The integration of scientific knowledge into international legal documents is crucial to ensuring the effectiveness of legal instruments on a global scale. This process involves several fundamental steps. Firstly, it requires consultation with scientific experts to guarantee that the best data and research are taken into account. Secondly, it is essential to adapt this scientific information into accessible legal language to facilitate its incorporation into standards. In addition, the implementation of mechanisms such as the precautionary principle is necessary to manage the uncertainties associated with the absence of complete data.

Additionally, updating legal standards in response to scientific advances is also essential. Close collaboration between lawyers, scientists and policy-makers is essential to ensure that new discoveries directly influence the development, application and adjustment of legal obligations in vital areas such as the environment, biodiversity, public health and emerging technologies.

In Latin America, there is a growing recognition of scientific voices and indigenous knowledge in the development of public policy, particularly with regard to natural resource management and biodiversity conservation. For instance, countries such as Bolivia, Ecuador and Peru are beginning to integrate traditional knowledge into their ecological strategies. Indigenous communities are increasingly present in international forums and are often consulted prior to the implementation of development projects. However, their influence is often hampered by structural inequalities and conflicts of economic and political interest.

There are also initiatives aimed at strengthening collaboration between scientists and indigenous peoples, enabling traditional knowledge to be put to better use in the management of environmental resources. Despite this progress, fully integrating these voices into public policy remains a major challenge.

In Costa Rica, the situation is similar. The contributions of scientists and indigenous populations are beginning to transform public policy, particularly in the fields of natural resource and environmental management. Institutions such as the University of Costa Rica and INBio are providing evidence to support sustainable policies, particularly in the areas of conservation and the fight against climate change. At the same time, the traditional knowledge of indigenous peoples, such as the Bribris and Cabécars, is gradually being incorporated into the management of national parks, although its inclusion is still limited.

Concerning maritime law, scientists play a role in the management of marine protected areas such as Coco Island, but the knowledge of coastal and indigenous communities is often underestimated, despite the importance of their sustainable practices.

Costa Rica's indigenous and local populations face numerous obstacles that limit their participation in decision-making processes concerning the environment and the sea. There is insufficient legal recognition of their rights, particularly with regard to their traditional territories. Moreover, they are often under-represented in decision-making bodies, far removed from centers of power and confronted with language and cultural barriers. Besides, commercial interests often take precedence over their basic needs. Lack of access to information and resources hinders their involvement, and their traditional knowledge is rarely valued. Although positive initiatives, such as training programs and partnerships, have emerged, further efforts are needed to establish a more inclusive and equitable decision-making framework.

How to cite: Blanco Rojas, K., Cudennec, A., and Gassiot, O. R.: The alliance between indigenous knowledge, science and law: towards more sustainable environmental management, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-157, https://doi.org/10.5194/oos2025-157, 2025.

Ocean data from systematic observations are the foundation for national, regional and global action. Ocean data underpins progress across many multilateral agreements including the UNFCCC and Paris Agreement, United Nations agreement on biodiversity beyond national jurisdiction, CBD Kunming-Montreal Global Biodiversity Framework, IMO, FAO, UNEP and the plastic treaty.

There is an urgent need for nations to strengthen and expand the global ocean observing system (GOOS) to build a sustained and sustainable critical ocean observing infrastructure, that delivers data at national, regional and global levels. Yet ocean observing networks and data systems are not recognized as critical infrastructure and often reliant on scientific research funding.

The strengthening and expansion of the global ocean observing system must be built from key advancements in and vision for ocean observing set in place by the Framework for Ocean Observing, the GOOS Strategy 2030, as well as more recently by the Ocean Decade Challenge 7 to Sustainably expand the Global Ocean Observing System.

We need to codesign the system and codeliver the services ensuring ocean observations as the raw ingredients for the value chain for, amongst other things, forecasting and early warning systems for multi-hazard risks, marine protection and safety, biodiversity positive resilient communities, climate change mitigation and adaptation, and sustainable ocean economy as well as understanding of the Earth system and indicators to inform decision making and policy.

How to cite: Post, J. and Heslop, E.: Co-designing the global ocean observing system for service delivery, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1334, https://doi.org/10.5194/oos2025-1334, 2025.

Plastics are an international governance priority because of extensive and resource-intensive production, uncontrolled
environmental releases, and failure to control the chemicals within the materials. We examine the
evidence that plastics have exceeded the planetary safe operating space, discussing how plastics pollution
affects multiple Earth system processes along the impact pathway from resource extraction and production
to release to environmental fate and impacts. Multiple lines of evidence capture the complex reality of these
novel entities; a single planetary boundary quantification would be detrimental. We demonstrate causal links
between plastics and other environmental problems, exacerbating the consequences of breaching other
planetary boundaries. We propose biophysically defined control variables for the planetary boundaries
framework as a way to measure, monitor, and mitigate global plastics pollution. We call for urgent action,
recognizing plastics pollution not only as a waste management problem but as an integrative part of climate
change, biodiversity, and natural-resource-use policy.

How to cite: Carney Almroth, B., Villarrubia-Gómez, P., Eriksen, M., Ryberg, M., and Cornell, S.: Plastics pollution exacerbates the impactsof all planetary boundaries, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-375, https://doi.org/10.5194/oos2025-375, 2025.

The United Nations Decade of Ocean Science for Sustainable Development (2021–2030; hereafter, the Decade) offers a unique opportunity to globally advance deep-ocean science. However, achieving meaningful progress requires moving beyond the conventional model of disconnected research that has resulted in a skewed understanding of the deep ocean, with data heavily concentrated in the North Atlantic, Pacific, the EEZ of economically developed nations, and a workforce that lacks diversity and is disproportionately from just a few geographic regions. These biases limit our capacity to address deep-ocean questions at the necessary global scale, and to support high-level policy processes, including the Agreement on Marine Biodiversity of Areas beyond National Jurisdiction and the Kunming-Montreal Global Biodiversity Framework.

At the onset of the Decade, the Deep-Ocean Stewardship Initiative (DOSI), being mindful of international policy process knowledge requirements, proposed to move beyond “business-as-usual” to a coordinated, community-led, global programme with the ability to advance our understanding of deep-sea marine life at unprecedented scale. The Challenger 150 programme, formally endorsed by the Decade in 2021, focuses on sharing capacity for deep-ocean research, expanding biological observations, building ecological knowledge and increasing the use of deep-sea knowledge in management and decision-making. Twelve regional and three technical scientific research working groups have been established under the programme to facilitate basin scale coordination of research and capacity building efforts, and to help standardise methods and measurements respectively. Half-way through the Decade, Challenger 150 hosts ten Decade actions/projects, has promoted the creation of an active African Network of Deep-water Researchers, reviewed the current knowledge on deep-sea biodiversity in the South and Central Atlantic and in the Arctic Ocean and endorsed over 30 research cruises in all ocean basins.  These activities are already leading to enhanced deep-ocean science knowledge in policy discussions, fed in by diverse voices from around the globe.

How to cite: Hilário, A., Howell, K., and Baker, M.: Successful new approaches for equitable deep-ocean science-policy engagement, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-551, https://doi.org/10.5194/oos2025-551, 2025.

Global environmental changes are affecting oceans, which absorb more than 90% of human-generated excess heat. Ocean acidification, along with rising sea levels and temperatures, and the resulting biodiversity loss, significantly impact the planet’s island socio-ecosystems. As the Oceanian region is known for hosting numerous biodiversity hotspots, Marine Protected Areas (MPAs) are a widely implemented public policy instrument for contributing to the preservation of marine ecosystems, particularly coral reefs. In French Polynesia, as in many other Pacific islands, MPAs (e.g., those included in the Marine Spatial Management Plan of Moorea) coexist with other environmental protection measures such as Regulated Fishing Areas (RFAs) and Rahui (e.g., Tautira in Tahiti or Ua Huka in the Marquesas islands), which correspond to a “traditional” mode of natural resource management that prevailed in pre-colonial times. Whether for MPAs, RFAs, or Rahui, which are now registered in the Polynesian environmental code, maps remain a crucial tool; first in the delimitation of protected areas – generally in consultation with scientists and increasingly with affected populations – then in their legal recognition through official cartography underpinned by regulations, and finally in their communication to the general public. In practice, the use of maps in this context – defining boundaries, (re)negotiating them, and communicating around them – is rarely questioned. However, the use of this artifact is inherently problematic. Indeed, the Cartesian principles governing maps convey a vision of an enclosed and disembodied space populated by “autonomous” objects (i.e., without intrinsic relationships with the other objects) whose identity is determined by sharp boundaries fixed in time. Traditional cartographic representation induces ipso facto major ruptures – Human-Human, Human-Non-Human, and Non-Human-Non-Human – which conflict with the several continuums through which Oceanians define themselves. This presentation aims to address ongoing reflections around this transdisciplinary research theme and present concrete applications to achieve, particularly through fuzzy logic, a cartography more aligned with the worldviews and practices of communities from Oceania. It will also be an opportunity to explore the epistemological and methodological challenges specific to Oceanist research that actually extend beyond the strict framework of cartography.

How to cite: Quesnot, T.: Mapping Marine Protected Areas in Oceania? Epistemological and Methodological Challenges, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-266, https://doi.org/10.5194/oos2025-266, 2025.

Early-career ocean professionals (ECOPs) are essential contributors at the science-policy interface, playing a crucial role in intergenerational knowledge sharing and capacity building. With their interdisciplinary backgrounds and training in modern methodologies, ECOPs are equipped to tackle pressing global challenges through innovative solutions. For example, they lead new research areas such as ocean-climate interactions and marine biodiversity, assisting policymakers in developing solutions based on the latest scientific evidence. By engaging with the science-policy interface, ECOPs who focus on biodiversity and ecosystem services effectively highlight the implications of biodiversity loss and environmental issues for policymakers. They link these challenges to critical concerns on the political agenda, including the economy, security, human health, and the Sustainable Development Goals adopted by all nations. Thus, increasing the involvement of early-career experts in knowledge production and policy development is vital for fostering engagement across both disciplinary and generational boundaries.

While ECOPs' participation in large-scale decision-making initiatives provides opportunities to enhance their collaborative skills—such as networking, interdisciplinary knowledge, and leadership—many barriers hinder their engagement. These challenges include a lack of knowledge-sharing and mentorship opportunities, along with limited access to training that is essential for navigating relevant sectors and disciplines. Additionally, access to professional opportunities, resources, and funding for developing networks and participating in transdisciplinary, interdisciplinary, and cross-sectoral projects is often restricted. Challenges such as the scarcity of long-term contracts, inadequate travel support, unpaid work, workplace harassment, and a highly competitive academic hierarchy further complicate the landscape for ECOPs.

The challenges faced by deep-sea ECOPs engagement in science to policy may be compounded by various factors, including geographic origin, gender, and native language. Deep-sea exploration and research are predominantly led by institutions in developed countries, resulting in undesirable practices like parachute science, harassment, bullying, and the exclusion of professionals from developing nations from planning, conducting, and publishing deep-sea research.

In this context, a questionnaire aiming to map challenges, needs and opportunities from deep-sea ECOP worldwide was developed. One-hundred twenty-six (126) respondents from developed and developing countries ranked the main challenges faced to participate into the science-to-policy interface and listed improved access to funding, information on contributing to decision-making processes, and greater networking opportunities with established professionals as important opportunities to enhance engagement. This work aims to present the results obtained through the questionnaire and discuss challenges faced deep-sea ECOPs, particularly those from developing countries. Finally, we will explore potential avenues for increased participation and innovative approaches to ocean sustainability and governance.

How to cite: Caldeira, M., Lopes, V., and Guilhon, M.: Challenges, needs and opportunities for deep-sea ECOPs in the science-to-policy interface – a bottom-up approach, One Ocean Science Congress 2025, Nice, France, 3–6 Jun 2025, OOS2025-1338, https://doi.org/10.5194/oos2025-1338, 2025.