Human health and environmental health are inextricably linked.  For Pacific Islanders, this is especially true for the ocean-human health connection. Marine organisms are of great value to Pacific Islanders ecologically, economically, and culturally. These “biocultural resources” are essential for traditional practices, nutrition and food security, and their population declines from human-induced stressors affect the physical, cultural  and mental health of stakeholders.   Pacific Islanders have some of the highest rates of coronary heart disease, diabetes, cancers and other non-communicable diseases tied to lifestyle changes resulting from the loss of marine resources, as well as from exposure to pollutants.  Marine organisms are also sentinels for the effects of environmental stressors, including pesticides, plastics, and radionuclides, on human health, and can be studied at various levels, from molecules to ecosystems.  Marine organisms can take up, trophically-transfer and bioaccumulate toxicants in their tissues, and are a conduit for ingestion by human seafood consumers.  A transdisciplinary collaboration between environmental and biomedical researchers resulted in the application of techniques developed from pharmacology to determine the effects of environmental toxicants on coral reproduction and the subsequent resilience of coral reef ecosystems of ecological, economic, and cultural value to the people of the Pacific.  These studies have expanded from chemical toxicants to the potential effects of the release of radioactively contaminated cooling water from the Fukushima Nuclear Power Plant disaster of 2011 into the Pacific Ocean that commenced in 2023 and is planned to continue for over 30 years.  The vitality and sustainability of ocean ecosystems are already compromised because of human activities and stressors including those resulting from overfishing, climate change and pollution. The continued dumping of pollutants into the ocean is unnecessary and irresponsible.  As marine pollution is both a transboundary and transgenerational issue, effective actions for source control and reduction are urgent if we are to leave a legacy of a healthy ocean for future generations.

How to cite: Richmond, R.: Ocean Health and Human Health are Inextricably Linked, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-164, https://doi.org/10.5194/oos2025-164, 2025.

The Kunming-Montreal Global Diversity Framework includes strategies to reduce biodiversity loss and restore degraded ecosystems. In Ghana, mangrove ecosystems are experiencing rapid degradation despite their ecological and economic relevance to coastal communities, and efforts to restore and conserve mangrove areas. Studies on the interrelationship between mangroves and sustainable livelihoods for indigenous coastal communities are scant although they are interdependent. This study employed a co-design transdisciplinary approach that involved remote sensing, transect walks and non-participant observation, 17 age- and sex-stratified focus group discussions from five mangrove-using communities and 15 key informant interviews with community leaders, government officials and mangrove owners. Interviews and discussions covered mangrove use and valuation, economic activities, gender roles and social relations, community benefits and conflicts, adaptation and change and future outlook of mangrove-based livelihoods. Findings indicate that mangroves are central to the livelihoods of local communities in the Volta Delta, mainly fuelwood harvesting and trade, as well as fishing and fish processing, tourism and small-scale commerce. Fuelwood harvesting and trade constitute the single largest economic livelihood source in many communities. Secondly, long-term mangrove conservation conflicts with local livelihoods, thus, regenerating mangrove systems is threatened by unsustainable continuous harvesting practices. Other challenges to mangrove conservation include land tenure conflicts, and environmental factors including declining soil quality and drainage issues. Community-led conservation strategies, such as Community Resource Management Areas (CREMA), promote sustainable harvesting practices and the introduction of alternative livelihoods in eco-tourism and aquaculture. However, the short-term economic returns are insignificant, and have the tendency to impoverish members of the value chain who provide labour for harvesting, handling and transporting. The success of mangrove conservation efforts depends on the cooperation of significant members in the mangrove trade value chain, and the availability of economically viable and culturally sensitive alternative livelihoods. This study underscores the importance of community education, inclusive compensation schemes, and strengthening of CREMAs to enhance local engagement in regenerating lost mangrove areas for conservation. The research aligns with the goals of the UN Decade of Ocean Science for Sustainable Development which seek to deliver the best knowledge available to decision makers.

How to cite: Atiglo, D. Y., Adzah, S., Kaiser, D., Eschenbach, C., Ankrah, A., Brix, H., and Mahu, E.: Regenerating Mangroves as Nature-based Solutions to Coastal Hazards: Implications for Sustainable Livelihoods in the Volta Delta, Ghana, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-544, https://doi.org/10.5194/oos2025-544, 2025.

Sustainable tourism is recognized for contributing to community development and biodiversity conservation globally. Promoting sustainable tourism is at the core of UNESCO Biosphere Reserves as an international tool for sustainable development, especially in marine and coastal ecosystems. This study assesses the potential of tourism activities for marine conservation through the case of the Malindi Watamu –Arabuko Sokoke Biosphere Reserve, coastal Kenya. This Biosphere Reserve includes coral reefs, rocky sea beds, sandy sea bed habitats, and mangrove forests. The site hosts a rich biodiversity including 6 taxa of endemic butterflies, 354 fish species from 56 families, 113 species of coral in 45 genera, 4 species of marine turtles, 9 species of mangroves and 71 species of aquatic birds. The study employed a mixed method approach combining a pre-analysis of local and international issues, review of key management plans, reconnaissance survey, and round tables and focused group discussions with key informants in environment and wildlife sectors, policy makers, civil society actors, and local communities. The study identified key challenges facing the ecosystem as climate change, rapid population increases, land degradation, waste management and low visibility of the Biosphere Reserve. The study indicates that the active participation of  local communities in the Biosphere Reserve through tourism activities has sustained the ecological integrity and functioning of the Biosphere Reserve over time in line with UNESCO statutory documents including: the Seville Strategy (1995), the Madrid Plan of Action (2008) and MAB Strategy (2016-2025) as well as Convention on Biological Diversity,  and Global Biodiversity Framework in conserving biodiversity, restoring and enhancing ecosystem services, and fostering the sustainable use of natural resources. A major output of this study is an ecotourism strategy for 2025-2030.

Key words: Biosphere Reserve, Climate change, Local communities, Marine and coastal ecosystems, Sustainable tourism.

How to cite: Wekesa, B. and Chambon, M.: Sustainable Tourism as a Tool for Marine Restoration and Conservation:  The Case of the Malindi Watamu- Arabuko Sokoke Biosphere Reserve, Kenya, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-979, https://doi.org/10.5194/oos2025-979, 2025.

Global climate change creates the urgency for sustainable resource use such as the wise management of freshwater resources. One of the primary drivers of modification or deterioration of estuarine ecosystems, especially in arid and semi-arid countries is freshwater flow reduction. The determination and implementation of environmental flows (E-Flows) has been informed by studies on the freshwater inflow requirements of estuaries and responses of estuaries to upstream dam releases. The quality, quantity and timing of freshwater inputs is identified to improve the health of estuaries to ensure the delivery of multiple ecosystem services to society. To facilitate improved implementation of E-Flow restoration, a Socio-Ecological management framework has been used to link ecological health to societal benefits and ensure source-to-sea connectivity. While restoration needs in estuaries are certainly not limited to E-Flows, adequate freshwater inputs are critical to the long-term effectiveness of most other restoration efforts, such as habitat restoration. Freshwater inflow maintains critical abiotic processes such as hydrological connectivity, in situ circulation and sediment transport. The prioritisation of estuaries for E-Flow restoration, underpins blue carbon ecosystem restoration, as for example salt marsh productivity relies on hydrological connectivity with the sea to ensure tidal exchange and the rewetting of dry or saline habitats. Despite progress in E-Flow determination and prioritisation, implementation of environmental flows is still lacking. Some global case studies are described where science has informed actions such as freshwater releases from dams to improve estuary health and downstream societal benefits. Freshwater releases have been used to keep the estuary mouth open to the sea, ensured mixing and provided recruitment pulses to the marine environment for invertebrates and fish.  Challenges associated with the implementation of E-Flow restoration include political will and a willingness to address past overallocation and illegal catchment activities; addressing this will be critical to ensure future resilience and estuary health. Climate change also results in implementation challenges, as this has created a shifting climatic and rainfall baseline with ripple effects in freshwater use and delivery to estuaries. These changes affect the state of estuaries after restoration, and will require revised management practices, especially a “learning-by-doing” approach.

How to cite: Adams, J. and Van Niekerk, L.: From science to action: environmental flows for estuary restoration, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1130, https://doi.org/10.5194/oos2025-1130, 2025.

The European Digital Twin of the Ocean (EDITO) provides an innovative set of user-driven and interactive decision-making tools. Within that framework, EDITO-Model Lab’s Focus Applications (FAs) demonstrate the capabilities of the next generation of ocean models under development in this project. We deliver our Focus Applications with a high technology readiness level across three thematic areas linked to key EU policy questions: marine biodiversity, greenhouse gas emissions from maritime shipping, and marine pollution. The Focus Applications are interactive virtual demonstrators hosted on the EDITO platform, which incorporate powerful technical components, such as data, software, and computational infrastructure, into a user-friendly environment. To ensure transparency, the input datasets, all processing tools, and generated outputs are published on the EDITO platform, enabling the fast creation of new user applications.

Our application on marine biodiversity maps habitat suitability in Marine Protected Areas (MPAs). Key habitat species, like seagrass, oyster beds, and mangroves, act as nature-based solutions against flooding while providing crucial food and shelter for protected and/or endangered species, including birds, fish, and marine mammals. EDITO’s habitat suitability maps can be used to better understand these species' behaviours and responses to changing environmental conditions, supporting more effective restoration and conservation actions. 

From a technological perspective, this application enables intermediate users to easily create reproducible habitat suitability maps anywhere along the global coast where ecological knowledge of habitat species is available. More specifically, intermediate users are enabled to (1) simulate new physical or biogeochemical spatial data using EDITO’s relocatable coastal numerical models, (2) use existing or add new ecological knowledge rules on the habitat species’ responses to physical and biogeochemical conditions, and most importantly, (3) compute habitat suitability maps by applying these ecological knowledge rules to the spatial data with the D-Eco Impact software, available from EDITO’s process catalogue.

The habitat suitability maps created by intermediate users can assist end-users, such as policymakers, with marine spatial planning and habitat restoration. This is crucial for protecting biodiversity in the global ocean and along coastal zones. The societal impact of this application is to enable the creation of third-party services that support policymakers in effectively (re-)assigning targeted Marine Protected Areas and (re-)defining active legislation. This aligns with the EU Biodiversity Strategy and international goals such as those in the EU’s Nature Restoration Law, which mandates that 30% of the ocean be conserved and 30% of degraded ecosystems be restored by 2030.

How to cite: Mészáros, L., Dols, F., Farrag, M., Veenstra, J., Elzinga, H., and El Serafy, G.: European Digital Twin Ocean Application on Habitat Suitability Mapping for the Restoration and Conservation of Marine and Coastal Ecosystems, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-759, https://doi.org/10.5194/oos2025-759, 2025.

The tropical island of Hainan is one of China's largest and oldest special economic zones, and its coasts were once lined with mangrove forests, seagrass beds and coral reefs. The beauty of these coastal ecosystems underpins its economic potential for tourism, which is currently an important and growing sector. However, activities in other major economic sectors, i.e. agriculture, aquaculture and urbanization/industrialization, are impacting and degrading the integrity of coastal ecosystems and thus their economic potential and the livelihoods of the people.

Intensive coastal development and transformation in the second half of the 20th century, aimed at boosting the economy and meeting the needs of a growing population, came at the cost of environmental degradation and overexploitation of natural resources. A major factor has been the massive deforestation of mangroves and their conversion into brackish water aquaculture ponds. Untreated wastewater is discharged into coastal waters, causing eutrophication. Seagrasses are severely degraded, declining in abundance and diversity, and in some places have disappeared altogether. Coral reefs are similarly affected by eutrophication, organic pollutants, overfishing, and other threats. The connectivity of coastal ecosystems is disrupted and the provision of ecosystem services is reduced.

Long-term research in the inter- and transdisciplinary Sino-German collaborative projects LANCET, ECOLOC and TICAS enabled us to delineate the causes and consequences of coastal development on ecosystem functioning, services and connectivity in Hainan's coastal zone. We established a science-society interface and developed and implemented measures for a more sustainable use of the coastal zone together with stakeholders from politics and civil society. Our activities fed into and supported national and provincial policies. Tailor-made approaches for individual stakeholder groups included awareness-raising through educational events in schools, public lectures, stakeholder workshops, radio interviews, art exhibitions and citizen science. Recommendations for decision-makers were published in a policy brief and training courses were conducted for aquaculture farmers. Finally, seagrass conservation and restoration projects implemented by transdisciplinary teams are up and running. The concept of knowledge exchange and the success of the implemented measures have also been published in the scientific literature. Hainan is an example of the problems associated with coastal development that can be observed around the world. It also demonstrates that knowledge exchange and collaboration between science and society can improve the societal use of research results on our way to sustainability. Further collaboration is planned to monitor the impact of policies and measures on ecosystem health and services.

How to cite: Jennerjahn, T., Chen, S., Diao, X., Fedder, B., Herbeck, L., Thomsen, E., Wang, D., Zhang, J., Zhao, H., and Zhao, M.: Toward sustainable use - Science and society working together to mitigate the impacts of coastal development on biodiversity, blue carbon and other ecosystem services, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-630, https://doi.org/10.5194/oos2025-630, 2025.

The deterioration faced by coastal marine ecosystems due to pollution, overfishing, climate change, the use of inadequate fishing gear and other factors have generated alerts worldwide; residents of coastal communities see their socioeconomic situation and every day environmental are undermined, which has led local grassroots organizations in these communities to seek solutions that allow them to properly take advantage of marine resources and conserve the species and their ecosystems.

In Central American countries such as Panama, Honduras and Costa Rica, thanks to the development of participatory processes between communities, government institutions and other actors, marine areas have been established with a defined legal framework focused on the protection, responsible use and protection of marine resources (Solís Rivera et al., 2012). These areas under the figure of co-management provide important benefits for ecosystems, local economies and the protection of cultural wealth.

The case of Costa Rica, since 2008 the figure of Marine Responsible Fishing Areas (AMPR acronym in spanish) was created, which according to the Degree Nº 35502-MAG, “are areas with important biological, fishing or sociocultural characteristics, delimited by geographic coordinates and where fishing activity is regulated”, which allows the use of fishing resources in the long term, the Costa Rican Institute of Fisheries and Aquaculture (INCOPESCA), as the regulatory authority, will work in collaboration with coastal communities and other institutions for its conservation, utilization, and management (2009).Therefore, AMPRs become spaces where joint efforts converge to protect marine ecosystems. 

The growing interest from various coastal communities in the country has resulted in Costa Rica now having 12AMPRs, located both on the Pacific and Caribbean coasts, representing over 1,500 km² of protected area (FAO, 2019). The first zone declared as an AMPR was the one located in the community of Palito, on Chira Island in the Gulf of Nicoya.

In 2017 the research titled: Socioeconomic and biological functionality of the Palito-Montero responsible marine fishing area on Chira Island, Gulf of Nicoya, Costa Rica was carried out. This study provided important information regarding the quality of the product that is extracted in the area as well as the socio-environmental and economic benefits that the people who make use of these resources and the cultural protection benefit from. It was demonstrated that hand rope fishing is a traditional selective art that captures larger species, allowing fishermen to earn greater profits compared to those who use trammel nets as fishing gear. On the other hand, another of the benefits detected as a result of the existence of AMPRs is the generation of productive alternatives such as tourism and mariculture (Ulate, 2020).  

The existence of these areas has generated important benefits not only for the people who use the resource responsibly but also for all those who are linked in the value chain. At the same time, awareness is generated about the importance of protecting resources. marine to maintain healthy ecosystems for future generations as well as historical richness through social and cultural interactions important aspects for local livelihoods.

How to cite: Ulate Garita, G. and Rodriguez Salas, I.: Marine Areas as a co-management tool for the conservation of marine resources and the social well-being of related populations, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-686, https://doi.org/10.5194/oos2025-686, 2025.