Dr Richard Unsworth, Chief Scientific Officer at Project Seagrass, along with 35 other leading scientists from across the UK, responds to proposals from the UK government to make licensing for marine restoration more complex and costly. Dear Rt Hon Steve Reed OBE MP and team, This letter sets out our
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Sea hares are odd looking creatures. They are mostly soft bodied but have a small internal shell, which separates them from their close relatives – sea slugs. The
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Cuttlefish are molluscs and join squid and octopuses in the Cephalopod family. Predominantly found in temperate and tropical areas, 120 species can be found around the world. Cuttlefish
Around the archipelago of Orkney, are some of the UK’s most pristine seagrass meadows. With numerous sheltered bays, low numbers of inhabitants, and crystal-clear waters, Orkney’s shores provide the ideal conditions for seagrass. However, much remains unknown about these important ecosystems. The Highland Park funded Sjogras Partnership was established to
Artificial reefs might help to restore the ocean’s ability to fight against climate change. The reefs boost the productivity of seagrass meadows by attracting fish, which can improve the ability of these habitats to lock up more carbon dioxide beneath the waves. Breeze blocks placed in one of the ocean’s
For approximately 3,000 years, generations of green sea turtles have returned to the same seagrass meadows to eat. This was discovered by Willemien de Kock, a historical ecologist at the University of Groningen, by combining modern data with archaeological findings. Sea turtles migrate between specific breeding places and eating places
Discussions of valuable but threatened ocean ecosystems often focus on coral reefs or coastal mangrove forests. Seagrass meadows get a lot less attention, even though they provide wide-ranging services to society and store lots of climate-warming carbon. But the findings of a new University of Michigan-led study show that seagrass
A study of eelgrass meadows planted by researchers from the University of Gothenburg shows that fauna return rapidly once the eelgrass has started to grow. Already after the second summer, the biodiversity in the planted meadow was almost the same as in old established eelgrass meadows. Eelgrass meadows have declined
“The downward trajectory of the world’s seagrass meadows must be reversed if we are to fight the planetary crisis” say leading seagrass scientists. The United Nations Sustainable Development Goals have recently been described as “the most important to-do list in the history of humankind”. Scientists from Project Seagrass and Swansea
A new study shows that seagrass fisheries provide a reliable safety-net for poor fishermen, since they perceive those habitats to maintain large fish catches over time. Surprisingly, even more so than coral reef fisheries, which people normally associate with small-scale fishery. Seagrass meadows are routinely used as a fishing habitat
Dr Richard Unsworth, Chief Scientific Officer at Project Seagrass, along with 35 other leading scientists from across the UK, responds to proposals from the UK government to make licensing for marine restoration more complex and costly. Dear Rt Hon Steve Reed OBE MP and team, This letter sets out our response as leading scientists, practitioners, and NGOs to the DEFRA consultation “Marine licences: changes to fees, exemptions and self-service licences”. We believe the proposed increases in fees and restrictions for marine licences will seriously undermine restoration efforts, making an already difficult activity even more challenging and, in many cases, unviable. The current licensing system for marine restoration is already unjust and fundamentally at odds with the UK Government’s national and international commitments. To introduce additional fees, administrative burdens, and restrictions at this time is, quite frankly, perverse. We specifically oppose: Any increase in fees for marine restoration licences. The urgent need is to remove fees entirely, not add to them. Further restrictions and additional charges on marine restoration projects larger than 5 hectares (we need marine restoration exemptions from this). Evidence clearly shows that scaling up restoration delivers greater resilience and enhanced ecosystem service (natural capital) benefits compared with small, fragmented projects. We specifically request: Practitioners need DEFRA to create a simplified, consistent, cost-free, and science-based licensing system for marine and coastal conservation. Currently, licensing is one of the most significant barriers to restoring the health of the UK’s seas. We see these proposed changes under the consultation as a missed opportunity to create such a system. The urgency could not be greater. Our climate and natural systems are breaking down, and the ocean is in crisis. In each of the last three summers (2023–2025), UK seas have endured unprecedented marine heatwaves. Never before has there been such a critical need for healthy coastal ecosystems that can bolster resilience, buffer climate impacts, and support food security. Yet our habitats have been decimated and continue to decline with DEFRA’s own assessment concluding that the UK marine environment is failing on 13 out of 15 indicators. Marine restoration is not optional; it is essential for our collective future. Restoring and conserving ocean habitats is also a legal obligation. The UK is a signatory to the Kunming–Montreal Global Biodiversity Framework and, under the Environment Act 2021, has binding targets for nature recovery. These commitments require all public bodies, including seabed owners to conserve and enhance biodiversity. The UK has already missed the Aichi Biodiversity Targets, largely due to regulatory barriers of the very kind now being proposed. Repeating these mistakes would be indefensible. The benefits of a streamlined licensing system are profound. It would enhance our capacity to tackle the climate and biodiversity crises, strengthen coastal resilience, and improve national food security. International examples demonstrate that simplified frameworks accelerate recovery and generate long-term ecological and social benefits. At conferences such as ReMeMaRe, UKSS, and the Seascape Conference, frustration with England’s current licensing regime has been a recurring theme. The system is widely regarded as unpredictable, inconsistent, costly, and burdensome, treating restoration projects as if they damage rather than enhance the marine environment. This not only delays urgent work but risks deterring vital investment in ocean recovery. The state of our marine environment illustrates the scale of the problem: estuaries are degraded, mudflats retreating, saltmarshes fragmented, and most seagrass meadows lost. Remaining habitats are scarce and highly vulnerable to climate change. Immediate reform is essential. Wales and Scotland are already moving in the right direction. Dialogue and regulatory reforms are creating enabling environments for restoration. England must now do the same. Without urgent change, regulation will remain a barrier to the large-scale environmental renewal that is desperately needed. We no longer have healthy ecosystems to use as restoration baselines. Historic habitats such as oyster reefs have vanished, while global heating accelerates ecological change. Restoration must therefore look forward, building climate-resilient ecosystems that reflect future needs rather than only past states. To do so, we need a legal and regulatory framework that supports ambition. The Kunming–Montreal Framework and the Environment Act 2021 require bold action, but these targets cannot be met without enabling legislation. In addition to the consequences of further restrictions on marine restoration for biodiversity, we also believe these restrictions place further restrictions upon our ability to reach Net Zero, and therefore see this as an issue not only for DEFRA but also for DESNZ. We therefore call on the Government to act swiftly to reform the licensing system for marine and coastal restoration. This is a practical and achievable step that would deliver immediate benefits for biodiversity, climate resilience, and food security. As scientists and practitioners at the forefront of UK marine research and restoration, we would welcome the opportunity to meet with you and your team to discuss solutions and pathways for progress. Yours sincerely, Dr Richard Unsworth FRSB, FHEA Associate Professor (Swansea University), Chief Scientific Officer (Project Seagrass) Signed on behalf of the following: Prof Martin J Attrill, Professor of Marine Ecology, University of Plymouth Dr Dan Barrios-O’Neill, Head of Marine Conservation, Cornwall Wildlife Trust Prof Michael Chadwick, King’s College London Sarah Chatfield, Nature Recovery Partnership Manager, Chichester Harbour Conservancy Dr Leanne Cullen-Unsworth, Chief Executive, Project Seagrass Dr Aline da Silva Cerqueira, Sussex Bay & King’s College London Dr Tim Ferrero, Senior Specialist – Hampshire & Isle of Wight Wildlife Trust Zia Fikardos, Marine Policy Officer, Royal Society for the Protection of Birds (RSPB) Angus Garbutt, Principal Scientist, UK Centre for Ecology & Hydrology Chris Graham, Head of Ocean Regeneration, Marine Conservation Society Tom Godfrey, Founder, Earth Change Dr Ian Hendy, Coastal Ecologist, Senior Lecturer, University of Portsmouth Chloë James, Seagrass Project Officer, Cornwall Wildlife Trust Prof Chris Laing, University of Exeter Dr Sally Little, Nottingham Trent University Louise MacCallum, Solent Seascape Project Manager, Blue Marine Foundation Niall McGrath, CEO, Robocean Ltd. Anouska Mendzil, Senior Science Officer, Project Seagrass & Swansea University Nigel Mortimer, Estuaries Officer, South Devon National Landscape Estuaries Partnership Dr Simon J. Pittman, School of Geography
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Sea hares are odd looking creatures. They are mostly soft bodied but have a small internal shell, which separates them from their close relatives – sea slugs. The sea hare gets it name from the two rhinophores sticking out from the top of the head as they look like the ears of hares. However, these appendages aren’t used for hearing, but for taste and smell. A sea hare’s favourite snack is seaweed, but they also eat seagrass. Interestingly, the colour of the seaweed species most prominent in their diet influences the colour of the sea hare individual, for example: diets made from mostly sea lettuce will lead to a green body colour and reddish-maroon sea hares will be eating mostly red seaweeds. Sea Hare on seagrass. Photo Credit Lewis M Jefferies A Sea Hare within an Orcadian seagrass meadow. Photo Credit Lewis M Jefferies When threatened, they can produce a cloud of ink which the sea hare can hide in to confuse predators. Scientists have found that this ink has antibacterial properties, thought to be useful in healing wounds and combating harmful bacteria. Additionally, they can produce a slime on their skin which makes the sea hare less tasty and puts predators off from eating it. Sea hare species can range from 2 to 70cm, but the ones found around the UK – Aplysia punctata or dotted sea hare – are on the smaller size of 7 – 8cm and can be found throughout the year in rock pools and shallow waters. They lay their eggs in long string-like structures attached to seagrass, with the seagrass meadow acting as a nursery environment when the eggs hatch. They are hermaphrodites, meaning individuals have both male and female mating organs. Despite this, they still reproduce with others, usually in a line with multiple individuals. Sea Hares in seagrass As well as seaweeds, sea hares will consume seagrasses too. As with many marine species, seagrass meadows provide an important nursery habitat. By attaching developing eggs to seagrass leaves, the eggs are protected from strong currents and predators, as well as providing a food source for newly hatched sea hares. Some species, such as the Phyllaplysia taylori or eelgrass hare, live solely on seagrass. Evidence has shown presence of sea hares increases seagrass productivity as a result of grazing on epiphytes on the leaves. A build-up of too many epiphytes will block the leaves ability to photosynthesize, so these little creatures can be very handy for us seagrass scientists! Sea Hare (with egg strings) on a blade of seagrass. Photo credit Lewis M Jefferies But do sea hares benefit society? Yes! They form an important part of diets around the world. For example, in Hawaii, people wrap the sea hare in to leaves and cook it in an underground oven, called an imu. In the Philippines, egg strands, known as lokot, are eaten raw with vinegar and spices. Samoa, Kiribati and Fuji also have sea hares as part of the traditional diet. Often it is women that will go out and collect the sea hares at low tide on mudflats and seagrass meadows and then sell them at markets, so sea hares have an important economic benefit to these societies too. For further information about how grazers such as the sea hare are beneficial to seagrass, look at this article.
In a new blog series, our Conservation Trainee Abi David explores some of the amazing creatures that call seagrass meadows their home. Cuttlefish are molluscs and join squid and octopuses in the Cephalopod family. Predominantly found in temperate and tropical areas, 120 species can be found around the world. Cuttlefish have an internal shell, known as the cuttlebone, which helps with buoyancy. By changing the gas to liquid ration, they can determine how much they float. Their diet generally consists of small molluscs, crabs, shrimp, small fish, octopuses and worms. To catch their prey, they use suckers attached to their two tentacles, which shoot out and grab unsuspecting victims. The flamboyant cuttlefish (Metasepia pfefferi) even uses venom to subdue its prey. To escape predators themselves, they can propel themselves forwards or backwards by expelling a powerful jet of water from their mantle cavity (main body). Cuttlefish in seagrass, Cornwall, UK. Credit Shannon Moran Ocean Image Bank Cuttlefish. Credit François Baelen Ocean Image Bank Like other cephalopods, cuttlefish have quite sophisticated eyes. They have two spots of highly concentrated sensor cells on their retinas – meaning they can look both forwards and backwards at the same time. This ability is aided by their W- shaped pupil, giving them a wide field of vision. It is thought cuttlefish eyes are fully developed before hatching, enabling them to begin observing their environment whilst still in the egg. Part of why I love cuttlefish so much is their ability to change colour using skin cells called chromatophores. They do this by expanding and contracting these cells to resemble colours and patterns found within their environment for camouflage and warning off predators. I could go on a lot more about this amazing ability, but this article by Gilmore, Crook, & Krans, gives a nice, detailed overview. So how do they utilise seagrass? Seagrass is an important habitat for cuttlefish. Many other creatures such as crabs, worms and snails call seagrass home, basically providing them with an all you can eat buffet. Additionally, like many other species, cuttlefish lay eggs on seagrass leaves as meadows provide a sheltered environment safe from currents and tides that may wash eggs away. Once these eggs have hatched, seagrass meadows provide a safe nursery site from predators. Cuttlefish eggs in seagrass, Dale, West Wales Why do we need cuttlefish? As with every other species on the planet, cuttlefish have their own unique purpose in the ecosystem. They are predators of a variety of species, meaning they help control populations – which is important to maintain a healthy ecosystem balance. They themselves are prey for commercial fish species such as Atlantic cod. In parts of the Mediterranean, Asia, and Europe, they provide an important part of human diets. Cuttlefish are, in my opinion, a hugely underrated species. Not only are they super cool with their colour changing abilities, but they are also an important part of many habitats and ecosystems across the globe. More information: Gilmore, R., Crook, R. & Krans, J. L. (2016) Cephalopod Camouflage: Cells and Organs of the Skin. Nature Education 9(2):1
Around the archipelago of Orkney, are some of the UK’s most pristine seagrass meadows. With numerous sheltered bays, low numbers of inhabitants, and crystal-clear waters, Orkney’s shores provide the ideal conditions for seagrass. However, much remains unknown about these important ecosystems. The Highland Park funded Sjogras Partnership was established to bridge these knowledge gaps. Now in its fourth year, Professor Joanne Porter’s MSc International Marine Science students from Heriot Watt University Orkney and Dr. Elizabeth Lacey and Dr. Calum Hoad from environmental charity Project Seagrass have focused on developing our scientific understanding of the pristine seagrass meadows found around Orkney’s shores, with mapping and quantifying the ecosystem services provided by Orcadian seagrass being top priorities. Often referred to as ‘marine powerhouses’, seagrass meadows can provide numerous benefits for the surrounding environment. Havens of biodiversity, they provide habitat, food, and shelter to thousands of species of fish, invertebrates, mammals, reptiles, and birds. As important fishing grounds, seagrass meadows provide access to food sources and support the livelihoods of millions of people around the world. Seagrass meadows can also trap carbon within the seabed and, if left undisturbed, can store this for millennia. Locating and mapping Orcadian meadows enables local protection, while gathering data to understand these habitats furthers seagrass science, impacting broader understanding and wider conservation efforts. Year 1 | 2022 During the first year of the partnership, then Heriot Watt University student Katy Waring set out to develop methods to assess the ecosystem services provided by seagrass around Orkney. This involved surveying seagrass meadows around Orkney’s shores using Baited Remote Underwater Videos (BRUVs), a non-invasive research tool, to collect data. Katy worked with local engineering firm Hamnavoe Engineering to design and develop the BRUVs and deployed them off Stronsay’s shoreline in the bay of Franks during the 2022 survey. This research provided evidence of the vital ecosystem service that Orcadian seagrass plays in providing habitats and spawning grounds to a variety of marine species, including Pollock and Atlantic Cod. Year 2 | 2023 In year two, then student Oliver Lee supported Dr Esther Thomsen of Project Seagrass to map seagrass meadows using a WINGTRA drone. Building on Katy’s research, Oliver went on to further document the biodiversity within Orcadian seagrass meadows through subtidal surveys at Mill Bay, Stronsay and at Tankerness, Orkney mainland. His research found an abundance of species inhabiting Orkney’s seagrass – further emphasising the significant role that these meadows have for the marine environment. Year 3 | 2024 Year 3 of the partnership supported the research of then students, Emily Powers and Emma Retson. Emily undertook surveys to understand variances of biodiversity in seagrass beds around the Isles. Her research explored how species diversity may be impacted by abiotic factors (such as seabed depth and tidal current flow) and found a higher richness of biodiversity in beds exposed to high tidal ranges and stronger tidal streams. Emma’s research focused on comparing infauna (animals living in the sediment beneath the seafloor) data from different sites and the influence of seagrass density on this. Sediment samples were extracted to enable the biodiversity associated within the sediment to be quantified. Local Stromness based expert Inga Williamson of Biotikos Ltd providing taxonomic expertise in identification of the infaunal organisms. Looking ahead In the summer months of 2025, the Sjograss Partnership will continue working together to better understand the health and extent of Orkney’s seagrass. This year, Dr. Elizabeth Lacey plans to establish ‘sentinel’ sites around the Orkney archipelago. These sites will be chosen to represent the characteristics of seagrass habitats across the islands. By routinely monitoring the sentinel sites into the future, the Sjograss Partnership will improve our picture of the dynamics and drivers of seagrass health in Orkney. In turn, this understanding could help us understand how and why seagrass is changing across Scotland. Within these sentinel sites, HWU PhD candidate Millie Brown is working on ecosystem services (carbon sequestration) of blue carbon habitat mosaics, as part of her SMMR funded scholarship research and MSc project student Alisha Underwood will be studying properties of the sediment associated with seagrass at Finstown and Tankerness. In addition, as part of setting up the sentinel sites, Dr. Calum Hoad from Project Seagrass will be experimenting with high-tech methods for mapping the extent of each seagrass meadow. In the water, the team will use a remotely controlled boat to capture echosounder data. In the air, the team will use sophisticated sensors attached to drones to take thousands of images of the seagrass meadows. From space, satellites will take pictures of Orkney every few days while the team is on the ground. By combining all of these types of data with data collected by hand (and snorkel!), the team will map the sentinel seagrass meadows of Orkney. Examining the strengths and weaknesses of each data source will help the team think about how best to map seagrass across the rest of Orkney, Scotland, and the UK. Hear more in person and get involved! The Sjogras Partnership will be working at seagrass meadows across Orkney from 19th July until 1st August. There are a few opportunities to meet the team in person, to learn more about seagrass, and even to see some seagrass in person: Renewables Revolution Open Day, 2-5pm on 23 July 2025, at the Orkney Research and Innovation Centre, where the Sjogras Partnership will be showcasing Orkney’s seagrass. A guided snorkel over a local seagrass meadow near Kirkwall on Sunday 27th July. Sign up will be necessary and spaces limited. The Orkney International Science Festival Family Day, 10-12.30 and 1-3pm on 6th September, at the Pickaquoy Centre, Kirkwall, where Project Seagrass and the local Heriot Watt team will be ready to talk all about seagrass science. We hope to see you there!
Artificial reefs might help to restore the ocean’s ability to fight against climate change. The reefs boost the productivity of seagrass meadows by attracting fish, which can improve the ability of these habitats to lock up more carbon dioxide beneath the waves. Breeze blocks placed in one of the ocean’s most endangered habitats provide an unexpected lift for fish. Seagrass meadows are found across the world, reaching from the tropics up into the lower reaches of the Arctic circle. They are incredibly valuable habitats, providing a nursery for young fish as well as sucking vast quantities of carbon dioxide from the atmosphere. However, with an area of seagrass the size of a football pitch being lost every 30 minutes, it’s more important than ever to find out how to turn things around. A new study in the Caribbean has shown that artificial reefs can help to bolster their growth in the tropics, even as threats such as fishing and nutrient pollution continue. Dr Jacob Allgeier, a co-author of the paper, says, ‘By attracting fish, whose faeces provide concentrated nutrients for the seagrass, the artificial reefs increase the primary production of the entire ecosystem.’ ‘We are now investigating how this cascades up the food web. The new energy has to go somewhere, so we are quantifying how it affects invertebrates and fish with our evidence suggesting that it is fuelling increases in both.’ The findings of the study were published in Proceedings of the Royal Society B. Artificial reefs and seagrass One of the biggest issues affecting seagrass is nutrient pollution, often from the release of human sewage. While the influx of nutrients can initially boost the growth of the meadows, it also promotes the growth of algae which reduces the amount of sunlight getting to the seagrass and harms it in the long run. Alongside fishing which causes levels of the fish faeces that fertilise the meadows to drop, it was thought that the combination of these two issues might work in unexpected ways to hinder the growth of seagrass. But the current study has revealed some surprising results. It has found that the productivity of seagrass in both disturbed and undisturbed meadows was increased by the presence of an artificial reef, while algae didn’t actually seem to pose an issue, even in areas where nutrient pollution was high. Mona Andskog, the PhD student who led the research, explains, ‘Artificial reefs built in seagrass create a positive feedback loop. They attract fish that use the reefs for shelter which, in turn, supply new nutrients from their faeces that fertilise the seagrass around the reef.’ ‘This increased primary production can increase invertebrate production by providing more food and shelter for invertebrates, which in turn provide more food for fishes.’ Experiments in Haiti, at some of the most fished sites included in the study, also showed that the artificial reefs were providing additional benefits to the fish. Large numbers of small fish were found at the site because of the difficulty in using nets around the reef, meaning that the overall biomass of fish was at times larger than in unfished areas measured elsewhere in the study. While artificial reefs present a promising option for tropical seagrasses, they’re likely to have a much more limited impact on temperate meadows. These waters already tend to have higher nutrient levels, meaning that any contribution the reef would made to overall growth would be small. The scientists now hope to explore how the placing of artificial reefs can affect seagrass ecosystems, as well as expanding their research to the Dominican Republic. ‘We will be testing how different configurations of artificial reef clusters can affect the production and fish community composition,’ Jacob says. ‘This includes the number of artificial reefs in each cluster, as well as their arrangement.’ ‘As with this research, we hope to simultaneously use the reefs to test fundamental questions about production in these highly impacted ecosystems as well as optimising the positive feedback that is initiated by the artificial reefs.’ More information: Mona A. Andskog et al, Seagrass production around artificial reefs is resistant to human stressors, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2023.0803 This story is republished courtesy of Natural History Museum. Read the original story here.
For approximately 3,000 years, generations of green sea turtles have returned to the same seagrass meadows to eat. This was discovered by Willemien de Kock, a historical ecologist at the University of Groningen, by combining modern data with archaeological findings. Sea turtles migrate between specific breeding places and eating places throughout their lives–this much was known. But the fact that this stretches over many generations highlights the importance of protecting seagrass meadows along the coasts of North Africa. The results were published in PNAS on July 17. When young green sea turtles hatch, their parents have already left for a long journey. The little turtles clumsily make their way off the beach into the ocean and, not yet able to navigate the long migration of their parents, float around for years. During this time, they are not very picky eaters, omnivores even. Then, at about five years of age, they swim to the same area where their parents went, to eat a herbivore’s diet of seagrass. Along the coasts of the eastern Mediterranean Sea, volunteers are active to protect the nests of the endangered green sea turtles. However, as Willemien de Kock explains, “We currently spend a lot of effort protecting the babies but not the place where they spend most of their time: the seagrass meadows.” And crucially, these seagrass meadows are suffering from the effects of the climate crisis. Analyzing sea turtle bones In the attic of the Groningen Institute of Archaeology at the University of Groningen, De Kock had access to boxes full of sea turtle remains from archaeological sites in the Mediterranean Sea area. The excavations were already done by her supervisor, Dr. Canan Çakırlar. “All I had to do was dig in some boxes,” De Kock says. By analyzing the bones, De Kock was able to distinguish two species within the collection of bones: the green sea turtle and the loggerhead turtle. De Kock was also able to identify what the sea turtles had been eating. This relied on a substance called bone collagen. By inspecting the bone collagen with a mass spectrometer, De Kock could detect what kind of plants the sea turtles must have eaten. “For instance,” De Kock explains, “one plant might contain more of the lighter carbon-12 than another plant, which contains more of the heavier carbon-13. Because carbon does not change when it is digested, we can detect what ratio of carbon is present in the bones and infer the diet from that.” Combining old and new Modern satellite tracking data from the University of Exeter then provided De Kock with information on the current traveling routes and destinations of sea turtles. Researchers from Exeter had also been taking tiny samples of sea turtles’ skins, which revealed similar dietary information as De Kock found in bones. De Kock was, therefore, able to draw conclusions, connecting diets of millennia ago to specific locations. She found that for approximately 3,000 years, generations of green sea turtles have been feeding on sea grass meadows along the coasts of Egypt and West Libya. The results for loggerhead turtles were less specific because they had a more varied diet. So, why is it relevant to know the eating habits of a species over many past generations? Because we collectively suffer from the shifting baseline syndrome: slow changes in a larger system, such as an animal population, go unnoticed because each generation of researchers redefines what the natural state was, as they saw it at the start of their careers. “Even long-term data goes back only about 100 years,” says De Kock. “But tracing back further in time using archaeological data allows us to better see human-induced effects on the environment. And it allows us to predict, a bit.” In fact, recent models have shown a high risk of widespread loss of seagrass in precisely these spots where green sea turtles have been going for millennia. This could be detrimental to the green sea turtle, precisely because of its high fidelity to these places. More information: de Kock, Willemien, Threatened North African seagrass meadows have supported green turtle populations for millennia, Proceedings of the National Academy of Sciences(2023). DOI: 10.1073/pnas.2220747120 Story provided by University of Groningen
Discussions of valuable but threatened ocean ecosystems often focus on coral reefs or coastal mangrove forests. Seagrass meadows get a lot less attention, even though they provide wide-ranging services to society and store lots of climate-warming carbon. But the findings of a new University of Michigan-led study show that seagrass ecosystems deserve to be at the forefront of the global conservation agenda, according to the authors. It’s the first study to put a dollar value on the many services—from storm protection to fish habitat to carbon storage—provided by seagrasses across the Caribbean, and the numbers are impressive. Using newly available satellite data, the researchers estimate that the Caribbean holds up to half the world’s seagrass meadows by surface area, and it contains about one-third of the carbon stored in seagrasses worldwide. They calculated that Caribbean seagrasses provide about $255 billion in services to society annually, including $88.3 billion in carbon storage. In the Bahamas alone, the ecosystem services provided by seagrasses are valued at more than 15 times the country’s 2020 gross domestic product, according to the study published online June 21 in the journal Biology Letters. “Our study is the first to show that seagrass beds in the Caribbean are of global importance in their areal extent, in the amount of carbon they store, and in the value of the economic services they provide to society,” said study lead author Bridget Shayka, a doctoral student in the U-M Department of Ecology and Evolutionary Biology. “The findings underscore the importance of conserving and protecting these highly threatened and globally important ecosystems, which are critical allies in the fight against climate change.” One way to prioritize seagrass conservation would be to include those verdant undersea meadows in global carbon markets through projects that minimize loss, increase areal extent or restore degraded beds. The idea of selling “blue carbon” offset credits, which monetize carbon stored in coastal and marine ecosystems, is gaining traction for several reasons. For one, many island nations that have already been impacted by climate change—through increasingly intense hurricanes or rising sea levels, for example—have large areas of valuable coastal ecosystems that store carbon and that provide other services to society. Blue carbon (the name refers specifically to carbon stored in coastal and open-ocean ecosystems while “green carbon” refers more broadly to carbon stored in all natural ecosystems) offset credits could be a way for wealthier countries to compensate for their contribution to human-caused climate change while at the same time benefiting the economies of impacted countries and helping to conserve coastal ecosystems, which are among the most impaired in the world. Threats to seagrass meadows include coastal development, chemical pollution, recreation, shipping and climate change. “Because seagrass ecosystems are both highly important for carbon storage and sequestration, and are highly degraded globally, they represent an important burgeoning market for blue carbon,” said marine ecologist and study senior author Jacob Allgeier, an associate professor in the U-M Department of Ecology and Evolutionary Biology. “Yet, to date, a fundamental impediment to both evaluating seagrass and promoting it in the blue carbon market has been the lack of thorough seagrass distribution data.” For their study, the U-M-led team used newly available seagrass distribution data collected by the PlanetScope constellation of small DOVE satellites. They classified Caribbean seagrass ecosystems as either sparse or dense and estimated the amount of carbon in plants and sediments using data from Thalassia testudinum, the dominant seagrass species in the region. The researchers then calculated a conservative economic value for the total ecosystem services provided by seagrasses in the Caribbean and for the stored carbon, using previously published estimates for the value of services including food production, nursery habitat for fishes and invertebrates, recreation and carbon storage. Grouper, queen conch and lobster are among the commercially harvested animals that rely on Caribbean seagrass. Green sea turtles, tiger sharks and manatees also depend on it. To estimate the dollar value of the carbon stored in Caribbean seagrass beds, the researchers used $18 per metric ton of carbon dioxide equivalents, borrowed from California’s cap and trade program. In addition to Caribbean-wide estimates, the researchers calculated values for individual countries in the region: The Bahamas has the largest share of Caribbean seagrass (61%), providing total ecosystem services valued at $156 billion annually, including $54 billion in carbon storage. Cuba ranks second in areal seagrass coverage (33% of the Caribbean total), with a value of $84.6 billion per year for all ecosystem services, including $29.3 billion for carbon storage. The dollar value of the carbon in seagrasses around Cuba is equivalent to 27% of the country’s 2020 GDP. “Importantly, the degradation of seagrass beds often leads to erosion and sediment resuspension, which can create a positive feedback of increased seagrass loss and the release of C stored in sediments,” the authors wrote. “Blue carbon finance thus represents a potential mechanism by which the global community can invest in conserving and protecting these vital ecosystems.” More than 60 species of seagrasses grow in shallow coastal waters around the world. They evolved from land plants that recolonized the oceans 70 to 100 million years ago. In a separate paper accepted for publication in the journal Proceedings of the Royal Society, Allgeier and colleagues show that the construction of artificial reefs in the Caribbean can help protect seagrass ecosystems from human impacts, including nutrient pollution and overfishing. Seagrasses use photosynthesis to pull carbon dioxide from the atmosphere, then store the carbon in plant tissues. The seagrasses are quickly inundated by sediments, slowing decomposition. As a result, more than 90% of the carbon stored in seagrass beds is in the top meter of sediment. Caribbean seagrasses and associated sediments store an estimated 1.3 billion metric tons of carbon, according to the new study. That’s a big number, but it’s just 1.09% of the carbon contained in above- and below-ground woody biomass in the Amazon, and just 1.12% of the carbon in the biomass and soils of the world’s temperate forests, according to the new
A study of eelgrass meadows planted by researchers from the University of Gothenburg shows that fauna return rapidly once the eelgrass has started to grow. Already after the second summer, the biodiversity in the planted meadow was almost the same as in old established eelgrass meadows. Eelgrass meadows have declined heavily in southern Bohus county in recent decades and in many places have disappeared altogether. Researchers at the University of Gothenburg have been working on the restoration of eelgrass meadows for twelve years. These meadows are important for biodiversity, as the eelgrass serves as habitat or nursery for young cod, crabs and shrimps for example. In a new study, the researchers have evaluated how rapidly replanted eelgrass gets populated by various invertebrates. The study has been going on for over two years in a bay near Gåsö island just west of Skaftö in Bohus county, and the findings are very positive. The researchers counted the abundance of invertebrates that live or burrow in bottom sediments or on the surface of bottom sediments. Size less important “The recolonization has been very rapid. After the first three-month growing season, up to 80 percent of the invertebrates had returned to the newly planted eelgrass,” says Eduardo Infantes, marine biologist at the University of Gothenburg. During the summer in 2019, the researchers planted the eelgrass shoots in four test plots of different sizes on the seabed, and with different spacing between the shoots. According to the researchers’ observations in autumn 2020, size has played less of a role in the recovery of biodiversity in the eelgrass meadows. In fact, even if the eelgrass has not had time to grow to the same density as in an established eelgrass meadow, the biodiversity is similar after only two growing seasons as in a reference area of preserved eelgrass in the same bay. Even smaller patches embedded within larger restoration plots showed good results. Their findings were reported in the journal Restoration Ecology. Can save money “This is good news for future restorations and new plantings of eelgrass meadows. We can plant new smaller plots with fewer shoots and this saves money because this is an expensive method for restoring biodiversity on the seabed,” says Eduardo Infantes. Eelgrass meadows have multiple functions that make it imperative to protect them. In addition to their important role in the coastal ecosystem, eelgrass roots bind the sediment and prevent erosion and limit resuspension of sediment in the water. More information: Karine Gagnon et al, Rapid faunal colonization and recovery of biodiversity and functional diversity following eelgrass restoration, Restoration Ecology (2023). DOI: 10.1111/rec.13887
“The downward trajectory of the world’s seagrass meadows must be reversed if we are to fight the planetary crisis” say leading seagrass scientists. The United Nations Sustainable Development Goals have recently been described as “the most important to-do list in the history of humankind”. Scientists from Project Seagrass and Swansea University have this week published a unique review that demonstrates how this “To-Do List” of Sustainable Development Goals provides a blueprint for achieving the net recovery of seagrass ecosystems. Conserving and restoring seagrass meadows contributes to achieving 16 out of the 17 Sustainable Development Goals. Recognising this wide role of seagrass meadows in helping achieve humanity’s ‘to-do list’ and thinking beyond their value in carbon sequestration and storage is critical to achieving the recovery of these degraded ecosystems. The call for urgent action comes after a review into the status of seagrass ecosystems and the major ecological role that they play in the coastal environment published in the leading academic journal Science and written by experts at the marine conservation charity Project Seagrass and Swansea University. Seagrass meadows are being increasingly looked to as a climate solution. However, seagrass ecosystems are sensitive to stressors and remain threatened across the globe. These degraded seagrass ecosystems are less effective at supporting biodiversity and tackling climate change. The authors state “Society needs to create meaningful pathways to net gain at local to global scales. Bold steps are needed through improved legal instruments to halt damaging factors such as bottom trawling, prevent use of damaging boating activities and to apportion responsibility for poor water quality that is causing the slow death of seagrass globally”. By recognising that seagrass meadows contribute to finding solutions to global problems such as food insecurity, water quality, wellbeing and gender equality, as well as the more well known issue such as biodiversity loss and climate change there becomes a more holistic view as to the benefits of taking large cumulative levels of action at local, regional and global scales. We need local and regional authorities to create a baseline of where seagrasses are now, where they used to be and where in the future they could be allowed to recover and be restored to get seagrass on the path to recovery. This needs to occur within the next decade if we are to fight climate change, to fight the biodiversity crisis, protect our coastlines and maintain global food security. Richard Unsworth (lead author) said “The world needs to rethink the management of our coastal environment that includes realistic compensation and mitigation schemes that not only prevent damage, but also drive the restoration, enhancement and creation of seagrass habitat. We also need a major shift in how we perceive the status of our marine environment by examining historical information, not just recent ecological baselines”. Ben Jones, a fellow author of the study added, “It is vital to work collaboratively as it is only through utilising scientific environmental studies and working as cogs in a global partnership for seagrass that meaningful change can happen”. Seagrass conservation faces substantial ecological, social and regulatory barriers and requires strong cross-sectoral partnerships to be put on the path to recovery. Identifying the solutions to seagrass conservation and restoration has never been more urgent and is critical to fight the planetary emergency. This can be achieved by using the Sustainable Development Goals as a blueprint towards recovery. Read the paper here.
A new study shows that seagrass fisheries provide a reliable safety-net for poor fishermen, since they perceive those habitats to maintain large fish catches over time. Surprisingly, even more so than coral reef fisheries, which people normally associate with small-scale fishery. Seagrass meadows are routinely used as a fishing habitat across the Indo-Pacific region to sustain millions of households by providing fish and other animals for food and income from fishing. A new study in Ocean and Coastal Management investigated how and why households use seagrass meadows across Cambodia, Tanzania, Sri Lanka and Indonesia in the Indo-Pacific region by conducting interviews that asked what habitats they used and which they preferred. Benjamin Jones, director of Project Seagrass and PhD student at the Department of Ecology Environment and Plant Sciences, Stockholm University, says: “Seagrass was the most common habitat used for fishing. Nearly half of all households we talked to preferred fishing in seagrass over other habitats such as coral, mangroves, open ocean, mud and rock for example. This was surprising because most people think of reef fisheries as the key tropical small-scale fishery, but we show that its actually engagement in seagrass fisheries that are much more characteristic of households.” When the researchers asked the fishermen why they preferred seagrass, they expressed a general feeling of reliability: seagrass meadows always provide large catches and fish and invertebrates are always found there. This is likely due to the ecological role that seagrass meadows play for fish. They provide valuable nursery habitats with lots of places for fish to hide and grow which means that there is often a high abundance of fish present. The study also revealed that 3 in 20 people across the region were reliant on seagrass meadows as their fishing ground and did not fish anywhere else. The research from households in 147 villages also revealed that reliance on seagrass meadows was strongly influenced by household income: “Household income had two different effects. On one hand, poorer households were less likely to own motorboats. These were reliant on seagrass as they were unable to fish elsewhere, seagrass is close to shore and easy to access without a motor. On the other hand, wealthier households were more likely to own certain types of fishing gear that incentivized them to use seagrass due to high rewards and low effort requirements. These were static fishing fences that don’t require a fisherman to be present” says Benjamin Jones. Study co-author and fellow Project Seagrass director Leanne Cullen-Unsworth, says “Our results highlight the need for empirical household scale data for management of seagrass meadows. People use and value seagrass for many different reasons so safeguarding seagrass is vital to ensure that all people, all of the time, have equitable and equal access to the resources seagrass provides.” The study was a collaboration between scientists from Stockholm University, Project Seagrass, Swansea University, Uppsala University, Hasanuddin University, among others. Open Access paper: Jones, B.L.H.; Unsworth, R.K.F.; Nordlund, L.M.; Eklöf, J.S.; Ambo-Rappe, R.; Carly, F.; Jiddawi, N.S.; La Nafie, Y.A.; Udagedara, S.; Cullen-Unsworth, L.C. Dependence on seagrass fisheries governed by household income and adaptive capacity. Ocean & Coastal Management 2022, 225, doi:10.1016/j.ocecoaman.2022.106247.
