Ocean momentum and resilience in 2025: Reflections on the 3rd UN Ocean Conference and the road ahead
By Nathalie Estievenart
2025 is shaping up to be a defining year for action at the intersection of ocean, climate, and biodiversity.
On July 23rd, the International Court of Justice (ICJ) issued a historic Advisory Opinion on the obligations of States to act on climate change, marking a watershed moment in the evolution of climate law. Yet just weeks later, on 15 August, negotiations in Geneva on a global plastics treaty collapsed without agreement after years of effort. The talks exposed sharp divides: high-ambition countries called for binding limits on virgin plastic, while oil- and gas-linked states pushed instead for downstream waste management, recycling, and delay. The collapse underscored both how much remains to be done to secure a strong and binding treaty, while highlighting how deeply plastics are entangled with the fossil fuel industry. With COP30 in Belém now fast approaching in November, all eyes are once again turning toward what could be a critical moment to mainstream ocean health within global climate action.
As these developments unfold, I have taken a moment to reflect on the third United Nations Ocean Conference (UNOC3), held in Nice in June, as part of the growing momentum for ocean action, climate justice, and resilience, especially for the most vulnerable states and coastal communities.
A turning point for ocean governance
UNOC3, co-hosted by France and Costa Rica, was the largest UN event ever focused on the ocean. It brought together 175 UN Member States, 64 Heads of State and Government, 28 Heads of UN, intergovernmental and international organizations, 115 ministers, 12,000 delegates, and more than 130,000 visitors. Over 1,000 parallel events unfolded across venues from the Blue Zone to the Whale, ranging from high-level dialogues and negotiations to booths and exhibitions featuring NGOs, private sector actors, Indigenous leaders, artists, and scientists.
Guided by the theme “Accelerating action and mobilizing all actors to conserve and sustainably use the ocean”, the conference placed SDG14 implementation at its core, calling governments, institutions, and communities to scale up solutions and close the ocean action gap.
Expectations were high and for good reasons. UNOC3 was seen as a turning point for ocean protection and its governance, by catalysing stronger policy, deeper collaboration, and transformative action leading up to 2030.
The ‘Whale’ venue at UNOC3
As part of this landmark occasion, I had the opportunity to attend the conference in multiple capacities. I was present on behalf of my UNDP team. I also joined as a graduate student from the Geneva Graduate Institute and the Fletcher School of Law and Diplomacy at Tufts University, finalizing my master’s thesis on “Equitable and Effective Marine Protected Areas: A Comparative Analysis of Cabo Pulmo and Raja Ampat Through the Marine Prosperity Area Framework”. Beyond professional and academic affiliations, I was especially honored to participate as an ocean advocate, eager to engage with the ocean community, experience the realities of international diplomacy, and learn from experts shaping the future of marine protection.
The conference allowed me to bridge my research and policy work, connect with ocean leaders, and deepen my commitment to ocean health. But more than that, the conference was an extraordinary opportunity to connect with the wider ocean community: bonding with ocean leaders, listening to stories from frontline communities, and feeling the collective urgency of those working toward the same goal, from diplomats and scientists to Indigenous leaders and youth activists. For me, the real momentum of the UNOC3 was the passion of the people. It was fascinating seeing how things I am passionate about resonate with others. It was the first time I witnessed such a comprehensive convergence of ocean voices –people with wildly diverse experiences but united by shared values. Some shape policy, others teach, restore ecosystems, or create through culture and storytelling. This richness of experience helped me realize how many ways there are to act, and how important it is to protect the space for all of them to coexist. I am grateful for the insights and meaningful connections, which I look forward to nurturing and building upon.
Key progress and remaining gaps
UNOC3 resulted in over 800 commitments and the Nice Ocean Action Plan. It sparked great momentum for the ocean that emerged across several fronts, as well as unfinished business/missed chances to protect the ocean. It shone a spotlight on the major threats facing our ocean, from overfishing and destructive bottom trawling to the looming risks of deep-sea mining and the real pressures facing coastal communities. But it also showcased solutions, from enforcing existing ocean protections to expanding marine protected areas and ensuring they are truly safeguarded.
High Seas Treaty: One of the most notable successes was the progress made on the High Seas Treaty, with ratifications rising from 31 to 50, just 10 short of the 60 needed for entry into force. Once enacted, the Treaty will enable the establishment of marine protected areas (MPAs) in international waters, which cover two-thirds of the ocean. Today, only 1.5% of these waters are protected, far below the 30x30 target. The final push now lies in governments completing ratifications and preparing implementation to make the Treaty legally binding. Protecting what is known as the common heritage of humankind safeguards 64 percent of the ocean’s surface area, encompassing the high seas that are integral to the ocean’s role in regulating climate, producing oxygen, and storing carbon. While the ocean as a whole generates 50 percent of the oxygen we breathe, absorbs 30 percent of human-driven carbon dioxide emissions, and captures 90 percent of the excess heat they produce, the high seas are essential to maintaining these processes. By sustaining migratory corridors and pelagic ecosystems that underpin global fisheries, they help reduce systemic risks from climate disruption and strengthen the resilience of coastal and island nations.
Marine Protected Areas (MPAs): There was a growing momentum to protect marine ecosystems and achieve the global 30x30 target to protect 30% of the ocean by 2030. The global coverage of MPAs has increased from 8.3% to 9.6%, with new designations announced by countries including French Polynesia, Tanzania, Colombia, Chile, Portugal, Marshal Islands, Sao Tomé & Príncipe. French Polynesia pledged to establish the largest MPA network in the world. Healthy ecosystems like mangroves, seagrasses, and reefs act as natural coastal defenses, absorbing wave energy, reducing storm surges, and limiting shoreline erosion, delivering measurable risk-reduction benefits for urban infrastructure and livelihoods. Yet, a central discussion throughout UNOC3 was not only the expansion of MPAs, but their quality. Most of them are either nominally protected or so laxly regulated that destructive fishing practices such as bottom trawling are permitted within their boundaries. This highlights the need to move beyond the number of MPAs and ensure that MPAs are not only declared but also effectively and equitably managed. A recurring theme across side events was the call to ban bottom trawling within MPAs, strengthen governance structures adapted to local needs, and foster inclusive dialogues among stakeholders, along with continued exchanges between managers and policymakers on best practices. Speakers also stressed the importance of connecting MPAs into coherent ecological networks. As someone who recently completed a master's thesis focused on the design and governance of MPAs, these discussions resonated deeply. My research compared Cabo Pulmo (Mexico) and Raja Ampat (Indonesia) through the Marine Prosperity Area (MPpA) framework, a holistic approach that evaluates MPAs not only on ecological outcomes but also social equity and where financial investments are used not just for conservation, but to improve the well-being of local communities. The framework, launched in 2025 and developed by experts I was fortunate to engage with at the conference, has started to gain real momentum, especially in Mexico, and was recognized by the World Economic Forum as representing a new hope in marine conservation and a global model for ocean management.
Panel on ‘Marine Prosperity Areas’, featuring Professor Octavio Aburto.
Deep-sea mining drew sharper political scrutiny, with growing calls for a moratorium or precautionary pause from 37 countries. But progress on ratifying the agreement remains slow, with 9 more ratifications needed. Deep-sea ecosystems are fragile and lightless environments that play a critical role in capturing vast amounts of carbon, helping to address legacy emissions, regulate climate, and reduce disaster risks from ocean warming and extreme weather. If disrupted by mining, it could undermine these functions, weakening both climate mitigation and hazard protection.
Ocean Finance: At UNOC, ocean finance took center stage as a critical lever to address one of the ocean’s most persistent challenges, the underfunding of SDG14. Over €8.7 billion was pledged for sustainable blue finance by 2030 through blended public–private mechanisms (4 billion euros of public funding and 4.7 billion euros of private/philanthropic funding). Yet this still falls short of the estimated $15.8 billion per year needed to reach 30x30, an investment that could unlock $85 billion in annual returns and avoid costs by 2050. Scaling ocean finance enables investment in nature-based defenses, resilient infrastructure, and adaptive coastal economies. This would reduce the multibillion-dollar annual losses from floods, storm surges, and ecosystem degradation while protecting lives, assets, and livelihoods.
Policy and Science: UNOC3 saw the launch of several Initiatives to bridge the science-policy gap. These include the Starfish Barometer, a peer-reviewed annual report tracking ocean health and social impacts, and the International Platform for Ocean Sustainability (IPOS), a science-policy interface initiative modelled on the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES), that aims to strengthen the capacity of States to implement their global ocean commitments more efficiently, rapidly and inclusively. A science-driven, inclusive, and solutions-oriented approach to decision-making is essential to address major ocean challenges like climate change, biodiversity loss, overfishing, and pollution, while ensuring that policies are anticipatory, risk-informed, and designed to prevent the creation of new vulnerabilities.
Governance and Inclusion: We also saw local and regional leaders step up. The Ocean Rise and Coastal Resilience Summit brought together mayors, coastal authorities, and SIDS representatives to shape adaptation strategies for communities most at risk. As someone working on disaster risk reduction, it was a powerful reminder that resilience must be rooted in local leadership. Embedding disaster risk reduction into governance processes ensures that adaptation measures are context-specific, informed by participatory hazard assessments, and designed to address both immediate exposure and long-term vulnerability in line with global resilience frameworks.
Plastic Treaty: In a side event at UNOC, over 90 United Nations Member States reaffirmed their commitment to negotiating an ambitious global plastics treaty through the Nice Wake Up Call for an Ambitious Plastics Treaty. In addition to having a significant carbon footprint, plastics weaken ecosystem resilience, threaten water and food security, and increase vulnerability by clogging drainage systems and eroding natural buffers, intensifying flood risks in coastal and urban areas. Addressing the full lifecycle of plastics, from extraction to disposal, through effective waste management is therefore essential to reduce these hazards, protect coastal defenses and biodiversity, safeguard public health, and ensure intergenerational equity while protecting livelihoods and enabling equitable transitions.
These developments demonstrate that UNOC3 has successfully mobilised the international community to advance crucial ocean governance frameworks, marking a decisive achievement and confirming that shared ambition can drive tangible progress.
But UNOC was also a strong reminder that far more is needed to protect and restore our ocean, especially by closing the financing gap for SDG14, still the most underfunded of all SDGs. While some progress was made, the conference largely missed addressing one of the most critical threats to ocean and climate health: fossil fuels. According to the Center for International Environmental Law (CIEL), “the Nice Political Declaration falls short of the commitments needed to protect the ocean, biodiversity, and climate from their greatest threat: fossil fuels. Halting the expansion of oil and gas, especially offshore, and rapidly and equitably reducing fossil fuel production and use must be at the heart of any action to protect the ocean and all life that depends on it”.
Additionally, little attention was given to tracking progress on past commitments made at UNOC1 and UNOC2. Without accountability and follow-up mechanisms, pledges risk remaining unfulfilled. Going forward, addressing root causes and ensuring accountability must now be priorities to truly safeguard the ocean.
Panel on ‘Mobilizing capital for a thriving blue economy’
Key Takeaways
One of the strongest messages emerging from UNOC3 was the importance of working holistically, systematically and not in a silo by fostering stronger coordination among nations, promoting integrated governance, building trust and sharing knowledge and expertise. It also meant ensuring that the future of ocean action must be grounded in science, guided by equity, and driven by collaboration.
UNOC3 reminded us of a future where:
No one is left behind
No one works in a silo
Knowledge leads to stewardship
Policies reflect science
Equity guides all action
Capacity is built over time
Trust and expertise are shared
A community of practice is cultivated
These aren't just recommendations, they are preconditions for delivering on SDG14 and achieving a just and resilient ocean future.
Looking ahead to Belém
As we prepare for COP30 in Belém, we must carry UNOC3’s momentum forward. That means financing the solutions we have identified, holding ourselves accountable to commitments, and embedding inclusion in every step of ocean-climate diplomacy. The ICJ’s advisory opinion and the upcoming plastics treaty negotiations add further urgency to transform ocean commitments into systemic change.
Acknowledgments
A heartfelt thank you to CIERP for connecting me with the Fletcher community attending UNOC3 in Nice. I am especially grateful to Professor Marcia Moreno-Báez for her guidance, mentorship, and the many enriching exchanges throughout the conference, particularly as it was a privilege to learn that she had worked on one of the case studies featured in my master’s thesis. Reuniting with my close friend and fellow Fletcher student, Paul-Emile Pissier, also made the experience all the more memorable. I am truly grateful to be part of such a supportive and inspiring community.
Pr. Marcia Moreno-Báez, Paul-Emile Pissier and Nathalie Estiévenart at UNOC3 in Nice, France
Nathalie Estievenart is part of the UNDP team in Geneva. She recently completed a master’s degree in International and Development Studies at the Geneva Graduate Institute, with an exchange at the Fletcher School of Law and Diplomacy at Tufts University during the fall semester 2024. Her work focuses on marine protected areas, climate resilience, and inclusive ocean governance, especially in support of coastal communities.