The FANNS programme took place between 2024 and 2026. One of the focuses within the programme was on improving the natural environment through a series of restoration trials across multiple Special Areas of Conservation in South and West Wales. These trials aimed to establish the most effective methods of planting seagrass
On the 7th, 8th, and 9th May, the Project Seagrass team hosted our 2026 Open Days at our Seagrass Nursery in Laugharne. The Seagrass Nursery Open Days are an annual opportunity for funders, partners, and members of the community to meet the team and learn more about the exciting work
Heat stress from marine heat waves can create a toxic relationship between seagrasses and a hidden ecosystem of bacteria, transforming a previously beneficial co-existence between marine plants and microbes into a harmful one, a University of Sydney and UNSW study has found. Seagrasses are marine flowering plants that act as
As our Fragment Walks from the 2025/26 season come to an end Project Seagrass Intern Anya Lamparelli reflects on this year’s efforts. A seagrass fragment is a precious and vulnerable thing. Torn free by winter storms and strong swells these delicate shoots with intricate root systems still attached wash ashore
A new study of the British Isles’ coastal ecosystems has revealed that nitrogen enrichment is significantly reducing the abundance and variety of marine life. The research, published by scientists at Swansea University and the charity Project Seagrass, warns that increasing nutrient flows are overriding local habitat conditions to restructure and
Residents and visitors to the Isle of Wight can now access information about the Island’s important seagrass habitats thanks to new signage installed through support from Seacology. The signage has been installed by Project Seagrass as part of ongoing efforts to protect and restore seagrass ecosystems within the Solent. The signs
Hannah Harrero and Stephanie Insalaco-Wyner, geographers from Florida, comment on differing methods of monitoring the resilience of seagrass meadows in Florida’s ‘Mosquito Lagoon’, following a number of extreme weather events. Florida’s Indian River Lagoon has been an ecosystem in decline going back to 2011, when harmful algal blooms led to a severe decline in
Heidi McIlvenny, PhD researcher from Queen’s University Belfast, comments on seagrass meadows in Northern Ireland and how seagrass meadows can recover but only if we tackle the pollution at its source. I spent last summer wading through seagrass meadows across Northern Ireland, from the sheltered waters of Strangford Lough to
Between the 17th and 23rd March 2026, members of the Project Seagrass team were on the Isle of Wight carrying out active restoration as part of the The Solent Seascape Project, the first project of its kind in the UK to initiate seascape-scale restoration. As part of The Solent Seascape
New research led by scientists at University of California’s San Diego’s Scripps Institution of Oceanography is shining a spotlight on one of the ocean’s most overlooked habitats: seagrass. Led by Scripps Oceanography Ph.D. candidate Rilee Sanders, the study documented the first successful restoration of open-coast seagrass (common eelgrass). The findings offer
The FANNS programme took place between 2024 and 2026. One of the focuses within the programme was on improving the natural environment through a series of restoration trials across multiple Special Areas of Conservation in South and West Wales. These trials aimed to establish the most effective methods of planting seagrass out into the field. Carmarthen Bay and Estuaries SAC Following site assessments and stakeholder engagement, Ellis Bay in Llanelli was identified as the site for the restoration trials within the Carmarthen Bay and Estuaries SAC. Zostera noltei was identified as the most appropriate species for restoration at this site due to the estuary’s intertidal nature and sediment characteristics. In May 2024, the Project Seagrass team were joined in the field by Carmarthen Bay & Estuaries European Marine Site Officer Judith Oakley and Carmarthen Conservation Coordinator Paul Aubrey. 75 Zostera noltei cores were transplanted from a healthy donor meadow near Llanelli to the Llanelli trial site using the plug method. Monitoring later that summer in August 2024 demonstrated positive results with a significant percentage (40 %) increase in growth from the initial core size, indicating strong early establishment and expansion. These results were highly encouraging, suggesting that Llanelli site conditions were suitable for Zostera noltei transplant success. Members of the Project Seagrass team, Carmarthen Bay & Estuaries, and Carmarthenshire Council collect Zostera noltei transplants from a donor meadow in Llanelli. A Zostera noltei core collected from a donor meadow ahead of transplantation. Building on the success of the 2024 trial, further planting took place in May 2025. 72 Zostera noltei transplants were collected from the donor meadow. The 2025 planting plots were located further towards the foreshore to enable the team to explore planting into alternative sediment types and to more closely reflect the distribution of the natural meadow on the western side of the Bay. Monitoring of both the 2024 and 2025 planting efforts took place in August 2025 with the 2025 planting plots evidencing significant loss. Shortly after transplanting, the site experienced a period of elevated temperatures followed by storm events. Sediment redistribution around the plots was evident during the team’s monitoring which may have destabilised newly planted cores, while heat stress would have compounded physiological stress following transplantation. The previous years planting survival was more varied but generally stronger with plots located closer to the low shore within muddier sediments showing higher survival rates and successful expansion, in some cases demonstrating up to 35% growth relative to the original core size. Plots positioned closer to the foreshore experienced comparatively greater loss. The contrast between 2024 and 2025 results highlights the importance of sediment stability and micro-site selection in transplant success. Given the positive expansion observed in 2024, there is a strong case for scaling up transplant effort within suitable sediment areas across the bay with plans for further transplant trials in Llanelli to build upon this learning. Severn Estuary SAC Within the Severn Estuary SAC, Butetown foreshore in Cardiff was selected as the site for planting trials. This location was identified based on Habitat Suitability Modelling, desk-based reviews, and in-field surveys which revealed the presence of three small, isolated Zostera marina seagrass patches at the site. In May 2024, the Project Seagrass team planted 60,000 Zostera marina seagrass seeds at the Cardiff site, using the Direct Injection Seeding (DIS) planting method developed by The Fieldwork Company. Monitoring later in the summer revealed no germination success from these planting efforts which led to a smaller repeat trial in 2025. A further 3,200 seeds were planted using the DIS method, this time adopting a Seagrass Hug configuration. The Seagrass Hug method has been developed by Anouska Mendzil, Senior Science Officer at Project Seagrass and Swansea University, and aims to determine whether surrounding seed plots with more established seagrass transplants provides protection for emerging seeds in restoration practices. This trial was undertaken in collaboration with the Seagrass Consortium. A total of 525 seagrass transplants were planted at the Cardiff site as part of the trials with varying degrees of success. 75 Zostera noltii transplants planted in 2024 initially showed signs of survival which would have established the presence of an additional seagrass species at the site, creating the potential for future development of a mixed meadow. However, by 2025 these transplants had been lost. 450 Zostera marina further transplants from the Project Seagrass Nursery were planted out in 2025, using coir pots of varying sizes and a mixture of plants that had been hardened outdoors in ponds at the Seagrass Nursery, while the remainder were grown inside the polytunnel. These trials allowed the team to undertake a comparison of transplant establishment by container type and nursery conditioning to inform future restoration approaches. Whilst monitoring highlighted that there had been significant loss from the initial number of transplants planted, several shoots persisted across the different planting methods. However, remaining shoots were generally found to be stressed and silt-covered, indicating environmental pressures at the site. Senior Science Officer Emma Fox undertakes monitoring at the Cardiff site Zostera noltii cores prepared for transplantation in May 2024 Throughout the programme of work, environmental data was gathered at the site to allow the team to monitor site conditions which might have impacted the success of the planting. Several environmental factors are likely to have influenced the restoration success at this particular site including elevated wave energy, high pool temperatures, silt smothering within intertidal pools, high epiphytic load, and the potential that the Zostera marina nursery stock used (from a source population in North Wales) may not represent the optimal ecotype for this environment. The Cardiff trials demonstrated that the Direct Injection Seeding method is not suitable for restoration at Cardiff under current site conditions. Transplant-based approaches showed limited but measurable persistence, with container type influencing relative survival. However, overall survival rates remain low, suggesting that environmental constraints may outweigh methodological refinements at the current scale of intervention. Further trials using transplants from a seagrass meadow in Stolford will allow the team to trial whether plants with a more comparable ecotype show higher levels of success at the site. Pembrokeshire Marine SAC Dale Bay within Pembrokeshire SAC, continued to serve
On the 7th, 8th, and 9th May, the Project Seagrass team hosted our 2026 Open Days at our Seagrass Nursery in Laugharne. The Seagrass Nursery Open Days are an annual opportunity for funders, partners, and members of the community to meet the team and learn more about the exciting work taking place on site. On the 7th and 8th May, the team were joined by representatives from Carmarthenshire Council Coastal Protection Team, Celtic Deep, Cygnet, Harth, Laugharne Citizen Science group, SeaLife, Marine Conservation Society, National Trust, Natural Resources Wales, Neath Port Talbot Council, Pembrokeshire Coastal Forum, qinetiq, Severn Estuary Partnership, Wildlife Trust of South & West Wales Swansea Group and 360 Aquaculture. Working collaboratively is essential for successful seagrass recovery and these events provided an opportunity for local stakeholders to discuss existing projects and opportunities for collaboration. On the 9th May the Seagrass Nursery opened its doors to members of the local community with visitors from Laugharne and the surrounding area joining the team to learn about recent developments at the site and seagrass restoration activity taking place in their local area. During the Open Days, visitors had the opportunity to join Nursery Manager Emily Yates for a guided tour of the site. This provided an insight into how the team are growing seagrass, our approach to storing seeds, and the research being undertaken into the best methods for seagrass cultivation. “The Seagrass Nursery Open Days are among some of my favorite days of the year! They provide a fantastic opportunity to welcome the local community to the site to show what we’re doing in Laugharne, as well as the wider work of Project Seagrass. It is great to meet so many enthusiastic people interested in our work whether it’s a first time or a returning visitor. Each year the Open Days provide us with an opportunity to share how the Nursery is developing and evolving over time.” Nursery Manager, Emily Yates. Nursery Manager Emily Yates delivers a tour of the Seagrass Nursery site Nursery Manager Emily Yates and Senior Science Officer Emma Fox delivering a tour of the polytunnel to Nursery Open Day attendees During 2026, 3,300 seagrass transplants were sent out from the Project Seagrass Nursery to support restoration projects across the UK and over half a million seeds stored from in-field seagrass seed collections. Significant developments are currently underway at the site, with plans for 12 additional ponds to be constructed within a second polytunnel over the summer. This will support our ambitions to develop a reliable, scalable source of UK-grown seagrass plants to supply restoration projects. A range of experimental work is currently taking place on the site. Visitors learned about the team’s recent restoration activity in the local area from Senior Science Officer Emma Fox. This has included planting trials across multiple Special Areas of Conservation in South and West Wales aimed at establishing the most effective methods of planting seagrass out into the field to support habitat recovery. Find out more about the planting trials. Katie Lee, Horticulture Supervisor at Salix with Open Day visitors Visitors at the Seagrass Nursery Open Day look out from the polytunnel over the outdoor ponds Katie Lee, Horticulture Supervisor at site partner Salix hosted a stand to discuss the work taking place on the wider site in Laugharne and Salix’s work to provide sustainable solutions to the challenges found in soil erosion control and river restoration projects. Seagrass meadows are havens of biodiversity, providing habitat, food, and shelter to thousands of species of fish, invertebrates, mammals, reptiles, and birds. Visitors also had the opportunity to experience the abundance of life within a seagrass meadow through Project Seagrass’ new VR experience. With music from the organisation’s patron Coldplay and footage from Welsh seagrass meadows, the experience provides an insight into the important role that seagrass plays for wildlife. Visitors had the opportunity to Project Seagrass’ VR experience “My Seagrass Adventure” A visitor explores UK seagrass meadows as part of the “My Seagrass Adventure” VR experience Project Seagrass is grateful for the support of our Seagrass Nursery funders who make this work possible.
Heat stress from marine heat waves can create a toxic relationship between seagrasses and a hidden ecosystem of bacteria, transforming a previously beneficial co-existence between marine plants and microbes into a harmful one, a University of Sydney and UNSW study has found. Seagrasses are marine flowering plants that act as fish nurseries, purify water and are crucial in coastal carbon storage. Their decline is often missed until it’s too late. The role soil microbes play in land plant health and climate resilience is well known. But for marine plants like seagrass, this science has largely been overlooked. “It’s worth paying attention to what happens in seagrass habitats as marine heat waves become more common. That information could be invaluable for conservation efforts,” said lead researcher Dr. Renske Jongen, from the School of Life and Environmental Sciences. In an underwater gardening experiment, biologists found a diverse bacterial ecosystem in the soil and around seagrass roots. The bacterial ecosystem was in a delicate balance, controlling the chemistry of the soil and seagrass health. Under increased water temperature, tiny bacteria living in the sediment among seagrass roots can reduce seagrass tolerance to climate change, stunting its growth and its ability to cope with heat stress. Higher temperatures favor bacterial species known to produce hydrogen sulfide, a compound toxic to seagrass, which may stunt seagrass growth. Plants previously exposed to warmer conditions suffer more from those changes in microbes. The researchers found seagrass growing in sediments from warm areas produces 34% less biomass when the natural sediment microbes weren’t disturbed. The findings show how bacterial communities are a hidden factor in recovering and restoring seagrass. “Just as microalgal symbionts (tiny organisms that rely on sunlight as energy) are key to the health of coral reefs, bacterial symbionts nestled at the roots and sediment of seagrasses can influence whether seagrass survives or declines,” said Dr. Jongen. “Even though seagrasses may look okay at first glance, what we’ve found below ground under increased temperature tells a different story.” Just as heat waves have hit terrestrial plants, marine heat waves have thinned out once lush and widespread seagrass meadows along the Australian coast. They are mainly found in shallow coastal waters and estuaries from tropical Queensland all the way down to the cool, temperate waters of Tasmania. Microbial communities also shape marine plants’ responses to environmental stress. Heat stress isn’t only about hot water. “Increased water temperatures dramatically change the ecosystem of microbes living among the seagrass roots and how microbes co-exist,” said senior author Associate Professor Ziggy Marzinelli from the University of Sydney. “Under heat stress, the microbial communities around seagrass roots shift in ways that can harm rather than help the plant.” How decades of industrial history created a real-world climate experiment In Myuna Bay in Lake Macquarie, history has created the perfect conditions for the research team to answer the question—”what would happen to seagrasses and microbes if water temperatures increased as projected by climate change models?” Since 1984, Eraring Power Station has continually fed a plume of warm estuarine water into the lake. This has made some of the lake waters up to three degrees warmer than ambient temperature for nearly four decades, mimicking both marine heat waves and what future oceans could be like along the Eastern Australia coast by 2090. “This has inadvertently created realistic conditions for the ultimate ‘gardening experiment’—for us to test how seagrass and below ground microbe health is shaped by exposure to higher-than-normal ocean temperatures,” said Dr. Jongen. “Locals are aware of the temperature increase in the area. It also has a reputation as a popular fishing spot because the hot water attracts a lot of fish species and everything from sharks to turtles have been seen here.” The research team transplanted Zostera muelleri, a species of sea grass native to coastal areas of Australia, into the lakebed. They also extracted and analyzed DNA to find the type of bacterial communities from the sediment and sediment from the seagrass roots to find how their composition changed at different temperatures. That was when they uncovered the change in bacterial communities and especially the relative increase of bacterial species that suppressed seagrass growth. “Our study highlights the overlooked role of microbes in tipping the balance in marine environments,” said Professor Paul Gribben from the University of New South Wales. “Seagrass restoration should not just focus on selecting species that are more heat tolerant, but also look deeper, below the ground surface—and, if needed, address microbial communities before transplanting or restoring seagrass meadows.” More information: This article is republished from Phys.org Read the research paper here: Ocean warming indirectly affects seagrass performance through effects on sediment microbial communities – Jongen – New Phytologist – Wiley Online Library
As our Fragment Walks from the 2025/26 season come to an end Project Seagrass Intern Anya Lamparelli reflects on this year’s efforts. A seagrass fragment is a precious and vulnerable thing. Torn free by winter storms and strong swells these delicate shoots with intricate root systems still attached wash ashore from subtidal seagrass meadows. If left stranded on the sand they will soon dry out, but on the Isle of Wight they are being given a second chance. Once a month at low tide, volunteers gather at Priory Bay, all eyes trained on the shoreline for a flash of green. Seagrass! Each fragment found is carefully collected and replanted into a growing community meadow. Since the initiative began three years ago 311 volunteers have joined the Project Seagrass team. Collecting 1,104 fragments over 16 fragment walks. 624 fragments have been replanted at Priory Bay, covering an area of 27 m2. Each month the volunteers revisit what they have already planted and monitor how the meadow is establishing, making field observations on what factors might be influencing its growth and survival. The remaining fragments have been replanted at the Seagrass Nursery in South West Wales; they will soon be used to support the team’s wider restoration work in the Solent. Fragment walks unfold under all conditions. Brilliant unbroken sunshine, pink sunsets, and cold grey mornings where the sky and sea blur into one. Yet the turnout remains steady, demonstrating the interest in and growing connection to seagrass meadows in the Solent. Many volunteers bring with them a deep lived knowledge of the coastline. They know how the beach shifts through the seasons, where sediment builds and erodes and when storms have reshaped the coast. This local insight has become an invaluable part of the project, helping guide where and how we replant seagrass. In turn, we can share our knowledge of ecosystem restoration and marine life. Creating a shared partnership where practitioners and locals learn from each other. Project Seagrass are working to restore 3.5 hectares of seagrass on the Isle of Wight as part of the Solent Seascape Project. Fragment walks allow us to trial new restoration methods while connecting with the local community. Thank you to every volunteer who has joined us in the Solent, we look forward to welcoming you back when the fragment walks restart in September 2026.
A new study of the British Isles’ coastal ecosystems has revealed that nitrogen enrichment is significantly reducing the abundance and variety of marine life. The research, published by scientists at Swansea University and the charity Project Seagrass, warns that increasing nutrient flows are overriding local habitat conditions to restructure and deplete coastal biodiversity. While the Planetary Boundaries for nitrogen and phosphorus flows have already been exceeded globally, this study provides a rare, large-scale assessment of how these nutrients impact the fine-scale diversity of our coastlines. Factors causing the pollution include sewage, agricultural waste, and poor land management. The study examined seagrass meadows in 16 different marine environments, including estuaries, lagoons, and islands. These ranged from the Orkneys Islands and the Firth of Forth to the Solent and the Island of Skomer. The findings were stark: higher nitrogen concentrations were consistently associated with a decrease in animal abundance and species richness. Specifically, the researchers found that an increase of nitrogen could correspond to an approximately 90 per cent decrease in the abundance of life per unit of available habitat area. “Eutrophication, the enrichment of water by nutrients, remains one of the most pressing environmental challenges in coastal waters, particularly regarding biodiversity loss,” said the authors. Key findings: Nitrogen as a driver: Nitrogen enrichment emerged as a consistent driver of biodiversity loss across the UK, even when accounting for the physical complexity of the environment; Habitat sensitivity: Coastal and lagoon environments showed the strongest declines under enhanced enrichment. In particular, phosphorus exhibited a devastating negative effect on life within lagoon environments; Site-specific impact: While some moderate enrichment was tolerated in specific estuarine settings, further enrichment in already impacted coastal sites exacerbated the loss of species; and, Beyond physical structure: Surprisingly, the physical traits of the marine vegetation (such as leaf length or biomass) had little influence on diversity compared to the overwhelming impact of local nutrient regimes. Crab in seagrass in Orkney Credit Lewis Jefferies Gastropods in seagrass. Credit Lewis Jefferies The researchers argue that current regional conservation targets may be insufficient. Because the effects of nutrients are “context-dependent,” effective management requires strategies tailored to the specific ecological conditions of a site. They concluded: “Our findings demonstrate that eutrophication alters biodiversity in complex ways. Effective management will require site-specific nutrient reduction and monitoring strategies that reflect local conditions rather than uniform regional targets.” The research was conducted by scientists from Swansea University, and Project Seagrass. The team used standardised sampling and mixed-effects modelling to isolate the drivers of biodiversity across the UK seascape. Read the research in full in Global Ecology and Conservation.
Residents and visitors to the Isle of Wight can now access information about the Island’s important seagrass habitats thanks to new signage installed through support from Seacology. The signage has been installed by Project Seagrass as part of ongoing efforts to protect and restore seagrass ecosystems within the Solent. The signs have been designed to raise awareness of seagrass meadows around the Isle of Wight in addition to highlighting ways that individuals can support these fragile ecosystems including through participation in Fragment Walks and uploading seagrass sightings to citizen science tool SeagrassSpotter. New seagrass signage installed at St Helen’s Duver Members of the Project Seagrass team installed new signage at locations on the Isle of Wight Two signs were installed in Seaview, the location of one of the Island’s extensive Zostera marina meadows and where Project Seagrass, Blue Parameters, and WarrenBoats have recently installed two Advanced Sustainable Mooring Systems (ASMS) to relieve pressure on the Island’s important seagrass habitats. A further sign has been installed at St Helens Duver, Priory Bay, the location of the start of our Fragment Walks and the site of one of our active restoration sites. Further poster versions of the signs will be installed at Ryde and other locations around the Island. Anouska Mendzil, Senior Science Officer at Project Seagrass and Swansea University said “The Isle of Wight is an UNESCO Biosphere Reserve, home to some of the most ecologically important marine and coastal habitats under threat – seagrass meadows. Across the Isle of Wight, new information signs now share the story of seagrass restoration and conservation, an effort led by Project Seagrass and the collective power of local community action, to contribute and enhance ecosystem recovery.” Seagrass signage installed at Seaview slipway Signage installed on the Southern Water building at St Helen’s Project Seagrass is grateful for the generous support from Seacology for making the creation and installation of these seagrass signs possible. Project Seagrass is also thankful to our stakeholders for their continued support and permission to install the signage.
Hannah Harrero and Stephanie Insalaco-Wyner, geographers from Florida, comment on differing methods of monitoring the resilience of seagrass meadows in Florida’s ‘Mosquito Lagoon’, following a number of extreme weather events. Florida’s Indian River Lagoon has been an ecosystem in decline going back to 2011, when harmful algal blooms led to a severe decline in seagrass, the foundational component of shallow coastal ecosystems. Seagrass meadows stabilize sediments, improve water clarity and provide critical habitat and forage for species ranging from invertebrates to sea turtles and manatees. Seagrass also generates a significant amount of economic activity in the state of Florida. The loss of seagrass in the Indian River Lagoon System undermined fisheries, tourism and wildlife, ultimately leading to the starvation of more than 1,200 manatees from 2020-25, peaking in 2021-22. Mosquito Lagoon is part of the Indian River Lagoon system that spans 28 miles (45 kilometers), running from Cape Canaveral in the south up to Ponce Inlet in the north. As in the rest of the lagoon system, years of nutrient pollution and recurring algal blooms had diminished seagrass cover to nearly zero by the early 2020s. By most accounts, Mosquito Lagoon had crossed a critical ecological tipping point. In the fall of 2022, hurricanes Ian and Nicole struck Florida’s east coast within six weeks of one another, bringing intense rainfall, storm surges and coastal erosion. In the immediate aftermath, seagrass declined even further. But a few months later, in the spring of 2023, seagrass began to return. Satellite imagery revealed rapid and widespread regrowth. Hannah and I are geographers who study environmental change. Our research documents this unexpected recovery and examines what it may reveal about ecosystem resilience in heavily degraded coastal systems. One of us, Hannah Herrero, is a Volusia County native who grew up around the lagoon. She returned to her hometown at the outset of the COVID-19 pandemic. It was there that some local guides and fishermen she’d known for years suggested that our team should use satellite imagery to look at the state of collapse in the lagoon. The study we designed as a result used satellite imagery and machine learning, a type of artificial intelligence that uses advanced algorithms to learn and predict patterns, to track seagrass dynamics in Mosquito Lagoon before, during and after the storms. This approach allowed us to observe change at a scale and frequency that is difficult to achieve using only traditional field survey methods. Florida Manatee Tracking seagrass from space Monitoring seagrass coverage “the old-fashioned way” involves going into the lagoon and laying out transects, straight lines that cut through a landscape, so standard observations could be recorded. We would then have to boat or wade all along those lines to measure seagrass extent and locations and create digital maps manually to show where it is present. As you can imagine, this is a time-intensive process that’s limited by how far you can boat or swim in a day, and by financial resources. So we decided to use satellite imagery instead. This method is not without its own challenges—water turbidity, or cloudiness, seasonal variability and the patchy nature of vegetation that grows on the bottom of the lagoon all make it difficult to observe seagrass growth directly on the imagery. To address this challenge, our study used imagery from NASA’s Harmonized Landsat–Sentinel program, which combines data from multiple satellites into a consistent record of photos of the same areas taken frequently over time. We analyzed imagery collected between September 2022 and January 2024, focusing on periods before and immediately after the hurricanes and throughout the subsequent recovery. We applied a type of machine learning model called Random Forest to classify each image into seagrass and nonseagrass categories. The machine learning algorithm is informed by training samples collected in the field, but once the model has learned the signature of seagrass, it is able to then apply the classification model to the rest of the lagoon and across time with limited human input. We can then validate this classification. Heading into the field First, we had to train the model using hundreds of GPS points collected in the field over multiple seasons. This step helps to ensure that satellite classifications align with on-the-ground conditions and are accurately interpreting the images. Over several weeks during the summers of 2020 through 2023, our team spent many hours navigating Mosquito Lagoon in a small skiff designed for shallow depths, recording seagrass presence. It wasn’t always easy — Florida summers are intensely hot and humid, and Mosquito Lagoon definitely lived up to its name. But we got to see a wide variety of wildlife, including manatees, dolphins, sea turtles and alligators. And occasionally, on lucky days, we even spotted a roseate spoonbill or reddish egret. Our experience in the field highlighted why this system matters: Mosquito Lagoon is a remarkably vibrant place, teeming with wildlife. These long days on the lagoon, surrounded by its biodiversity and immersed in its unique sense of place, are what anchor the remote sensing data to on-the-ground ecological conditions and make the resulting models credible. The authors wade into Mosquito Lagoon to track seagrass growth as they train their AI model. Captain William B. Wolfson, Grassroots Guide Service, New Smyrna Beach, FL What we found Our analysis reveals three distinct phases of seagrass coverage. First, seagrass declined sharply following hurricanes Ian and Nicole. By December 2022 and early 2023, satellite imagery showed virtually no detectable seagrass across the lagoon. Then, in March 2023, we identified a statistically significant shift. Seagrass began to reappear, initially in small, scattered patches. Finally, during late spring and summer 2023, seagrass expanded rapidly. By July 2023, it covered more than 20% of the lagoon—levels not observed in more than a decade. Coverage then declined again during the winter of 2023–24, as expected based on seasonal growth cycles. But even our last observation, completed in January 2024, showed seagrass covering 4.3% of the lagoon, substantially higher than pre-recovery levels during the winter season. In spring 2026, seagrass in Mosquito Lagoon has remained at stable levels. Although it still experiences fluctuations due to algal blooms, seasonality and other changes in the ecosystem, we have not seen a
Heidi McIlvenny, PhD researcher from Queen’s University Belfast, comments on seagrass meadows in Northern Ireland and how seagrass meadows can recover but only if we tackle the pollution at its source. I spent last summer wading through seagrass meadows across Northern Ireland, from the sheltered waters of Strangford Lough to the exposed coast at Waterfoot Bay. I was collecting seagrass leaves and testing them for nitrogen pollution. Every meadow I visited sits inside a marine protected area – a stretch of sea that’s been given legal protection to safeguard the wildlife living there. And every single one was polluted beyond the limit for healthy seagrass. Seagrass meadows are among the most valuable habitats in our coastal waters. They store carbon, nurture young fish and shellfish, stabilise sediment and buffer shorelines from storms. They are also woven into the heritage of coastal communities who have fished and foraged around them for generations. But they are disappearing worldwide, and nitrogen pollution from farming, sewage and urban runoff is one of the biggest reasons why. It’s easy to assume that designating an area as “protected” keeps the habitat inside it safe. My research shows that, for seagrass, this assumption is dangerously wrong. Physical protection from anchors and dredging means little when pollution flows freely across the boundary from the land. What matters most for seagrass is not lines drawn on a map, but what happens on shore. To understand how much nitrogen pollution seagrass is absorbing, we can measure nitrogen content in the leaves themselves. Seagrass continuously takes up nutrients from the surrounding water, so the chemistry of its tissue works like a long-term pollution record. And my results showed that every meadow in Northern Ireland exceeded the pollution limit. But knowing the pollution level is only useful if you know how much is too much, and what it means for the health of the meadow. To answer that, we pulled together data from 13 countries across the northern hemisphere and found a clear pattern. A catshark shelters among seagrass. Shannon Moran / Ocean Image Bank When nitrogen in the leaves rises above 1.8%, seagrass starts to suffer and loose plant growth. Above 2.8%, the decline accelerates rapidly, and in this danger zone small increases in pollution trigger disproportionately large plant losses. Think of it as a traffic light system: green is below 1.8% where meadows can cope; amber is between 1.8% and 2.8%, where managers should be watching closely and acting to reduce pollution; and red is above 2.8%, where urgent intervention is needed before the damage becomes irreversible. The starkest example of a meadow in the red zone comes from Dundrum Bay, on the County Down coast. According to government assessments, it’s healthy. But my data tells a different story. Nitrogen levels here were nearly double the pollution limit of 1.8%. Surveys over the past decade paint an even bleaker picture: where lush meadows once thrived, dense mats of green algae now smother what little remains. This meadow has likely crossed a tipping point, and may never recover even if we clean up the pollution. A few miles up the coast we see a very different picture. At Castle Espie, beside a wetland reserve in Strangford Lough, a seagrass meadow is thriving. The plants here belong to the same genetic population as struggling meadows elsewhere in the lough. But the difference is that the reserve’s reedbeds and willows act as natural filters, cleaning the water that runs from the land before it reaches the sea. The same species with the same level of marine protection, but dramatically different outcomes. The difference is what happens on land. But current monitoring methods aren’t designed to spot this kind of trouble before it’s too late. An early warning system Current monitoring methods tend to measure how much seagrass is still there. But by the time a meadow visibly shrinks, the damage may already be done. The tissue chemistry approach we used picks up stress signals much earlier, while there is still time to act. The nitrogen thresholds my research identifies could give environmental agencies a practical early warning system: meadows at or above 1.8% need closer watching, and those at or above 2.8% need urgent action to reduce nutrient pollution from catchments. Seagrass meadows can recover but only if we tackle the pollution at its source. That means better management of urban and agricultural runoff, investment in sewage treatment and recognising that marine conservation cannot stop at the high tide mark. If we lose these meadows, we lose their carbon stores, their fish nurseries, the coastal protection they provide, along with a piece of our coastal heritage. More information: This article is republished from The Conversation
Between the 17th and 23rd March 2026, members of the Project Seagrass team were on the Isle of Wight carrying out active restoration as part of the The Solent Seascape Project, the first project of its kind in the UK to initiate seascape-scale restoration. As part of The Solent Seascape Project, Project Seagrass is working to restore 3.5 hectares of seagrass in the Solent. During this spring’s planting efforts, the team planted 175,416 seagrass seeds using the Dispenser Injection Seeding (DIS) method and 1,154 seagrass transplants from our Seagrass Nursery, planting across an area of 0.77 hectares. Find out more about the activity that took place: Fragment Walk The March fieldwork efforts commenced with a Fragment Walk at Priory Bay. Fragment Walks are a community-based seagrass restoration initiative and form one of the approaches to active restoration that Project Seagrass is undertaking on the Isle of Wight as part of The Solent Seascape Project. Seagrass meadows are sensitive habitats which can be easily uprooted. As a result of storms or other disturbances, fragments of seagrass (individual seagrass plants with the rhizome or reproductive root and node system still intact) can become dislodged, uprooted, and washed up onto beaches. Fragment Walks involve collecting and re-planting these dislodged seagrass fragments, giving them another chance to thrive. During March’s Fragment Walk, the team were joined by 11 volunteers. Together, the group walked along the beach from St Helens to Priory Bay collecting over 100 dislodged seagrass fragments which were then re-planted in a dedicated seagrass community garden at Priory Bay. Over 100 seagrass fragments were collected at Priory Bay as part of March’s Fragment Walk. These were re-planted in a Community Garden at Priory Bay. 11 volunteers supported the activity, supporting active restoration on the Island. Planting Preparation Workshop One of the methods used for active seagrass restoration on the Isle of Wight is planting seagrass transplants. This year’s Planting Preparation Workshop took place at Sea View Yacht Club where 17 volunteers helped the team to prepare 1,154 transplants from the Project Seagrass Seagrass Nursery for planting out into the field. The preparation process for the transplants involves carefully attaching bamboo pins to seagrass rhizomes which provides them with increased stability when they are planted out into the field. March’s Planting Preparation Workshop took place at Seaview Yacht Club Seagrass transplants from the Project Seagrass Seagrass Nursery are prepared for planting out into the field by attaching bamboo pins to the rhizome Seagrass Planting Project Seagrass’ planting as part of The Solent Seascape Project is located at two Isle of Wight sites: Priory Bay and Thorness. Alongside the 1,154 seagrass transplants from the Project Seagrass Seagrass Nursery, the team planted 175,416 seagrass seeds across the sites using the Dispenser Injection Seeding (DIS) method, a method developed by The Fieldwork Company. This year’s seed planting incorporated experimental work to compare the germination success of subtidal and intertidal seed populations collected from Isle of Wight seagrass meadows in Yarmouth, Ryde, and Bembridge as part of last summer’s seagrass seed collections. Baseline measurements were taken at our experimental plots including drone images, pH, salinity, and sediment samples. This provenance experiment will help to inform where seeds are collected from for future restoration activity. Over the course of the fieldwork trip the team planting across an area of 0.77 hectares, an important step in the restoration of the Solent’s important seagrass habitats. Project Seagrass Nursery Manager Emily Yates plants seagrass at Thorness using the DIS method Project Seagrass Operations Lead Eve Uncles plants seagrass transplants from the Seagrass Nursery out into the field at Thorness
New research led by scientists at University of California’s San Diego’s Scripps Institution of Oceanography is shining a spotlight on one of the ocean’s most overlooked habitats: seagrass. Led by Scripps Oceanography Ph.D. candidate Rilee Sanders, the study documented the first successful restoration of open-coast seagrass (common eelgrass). The findings offer promising insight into the feasibility of restoring high-value coastal habitats in the future. The work is published in the journal Estuaries and Coasts. Seagrasses act as ecosystem engineers, creating complex underwater habitats that support life along the coast. Around the world, these habitats are increasingly threatened by climate change and human impacts like coastal development, invasive species and overfishing. While most West Coast seagrass research has focused on protected bays and estuaries, this study focused on open-coast areas off Catalina Island. Drawing on nearly a decade’s worth of surveys, the team examined everything from seagrass structure to fish communities and ocean conditions to identify where restoration might succeed. Juvenile señorita (Oxyjulis californica) utilize the protective canopy of the open-coast seagrass restoration site at Button Shell, Catalina Island. Credit Adam ObazaPaua Marine Research Group Two bat rays (Myliobatis californica) soaring over an open-coast eelgrass (Zostera marina) bed on Catalina Island. Credit Adam ObazaPaua Marine Research Group The results were encouraging, as the researchers completed the first transplant of open-coast common eelgrass (also known as Zostera marina). Within a year, the restored site began functioning like a natural meadow, supporting fish communities and ecosystem structure, and by year two, it was even healthier and more biodiverse than natural reference meadows. “Seagrasses are kind of an unsung hero of nearshore ocean habitats,” said Sanders. “They provide nursery habitat for young fish, store carbon in sediments and support immense biodiversity in places that might otherwise be sandy seafloor. Being able to quickly restore that structure and function on the open coast is really exciting.” The findings suggest that open-coast environments could become a valuable new tool for seagrass restoration and conservation in California, especially as coastal development and climate change reduce the available suitable habitat in bays and estuaries. And sometimes restoration has surprising benefits. During monitoring, researchers even captured images of an endangered sea turtle visiting the restored meadow. In short: if we plant seagrass, the ecosystem may follow. More information: This article is republished from PHYS.ORG and provided by the University of California – San Diego. Rilee D. Sanders et al, Open-Coast Eelgrass (Zostera marina) Transplant Catalyzes Rapid Mirroring of Structure and Function of Extant Eelgrasses, Estuaries and Coasts (2025). DOI: 10.1007/s12237-025-01609-x
