carbon sequestration. However, these ecosystems are encountering unparalleled challenges primarily due to climate change and anthropogenic activities contributing to marine pollution, jeopardizing ecosystem integrity. The deterioration and destruction of coastal habitats undermine the natural resilience of these regions. Thus, implementing meticulously designed Nature-based Solutions (NbS) can facilitate the restoration and rehabilitation of compromised coastal ecosystems, mitigate marine pollution, and enhance economic and societal advantages cost-effectively and sustainably. Examples encompass the rehabilitation of essential habitats, including seagrass and salt marshes, to safeguard biodiversity and facilitate carbon sequestration, as well as the management of coastal habitats to conserve biodiversity and shield populations from extreme weather phenomena. This research seeks to perform a thorough evaluation of the efficacy and potential of Nature-based Solutions (NbS), including habitat restoration, green infrastructure, and ecological engineering, in mitigating pollution effects and fostering long-term environmental sustainability, while also formulating a conceptual model for their effective application. The research will enhance the understanding of coastal resilience and offer pragmatic recommendations for coastal management and planning.

Keywords: coastal pollution, habitat sensitivity, habitat degradation, ecosystem services, MarESA framework, nature-based solutions, DPSIR, Ria Formosa.

How to cite: Boe, G. G.: Nature-based Solutions (NbS) for Coastal Ecosystem Resilience Enhancement: Towards a Conceptual Model for Marine Pollution Mitigation, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-203, https://doi.org/10.5194/oos2025-203, 2025.

Coral reef ecosystems are unbearably at risk. The predictions are dire - 99% of corals will die by 2050, under current climate trajectories. With only 1% of corals, the hundred of millions of people that rely on coral reefs do not have a reliable future. Scientists, managers, and local communities are in a race against time and the changing climate to preserve what they can. The Coral Restoration Consortium has been galvanizing the coral restoration community since 2017 by summarizing science and practice into useful guidance and facilitating connections among MPA managers, community groups, scientists, and policy makers. This talk will outline the state of coral restoration writ large - what is being done, what is still left to do, and what are the best ways of doing it. There are enormous challenges - recurrent bleaching, disease, overfishing. Yet significant progress has been made - the scale of reef restoration is increasing, innovative techniques are being replicated throughout the tropics, photographic monitoring is more accessible. Most importantly, incredible personal dedication has been multiplied by hundreds of community-groups across the globe. The people in the coral restoration community are up against daunting predictions; but they have incredible strength and heart. Come and learn the latest about the most resilient and widespread ocean conservation movement on planet earth. 

How to cite: Vardi, T. and Levy, J.: The Coral Restoration Consortium: building community to rebuild reefs, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-870, https://doi.org/10.5194/oos2025-870, 2025.

In this paper, we analyze China’s capacity to advance global ocean equity by assessing how it mobilizes the assemblage of the concept, policy discourse, equity principles, and UN instruments around the Maritime Community of Shared Future (MCSF), and UN instruments for equity. From a relational perspective, capacity refers to unrealized potentials that nonetheless influence actors to move in a certain trajectory. To conduct this analysis, we adopt a mixed-method approach combining observation and discourse analysis to critically examine data from global ocean meetings including the 2022 UN Ocean Conference, 2021-2022 CBD COP 15, and 2021-2023 negotiations of areas beyond national jurisdiction (BBNJ). Our findings reveal that China frames equity within the context of international order and responsibilities under the UN ocean framework, reflecting high justice in Chinese Confucian justice configuration. However, current efforts neglect Chinese Confucian low justice considerations, such as fair treatment and equal social systems. In addition, China neither frames itself as a subject of equity nor a provider of equity, but a partner facilitating the equitable transition of international development. Moreover, China mobilizes distribution as the dominant dimension of equity, and only mentions UN's Common but Differentiated Responsibilities and Common Heritage Principles in their discourse on global ocean negotiation. China’s current approach to equity mobilization does not effectively address tension with the Western liberal perception of justice and rights, difficulties in the pragmatic operationalization of China’s “win-win” and “reasonableness” principles, and challenges in balancing regional and local cultural diversity. By configuring more equity narratives towards multidimensional equity and the UN instruments for equity in global ocean negotiations, China could enhance its capacity to lead an equitable and sustainable transition of global ocean governance.

How to cite: Lin, X. and Goron, C.: Towards An Equitable “Maritime Community with a Shared Future”? China’s Equity Mobilization in Global Marine Governance, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1538, https://doi.org/10.5194/oos2025-1538, 2025.