- Marking the midway point in the U.N. Decade of Ocean Science for Sustainable Development, 2025 was a key year for the ocean.
- The past 12 months brought landslide multilateral wins for ocean policy, unprecedented ocean financial commitments, and increasing momentum to protect 30% of the ocean by 2030.
- Here, marine scientists, policy experts and a communications expert lay out the key ocean stories from the past year.
- This post is a commentary. The views expressed are those of the authors, not necessarily Mongabay.
2025 was a key year for ocean policymaking, marking the midway point in the U.N. Decade of Ocean Science for Sustainable Development. The past 12 months brought landslide multilateral wins for ocean policy, unprecedented financial commitments for marine conservation, and increasing momentum to protect 30% of the world’s oceans by 2030.
Here, marine scientists, policy experts and a communications expert lay out the key ocean stories from the past year.
1. Multilateral breakthroughs reshape ocean governance
In a rare breakthrough for ocean governance, two multilateral treaties reached enough ratifications by member states in 2025 to trigger their legal entry into force. The Biodiversity Beyond National Jurisdiction (BBNJ) Treaty, known commonly as the High Seas Treaty, reached the milestone of 60 ratifications in September, triggering its entry into force in January 2026. The treaty is a legally binding international agreement safeguarding marine life in areas beyond the jurisdiction of any nation. Making up two-thirds of the ocean, these regions play a critical role in the planet’s life support system, regulating the climate and providing oxygen, and host critical ecosystems and species. Following the milestone, in November the High Seas Treaty won the Earthshot Prize in the “Revive Our Seas” category, celebrating two decades of advocacy and international cooperation to make the treaty a reality.
The World Trade Organization’s treaty to ban harmful fisheries subsidies also came into force in September this year, after 24 years of negotiations. The treaty, called Fish One, bans government subsidies that support the fishing of already-overfished stocks, and curbs those that contribute to illegal, unreported and unregulated (IUU) fishing. The treaty will help rebuild the nearly 40% of global fish stocks that are already overfished, and curb an estimated $22 billion that governments spend each year on so-called harmful subsidies. “The agreement is an historic and necessary first step as it shows that multilateral cooperation on ocean sustainability is possible,” Rashid Sumaila, an expert in fisheries economics at the University of British Columbia, Canada, said in a recent Mongabay story about the ban.
2. New capital flows and players transform the ocean economy
Finance was firmly on the agenda of numerous multilateral negotiations this year, with participants recognizing money as a critical enabler to reach climate and biodiversity goals. In his opening statement at this year’s United Nations Ocean Conference, held in June in Nice, France, U.N. Secretary-General António Guterres stressed that Goal 14, “Life Below Water,” remains the least funded of the 17 Sustainable Development Goals. “This must change,” he said. “We need bold models to unlock private capital.” The 10th Our Ocean Conference in Busan, South Korea, in April secured $9.1 billion in new financial commitments from 287 voluntary pledges across 113 countries, including the European Union’s pledge of more than 300 million euros ($332 million), and South Korea’s $2.65 billion “Korea Blue Action Plan.”
In June, the Blue Economy and Finance Forum (BEFF) in Monaco announced 8.7 billion euros ($10.1 billion) in new finance committed to accelerating the transition to a regenerative ocean economy, with 25 billion euros ($29 billion) of investments already identified. Some of this amount came from the multilateral Development Bank of Latin America and the Caribbean (CAF) announcing it would invest $2.5 billion into the region’s blue economy. Following the BEFF, the European Union unveiled the Ocean Pact, with more than 1 billion euros ($1.2 million) in new funding. Separately, institutions including French bank BNP Paribas, leading European asset manager Eurazeo, French financial institution Mirova, and U.S. software company Salesforce endorsed the #BackBlue Ocean Finance Commitment, which aims to integrate ocean considerations into financial and insurance decision-making. The new endorsement took #BackBlue’s reach beyond $3.45 trillion of assets under management.
3. Steps toward 30×30
This year brought increased momentum toward protecting 30% of our ocean by 2030 (part of the “30×30” target of the 2022 Kunming-Montreal Global Diversity Framework), with a raft of announcements from countries around the world. The Melanesian Ocean Reserve, a 6-million-square-kilometer (2.3-million-square-mile) expanse of ocean and islands across the southwestern Pacific, will become the first multinational ocean reserve on Earth to be led solely by Indigenous people. French Polynesia announced the creation of the world’s largest marine protected area. California announced this year that it has conserved 21.9% of its coastal waters, marking good progress toward the commitment it made to 30×30 in 2020. And Australia’s environment minister, Murray Watt, announced a review of 44 of Australia’s marine parks in order to “lay the foundation” to increase the area of the country’s ocean with higher levels of protection.
The “Ocean Protection Gap” report from the Together for the Ocean campaign, which represents two dozen NGOs and other organizations, revealed that just $1.2 billion per year currently flows to ocean protection efforts, a fraction of the $15.8 billion needed annually to deliver 30×30. But establishing protected areas doesn’t only benefit conservation: the report revealed that protecting 30% of the ocean could unlock around $85 billion per year by 2050 in avoided costs and annual returns.
As of December 2025, just 9.61% of the ocean is designated as marine protected areas (MPAs), and just 2.9% is considered fully or highly protected. In June, the 30×30 Ocean Action Plan by the Friends of Ocean Action, an international coalition of ocean leaders, identified that an additional 4.7% of global waters are under consideration for protection as large MPAs. If realized, they would raise total global marine protection to an estimated 14.3%.
While still falling short of 30%, global ambitions and progress toward expanding MPAs; adding high-seas MPAs; and counting areas that aren’t necessarily intended to protect biodiversity but do, known as “other effective area-based conservation measures” (OECMs), toward the goal show positive steps toward 30×30.
4. The world reached its first climate tipping point — in the ocean
After decades of warnings that sustained temperatures greater than 1.5° Celsius (2.7° Fahrenheit) above pre-industrial levels would risk irreversible changes to Earth’s systems, the world crossed its first climate tipping point in 2025. Tipping points occur when gradual pressures trigger abrupt shifts, pushing ecosystems into new states. In the ocean, climate change, species loss and nutrient disruptions drive these transitions, reshaping food webs, habitats and ecosystem functions that are vital to human well-being.
In October, 160 scientists published a report warning that warm-water coral reefs are now in long-term decline and unlikely to recover unless global temperatures quickly return to 1.2°C (2.2°F) above preindustrial levels. While these species have been experiencing mortality for some time, this year, the global coral bleaching event that has been ongoing since January 2023 and is the worst such event on record, has pushed most coral reefs beyond survival thresholds, with nearly 85% of reefs in more than 80 countries already affected by extreme ocean temperatures.. While some species may persist, this collapse threatens a quarter of marine species and millions of livelihoods.
Coral decline signals proximity to other tipping points. These include the potential collapse of the Atlantic Meridional Overturning Circulation, a critical current system whose disruption could trigger catastrophic global impacts, freezing some regions, overheating others, altering monsoon seasons and raising sea levels. Other anomalies, such as the unprecedented failure of Panama’s annual cold-water upwelling in September, suggest additional thresholds may be near, with consequences for nutrient cycles and marine food webs. Crossing one tipping point can accelerate others, compounding risks and adverse outcomes, risking destabilization and the collapse of systems essential to human health and survival.
5. Pacific leadership elevates the ocean in global climate negotiations
After a years-long campaign led by young lawyers and organizers in the Pacific island country of Vanuatu, the International Court of Justice issued a landmark opinion in July recognizing climate change as an “urgent and existential threat.” The decision enables the development of legal mechanisms to hold governments accountable for actions that contribute to climate change.
The Pacific is one of the most climate-vulnerable places in the world, a region where whole island communities are expected to disappear due to sea level rise and intensifying tropical storms.
Alongside Pacific leadership, 2025 saw Indigenous peoples and local communities around the world reclaim seats at the table. The first Subsidiary Body on Article 8(j) of the Convention on Biological Diversity, which relates to Indigenous peoples and local communities, convened in Panama, establishing Indigenous leadership and including, among other things, ocean concerns within biodiversity conversations. Similarly, during the COP30 climate summit in Brazil in November, Indigenous participation and protest took center stage, with productive disruptions creating opportunities for direct engagement between COP leadership and organized Indigenous groups.
However, countries like Papua New Guinea and others were vocal about their dissatisfaction with the compromise between Australia and Turkey to host COP31 in 2026. Next year’s COP, which commentators had hoped would be referred to as the “Pacific COP” had Australia been selected as sole host, will ultimately be held in Turkey, with the two countries sharing responsibility to coordinate the actual negotiations and host the event, respectively.
Banner image: Scalloped hammerhead sharks (Sphyrna lewini), photographed in Yonaguni, Japan. Image by Masayuki Agawa via Ocean Image Bank.
Alfredo Giron is the head of ocean at the World Economic Forum and Friends of Ocean Action, leading strategy across a range of ocean work. He has wide experience spearheading the creation of public-private partnerships to address pressing ocean challenges related to accelerating the transition of businesses towards regenerative ocean practices, marine conservation and restoration, and sustainable fisheries management. Ana K. Spalding is director of the Adrienne Arsht Community-Based Resilience Solutions Initiative and a marine social scientist at the Smithsonian Tropical Research Institute (STRI) in Panama, where she leads a research team focused on marine conservation and ocean governance. Erin Skoczylas is the communications lead of the ocean agenda at the World Economic Forum and the Friends of Ocean Action. She has led communications and storytelling for environmental topics across international organizations, including fisheries management, marine conservation, ocean finance and the blue economy. Vanessa Constant is associate director of the Adrienne Arsht Community-Based Resilience Solutions Initiative at STRI. A marine ecologist and policy expert with extensive experience bridging science, policy and partnerships to drive meaningful change, she brings interdisciplinary insights to support the advancement of pan-Smithsonian resilience activities.
Citations:
Ren, Q., Xie, S. P., Peng, Q., Li, Y., & Wang, F. (2025). Equatorial Atlantic mid-depth warming indicates Atlantic meridional overturning circulation slowdown. Communications Earth & Environment, 6(1), 819. doi:10.1038/s43247-025-02793-1
Loriani, S., Aksenov, Y., Armstrong McKay, D. I., Bala, G., Born, A., Chiessi, C. M., … Tharammal, T. (2025). Tipping points in ocean and atmosphere circulations. Earth System Dynamics, 16(5), 1611-1653. doi:10.5194/esd-16-1611-2025
O’Dea, A., Sellers, A. J., Pérez-Medina, C., Pardo Díaz, J., Guzmán Bloise, A., Pöhlker, C., … Haug, G. H. (2025). Unprecedented suppression of Panama’s Pacific upwelling in 2025. Proceedings of the National Academy of Sciences, 122(36). doi:10.1073/pnas.2512056122
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