Every subdivision today shapes the city of tomorrow (Azalou, 2015). Designed as tools capable of planning space, opening the city, and creating it to meet the socio-economic infrastructure needs of the population, land subdivision operations in Benin are at the center of serious concerns, even facing challenges from the central government. 'Planning issues are raised in terms of occupying areas unsuitable for housing, fragility of built surfaces, and the quality of sanitation works.' (Danvide, 2015). Nowadays, locating changes in land use and associated landscape transformations, drawing or mapping the future landscape shaped by change dynamics, is no longer possible without appropriate technologies and tools.

The present study aims to examine the factors influencing the degradation of Cotonou’s lagoon wetlands and to analyze the technological, legal, and politico-administrative responses to curb the degradation of these areas in the Republic of Benin. The methodological approach involves documentary research primarily focused on analyzing all scientific documentation related to wetlands, subdivisions, and sustainable development issues. We also conducted surveys and collected satellite data. Thus, subdivision operations, while involved in land use changes and the degradation of wetlands, are not solely responsible. Human activities and other anthropogenic pressures are also implicated in the degradation of these areas. In Benin, besides digital and two- and three-dimensional technologies, there is a full legal framework in place to curb the degradation of wetlands in southern Benin and to protect the water bodies and waterways of Greater Nokoué, including Law 2018-10 of July 2, 2018, on the protection, development, and enhancement of the coastal area in the Republic of Benin.

How to cite: Adjagan, K. E. and Adegbinni, A.: Influences of Subdivision Operations on the dynamics of Lagoon Wetlands on the Benin Coastline, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-59, https://doi.org/10.5194/oos2025-59, 2025.

Coastal development, sea level rise, and increasing frequency and severity of storms are driving the expansion of artificial coastal defences such as seawalls. These generally replace natural shorelines, leading to biodiversity loss and reduced ecosystem services. Ecologically engineering artificial coastal structures can improve their capacity to supportbio-diverse communities while still retaining their engineering function. Retrofitting with blocks or tiles to encourage the natural colonisation of marine organisms is the most viable option for increasing biodiversity on pre-existing species-poor permanent sea defences. Concrete tiles designed by the Experimental Marine Ecology Lab, National University of Singapore, are moulded with complex structural components (at 4 mm to 56 mm scale) and have been demonstrated to increase native biodiversity on local shores. BioBoss2, the latest iteration, is a hexagonal tile that incorporates complex topographical components that have been shown previously to increase species richness. Determining the optimal density to deploy enhancement tiles remains an ongoing challenge. Here, we test four densities (15%, 20%, 25%, and 30% cover) using species richness as an indicator of efficacy. We also compare the effects of two surface textures (rough and smooth). Tiles were installed along a 1.125 km section of seawall revetment in Singapore. Each configuration was replicated five times, resulting in 40 sections randomly allocated along the seawall, with a 15-meter gap between adjacent sections. A total of 1,500 tiles were deployed, making this the largest-scale installation of its kind in the world. The outcomes of this ambitious ecological engineering project will inform marine conservation and planning strategies in areas where coastal development is both intensive and inevitable.

How to cite: Chew, A. A. N., Hartanto, R., Poquita-Du, R. C., Griffin, K., Tan, Y. C., Teo, C. S., Ong, G. X. T., Peh, T. H. Y., Teo, J. W. B., Koh, M. Y. C., Tan, X. Y. Z., and Todd, P. A.: Enhancing biodiversity on Singapore’s seawalls: Large-scale testing of eco-engineering solutions, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-111, https://doi.org/10.5194/oos2025-111, 2025.

UN Ocean Summit

One Ocean Science Congress 2025

Ocean protection quality is lagging quantity: Applying a scientific framework to assess real progress against the 30 by 30 target – and proposing a blueprint for effective headway

Theme 3, Session T3-1

Climate-smart, area-based management approaches, including marine protected areas

Elizabeth P. Pike, Jessica M. C. MacCarthy, Sarah O. Hameed, Nikki Harasta, Kirsten Grorud-Colvert, Jenna Sullivan-Stack, Joachim Claudet, Barbara Horta e Costa, Emanuel J. Gonçalves, Angelo Villagomez, Lance Morgan, Johnny Briggs

The international community set a global conservation target to protect at least 30% of the ocean by 2030 (“30 x 30”) to reverse biodiversity loss, through marine protected areas (MPAs) and Other Effective Conservation Measures (OECMs). Approximately 99% of global marine protections submitted to the World Database of Protected Areas (WDPA) are currently within MPAs. However, varied design and implementation results in significantly different conservation outcomes, making MPA coverage alone an inadequate metric. We used The MPA Guide framework combined with local knowledge to assess the world’s largest 100 MPAs by area, representing nearly 90% of reported global MPA coverage and 7.3% of the global ocean area, and analyzed the distribution of MPA quality across political and ecological regions. This represented the most detail assessment of the quality of progress against the 30x30 goal, to date. We found that a quarter of the assessed MPA coverage is not implemented, and one-third is incompatible with the conservation of nature. Two factors contribute to this outcome: (1) many reported MPAs lack regulations or management, and (2) some MPAs allow high impact activities. Fully and highly protected MPAs account for one-third of the assessed area but are unevenly distributed across ecoregions in part because some nations have designated large, highly protected MPAs in their overseas or remote territories.

During the UNOC Science Congress, we propose to present an update of the Top 100 Analysis, integrating a more recent update of progress towards 30x30 and in consideration of new commitments made during the COP16 UN Biodiversity Conference held in Colombia. We will offer a framework for making effective progress towards 30x30, which will include consideration of protections designated in areas beyond national jurisdiction (via the UN High Seas Treaty) and enhanced recognition of OECMs within various governance structures (from Regional Fisheries Management Organisations (RFMOs) to Locally Managed Marine Areas (LMMAs)). In all instances we will detail the core enabling conditions required to effectively safeguard representative marine ecosystems from destructive human activities.

How to cite: Pike, B., Briggs, J., MacCarthy, J., Hameed, S., Harasta, N., Morgan, L., Grorud-Colvert, K., Sullivan-Stack, J., Claudet, J., Horta e Costa, B., Gonçalves, E., and Villagomez, A.: Ocean protection quality is lagging quantity: Applying a scientific framework to assess real progress against the 30 by 30 target – and proposing a blueprint for effective headway, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-123, https://doi.org/10.5194/oos2025-123, 2025.

Despite high confidence in global evidence on the effects of climate change on marine ecosystems and maritime sectors, implementation of climate-smart marine spatial plans is scarce. Collaboration at the science-policy interface is seen as a key accelerator towards making this ambition a reality. We report here on such a successful collaboration. Co-delivered transdisciplinary research involving UK marine and social scientists, economists, data engineers and software developers, as well as agencies with statutory responsibility for marine planning, conservation and resource management, has led to the development of fit-for-purpose climate data products and a transdisciplinary, web based and AI assisted decision support tool (ASPACE) which are already helping UK marine planners and those working on the spatial management of fisheries and MPAs to make climate-smart, economically viable and socially acceptable decisions about space allocation. Clear climate impacts are projected in the UK EEZ within the coming decades, extending from coastal areas across the continental shelf, and affecting species and habitats of high conservation and commercial value. However, opportunities also emerge for interventions that optimise the use and/or conservation of climate change refugia for different maritime sectors, and to protect ocean carbon towards climate change mitigation, which are economically feasible and aligned with the values held in different regions of the UK. This work is an important example of how co-designed and co-delivered research can help accelerate the change in marine policy we need, to promote climate actions necessary to deliver climate change adaptation and mitigation necessary to support sustainable ocean planning, for our ocean wildlife and for dependent communities. Knowledge sharing beyond this project is now supporting others in Europe, Western Indian Ocean, SE Asia and beyond, helping create similar decision-making chains that may, too, support our future ocean and its people under climate change.

How to cite: Queiros, A. and the MSPACE team: Marine Spatial Planning addressing climate effects in the UK and beyond, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-188, https://doi.org/10.5194/oos2025-188, 2025.

Flight initiation distance (FID), the distance at which an organism begins to flee from an approaching threat, is a major component of antipredator escape behavior and a potential indicator of threat perception in fishes. In this study, we analyzed the FID of three important rocky-reef fish species targeted by spearfishers, which are of commercial and recreational importance. We tested predictions that FID to a diver threat increases with the following factors:(1) fish body size, (2) less restricted access regimes, and (3) increased historical fishing pressure. We studied three size ranges of three rocky-reef fish species,in three different access regimes (i.e., open access, territorial user rights for fishery areas, no-take marine protected areas), and in two regions (northern and central region with different levels of fishing pressure depending on the species). We conducted an ANOVA to analyze pairwise interactions. We used the mean square criterion to select the models that best explained the variation of our response variable. Our findings indicate that FID can be distinctly elucidated by factors such as individual size, species, access regimes, and regions. Additionally, our models show that interactions involving regions and either species or size further contribute to explain FID variability. FID was higher in larger fishes and those of higher commercial value, outside marine reserves and in the region with the highest historical fishing pressures (based on landings data). This study supports the predictions that increased FID is associated with the threat posed by spearfishing activities. Furthermore, our findings indicate that spearfishing may already be altering the behavior of rocky-reef fifishes on the north-central coast of Chile.

How to cite: Contreras-Drey, F. J. and Gelcich, S.: Escape behavior of rocky-reef fish reveals the impact of spearfishing across different management regimes, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-200, https://doi.org/10.5194/oos2025-200, 2025.

Southeast Asia’s extensive coastline contains a suite of blue carbon ecosystems that all play important roles in the storage of carbon – a so-called Nature Based Solution for climate mitigation. However, the scale of this stored carbon, and how it may respond to future climate change is uncertain, and remains a key hinderance in the widescale adoption of blue carbon conservation policy. In the SCOPE project, we are mapping the carbon storage potential of key blue carbon ecosystems along the Vietnam and Cambodia coastline: mangrove forest, seagrass meadows, coral reef lagoons, tidal marshes and mud flats. Our big data approach allows us to consider historical, present-day and future habitat distributions and their blue carbon capacity (in terms of sediment carbon storage, sediment accumulation rate, above-ground and below-ground biomass, carbon flux, photosynthetic rate, growth rate, species composition). Utilising habitat suitability modelling and ensemble forecasting allow us to identify: blue carbon storage hotspots, areas at risk of carbon loss and the effects of blue carbon management, habitat restoration and land-use change. By providing a robust knowledge base about the blue carbon potential of the region, we are now using this as the foundation for co-creating actionable steps for a sustainable blue carbon management plan that harmonises local and national priorities for social inclusion, environmental resilience, and economic viability across southeast Asia.

How to cite: Joshi, S., Pekkari-Juto, F., Long, V. H., Cuc, N. T. K., Kamenos, N., Hien, H. T., Chi, V. K., Sandström, C., and Burdett, H.: Habitat Suitability Modelling of Blue Carbon Habitats in Southeast Asia, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-243, https://doi.org/10.5194/oos2025-243, 2025.

The Scientific Strategy of the Port-Cros National Park (PCNP), a terrestrial and marine protected area located in the north-west Mediterranean sea, is a framework document to provide the scientific requirements and priorities for all disciplines for 2023-2032, targeting a long-term perspective. It promotes the ethical principle of 'evocentricity' that insists on the maintenance of ecological functions and the dynamics of change.

The humans are a component within the ecosystem; contributing, as for the other species that constitute the ecosystems, to the functions of predator, disturbing element, and also receiver of information and services from other living species, as manager, protector, vector of knowledge, etc. All species - including humans - play a role in the evolution process. The scientific goal of the PCNP is to understand these underlying processes, to identify their tangible manifestations and to endeavour to guarantee their functioning.

Human occupation has shaped landscapes for thousands of years, and rare are the ecosystems that have evolved free of anthropogenic pressure for a long period. About 60 years after its creation, the PCNP is becoming a life-sized laboratory, a reference space for the expression of dynamics of change that are less influenced by humans. These rare sites are exceptional and specific since they are the only places where, for example, processes may fully develop up to reaching the phases of the ageing, death and degradation of the vegetation. The PCNP’s integral reserves, spaces free of direct human impact, also contribute to ecological solidarity by leaving room for the expression of other components of the ecosystem within the territory and contributing to the ecological networks.

Part of the research carried out at the PCNP aims at finding answers to management issues. In the context of a peri-urban national park, decisions regarding actions that might have a greater or lesser impact should be discussed in the light of the moral and patrimonial responsibility of the PCNP for endangered habitats and species at local, national or even international scale, and also with regard to the irreplaceable nature of elements with high conservation priority. This requires first the formulation of a prior diagnosis to determine the priority sites for intervention, then to tailor or adapt the management measures and methods to the local context, and finally to assess the pertinence and effectiveness of the measures deployed (or the effects they may have had). Adaptive management should also better integrate the recommendations derived from the humanities and social sciences and examine the relationships that humans may have with other species. A better co-existence and co-evolution between human societies and their environment, taking into account biological, ecological and societal components, should be the ultimate goal that will allow human societies to preserve their local natural heritage and raise awareness to associate each and everyone of us.

How to cite: Barcelo, A., Bonnaud, E., and Taupier-Letage, I.: Scientific Strategy 2023-2032 of the Parc National de Port-Cros (Provence, France), One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-357, https://doi.org/10.5194/oos2025-357, 2025.

The Important Marine Mammal Area (IMMA) program was launched in 2016 by the IUCN Marine Mammal Protected Areas Task Force as a response to the conservation crisis in the protection of marine mammals and wider global ocean biodiversity. IMMAs identify discrete portions of habitat, important for one or more marine mammal species, which have the potential to be delineated and managed for conservation. Scientific experts identify IMMAs during regional workshops based on criteria covering critical aspects of marine mammal biology, ecology and population structure.

Between 2016-2024, eleven expert workshops - engaging more than 300 experts - have resulted in the identification of 280 IMMAs located in over 100 countries or territories across 80% of the world’s ocean. Candidate IMMAs undergo independent peer review before acceptance and are then disseminated via a searchable database and dedicated online e-Atlas. IMMAs identified to date provide important habitats for 93 of the 135 recognised marine mammal species. Around 69% of IMMAs in the network were identified based on habitat for marine mammal species that are threatened on the IUCN Red List. Approximately 58% of IMMA surface areas occur within Exclusive Economic Zone waters, while 42% fall within areas beyond national jurisdiction.

IMMAs are increasingly utilised in environmental impact assessments, marine spatial planning exercises, maritime traffic routing, and international, national, and regional conservation, policy and management initiatives. These include those governed through the Convention on Migratory Species (CMS) and Convention on Biological Diversity (CBD), the design and management of Marine Protected Areas (MPAs) and the development of MPA networks. The Task Force is working toward completing a global network of IMMAs that will contribute to the Global Biodiversity Framework (Target 3) of protecting 30% of the ocean by 2030 and to the identification of areas to be protected based on the UN BBNJ Treaty.

How to cite: Notarbartolo di Sciara, G., Braulik, G., Lanfredi, C., Minton, G., Panigada, S., Politi, E., Zanardelli, M., and Hoyt, E.: The Important Marine Mammal Area Network: the growing tool for assisting global conservation efforts to protect marine mammal habitats, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-437, https://doi.org/10.5194/oos2025-437, 2025.

The Mediterranean Sea presents a striking contrast as a biodiversity hotspot and one of the world's most popular touristic destinations. The coastlines of Mediterranean countries are heavily developed, densely populated, and significantly impacted by human activities. Protecting these urban coastal regions through Marine Protected Areas (MPAs) is essential for preserving the ecological value of its marine biodiversity. However, implementing effective MPAs in densely populated urban zones poses considerable challenges, necessitating the creation of suitable management strategies. This step requires first establishing a clear definition of what constitutes "urban" within the marine protection context. In that respect, our work focuses on examining several local case studies within the Mediterranean Sea. This study aims to (1) develop urban variables that enable the classification of MPAs based on levels of urbanization, and (2) define the characteristics of an "urban MPA" by establishing relevant thresholds. MPAs selection criteria were mainly: the presence of at least one "no-take zone", the existence of an implemented management plan, and the availability of ecological data. An urban indicator was created from nine variables derived from population metrics and satellite imagery analysis using QGIS software. A total of 20 MPAs were scored on a scale of 1 to 5 for each variable, and an overall average score was calculated to determine the urban indicator for each MPA. We found that (1) the developed urban indicator effectively clusters MPAs, (2) only 6 out of the 20 MPAs can be classified as urban MPAs, (3) urban MPAs tend to be easily accessible and located near densely populated area, while (4) non-urban MPAs may also be found in highly touristic areas. This study provides initial insights into the profiles of MPAs located in urban contexts. Our findings contribute to integrating marine conservation with geographical and social sciences. To go further, analyzing differences in the management and governance of urban versus non-urban MPAs will highlights valuable management tools that could enhance ecological effectiveness and foster social acceptance, tailored to the urbanization level of each MPA.

How to cite: Marty Gastaldi, J., Lazaric, N., and Derijard, B.: Urban typology of Marine Protected Areas (MPAs): exploratory and technical study, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-452, https://doi.org/10.5194/oos2025-452, 2025.

Since 2010, and every four years, MedPAN (the Network of Mediterranean MPAs managers) and the UNEP/MAP Regional Activity Center for Specially Protected Areas (SPA/RAC) have been working with Mediterranean countries, NGOs, MPA management bodies, and other regional organisations to assess progress toward international and regional marine protected area (MPA) targets. By 2020, 8.33 % of the Mediterranean Sea had been designated as MPAs. However, 97.33 % of this protected surface lies within the waters of EU member states, highlighting a stark disparity in protection efforts across the region.

An online survey conducted in 2020 captured the experiences of managers from 152 nationally designated Mediterranean MPAs, providing valuable insights into the resources, governance, and management practices that influence MPA effectiveness. The survey revealed that regulating human activities within MPAs is critical to achieving conservation goals, but effectiveness remains tied to the availability of key resources such as funding, governance frameworks, and practical management tools.

Notably, only 0.04 % of the Mediterranean Sea—approximately 1,096 km²—is designated as no-go, no-take, or no-fishing zones, representing the highest level of protection. There has been no significant expansion of these high-protection zones over the past decade. The cumulative size of these areas varies greatly, with the smallest covering 0.01 km² and the largest spanning 156 km². Half of these MPAs have zones smaller than 2 km², and three-quarters are under 6 km². Only 18 MPAs exceed 10 km², and just 2 MPAs protect areas larger than 100 km².

The analysis also highlights a striking imbalance in financial and management capacities. Only 7 % of MPAs with no-go, no-take, or no-fishing areas have a suitable budget for effective management, all located in EU member states in the western Mediterranean basin. Furthermore, only 15 % of MPAs with no-go, no-take, or no-fishing areas have fully implemented management plans, while 37 % have partially implemented plans, and 21 % lack any management plan.

Given the escalating pressures on the Mediterranean's marine ecosystems—including human activities, pollution, invasive species, and climate change—there is an urgent need to strengthen the network of MPAs. This can be achieved by enhancing the network's collective capacity to address mounting environmental challenges, as well as by supporting individual MPAs. Efforts should include closing gaps in protection and ensuring the necessary conditions for effective management, ultimately leading to greater ecological benefits.

How to cite: Gallon, S., Kheriji, A., and Neveu, R.: Assessing the Progress and Effectiveness of Marine Protected Areas in the Mediterranean: A Decade of Insights, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1085, https://doi.org/10.5194/oos2025-1085, 2025.

How to cite: Rayo Luengo, S., Blaskovic, A., Merotto, L., Barrazzetta, F., Garrabou, J., Bueno Pardo, J., Hadjieftychiou, S.-I., Petrou, A., Dos Santos Gonçalves, J., Horta e Costa, B., Blanco, A., and Ojea, E.: Co-creation and transference of a Climate Change Vulnerability Assessment tool for MPA managers: evidence from the Mediterranean Sea, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1225, https://doi.org/10.5194/oos2025-1225, 2025.

Malaysia is recognized as one of the world’s largest mega biodiversity countries. Under the Malaysia National Biological Diversity Plan (2022-2030), the protection and conservation of marine organisms and their ecosystems are prioritized in alignment with the natural climate solutions outlined in the UN Sustainable Development Goals 2030. A key focus of this initiative is the conservation and restoration of vital species, habitats, and vulnerable ecosystems, including seaweed species like red algae eucheumatoid, which supports Malaysia’s economic, social, and ecological systems. Despite its importance, protection efforts for this species have been limited, and scientific data indicate a concerning decline in genetic diversity among commercial and wild populations.

To support effective conservation, we assessed Malaysia’s national concept, targets, strategies, and actions related to biodiversity as outlined in national policies, legislations, and the marine conservation framework, with particular attention to seaweed. We reviewed four national and local policies and five legislations addressing biodiversity and ecosystem management. Thematic analysis revealed: 1) Only national policies specifically focused on biodiversity and conservation include clear concepts, strategies, targets, and actions; however, these are often unbinding, 2) Policies and legislation on biodiversity typically lack explicit references to seaweed due to its lower prioritization, 3) The lack of prioritization in setting conservation targets has contributed significantly to the shortcomings in achieving conservation objectives, and 4) Education is crucial to build community awareness about the ecological and commercial value of seaweed biodiversity. Understanding regional capacity and resources is essential to achieving conservation goals effectively.

The agenda surrounding biodiversity conservation is increasingly highlighted in international forums such as the Biodiversity COP 16 held in Cali in October 24 and Climate COP 29 in November 24. At these events, discussions emphasized the interconnectedness of biodiversity loss and climate change while promoting ecosystem-based approaches as viable solutions that address multiple global challenges simultaneously. The emphasis on integrating biodiversity considerations into climate action reflects a growing recognition of the need for cohesive strategies that leverage synergies between various environmental frameworks. By addressing policy gaps and capitalizing on opportunities for collaboration across sectors, Malaysia can enhance its approach to biodiversity conservation while fostering sustainable practices that benefit both ecosystems and local communities benefiting from opportunities arising from the seaweed sector.

How to cite: Kambey, C. S. B., Lim, P.-E., Poong, S.-W., Kassim, A., Beattie, S., Cottier-Cook, E. J., Brodie, J., and Nagabhatla, N.: Assessing Malaysia's Biodiversity Plan: Seaweed Conservation in Policy and Legislation, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1277, https://doi.org/10.5194/oos2025-1277, 2025.

The EFFECTIVE project represents a pioneering endeavor in Mediterranean biodiversity conservation and management, aligned to meet conservation targets by 2030. Outputs such as the Ecosystem-Based Management System (EBMS), the Nature-based Technological Solutions Toolbox, and the Blue Parks Digital Twin demonstrator validate the project's capacity to address conservation objectives effectively. By leveraging the EBMS framework and innovative technologies like the BioBoosting System (BBS)  a multi-layered biomimetic micro-reefs from natural substrateand and Geocorail process natural rock" made from elements found in the marine ecosystem,floating innovative coral nurseries and cold-water reef restoration, EFFECTIVE tackles climate change challenges while reinforcing marine protected areas and promoting habitat restoration. Monitoring and analysis within the Blue Parks Digital Twin facilitate data-driven decision-making and citizen science participation. These integrated solutions promote ecosystem protection, address climate change impacts, and foster a sustainable ocean economy. Additionally, EFFECTIVE emphasizes the importance of safeguarding Mediterranean marine habitats, including critical migratory routes for cetaceans, through strategic conservation measures. By embracing a holistic approach that integrates ecological evidence with social, political, and economic considerations, EFFECTIVE aims to enhance the resilience and long-term health of marine ecosystems, epitomizing a united effort towards marine conservation.

How to cite: Preciado, N., Crespo, M., Felis, I., Sanz, J. C., and Martinez, R.: Enhancing social well-being and economic prosperity by reinforcing theeFFECTIVEness of protection and restoration management in MediterraneanMPAs, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1484, https://doi.org/10.5194/oos2025-1484, 2025.

To what extent has humanity degraded ecosystems? This is a crucial question we need to ask ourselves if we are to reconcile our relationship with nature and imagine a more desirable future. Although everyone has heard anecdotal accounts of once-abundant species from previous generations, systematic quantification of ecosystem degradation over time is difficult to achieve due to limited historical data. Instead, it is possible to use the most pristine ecosystems known today to estimate the lower bound of our current impact on nature. By measuring 22 potential contributions of fish communities to nature and people in over 2000 tropical reefs, we have explored the impact of anthropogenic activities and conservation measures on fish communities. By explaining these contributions by more than 40 environmental, habitat and human covariates, we conducted counterfactual scenarios on unprotected and protected reefs to measure the effect of anthropogenic activities and conservation measures on contributions to Nature and People. We show that anthropogenic activities have massively reduced the biomass and diversity of fish communities on tropical reefs, reducing the total measured contributions by an average of 10%. Despite a non-negligible impact on biomass and IUCN species richness, conservation efforts to date have only been able to offset the decline by a few percent. Our results show that despite the undoubted benefits of current protected areas, reef protection cannot and will not compensate for all our extraction, pollution and ecosystem destruction. A change in our relationship with nature is therefore urgent and imperative if we are to imagine an enviable future for nature and people.

How to cite: Flandrin, U., Mouquet, N., Albouy, C., Edgar, G., Hautecoeur, C., Maire, E., McLean, M., Loiseau, N., Stuart-Smith, R., and Mouillot, D.: The human footprint and conservation legacy on 22 forms of nature's contribution in tropical reefs, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1512, https://doi.org/10.5194/oos2025-1512, 2025.

Achieving global and regional policy goals to protect 30% of marine areas by 2030 requires an integrated strategy that incorporates the full complexity of ecosystem processes and functions. This study (i) introduces a framework for enhancing ecosystem-based conservation and management by utilising the Ecologically or Biologically Significant Marine Area (EBSA) criteria established under the Convention on Biological Diversity (CBD), and (ii) demonstrates its application in the Bay of Biscay (Northeast Atlantic), explicitly accounting for benthic and pelagic aspects of the ocean environment.

The framework provides a structured workflow for identifying the areas of high ecological significance within an analysed region, moving beyond single-species or habitat protection to incorporate ecosystem-level processes and stressors, including those driven by climate change. It guides key stages of EBSA criteria operationalisation, including area delineation, identification of target ecological features, data collection, evaluation of data quality and coverage, and spatial analysis and interpretation. This approach allows relative ecological significance to be assessed at a spatial resolution suitable for informing regional or national decision-making. An embedded method for evaluating data quality and spatial coverage further enables spatially explicit assessments of uncertainty and data gaps.

The framework was tested in the Bay of Biscay, a transboundary region characterised by high productivity and structurally complex seafloor sustaining a rich diversity of marine life. Using a systematic conservation prioritization approach that integrates both benthic and pelagic realms and accounts for climate-driven changes, we demonstrate how diverse datasets can be aligned with EBSA criteria to evaluate ecological significance. This assessment offers valuable insights into key ecological processes and forms a foundation for ecosystem-based management, supporting the identification of priority areas for conservation while also informing broader marine spatial planning, such as guiding regulations of fisheries and other human activities.

The showcased framework can be adapted in other regions, whether data-rich or data-poor, enhancing broader ecosystem-based conservation and spatial management efforts while ensuring transparency and reproducibility.

How to cite: Lukyanova, O., Pouso, S., García-Barón, I., Borja, A., Bas, M., Cormier, R., Katsanevakis, S., Neuenfeldt, S., Stelzenmüller, V., and Galparsoro, I.: Operationalising Ecologically or Biologically Significant Marine Area Criteria for Ecosystem-Based Conservation and Management: The Bay of Biscay Case, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-961, https://doi.org/10.5194/oos2025-961, 2025.

Astola Island, also known as Jezira Haft Talar, is Pakistan's first Marine Protected Area (MPA), designated to conserve its unique terrestrial, intertidal, and marine ecosystems. Located 18.6 nautical miles southeast of Pasni in Balochistan, Astola Island MPA covers a core marine zone of 225.83 km² and an outer buffer zone of 175.64 km². The island features a rugged topography with steep rocky cliffs on the southern side, sandy beaches on the northern side, and diverse habitats including coral patches, sandy shores, and rocky crevices that support a wide array of flora and fauna. Astola Island hosts 30 plant species, eight species of reptiles including the endemic Saw-scaled viper (Echis carinatus astolae), and 61 avian species, among which are significant populations of migratory birds. The island is a crucial nesting site for green turtles (Chelonia mydas) and there have been offshore sightings of hawksbill turtles (Eretmochelys imbricata). The surrounding waters are rich in marine biodiversity, with more than seventy-five recorded fish species, 25 coral species (hard and soft coral colonies), and recorded sightings of threatened marine mammals like the Indo-Pacific finless porpoise (Neophocaena phocaenoides) and the Arabian Sea humpback whale (Megaptera novaeangliae). The socio-economic importance of the island is tied to its rich fishing grounds, which support around 800 households, primarily from Pasni and other nearby fishing towns. Astola Island also holds cultural significance as a historic shipwreck site and a religious site for both Hindu and Muslim communities. Despite its ecological, economic and cultural significance, Astola Island faces multiple threats, including invasive species like black rats and mesquite (Prosopis juliflora), Illegal unregulated and unreported fishing activities, pollution from discarded waste, as well as impacts from climate change such as coral bleaching and coastal erosion. To address these challenges, IUCN Pakistan in consultation with the MPA custodian authority Balochistan Forest and Wildlife Department and Pakistan’s National Coordinating Body on MPAs developed the Astola Island MPA Management Plan with the aim of conserving the island's biological, ecological, cultural, and socio-economic values. Key priorities include establishing a mainland MPA information center at Pasni and a field station on Astola Island, enforcing environmental laws, and controlling visitor numbers to prevent habitat degradation. Research conducted over the past year aimed to assess the existing status of biodiversity, identify key challenges, and recommend management strategies through a recognised MPA management plan to ensure that Astola Island remains a vital conservation area, balancing ecological protection with sustainable resource use for the long-term benefit of Pakistan. The management strategy focuses on habitat conservation, waste management, invasive species control, sustainable fisheries, and ecotourism management. Additional programs are designed to support community engagement, alternative livelihoods, education, scientific research, and monitoring and evaluation using SMART indicators.

How to cite: Macintosh, D., Ullah, S., Malik, I., Rahim, A., Soomro, N. A., Samoo, A. H., and Shah, S. U. R.: Astola Island Marine Protected Area: An Overview of Present Biodiversity, Challenges, and Strategic Management Planning, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1272, https://doi.org/10.5194/oos2025-1272, 2025.

Protecting marine biodiversity amidst climate change requires advanced planning that addresses the three-dimensional complexity of marine ecosystems. Existing conservation efforts in China lack sufficient depth-specific planning to safeguard vulnerable species habitats across the water column. In response, we developed a three-dimensional marine planning framework using data for 8,452 marine species, integrating climate models to project species distributions and assess vulnerability under three CO₂ scenarios (RCP2.6, RCP4.5, RCP8.5) by 2100. Results indicate substantial habitat loss and poleward shifts, with over 50% of current habitats potentially unsuitable under high-emission scenarios. This study identifies new, low-regret conservation priorities encompassing 15.6% of China’s adjacent seas, targeting areas with high vulnerability, such as the West and East seas of Liaodong Peninsula and seas around Hainan and Taiwan Islands. Our findings offer a crucial foundation for a depth-inclusive MPA network, promoting resilience in marine conservation under a warming ocean.

How to cite: Wang, Z. and Cao, L.: A Three-Dimensional Framework for Climate-Resilient Marine Conservation in China’s Seas, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-475, https://doi.org/10.5194/oos2025-475, 2025.

In coastal marine environments, the renewal of necto-benthic Teleost populations depends on the availability of various essential habitats at key stages in the species' life cycle, notably spawning and nursery habitats. The creation of strong protection zones (“no-take zones”) is effective in protecting adult breeding populations; however, nursery habitats require a different type of protection, to protect them from a transformation of their characteristics, essential to their nursery role; moreover, different species use different habitats within the coastal habitat mosaic, or use them successively during ontogenic migration. Knowing the typology of these habitats, their location (mapping) and their availability (relative surface areas) is therefore key information for guiding the zoning of management measures. In the Mediterranean, several habitats and ecotones are known for their nursery role. Our Medhab program, as part of the PAMM (2018-2022), has enabled us to complete their mapping, particularly for one of the little-documented nursery habitat types that do not fall within the scope of standardized biocenosis mapping, i.e. specific facies (in this case shallow heterogeneous rocky bottoms). On the basis of our mapping work locating and quantifying the availability of this nursery habitat along the 2700 km of French Mediterranean coastline, in addition to existing mapping (e.g. Posidonia meadows), we have set out recommendations for the zoning of management measures, notably the designation of reinforced protection areas.

How to cite: Cheminée, A., Djaoudi, K., and Nunez, L.: Presence and diversity of key habitats as criteria for zoning enhanced protection areas: the Mediterranean case of habitats acting as nurseries for juvenile fish, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1493, https://doi.org/10.5194/oos2025-1493, 2025.

The fisheries industry has made tremendous strides in recent years, developing into a main economic sector for Vietnam and making it one of the world's leading exporters of seafood. In 2023, the overall amount of the fisheries sector's exports was USD 9.29 billion. The overall fishery production was 9.23 million tons, of which 3.8 million tons were exploited, and 5.43 million tons were produced by aquaculture. This result has contributed significantly to the country's economic growth, strengthened livelihoods, and stabilized people's lives in coastal provinces. Marine biodiversity, with an emphasis on marine ecosystems, plays a critical role. As a result, protecting aquatic habitats is a critical challenge that is no longer limited to a single nation or region, but has become a hot news topic and a global concern. In 2017, the National Assembly passed Law on Fisheries that supplements the 2003 law with a focus on the protection and conservation of marine resources and biodiversity to ensure sustainable fishing industry. The 2017 law details Illegal, Unreported and Unregulated (IUU) fishing activities and stipulates strict punishments compared to administrative penalties for violations in other fields. It takes into account EU recommendations, and extends to fishery products sourced from illegal fishing for temporary importation, re-export, temporary export, re-import, trans-shipment and transit through Vietnamese territory.

In fact, the marine protected area plays a critical role in sustainable fisheries development in Vietnam by conserving marine biodiversity, preserving marine ecosystems, protecting the traditional fishing grounds. Thus, it contribute the natural resources to maintain livelihoods for 10 millions people to work in fishery sector and associated coastal fishermen communities. Up to now, Vietnam has established and put into operation a network of 12 out of 16 marine protected areas and national parks with marine conservation components. this system of marine protected areas occupies an area of about 0.24% of the sea area of Vietnam. The goal is to reach 6% of Vietnam's sea area by 2030. Marine protected areas hold nearly 70,000 ha of coral reefs, 20,000 ha of seagrass beds and mangroves, most of the breeding grounds, spawning grounds, and habitats of economic aquatic species; nearly 100 endemic and endangered species.

Those, the science evidences of the consequences in the wild fish stock recovery after the marine protected areas established. The country faces challenges between coastal urbanization trends and conservation tasks. It demands strong efforts and commitments from the central government to local authority and stakeholders to expand the total marine areas for protection.

Keywords: marine biodiversity, marine ecosystem, fishery resources, marine protected area.              

*Corresponding author: Nguyen Van Quan, email: quannv@imrer.vast.vn

How to cite: Nguyen Van, Q.: The Role of Marine Protected Areas In Sustainable Fisheries Development In Vietnam, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1591, https://doi.org/10.5194/oos2025-1591, 2025.