Fauna return rapidly in planted seagrass meadows, study shows
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
Why saving the world’s seagrass is part of the most important to-do list in the history of humankind
“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 Glimmer of Hope for Seagrass in the Wakatobi National Park?
Back in December 2015 I spent a couple of weeks in the Wakatobi, Indonesia, initiating phase II of the Wakatobi Seagrass Program. This seeks to build on work carried out though a previous project “Recognising the role of seagrass meadows in food security: re-prioritising the marine conservation agenda” (2011-2014), which was conducted in the same location. That project evidenced the direct economic value and food security potential of seagrass meadows and prompted local government and community stakeholders to place seagrass on their conservation agendas for the first time. The Wakatobi project demonstrated how seagrass associated species provide an essential source of protein and income to the vast majority of people in the region. We provided evidence of the links between seagrass and food security and highlighted that these currently expansive ecosystems remain largely ignored within formal legal or environmental management frameworks, even within an MPA at the heart of the Coral Triangle. Seagrass meadows provide an essential source of protein and income to the vast majority of people in the region. The outputs from the first project are being used to drive forward discussions between local stakeholders to bring about change. And although their value is somewhat recognised in the Wakatobi, these expansive ecosystems are threatened by a myriad of anthropogenic activities. The host of threats at play within the Wakatobi range from mangrove destruction to overfishing and aren’t going to disappear overnight. Phase II of the Wakatobi Seagrass Program seeks to work on these threats through local, community level action, and devising strategies to work with formed the basis of my trip. Seagrass meadows across the Wakatobi are threatened by a host of factors. Overfishing has left many meadows lifeless. As communications developed with our local partner, FORKANI, it seemed clear that one of the issues they felt was dominant, was the issue of run-off. Terrestrial run-off causes huge problems for seagrass through both sedimentation and eutrophication, and as the destruction of mangroves (15% of mangrove forest has been destroyed by local community members seeking firewood and construction materials) and forest areas continues, the ability for land to absorb and store water lessens. Given this, FORKANI proposed an exciting idea to rehabilitate both mangrove and forest areas around rivers in 3 key villages, not only to reduce impact on seagrass but to improve the continually worsening problem of water storage on the island of Kaledupa. However, with so much forest now converted to palm plantations, choosing areas to rehabilitate wasn’t going to be an easy task, and choosing areas that were key was even harder. FORKANI were amazingly resourceful when it came to the practicalities of choosing locations, mapping each river in a way that made it easy to pin point areas that needed the most work. Sometimes working the old fashioned was has its perks, and the relative ease in which they categorised each river was efficient and effective. FORKANI have now chosen areas to rehabilitate and are currently working on preparing the areas and seedlings, while also beginning to monitor seagrass in front of each village to track their own progress. Conducting river mapping was efficient and effective and allowed FORKANI to choose key areas for rehabilitation Even though discussions were productive, overfishing is still the “elephant in the room” that nobody wants to talk about. Although dynamite and cyanide fishing are now almost absent across the national park, at least that’s what we’re told, the unsustainable removal of juvenile fish is still a widespread issue. Fish fences, or “sero” as they are locally called, are one of the biggest issues facing the Wakatobi National Park and tentative UNESCO World Heritage Site. These fish fences, scar’s upon the face of the park’s beauty, fish 24/7 and, as we’ve discovered, are not only restricted to seagrass meadows. Fish fences have left both reefs and seagrasses looking like barren wastelands. Fishing 24/7. The Sero are non selective and never stop fishing Tackling the overfishing problem will take time, but by tapping into the past, we can begin to improve the future of the Wakatobi’s coastal fisheries. For centuries, isolated communities across the globe have respected a delicate balance with the ocean — taking fish only from certain areas, of certain sizes and with specific methods to maintain a healthy ecosystem and supply of fish for present and future. Now, with two key fishing villages keen to work on adopting community managed no-take areas there is some serious hope for the future. This solution, which builds on and adapts successful fisheries management techniques, provides a win-win for coupled socio-ecological systems, protecting fishers wellbeing as well as the health of marine ecosystems. Systems like this, that are well-managed, result in more fish — and not just by a few. By adopting this formula, and continually managing their fishery, communities can expect to see a potential increase of up to 56 percent in fish abundance and a potential increase in yield of up to 40%. In 2006, then Indonesian President Susilo Bambang Yudhoyono made a hugely ambitious promise to conserve a “global epicentre of marine life abundance and diversity”, stating that Indonesia would preserve 10 million hectares of ocean lying in the Coral Triangle. In 2009, he doubled this commitment to 20 million hectares by 2020. The the 1.39 million hectare Wakatobi National Park contributes to the 16.6 million hectares already protected – but given the status of seagrasses and the vast overfishing problem, serious questions about the meaning ‘protected’ arise. Is the Wakatobi destined to become a site of World Heritage value or just a wasteland? The Wakatobi’s communities are centre to answering this question. Although their sense of ownership always has been present, with these proposed mitigation measures being taken a little more seriously by communities, its clear that with a little motivation the people of Kaledupa can be tremendously proactive. This gives us a glimmer of hope for seagrass in this dynamic region of the world. The future of the Wakatobi is dependent on its communities, yet the
Restoring our Damaged Seagrass Meadows
When you think about areas requiring bold initiatives to protect the environment, the small Welsh costal village of Porthdinllaen might not be the first place that comes to mind, and with only two dozen buildings and a miniscule population you might find it surprising that the environment there is under threat. Porthdinllaen is a part of a marine conservation area called Pen Llŷn a’r Sarnau Special Area of Conservation (SAC) which extends from Nefyn, on the north coast of the Llŷn, to Clarach, about a mile north of Aberystwyth. The presence of seagrass within the SAC is one of the reasons the area is so special. Due to its location, sheltered from all but north-easterly winds, Porthdinllaen is the perfect place for seagrass to grow and as such the seagrass meadow there is thought to be the largest and densest in Wales covering an area the size of 46 football pitches. However, its natural sheltered location also makes it an ideal natural harbour, and it is here where the problems lie. The sheltered harbour, the only such haven on the Llŷn Peninsula, has been used for many centuries as a place to run to for shelter in a storm offering safe anchorage. It is now a lively, but small fishing port with around 90 moorings, each of which is having a negative effect on the seagrass meadow. Damage of boat moorings within the seagrass meadow at Porthidinllaen It’s estimated that around 10% of the seagrass at Porthdinllaen has been lost due to moorings alone, but moorings aren’t the only problem. Anchoring within the seagrass meadow is also a common sight. By far the biggest concern within the extensive intertidal seagrass meadows of the site are tractors and 4×4 vehicles, which routinely cross the seagrass to retrieve the fishermen’s catch. These issues fragment the seagrass causing it to become patchy and no longer a continuous area of habitat for fish. Fragmented meadows are more vulnerable to the effects of erosion. Tractor damage to the Porthdinllaen seagrass meadow Not all doom and gloom! Its not all doom and gloom though, Project Seagrass has now begun the first ever seagrass restoration trial in Wales with the hope of developing a novel method to restore our damaged seagrass meadows and consequently help support our declining fisheries. Interest in seagrass restoration in the UK is increasing as the value of seagrass ecosystems is recognized by scientists, managers and regulators. However, despite this interest action remains limited. The UK Biodiversity Action Plan for seagrass beds specifically details the restoration of 1000 hectares of seagrass during 1997-2010. Transplantation trials in the 1980’s, the early 1990’s and in the last two years were carried out around the south coast of England, but with little success in the long-term. No seagrass in the UK has been restored to date. Seagrass seeds ready for sorting During our 2015 summer SeagrassWatch survey we collected a number of Zostera marina shoots laden with seeds. Having let the seeds harden and mature within their seed pods in the aquaria at Swansea University we then sorted the seeds and placed them into hessian bags, ready for planting. During our autumn 2015 SeagrassWatch survey we buried these bags in areas of bare sediment and will check the progress during our 2016 winter, spring, summer and autumn surveys. Despite some poor survey conditions, we planted over 1,500 seeds. If this trial is successful we hope to continue and expand the restoration trial across Wales introducing seeds from other areas to create a genetic mix that allows for hardier and more resilient seagrass meadows in the face of environmental stresses, such as climate change. Planting the hessian bags at Porthinllaen