Scientists warn that the future of our oceans and climate goals depends on reconnecting the ecological threads that hold coastal habitats together. A new study, launched at the International Seascape Symposium II at ZSL (Zoological Society of London), and published to align with UN Ocean Decade Conference represents two years
In this article, Project Seagrass CEO Dr Leanne Cullen-Unsworth reflects on the United Nations Ocean Conference: The 2025 United Nations Ocean Conference, co-organized by Costa Rica and France was held in the coastal city of Nice, France from 9 to 13 June. Over 15,000 people participated, including 2,000 scientists and
Scientists warn that the future of our oceans and climate goals depends on reconnecting the ecological threads that hold coastal habitats together. A new study, launched at the International Seascape Symposium II at ZSL (Zoological Society of London), and published to align with UN Ocean Decade Conference represents two years of work by an international team led by the University of Portsmouth, with support from ZSL and University of Edinburgh. It delivers the most comprehensive report to date on how coastal habitats in temperate regions function not in isolation, but as interconnected systems—a concept known as ecological connectivity. “Coastal habitats like oyster reefs, salt marshes, kelp forests, and seagrass meadows are often treated as separate entities in policy and restoration, but in reality, they are tightly bound together by the flows of water, life, and energy,” said lead author Professor Joanne Preston, Institute of Marine Sciences at the University of Portsmouth. “To meet our global climate and biodiversity targets, we need to restore the entire seascape.” Published in npj Ocean Sustainability to coincide with World Ocean Day and the midpoint of the UN Decade on Ecosystem Restoration, the paper makes the case that reconnecting these habitats is fundamental to repairing the damage caused by centuries of degradation, and to achieving international targets under the Kunming-Montreal Global Biodiversity Framework, Paris Agreement, and the Sustainable Development Goals. Schematic figure illustrating how structural connectivity, functional connectivity, mechanisms and ecosystem service delivery relate. Examples of structural connectivity are denoted by blue arrows and font, functional connectivity by orange arrows and font and mechanisms are indicated by green arrows and font. The light blue icons provide examples of ecosystem services delivery enhanced by the connectivity across seascape habitats. Credit: npj Ocean Sustainability (2025). DOI: 10.1038/s44183-025-00128-3 Conceptual diagram of how ecosystem services from a restored and connected seascape underpins the interrelationships between climate mitigation, biodiversity and human wellbeing. Credit npj Ocean Sustainability 2025 Dr. Philine zu Ermgassen, Changing Oceans Group, University of Edinburgh, said, “Ecological connectivity allows organisms, nutrients, sediment, and energy to move between different marine habitats. These exchanges drive crucial ecosystem services—from carbon storage to water filtration, coastal protection to fishery productivity.” The research compiles evidence from global temperate regions showing that habitat co-location consistently improves ecosystem service delivery. In California, for example, seagrasses grow more robustly when adjacent to oyster reefs. On the U.S. East Coast in the Chesapeake Bay region, oyster beds dramatically increase water clarity and nutrient removal. Additionally, in New Zealand, kelp-derived carbon boosts fish populations in fjords. “Connected habitats are more productive, more resilient, and more beneficial to people,” said co-author Alison Debney, Estuaries and Wetlands Program Lead at ZSL. “Restoring isolated patches isn’t enough. We need to think like the sea—fluid, linked, dynamic— and we need to act at scale.” In response, the authors propose a formal definition of seascape restoration: the concurrent or sequential restoration of multiple habitats to rebuild functional, resilient, and connected marine ecosystems. They call for a shift away from “feature-based” conservation approaches toward holistic, connectivity-based planning. This includes updating marine protected area (MPA) frameworks, development policies, and restoration funding criteria to account for the value of ecological links across habitats. “We are at a critical moment,” said Professor Preston. “The UN Decade on Ecosystem Restoration and the Decade of Ocean Science give us the tools and momentum. But unless we restore the seascape as a whole—the full mosaic of habitats and their connections—we risk missing the targets set by policymakers.” The study outlines clear recommendations to policymakers, including: Mainstreaming seascape connectivity into climate and biodiversity policies Integrating restoration goals across land-sea interfaces Recognizing the role of connectivity in climate mitigation and adaptation Updating environmental assessments to evaluate ecosystem service delivery at the seascape scale Illustration of the role of connectivity in modulating ecosystem service delivery across the coastal seascape. Arrows relate to icons of the same color, with the arrowhead indicating the habitat in which the ecosystem service is enhanced through connectivity with the source habitat. Credit: npj Ocean Sustainability (2025). DOI: 10.1038/s44183-025-00128-3 “We need to view coastal habitats as interconnected systems,” said co-author Rosalie Wright, Blue Marine Foundation. “Our fragmented policy and regulatory approaches must transition to holistic, seascape-scale thinking. Addressing these barriers will enable the urgently needed recovery of our coastlines.” This work directly supports Target 2 of the Global Biodiversity Framework, which calls for at least 30% of degraded coastal and marine ecosystems to be under effective restoration by 2030, specifically enhancing connectivity and ecological function. The findings come amid growing concern over the collapse of marine habitats in temperate zones. Over the past two centuries, the U.K. alone has lost up to 95% of its oyster reefs, over 90% of its seagrasses, and vast expanses of saltmarsh. These losses jeopardize not only biodiversity but also carbon storage, fish stocks, and coastal protection. Restoring at scale and in a way that mirrors the ecological realities of the coast offers a powerful nature-based solution to the interlinked crises of climate change, biodiversity loss, and pollution. As the world gathers momentum around ocean recovery, the message from the science is unequivocal: seascape-scale restoration is not optional. It is essential. More information: J. Preston et al, Seascape connectivity: evidence, knowledge gaps and implications for temperate coastal ecosystem restoration practice and policy, npj Ocean Sustainability (2025). DOI: 10.1038/s44183-025-00128-3
In this article, Project Seagrass CEO Dr Leanne Cullen-Unsworth reflects on the United Nations Ocean Conference: The 2025 United Nations Ocean Conference, co-organized by Costa Rica and France was held in the coastal city of Nice, France from 9 to 13 June. Over 15,000 people participated, including 2,000 scientists and more than 60 world leaders. Discussions aimed to shine a light on the challenges of unlocking sustainable ocean investment and how to reinforce the role of marine science in policymaking. Our Project Seagrass team was delighted to be able to attend and contribute to the Conference receiving special accreditation to join the full programme by the UN. The Conference was insightful, inspiring, hopeful, overwhelming, challenging, in short it evoked an epic rollercoaster of emotions both negative and positive respectively around the declining health of our oceans and the demonstrated passion to drive change shown by individuals from across the globe. There was much conversation about David Attenborough’s ‘Ocean’, with divided opinion on the contents and emphasis of the film. For me, this was Sir David doing what he does best and providing an engaging and heartfelt narrative to grip a generalist audience of millions and share the beauty and importance of our ocean whilst highlighting a very real and current threat. Regardless of opinion, the impact of ‘Ocean’ was clear as a persistent thread through the narrative of the conference, and subsequent commitments from governments across the globe to strengthen protection of designated marine areas. This includes the UK Government proposing bottom trawling bans in all English offshore marine protected areas. It’s a start, but we need continued public pressure to ensure a move from proposal to action. We also need much bigger commitments to save our ocean which in turn, if healthy, will respond to the nature and climate crises we are facing. It was encouraging to observe in the Blue Zone some high-level dialogue drawing the connections between land and sea, with even land-locked countries demonstrating interest in ocean health and their impact on it. It’s critical that we target preserving and increasing biodiversity across environmental boundaries for sustainable futures. It’s also clear that we’ve actually moved beyond a need for sustainability. To sustain is to maintain in the same state, when what we so clearly need is environmental recovery at scale and through a connected approach. We will not achieve any environmental or human wellbeing targets taken in isolation. It was repeatedly acknowledged that the ocean is our lifeline, and not just for the 40% of humanity living along coastlines or three billion people reliant on seafood across the globe, but for everyone. Our ocean and the biodiversity it contains sustains life on our planet as we know it. Every part of the global ocean in important, and every part is threatened. Coastal waters, containing 70% of marine biodiversity, are particularly vulnerable at the interface of land and sea with both land-based and ocean-based threats having an impact. Lots of emotive statements were made, all the right words but the associated specific actions needed to drive change and achieve any targets seem elusive. There also seemed to be an imbalance in terms of habitat representation. Seagrass was one coastal habitat receiving limited attention at the United Nations Ocean Conference. Which highlights that there is still much to do to gain acknowledgement that this is a critical habitat alongside, for example, better understood coral reefs, mangroves, and saltmarshes. Seagrass is a habitat that underpins marine biodiversity and delivers a wide range of ecosystem services vital to planetary health, climate resilience, and human wellbeing. Seagrass does this to varying degrees across its near global range. Seagrass systems contribute to targets within all the UN Sustainable Development Goals. Yet, they remain underrepresented in global scale conservation and climate initiatives, and on the formal programme at such a significant conference. UNOC3 was held at the midpoint of the UN Ocean Decade. A decade dedicated to delivering the science we need for the ocean we want. But five years into the decade, our oceans remain far from recovery. We are not on target to meet Sustainable Development Goal (SDG) 14 (life below water) which means we will also be unable to meet other dependent SDGs. Knowledge is improving and the science is clear, but we need to be better at sharing and building on each other’s advances. We also need clearer pathways to influence decision making. In fact, the conference highlighted multiple needs for any chance of achieving ocean recovery at scale. This list is long, but here are just a few examples: We need explicit processes for different sectors to be able to contribute the vast amounts of data that is currently sat on inaccessible hard drives or within unsearchable grey literature. There were repetitive calls for both new and existing data to be shared, this sharing of data and knowledge would serve to turbocharge rather than duplicate efforts on the road to planetary recovery. This goes hand in hand with a need for improved funding for evidence based environmental recovery practices. For me this shouldn’t be an emphasis on initiatives towards financial gain for investors but rather an investment in the resource that sustains and fulfils us all. Too often that connection feels lost, which is disheartening and concerning. Governments need to analyse and respond to the needs of communities. How do they do this? They need data! And sectors within Governments need to work together and pull in the same direction with coordinated approaches. We need to communicate effectively beyond disciplinary, national, and sector boundaries. Finding common language is challenging. Another recurring theme. Critically, we need people to reconnect with nature, and possibly more than that, recognise that we are nature – we need trees, fish, saltmarsh, seagrass and all the wellbeing benefits that they provide – people are disconnected and that’s a big problem. This raises questions of justice and equality, social justice is needed to improve our shared environment. The conference concluded with the adoption of a political
