The Ocean is in crisis. Coral reefs are bleaching, seagrass meadows are vanishing, mangroves are being cleared, and biodiversity is plummeting. Scientists estimate we’ve already lost up to 50% of global saltmarshes, 35% of mangroves, and 20% of seagrasses. Yet alongside this sobering decline, momentum for marine restoration has never
Posidonia seagrass meadows, veritable underwater forests, play a major ecological role. Under constant pressure from human activity, scientists are looking for ways to ensure their survival, in particular by carrying out restoration campaigns. A study conducted by the University of Liège at the marine and oceanographical research station STARESO (Calvi,
Our oceans and coasts are home to ecosystems that provide immense benefits to people, from food and livelihoods to carbon storage and coastal protection. In particular, seagrass meadows are archetypal social-ecological systems (SES), linking human well-being to ecosystem health. But to manage these systems effectively, we need access to both ecological
Beneath the surface of the Chesapeake Bay, a subtle but dramatic shift is taking place as eelgrass gives way to its warmer-water relative, widgeon grass. A new study from researchers at William & Mary’s Batten School & VIMS shows that this seagrass swap could have ecological impacts across the Bay’s
Seagrasses, foundational species in coastal ecosystems worldwide, are surprisingly few in documented diversity—with only about 70 species identified globally, despite their widespread distribution and ecological importance. Complicating matters, their high phenotypic plasticity within species makes precise classification challenging. Against this backdrop, a research team led by Prof. Zhou Yi from
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
For millennia, humans lived as hunter-gatherers. Savannas and forests are often thought of as the cradle of our lineage, but beneath the waves, a habitat exists that has quietly supported humans for over 180,000 years. Archaeological evidence suggests that early humans migrated along coasts, avoiding desert and tundra. So, as Homo spread from
Published in the journal Ocean and Coastal Management, the research set out to establish the value of local ecological knowledge (LEK) and its ability to generate high-quality habitat maps around five Greek islands in the eastern Aegean Sea. Ten fishermen, based on their individual experience and knowledge, were asked to pinpoint areas
A new study led by the University of South Florida highlights the urgent need to protect marine ecosystems in shallow water near the shore —an area that many beachgoers don’t realize is highly important to fish populations. Known as tidal flats, these coastal waters are characterized by a complex mosaic
Seaweed farming is a rapidly expanding global industry. As a food resource, it has high nutritional value and doesn’t need fertilisers to grow. Seaweed provides valuable habitats for marine life, takes up carbon and absorbs nutrients, plus it helps protect our coastlines from erosion. Usually, seaweeds grow on hard, rocky surfaces. Yet, to
The Ocean is in crisis. Coral reefs are bleaching, seagrass meadows are vanishing, mangroves are being cleared, and biodiversity is plummeting. Scientists estimate we’ve already lost up to 50% of global saltmarshes, 35% of mangroves, and 20% of seagrasses. Yet alongside this sobering decline, momentum for marine restoration has never been greater. The United Nations’ Decade on Ecosystem Restoration (2021–2030) and the Kunming–Montreal Global Biodiversity Framework both set ambitious targets: restoring 30% of degraded ecosystems, including those underwater, by 2030. So the question is: if the will, the science, and the funding are building, what’s holding us back? According to a team of 25 scientists and practitioners from 18 countries, one of the biggest obstacles isn’t just the technical challenge of restoration itself, it’s the licensing and regulation systems designed to govern it. In their recent paper, Rethinking Marine Restoration Permitting to Urgently Advance Efforts, they argue that outdated, overly complex permitting processes are unintentionally slowing down the very projects needed to restore the oceans. Marine Restoration Is Still Young Unlike reforestation on land, which has centuries of trial and error behind it, marine restoration is still in its infancy. Early projects in kelp, oysters, and seagrass go back decades, but systematic science-based restoration is relatively new. Failures are common, often because methods are untested or ecological dynamics are poorly understood. But those failures are not a reason to stop—they are opportunities to learn. Unfortunately, knowledge sharing is patchy, with unsuccessful projects often going unreported. This means mistakes are repeated instead of avoided. When Regulation Backfires No one disputes that regulations are essential to protect fragile ecosystems. But the paper highlights a paradox: the very laws meant to safeguard marine environments can also block or delay restoration. Permitting processes are frequently designed for terrestrial development projects, not marine habitat recovery. This mismatch means approvals are expensive, slow, and sometimes impossible to obtain. For instance, restoration within marine protected areas is often heavily restricted, even when the activity would clearly benefit the marine ecosystems and its biodiversity. The result? Practitioners may choose suboptimal sites just to avoid regulatory headaches, or abandon projects altogether. In some cases, frustrated groups even take matters into their own hands through “covert restoration,” risking legal trouble to get reefs or seagrasses replanted. Why “Business as Usual” Won’t Work Complicating matters further is climate change. Even if the world manages to stay under the 1.5°C target of the Paris Agreement, marine ecosystems face enormous risks. Marine heatwaves, shifting species ranges, and rising seas mean that simply recreating past habitats is no longer realistic. Instead, the authors argue for a forward-looking approach: restoration must aim to create resilient ecosystems for the future, not replicas of the past. That may involve controversial tools like assisted gene flow, assisted migration, or even repurposing invasive species to provide ecological functions. While these approaches raise ethical questions, the authors stress that clinging to outdated baselines is more dangerous than carefully exploring new ones. The Case for Innovation “Sandpits” One of the paper’s most intriguing proposals is the creation of innovation sandpits, dedicated spaces where scientists and practitioners can test new restoration methods under flexible permitting conditions. The idea is to encourage creativity and experimentation, similar to the culture of innovation that drove the U.S. “moonshot” program. Such sandpits could allow restoration at meaningful scales, where failures are expected but also monitored and shared, building collective knowledge. Crucially, this would need to be done with free, prior, and informed consent from local communities, ensuring equity and transparency. Scaling Up Takes Time Another bottleneck is time. Most restoration permits are short-term, three to five years at most. But successful marine recovery often requires decades of continuous effort. Seagrass meadows, oyster reefs, and mangrove forests don’t mature overnight. Short permits create interruptions, forcing projects to restart and making funding insecure. For large-scale recovery, licensing must align with ecological realities: long-term horizons, continuity, and scale. Small, scattered projects will never be enough. Strategic national and international coordination is needed to identify suitable areas, streamline approvals, and pool resources. Equity and Responsibility The paper also highlights the importance of equity. Restoration is not just about biodiversity; it directly impacts the people who live alongside these ecosystems. Indigenous communities, local fishers, and coastal residents must have a say in how projects are planned and implemented. Otherwise, well-meaning initiatives could unintentionally restrict access to resources or sideline traditional knowledge. The authors emphasise that urgency must not become an excuse for ignoring equity. Social inclusion, fairness, and justice are essential for lasting success. Six Steps Toward Better Restoration Licensing The authors conclude with a six-point agenda for change: Embrace novelty: Use innovative tools (genetics, assisted migration, new technologies) to prepare for future conditions, not past baselines. Establish sandpits: Create safe zones for testing and scaling new methods. Strategic restoration zones: Designate areas where permits are streamlined and projects are protected from future disturbance. Transparent reporting: Mandate open sharing of successes and failures, so the whole field can learn. Streamlined, long-term permits: Align licensing with ecological timescales and assume restoration is a positive activity by default. Remove fees, add incentives: Instead of charging for permits, reward landowners and stakeholders who enable restoration. Looking Ahead Marine restoration has the potential to be a cornerstone of the “blue revolution” needed to sustain life on Earth. But to succeed, governments, regulators, scientists, and communities must rethink how we design the systems that enable it. As the authors argue, the goal is not deregulation, but smarter, more adaptive regulation. The ocean is changing rapidly, and restoration must change with it. By fostering innovation, embracing uncertainty, and prioritising resilience and equity, we can give our seas a fighting chance.
Posidonia seagrass meadows, veritable underwater forests, play a major ecological role. Under constant pressure from human activity, scientists are looking for ways to ensure their survival, in particular by carrying out restoration campaigns. A study conducted by the University of Liège at the marine and oceanographical research station STARESO (Calvi, Corsica) reveals that the transplantation method directly influences the root microbiome, which is essential for the survival of the plants. These results pave the way for more effective and sustainable restoration techniques. The paper is published in the journal Environmental Microbiome. Roots growing on a Posidonia cutting transplanted using metal staples. Arnaud Boulenger conditioning Posidonia roots for genetic analysis of the microbiome. Credit: University of Liège, Arnaud Boulenger Often compared to terrestrial forests, Posidonia oceanica seagrass meadows form off the coast of the Mediterranean. These ecosystems act as environmental sentinels, stabilizing the seabed, storing carbon, and harboring exceptional biodiversity. Unfortunately, scientists have been observing a decline in their population for many years due to coastal urbanization, boat anchoring, and climate change. To halt this decline, researchers are experimenting with transplanting cuttings. “Until now, efforts have focused mainly on their visible survival, i.e., root recovery and leaf growth,” explains Arnaud Boulenger, a Ph.D. candidate in oceanography at ULiège (Belgium). “However, the study we conducted at STARESO reveals that the health of seagrass beds also depends on an invisible network of microorganisms associated with the roots.” It is therefore not enough to simply replant the seagrass meadows; we must also ensure the good health of their microbiome. By testing three transplantation techniques—metal staples, coconut fiber mats and potato starch structures—the team showed that the choice of substrate profoundly changed the composition of the microbiome. “Staples, which allow direct contact with the sediment, promote the establishment of key bacteria such as Chromatiales and Desulfobacterales, which are essential for the sulfur and nitrogen cycles,” the researcher explains. “Conversely, the other methods delay this beneficial colonization.” Scientists highlight that restoration methods must now incorporate this microbiological dimension, as these bacteria play a direct role in plant resilience. “These results are groundbreaking,” says Sylvie Gobert, oceanographer. “This is the first time that a study has demonstrated in situ the importance of the microbiome in the success of Posidonia transplantation. The results we have obtained open up concrete perspectives, such as the inoculation of beneficial bacteria or the design of supports that facilitate root-sediment interaction.” Restoring a seagrass bed is therefore much more than just replanting cuttings underwater. It means recreating an entire ecosystem, both visible and invisible, in which bacteria play a crucial role. As Boulenger sums it up, “it’s a bit like replanting a forest, while also ensuring that the soil that nourishes it is brought back to life.” More information: This article is republished from PHYS.ORG and provided by the University of Liège. Arnaud Boulenger et al, Microbiome matters: how transplantation methods and donor origins shape the successful restoration of the seagrass Posidonia oceanica, Environmental Microbiome (2025). DOI: 10.1186/s40793-025-00764-9
Our oceans and coasts are home to ecosystems that provide immense benefits to people, from food and livelihoods to carbon storage and coastal protection. In particular, seagrass meadows are archetypal social-ecological systems (SES), linking human well-being to ecosystem health. But to manage these systems effectively, we need access to both ecological data (such as habitat extent, biodiversity, or water quality) and social data (such as fishing activity, governance, or community use). In a new paper led by Uppsala University, Project Seagrass Chief Conservation Officer Dr. Benjamin Jones, joined forces with scientists from Sweden and the USA to explore how researchers and managers can better use open-access data to integrate these perspectives and improve decision-making. Why this data matters Over the past decade, the amount of freely available ecological and social data has exploded. From satellite-derived habitat maps to global fisheries datasets, there is now a wealth of information that could support more holistic approaches to conservation and management. Such data includes the likes of our very own SeagrassSpotter dataset. Yet, this opportunity comes with challenges. For many practitioners, the biggest barrier is knowing where to find relevant datasets and how to make sense of them in a way that reflects both the ecological and social dimensions of coastal systems. Without broad interdisciplinary training, it can be easy to feel overwhelmed by the sheer volume and complexity of open data sources. To address this challenge, we developed a workflow based on a social-ecological systems framework to help researchers systematically identify the types of variables they need (e.g., ecological, social, or governance-related) and guides the search for appropriate open datasets. The workflow was demonstrated using seagrass meadows in the Tropical Indo-Pacific, a region where millions of people depend directly on coastal ecosystems. This provides a strong test case for exploring how open data can inform both research and management and highlights just how much open-access information is already available, from global biodiversity repositories to socioeconomic databases, and how it can be assembled into a more complete picture of system dynamics. The study underscores the huge potential of open data to support inclusive and interdisciplinary approaches in coastal science. It allows researchers to explore ecological and social indicators side by side, ask new, cross-cutting research questions, support management decisions even in data-poor regions and facilitate collaboration across disciplines and geographies. However, there are important challenges. First, data can be patchy or biased, with strong coverage of biophysical variables but limited social or long-term monitoring data. Second, many datasets are coarsely aggregated or inconsistent in spatial and temporal coverage. Third, users often require specialised technical skills to access, harmonise, and analyse the data and finally, the “paradox of choice” means the sheer volume of available datasets can be overwhelming without a clear framework to guide selection. These limitations highlight the need for continued investment in training, better tools, and improved data-sharing practices. The paper also emphasises the importance of contributing data back into open repositories such as the Ocean Biodiversity Information System. By sharing primary data openly, researchers and practitioners not only enhance the value of their own work but also support a stronger, more connected global community. Project Seagrass is committed to this via its open access SeagrassSpotter database, and the newly launched SeagrassRestorer. This cultural shift towards open data sharing, proper attribution of data collectors, and incentivising contributions is essential if we are to unlock the full potential of open data in advancing coastal science and conservation. Frameworks like this provide a structured way of navigating the open-data landscape. By combining social and ecological variables, researchers and managers can move beyond siloed approaches to develop a truly integrated understanding of coastal systems. For seagrass meadows and other critical coastal habitats, this means being better equipped to anticipate change, design effective interventions, and ensure the long-term provision of ecosystem services that millions of people depend upon. In short: open data, when harnessed effectively, is a powerful tool for bridging science and society and for building more sustainable futures for our coasts.
Beneath the surface of the Chesapeake Bay, a subtle but dramatic shift is taking place as eelgrass gives way to its warmer-water relative, widgeon grass. A new study from researchers at William & Mary’s Batten School & VIMS shows that this seagrass swap could have ecological impacts across the Bay’s food webs, fisheries and ecosystem functions. Published in Marine Ecology Progress Series, the study reveals that while both seagrass species offer valuable habitat, they support marine life in very different ways. The researchers estimate that the continued shift from eelgrass to widgeon grass could lead to a 63% reduction in the total quantity of invertebrate biomass living in seagrass meadows in the bay by 2060. “Several factors including water quality, rising temperatures and human development are threatening eelgrass in the Chesapeake Bay. In its place, particularly in the middle Bay, widgeon grass has expanded due to its ability to tolerate warmer, more variable conditions,” said Associate Professor Chris Patrick, who is also director of the Submerged Aquatic Vegetation (SAV) Monitoring & Restoration Program at the Batten School of Coastal & Marine Sciences & VIMS. “However, the two grasses provide structurally distinct habitats that shape the animals living within.” All grasses are not created equal While working with Patrick and earning her master’s degree at the Batten School & VIMS, lead author Lauren Alvaro engaged in extensive fieldwork studying seagrass meadows in Mobjack Bay. Her team surveyed and compared habitats consisting of eelgrass, widgeon grass as well as mixed beds. They documented everything from burrowing clams and snails to crabs and fishes to get an idea of life living within the sediment and among the grasses. The findings showed that while widgeon grass supports more individual invertebrates per gram of plant material, eelgrass meadows are home to larger animals and have more plant biomass per square meter. As a result, eelgrass supports a greater total animal biomass per square meter. “Our findings suggest that we’re likely to see a fundamental shift in the structure of the food web that favors smaller creatures as eelgrass is replaced by widgeon grass,” said Alvaro. “The eelgrass meadows produced fewer animals, but they’re bigger and more valuable to predators like fish and blue crabs.” Much of the difference is due to the physical characteristics of the two types of seagrasses. Widgeon grass beds have a greater surface-to-biomass ratio due to their narrower leaf structure, which provides more area for small invertebrates to cling to. However, eelgrass’s broader leaves provide a type of canopy favored by animals like pipefish, blue crabs, and larger isopods, which are small shrimp-like crustaceans. The bigger picture The researchers extrapolated their findings and estimated that current seagrass habitats in the Chesapeake Bay support approximately 66,139 tons of invertebrate biomass living in the sediment and among the grass beds and produce 35,274 tons of new animal biomass each growing season. Termed “secondary production,” this is the biomass the habitat makes available to higher levels of the food chain. If seagrasses continue to shift as expected, by 2060 secondary production could be reduced by more than 60% under a scenario where no further nutrient reductions occur. Nutrient runoff into the Bay is the largest threat to submerged aquatic vegetation. Even in a best-case nutrient management scenario, the Bay could still lose approximately 15% of secondary production biomass. “Within the limits of our study, it wasn’t possible to determine whether it was the meadow’s physical structure, the meadow area, or available food sources that contributed to greater numbers of fish in the eelgrass meadows,” said Alvaro. “This makes it difficult to accurately estimate fishery-level impacts of changes in meadow composition, but several lines of reasoning support an expectation of reduction in numerous commercial and recreational species.” The study adds to a growing body of research documenting the effects of changes in foundational species influenced by a warming planet. The authors cite similar research involving Florida’s mangroves and a worldwide shift from coral to algae-dominated ecosystems. As states within the Bay’s extensive watershed work to maintain and improve the health of the estuary, the team hopes their findings will help inform management decisions and restoration strategies. Protecting and restoring the remaining eelgrass and better understanding the role of widgeon grass may help preserve ecological resources for future generations and provide a buffer against future shocks. More information: This article is republished from PHYS.ORG and provided by Virginia Institute of Marine Science. Lauren Elizabeth Alvaro et al, Changing foundation species in Chesapeake Bay: implications for faunal communities of two dominant seagrass species, Marine Ecology Progress Series (2025). DOI: 10.3354/meps14901
Seagrasses, foundational species in coastal ecosystems worldwide, are surprisingly few in documented diversity—with only about 70 species identified globally, despite their widespread distribution and ecological importance. Complicating matters, their high phenotypic plasticity within species makes precise classification challenging. Against this backdrop, a research team led by Prof. Zhou Yi from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS), in collaboration with researchers from Germany’s GEOMAR Helmholtz Center for Ocean Research Kiel and other institutions, has discovered cryptic speciation within Nanozostera japonica—a seagrass species common across the Northwest Pacific. The findings were published in New Phytologist. Co-existence of diploidy and triploidy within a population of Nanozostera japonica. Credit New Phytologist, 2025 Nanozostera japonica is rare among seagrasses as it’s able to thrive in both temperate and tropical-subtropical coastal zones. Native to the Northwest Pacific, it spread to North America’s Pacific coast in the early 20th century via oyster shipments. Its phenotypes vary sharply across geographic regions, and prior research using microsatellite markers revealed striking genetic differences between northern and southern populations—hinting that what is currently classified as Nanozostera japonica might include multiple species. To test this hypothesis, the team assembled high-quality, chromosome-level reference genomes from Nanozostera japonica samples collected in northern and southern China. They then conducted whole-genome resequencing of 17 populations spanning the Western Pacific. Genomic analyses showed the northern and southern clades diverged approximately 4.16 million years ago (Ma). Notably, the southern clade is more closely related to its European sister species Nanozostera noltii, with a more recent split at about 2.67 Ma. “The genetic divergence between these two clades exceeds typical intraspecific differences,” noted Dr. Zhang Xiaomei. The study also identified hybrids between the clades in their contact zone, all of which are first-generation diploids or triploids—with no evidence of higher-order hybrids. This pattern strongly indicates reproductive isolation, a key marker of distinct species. Further comparative genomic work revealed a massive ~42 megabase (Mb) chromosomal inversion with fixed differences between the clades, likely contributing to their reproductive separation. “This work shows that what we currently recognize as Nanozostera japonica actually comprises two distinct species,” said Prof. Zhou. “It provides critical insights for future seagrass classification and conservation strategies.” This marks the first time cryptic seagrass species have been identified using comprehensive population genomics. The study suggests seagrass diversity may be significantly underestimated, underscoring the need for more extensive population genomic research on these ecologically vital organisms. More information: This article is republished from PHYS.ORG and provided by the Chinese Academy of Sciences. Xiaomei Zhang et al, Uncovering the Nanozostera japonica species complex suggests cryptic speciation and underestimated seagrass diversity, New Phytologist (2025). DOI: 10.1111/nph.70355
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
For millennia, humans lived as hunter-gatherers. Savannas and forests are often thought of as the cradle of our lineage, but beneath the waves, a habitat exists that has quietly supported humans for over 180,000 years. Archaeological evidence suggests that early humans migrated along coasts, avoiding desert and tundra. So, as Homo spread from Africa, they inevitably encountered seagrasses – flowering plants evolved to inhabit shallow coastal environments that form undersea meadows teeming with life. Our recently published research pieces together historical evidence from across the globe, revealing that humans and seagrass meadows have been intertwined for millennia – providing food, fishing grounds, building materials, medicine and more throughout our shared history. Our earliest known links to seagrass date back around 180,000 years. Tiny seagrass-associated snails were discovered in France at Paleolithic cave sites used by Neanderthals. Too small to be a consequence of food remains, these snails were likely introduced with Posidonia oceanica leaves used for bedding – a type of seagrass found only in the Mediterranean. Neanderthals didn’t just use seagrass to make sleeping comfortable – 120,000 year old evidence suggests they harvested seagrass-associated scallops too. A bountiful supply of food Seagrass meadows provide shelter and food for marine life, such as fish, invertebrates, reptiles and marine mammals. Because they inhabit shallow waters close to shore, seagrass meadows have been natural fishing grounds and places where generations have speared, cast nets, set traps and hand-gathered food to survive and thrive. Long before modern fishing fleets, ancient communities recognised the value of these underwater grasslands. Around 6,000 years ago, the people of eastern Arabia depended on seagrass meadows to hunt rabbitfish – a practice so prevalent here that remnants of their fishing traps are still visible from space. Historic stone fish traps designed to capture seagrass associated fish as the tide retreats. Photos Benjamin Jones Satelite image Apple Maps Seagrass meadows have even been directly harvested as food. Around 12,000 years ago, some of the first human cultures in North America, settling on Isla Cedros off the coast of Baja California, gathered and consumed seeds from Zostera marina, a species commonly called eelgrass. These seeds were milled into a flour and baked into breads and cakes, a process alike to wheat milling today. Further north, the Indigenous Kwakwaka’wakw peoples, as far back as 10,000 years ago, developed a careful and sustainable way of gathering eelgrass for consumption. By twisting a pole into the seagrass, they pulled up the leaves, and broke them off near the rhizome – the underground stem that is rich in sugary carbohydrates. After removing the roots and outer leaves, they wrapped the youngest leaves around the rhizome, dipping it in oil before eating. Remarkably, this method was later found to promote seagrass health, encouraging new growth and resilience. Today, seagrass meadows remain a lifeline for coastal communities, particularly across the Indian and Pacific Oceans. Here, fishing within seagrass habitats is shown to be more reliable than other coastal habitats and women often sustain their families by gleaning – a fishing practice that involves carefully combing seagrass meadows for edible shells and other marine life. For these communities, seagrass fishing is vital during periods when fishing at sea is not possible, for example, during tropical storms. When seagrasses returned to the sea around 100 million years ago, they evolved to have specialised leaves to tolerate both saltwater submergence and periods of time exposed to the sun during tidal cycles. This allowed seagrasses to flourish across our coastlines, but also made them useful resources for humans. Mudbricks discovered at the Malia Archaeological Site, Crete, contain remains of seagrass leaves. Olaf Tausch Wikimedia Commons Seagrass leaves, once dry, are relatively moist- and rot-proof – properties likely discovered by ancient civilisations when exploring the uses of plants for different purposes. Bronze age civilizations like the Minoans, used seagrass in building construction, reinforcing mudbricks with seagrass. Analysis of these reveal superior thermal properties of seagrass mudbricks compared to bricks made with other plant fibres – they kept buildings warmer in winter and cooler in summer. These unique properties may have been why early humans used seagrass for bedding and by the 16th century, seagrass-stuffed mattresses were prized for pest resistance, requested even by Pope Julius III. Three hundred year old seagrass thatched roof from the island of Læsø, Denmark. Jack Fridthjof/Visitlaesoe By the 17th century, Europeans were using seagrass to thatch roofs and insulate their homes. North American colonialists took this knowledge with them, continuing the practice. In the 19th century, commercial harvesting of tens of thousands of tonnes of seagrass began across North America and northern Europe. In the US, Boston’s Samuel Cabot Company patented an insulation material called Cabot’s “Quilt”, sandwiching dried seagrass leaves between two layers of paper. These quilts were used to insulate buildings across the US, including New York’s Rockefeller Center and the Capitol in Washington DC. A legacy ecosystem – and a living one The prevalence of seagrass throughout human civilisation has fostered spiritual and cultural relations with these underwater gardens, manifesting in rituals and historical customs. In Neolithic graves in Denmark, scientists found human remains wrapped in seagrass, representing a close connection with the sea. “If we have depended on seagrass for 180,000 years—for food, homes, customs—investing in their conservation and restoration is not just ecological, it’s deeply human,” said Project Seagrass’ Chief Conservation Officer Dr Benjamin Jones. “They were not just background scenery — they were practical, valuable, and even life-saving. They’re also solutions hiding in plain sight for things like food resilience — habitats that offer communities today a lifeline in times of need.” Our new research tells us that seagrass meadows are not just biodiversity hotspots or carbon storage systems. They are ancient human allies. This elevates their value beyond conservation – they’re repositories of cultural heritage and traditional knowledge. They were practical, valuable, and deeply integrated into human cultures. We have depended on seagrass for 180,000 years – for food, homes, customs – so investing in their conservation and restoration is not just ecological, it’s deeply human.
Published in the journal Ocean and Coastal Management, the research set out to establish the value of local ecological knowledge (LEK) and its ability to generate high-quality habitat maps around five Greek islands in the eastern Aegean Sea. Ten fishermen, based on their individual experience and knowledge, were asked to pinpoint areas where they believed seagrass beds could be found along the coastlines of their respective islands. The maps they produced were then compared with satellite data of the same regions, with analysis showing an average accuracy of 78% – and a high of 92%. The fishermen’s maps were also 11% more accurate than those used by the Greek government in the development of environmental policies, with more than half of the government maps underestimating the scale of seagrass beds found across the region. The researchers say their findings are a clear demonstration of the value of tapping into local knowledge, and how doing so can be a low-cost means of generating environmental data without compromising the high accuracy needed for the data to still be valuable for policy use. Ten fishermen, based on their individual experience and knowledge, were asked to pinpoint areas where they believed seagrass beds could be found along the coastlines of their respective islands. Credit Konstantis AlexopoulosUniversity of Plymouth The study was carried out by researchers from the University of Plymouth and the Archipelagos Institute of Marine Conservation. They worked closely with fishermen on the islands of Fourni, Arki, Patmos, Lipsi and Leros, each of which are home to communities made up largely of small artisanal fishing vessels. Konstantis Alexopoulos, a BSc (Hons) Ocean Science and Marine Conservation graduate from the University of Plymouth, now pursuing a Ph.D. with the Scott Polar Research Institute at the University of Cambridge, is its lead author. He said, “Some of the fishermen we spoke to had been sailing the same waters every day for more than 60 years. That experience has given them a huge amount of knowledge, but we wanted to test precisely how accurate their empirical data were in comparison to more traditional sources of information. “For some personal recollections to be 90% as accurate as the data provided from satellites is really impressive, and something we should be taking into greater account. It also highlights the importance of gathering such information, as there is a huge wealth of data within local fishing communities that is otherwise at risk of being lost as fewer younger people enter the profession in the future.” Those involved in the research say it is another example of how communities, scientists and decision-makers could work in collaboration to meet ambitions set out within the United Nations Sustainable Development Goals. And despite it being centered around the eastern Aegean Sea, they believe their findings – and the methods used to reach them – will be relevant in other parts of the ocean. In particular, they say LEK could play a pivotal role in generating a greater understanding of deeper marine ecosystems which satellites can’t see and for which there are currently little or no maps available to guide management decisions. Dr. Abigail McQuatters-Gollop, Associate Professor of Marine Conservation at the University and the current study’s senior author, added, “There is a huge global drive to get more people involved in projects that incorporate elements of citizen science. “Despite that, expert local ecological knowledge is still being dismissed or discredited by those making decisions about the environment. But just because information hasn’t been generated by expensive technology, it doesn’t make it any less valuable. “Using people’s life experiences, gathered from fishing and living in an area over many years, alongside other scientific data can help us develop and implement actions that maintain a healthy global ocean.” More information: Konstantis Alexopoulos et al, Is sparse local ecological knowledge accurate enough for policy? A seagrass mapping case study from five Greek islands in the Eastern Aegean Sea, Ocean & Coastal Management (2025). DOI: 10.1016/j.ocecoaman.2025.107627
A new study led by the University of South Florida highlights the urgent need to protect marine ecosystems in shallow water near the shore —an area that many beachgoers don’t realize is highly important to fish populations. Known as tidal flats, these coastal waters are characterized by a complex mosaic of habitats, such as sand, mud, coral rubble, seagrass meadows, oyster reefs, coral reefs and mangroves. They are vital nursery grounds for diverse marine life, including reef fish, sharks and rays and are critical to global seafood supplies, local economies and overall marine health. The findings from a team of interdisciplinary marine experts, “Habitat management and restoration as missing pieces in flats ecosystems conservation and the fishes and fisheries that they support,” are published online in Fisheries. The team created 10 core strategies that boaters, anglers, wildlife managers and policymakers can adopt to prioritize and preserve marine flat ecosystems including seagrass meadows from humans and intensified weather events. At the top of the list is considering fish, such as tarpon, as flagship and umbrella species, as their protection would benefit additional species that use the same habitats. They urge habitat management and restoration to be at the forefront of the community’s mind, starting with integrating them into local government and coastal development and planning processes. Recent research from Project Seagrass, based on a fishery in South Florida, highlights the need for more diverse knowledge holders in local knowledge research and application to ensure that management recommendations arising from local knowledge are not skewed towards the most vocal individuals. The University of South Florida team believes this will lead to resilient shorelines and shallow-water habitats, providing long-term benefits for coastal communities and the marine life that depends on them. “The ecological connections between these ecosystems and other marine habitats are vital for the lifecycle of various species, many of which are integral to fisheries,” said Lucas Griffin, assistant professor in the USF Department of Integrative Biology. For the last decade, Griffin has studied fish and their migration patterns in a variety of areas, including the Florida Keys, witnessing firsthand how tidal flats are rapidly changing. Inspired by that work to take action, Griffin partnered with experts from the Florida Fish and Wildlife Conservation Commission, Carleton University and the University of Massachusetts Amherst to develop a plan that can be applied locally and globally to help protect tidal flats. “The Florida Keys are a biodiversity hotspot where wildlife and fish depend on flats habitats,” Griffin said. “But these ecosystems are at risk—from coastal development and harmful algal blooms, to heat waves and boats running aground on sensitive habitats, like seagrass. Iconic recreational fish like tarpon, permit and bonefish rely on these flats, contributing millions of dollars to the local economy each year. “Despite their importance, there is not a lot of direct habitat management to protect these ecosystems. We need to address questions like how much good habitat remains, what can be restored and what has already been lost.” Overfishing, habitat degradation, coastal development and environmental conditions have contributed to these fragile habitats disappearing around the world. In Florida, intensified weather, such as heat waves and hurricanes, has further compounded these issues. “Effective habitat management and restoration are critical, but have been overlooked for flats ecosystems,” Griffin said. “Implementing these principles can help secure the biodiversity, fisheries and ecosystem services that millions of people depend on.” More information: This article is republished from PHYS.ORG and provided by the University of South Florida. Study: Habitat management and restoration as missing pieces in flats ecosystems conservation and the fishes and fisheries that they support,, Fisheries (2025). Flats ecosystems are characterized by a complex mosaic of habitats, such as sand, mud, coral rubble, seagrass meadows, oyster reefs, coral reefs and mangroves. They are vital nursery grounds for diverse marine life, including reef fish, sharks and rays. Credit: Andy Danylchuk, University of Massachusetts Amherst
Seaweed farming is a rapidly expanding global industry. As a food resource, it has high nutritional value and doesn’t need fertilisers to grow. Seaweed provides valuable habitats for marine life, takes up carbon and absorbs nutrients, plus it helps protect our coastlines from erosion. Usually, seaweeds grow on hard, rocky surfaces. Yet, to farm seaweed, potential areas need to be easily accessible and relatively sheltered. This is where seaweed can grow with limited risk of being dislodged by waves. Seaweed farms in Asia, in countries like China and Indonesia, are responsible for more than 95% of global seaweed production. Seaweed farms, particularly those in Southeast Asia, are commonly in the very same environments where seagrass meadows thrive. Competition for resources ensues. Evidence shows that tropical seaweed farms, when placed in or on top of tropical seagrass meadows leads to a decline in the growth and productivity of seagrass. There is also evidence that seaweeds outcompete seagrasses in cooler waters, especially when nutrients in the water are very high. Despite negative interactions, such as shading, between seaweed and seagrass, some scientists now advocate for a global expansion of seaweed farming in areas where seagrass grows. This call, comes at a time when seagrass global initiatives are trying to stem seagrass loss. Efforts are underway to expand these habitats to their once extensive range to help fight climate change and biodiversity loss. Seagrass meadows are a crucial store of carbon, providing habitats for a wide array of animals. Why farm seaweed on top of seagrass? The reason that some scientists are advocating for farming seaweed in seagrass is that their research claims that the presence of seagrass reduces disease causing bacterial pathogens by 75%. A major win for a relatively low tech industry where seaweed disease outbreaks hinder production. These scientists are not the only ones advocating for seaweed production at scale. Global conservation charities, like World Wildlife Fund and The Nature Conservancy, as well as the Earthshot prize launched by Prince William all support seaweed cultivation programmes in areas likely to contain abundant seagrass. However, together with other scientists, we have argued in an academic response in the journal PNAS that their claim is premature. We are concerned that, without appropriate management, these seaweed programmes threaten marine biodiversity and the benefits that humans get from the ocean. Despite historic and globally widespread seaweed cultivation, effects on seagrass have mostly been ignored. Where studies exist, effects have been negative for seagrass, its ability to capture carbon, and the diverse animals that call it home. Entanglement of migratory animals, such as turtles and dugong with seaweed also needs wider consideration. This is especially the case given new legal frameworks to protect their habitat, and there is ongoing concern for these species being killed by seaweed farmers. The equity of coastal fishing grounds also comes into question, as communities that use seagrass for fishing are most likely to lose access. Conservation charities advocate for tropical seaweed farms for good reason. This is to improve community resilience in the face of degrading coral reefs and overfishing. While projects mostly have the best intentions, they often don’t consider cascading unintended consequences, nor the equity of the whole community. In reality, seaweed farm placement is effectively akin to ocean grabbing (the act of dispossession or appropriation of marine resources or spaces) with farmers winning on a “first come, first serve” basis, despite not owning the seabed. Some seagrass meadows in Zanzibar, Tanzania, have recovered since seaweed farms have been removed. GoogleEarth Sustainable standards If seaweed farming is to be expanded, standards for sustainability must be upheld and strengthened. In 2017, a sustainable seaweed standard was launched by the Aquaculture and Marine Stewardship Councils. But few tropical seaweed farms meet the criteria outlined in this standard due to known consequences that affect seagrass (rightly defined in the standard as vulnerable marine habitats) and likely negative effects on endangered species, like dugong, that frequent seagrass habitats. Seaweed cultivation strategies have mixed evidence for long-term success. In Tanzania, many farmers have abandoned the industry due to low monetary rewards compared to the investments they put in, and some evidence suggests that the activity reduces income and health, particularly for women. Where seaweed cultivation has been implemented to reduce fishing pressure, it has instead increased (and often just displaced) fishing activity. Given the rapidly increasing threats faced by tropical marine habitats despite the role they play in climate resilience, understanding trade-offs prior to large scale expansion of seaweed farming is a priority. To reduce further any negative effects, international programmes and research advocating for large-scale seaweed farms need to align more readily with the seaweed standard. More information: This article was published in The Conversation Jones. et al, Risks of habitat loss from seaweed cultivation within seagrass, PNAS (2025). https://doi.org/10.1073/pnas.242697112 Seaweed farms are often placed on top of seagrass meadows. Niels Boere/flickr A women prepares seaweed ropes for deployment in the Wakatobi, Indonesia. Benjamin Jones/Project Seagrass
