From 9 to 13 June 2025, France and Costa Rica will co-host the 3rd United Nations Ocean Conference (UNOC3) in Nice, France. After New York in 2017 and Lisbon in 2022, this year’s conference is held under the theme “Accelerating action and mobilising all actors to conserve and sustainably use the ocean”. It aims to strengthen the protection and sustainable use of the ocean, seas and their resources – particularly by advancing the implementation of Sustainable Development Goal 14 (SDG 14): Life Below Water. In light of increasing pressure on marine and coastal ecosystems – whose impacts are becoming more visible both for marine life and the communities that depend on it – UNOC3 is set to be a critical milestone in reviving weakened international cooperation and enhancing collective action for the ocean.
A Decisive Moment for International Cooperation
The ocean covers over 70% of the Earth’s surface. It is vital for climate regulation, global biodiversity, and the livelihoods of billions of people. It plays a central role in climate balance, oxygen production, food and energy security, culture and health. Yet, the ocean is bearing the consequences and impacts of climate change, overexploitation of its resources, pollution (plastic, chemical, etc.) and multiple anthropogenic pressures – causing the degradation of marine ecosystems, sometimes irreversibly, and increasing the vulnerability of populations that depend on it.
UNOC3 therefore represents a turning point. Protecting the ocean requires coordinated action between States and the engagement of all stakeholders—scientists, NGOs, the private sector, local communities, financial institutions, and philanthropic actors. At a time when multilateralism is under strain, with growing climate scepticism and some wishing to further exploit it, this conference offers a unique opportunity to prove that collective solutions to global challenges are possible, and to trigger concrete global action to protect the ocean.
UNOC3: A Lever to Strengthen Ocean Governance
Significant commitments and actions are expected from States and all stakeholders to accelerate the implementation of SDG 14 and meet its targets by 2030. While it’s at the core of UN Ocean Conferences, this edition stands out for its broader ambition: to catalyse a deep transformation of ocean governance. This conference is particularly symbolic for France: it is the first time the country is hosting a UN conference on its soil since COP21 in 2015. A decade after the Paris Agreement, the French Government aims to make UNOC3 a landmark event for the ocean, similar to what COP21 was for the climate.
Among the priorities highlighted by President Emmanuel Macron at the “SOS Ocean” event is the need to fast-track the entry into force of the Treaty for the protection of marine biodiversity (BBNJ). As of today, 28 countries have ratified the treaty and 32 more ratifications are still needed. Another key priority is achieving the goal of protecting 30% of the ocean by 2030, as set out in the Global Biodiversity Framework (2022), through voluntary State commitments. As the world’s second-largest maritime nation, with nearly 11 million km² under its jurisdiction, France has a particular responsibility. It can only prove leadership by aligning its global commitments with domestic actions – championing this target internationally while implementing exemplary policies at home. This includes ensuring strict protection of at least 10% of its maritime areas, both in mainland France and overseas territories, in accordance with EU recommendations and international scientific standards. Civil society has high expectations on this issue, as demonstrated by an op-ed signed by 62 leading figures from the ocean community.
What about the ocean-climate-biodiversity nexus? It will be addressed through the lens of adaptation, notably at the Ocean Rise & Coastal Resilience Summit (June 7th). It will also be the focus of one of the ten high-level thematic sessions “Ocean Action Panel” on 10 June. Moreover, the tenth anniversary of the Paris Agreement will be commemorated during the event “Making Waves from Nice to Belém”, co-organised by the governments of Brazil and France, the Ocean & Climate Platform (OCP), and many partners. This event holds particular importance as UNOC3 is a key step on the road to COP30, which will take place in Belém, Brazil, in November 2025 and where member States are expected to present more ambitious national climate strategies.
An Unprecedented Mobilisation of Civil Society
Recognising the key role played by civil society in advancing ocean protection, the governments of France and Costa Rica appointed Loreley Picourt (Director General of the Ocean & Climate Platform) and Rémi Parmentier (founder of The Varda Group) to mobilise international civil society in the lead-up to the conference. The launch of the “Call to All the Voices of the Ocean”, to which 120 civil society organisations responded, marked the start of this mobilisation and led to the identification of three main priorities for UNOC3: accelerating ocean governance, ensuring accountability, and anticipating the future of the ocean and SDG 14.
In response, two initiatives were launched. The Ocean & Climate Platform, in collaboration with CNRS and Friends of Ocean Action and with support from Dona Bertarelli Philanthropy, initiated the visioning exercise “An Ocean of Possibilities”. As part of this process, a global consultation and a series of interviews were carried out, along with workshops bringing together experts, practitioners, and representatives of the ocean community. Together, they developed scenarios for a sustainable future for the ocean and identified actions to turn them into reality. These outcomes will be presented at the One Ocean Science Congress, showcased during World Ocean Day, and highlighted at UNOC3. In parallel, the Let’s Be Nice to the Ocean initiative calls for a deep paradigm shift. Supported by over 100 organisations, it promotes the Ocean Protection Principle, whereby any new human activity in the ocean must prove it will not harm the environment before being authorised. The outcomes of both initiatives will be presented on 8 June 2025, World Ocean Day, at the event “The Future is Now: Let’s Dive into an Ocean of Possibilities.”
In Nice, civil society mobilisation will be unprecedented. It will begin on 7 June with a universal sea dip and the Blue March, bringing together citizens committed to protect the ocean. World Ocean Day 2025, on 8 June will be a highlight, featuring numerous events. From 2 to 13 June, “La Baleine” – heart of the Green Zone of UNOC3, open to participants to the conference and the public – will host a rich programme. The OCP is organising many events there, notably as a partner of the Ocean Basecamp and the Archipel Pavilion.
Three Special Events to Raise Ambition
Several key events will pave the way for discussions at UNOC3. From 3 to 6 June, the One Ocean Science Congress (OOSC), organised by CNRS and Ifremer, will bring together the French and international scientific communities. Its aim is to provide world leaders and all UNOC3 participants with scientific knowledge on ocean health, dynamics and future trajectories, as well as its conservation, sustainable use, and the services it provides to society. Scientific recommendations will be issued to Heads of state and government.
On Saturday 7 June 2025, the Ocean Rise & Coastal Resilience Summit, co-organised by OCP and the City of Nice with support from the Governments of France and Costa Rica, will focus on the resilience of coastal cities and regions to sea level rise. Coastal leaders and island nation representatives from around the world have been invited, along with key actors of the transition – research institutes, financial actors, civil society, networks of cities, and more. This event will mark the launch of the Ocean Rise & Coastal Resilience Coalition, which aims to promote adaptation and resilience to rising sea levels. It will facilitate the sharing of best practices and cooperation between coastal regions, scientific bodies, financiers, and other stakeholders. This Coalition will offer an unprecedented advocacy and cooperation platform on coastal adaptation. It will be chaired by the Mayor of Nice, Christian Estrosi, and hosted by the Global Centre for Climate Mobility (GCCM). This coalition builds on the Sea’ties project launched by the OCP in 2020.
The Blue Economy and Finance Forum (BEFF) will take place in Monaco on 7–8 June 2025, co-organised by the Principality of Monaco, the Prince Albert II of Monaco Foundation and the Oceanographic Institute – Prince Albert I of Monaco Foundation. This event will bring together actors from the finance and economic sectors to discuss key challenges in transitioning to a sustainable and regenerative blue economy. It will showcase innovative projects and solutions aimed at accelerating cross-sectoral engagement in ocean protection.
A Conference at the Crossroads of Urgency and Hope
UNOC3 represents a pivotal moment. With only five years remaining to achieve the 2030 Agenda for Sustainable Development, the international community can no longer delay concrete action. It must demonstrate ambition, political will, and coherence to ensure this conference is not just another event, but a true turning point for the ocean. In this context, the political declaration of UNOC3 – negotiated in advance in New York and submitted for adoption in Nice – must send a clear and unequivocal signal on the urgency of protecting the ocean, restoring its health, ensuring the sustainable use of its resources, and strengthening its resilience. Yet beyond words – particularly as the declaration is not binding, the true impact of UNOC3 will be measured by the concrete, measurable and effectively implemented commitments made. Only then will UNOC3 mark a true shift: towards a united ocean community where everyone plays their part in implementing solutions and, finally, turning commitment into action.