Seagrass meadows play a critical role in keeping our oceans healthy and stocked with food, providing valuable nursery habitat to over 1/5th of the world’s largest 25 fisheries. Seagrass meadows are also important to small-scale fisheries, particularly as a place to find and collect a reliable source of food with some
196 of the world’s nations are committed under the Kunming-Montreal Global Biodiversity Framework to tackling nature loss. Habitat restoration is a major pathway to tackling this loss. For marine habitats such as seagrass, such restoration is often portrayed as an easy answer to fighting many of our planetary ills causing
“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
Mosquito nets designed to prevent malaria transmission are used for fishing which may devastate tropical coastal ecosystems, according to a new scientific study. The researchers found that most of the fish caught using mosquito nets were smaller than a finger and potentially collect hundreds of individuals. Malaria is a serious
Seafood consumption is both a love and a necessity for hundreds of millions of people all across the world. And the supply of seafood is a key part of maintaining food security for the whole planet. But as demand for seafood is increasing, stocks of wild fish and invertebrates (such
At least 7.3m tons of fish (usually dead or dying) are thought to be discarded each year from marine fisheries around the world. But these estimates come mostly from observations of large-scale industrial fisheries. Limited attention has been paid to small-scale fisheries, which are assumed to have low discard rates –
Britain’s seagrass is a refuge for numerous species of fish, stabilises sandy beaches, and helps to lock away the carbon which humans produce. The meadows that surround the country’s coast have been called the “canaries of the sea”, due to their sensitivity to a changing environment. And like a canary
Fishing in seagrass occurs around the globe; if there is seagrass (and people) there is fishing. Still, the nature and extent of fisheries in seagrass is poorly understood. It is a prerequisite for natural resource management to understand resource exploitation, therefore we decided to investigate this further. Seagrasses are plants that
Seagrass meadows play a critical role in keeping our oceans healthy and stocked with food, providing valuable nursery habitat to over 1/5th of the world’s largest 25 fisheries. Seagrass meadows are also important to small-scale fisheries, particularly as a place to find and collect a reliable source of food with some countries (e.g., Indonesia) seeing up to 60% of coastal populations dependant on seagrass for access to food. However, fisheries are more than just sources of food—they are also lifelines for millions of people worldwide, underpinning livelihoods, culture, and well-being. Yet despite their important role, managing these resources, especially in the face of climate change and overfishing, is becoming harder due to a lack of solid data. This is where Indigenous and Local Knowledge (ILK) could support Fisheries Science. A recent study undertaken by Project Seagrass systematically reviewed 397 fisheries-related research articles and revealed that Indigenous and local communities hold key insights into the ecosystems they live in. Indigenous and local communities have often been fishing in their local areas for generations and possess detailed knowledge about species behaviour, habitats, and environmental changes which could fill significant gaps in formal scientific research. The Problem: Gaps Between Indigenous and Local Knowledge and Scientific KnowledgeWhile the scientific community acknowledges the importance of ILK, a large challenge remains: ILK is largely qualitative, based on observations and traditions, whereas fisheries management is based on quantitative data—numbers, charts, and models. Despite efforts to utilise information from scientific knowledge and ILK, the integration has been slow with many studies still viewing ILK as something that needs to be validated through scientific data. The Solution: A New Approach to Fisheries Research The research highlights the need for more collaborative methods to enhance Fisheries Management by integrating ILK and scientific knowledge. Rather than simply comparing Indigenous and Local Knowledge to scientific data, we should view these knowledge systems as complementary. ILK can inform fish population trends, help establish marine protected areas, and guide sustainable fishing practices with a greater chance of success. What’s Next? Moving Towards Integrated Fisheries Management It is crucial to respect both Indigenous and Local Knowledge and scientific knowledge as equally valid. By intertwining these knowledge systems, we can build a more holistic and effective approach to fisheries management, ensuring that the voices of Indigenous and local communities are heard and their knowledge utilized. The next wave of fisheries science should aim to bridge the gap between data-driven science and the rich, qualitative insights from those who know the waters best. The future of sustainable fisheries management depends on it. More information: Jones et al, New directions for Indigenous and local knowledge research and application in fisheries science: Lessons from a systematic review. Fish and Fisheries (2024) DOI: https://doi.org/10.1111/faf.12831 Explore our blog for insights on the latest research from across the globe. Click here
196 of the world’s nations are committed under the Kunming-Montreal Global Biodiversity Framework to tackling nature loss. Habitat restoration is a major pathway to tackling this loss. For marine habitats such as seagrass, such restoration is often portrayed as an easy answer to fighting many of our planetary ills causing this nature loss. But as evidence grows of the issues and challenges of such activities, scientists from Project Seagrass and Swansea University have outlined ten golden rules to help improve this restoration. Their work is published today in an Open Access article in the journal Plants People Planet. The article responds to the increasing pressures faced by seagrass ecosystems globally and the need to rapidly rebuild marine life. The authors highlight throughout that in order to restore our ocean biodiversity, we first need to focus on reducing the stressors to these habitats, namely water quality, boating and coastal development. The authors who have been studying seagrass conservation and restoration argue for a shift beyond a singularised view of restoration as being about planting new meadows to a combined view where damaged and fragmented meadows are rejuvenated; threatened and diminishing meadows are protected; and more meadows become resilient. The rules confirm the need for collaborative approaches to restoration which create biodiverse ecosystems that support coastal communities and improve communities. Dr Richard Unsworth, lead author on the paper who is the Chief Scientific Officer at Project Seagrass and Associate Professor at Swansea University said, “To rebuild marine life at the scale and speed required to fight the biodiversity crisis and the climate emergency we need to think bigger, whereby we bring degraded habitats back to life at the same time as creating vast new habitat in support of coastal livelihoods, and community resilience” The paper has been published following the International Seagrass Biology Workshop (ISBW15) hosted in Naples, Italy earlier this year, the theme of this which was “Seagrasses in the Anthropocene”. As human activities place ever-increasing pressure on seagrass ecosystems at both a local and global scale the resulting changes in environmental conditions have altered seagrass ecosystems to an extent that has not previously been observed. The challenge currently facing the global community is the need to establish a new baseline and protect, restore, and rehabilitate the seagrass ecosystems that currently remain. Dr Benjamin Jones, Chief Conservation Officer at Project Seagrass and author of the paper says: “Coastal environments suffer from excess nutrients and contaminants from poor land management, deforestation and ineffective pollution management. If we are to place seagrass on a pathway to global net gain, for restoration to have any meaningful contribution, we also need to think about restoring watersheds and thinking upstream – restoring the land to restore the sea”. The ten golden rules originally developed by Unsworth and Jones for seagrass restoration, and outlined below, aim to ensure that existing seagrass is protected, that multiple and diverse stakeholders are involved in planning to support the selection of appropriate sites and ongoing stewardship, that appropriate restoration methods are utilized, and that realism is adopted in the face of the challenges surrounding global restoration efforts particularly in light of ongoing climatic pressure. Dr Leanne Cullen-Unsworth, CEO at Project Seagrass and an author of the paper says: “Fantastic progress is being made in the field of conservation and restoration of seagrass meadows, but in order for this to happen at the scale and speed required, we wanted to set out a series of holistic guidelines, based on available research and experience, that practitioners can follow for improved chances of success.” 10 Golden Rules for restoration to secure resilient and just seagrass social-ecological systems (set out in detail below) Protect existing seagrass first Work together Create biodiverse ecosystems with multiple functions for people and planet Select appropriate sites for restoration Determine appropriate restoration methods Use resilient plant materials and future proof your project Maximize the potential opportunity of the restoration Plan ahead for infrastructure, capacity, and restoration material Develop realistic informed goals and reporting Make it pay 10 Golden Rules (Detailed summary of the paper) 1. Protect existing seagrass first Amidst the context of growing interest in seagrass restoration, the authors emphasize that it is much slower, more difficult, and more expensive to re-plant seagrass meadows than it is to protect those that currently remain. Protection from localized stressors can relieve pressure on our existing seagrass be this through the implementation of improved water quality from better catchment management, reduced boating damage, establishment of Marine Protected Areas or through the encouragement of alternative low-impact livelihoods, tourism, and fishing practices. The authors also outline the need to prioritise which seagrass meadows to protect taking into consideration predicted future climatic conditions such as changing temperatures, sea level rise, land use change, and the gradual topicalization of temperate systems. 2. Work together Restoration is a collaborative process and the authors discuss the importance of the involvement of multiple and diverse stakeholders, expertise, and experience throughout all stages of the restoration process. Seagrass social-ecological systems support diverse uses and livelihoods, from fishing and recreation, to harvesting of raw plant material. Rights and equality are central, and stakeholders should be encouraged to continue activities, not just undisturbed, but enhanced by increased seagrass resilience. Engaging local communities and stakeholders during the site selection period is essential as these groups will often become the long-term custodians of the restoration site. Without working together, long-term seagrass restoration at scale is simply not possible and finding ways to bring people together to co-design restoration projects will enhance the social capital of resulting habitats. 3. Create biodiverse ecosystems with multiple functions for people and planet The overarching aim of seagrass restoration should be to maximise the biomass and biodiversity of meadows such that they support diverse and resilient ecosystem functioning and services for people and planet. The authors discuss how natural systems simultaneously produce multiple ecosystem services that interrelate in complex and dynamic ways. An overly narrow focus on a limited set of ecosystem services can lead to
“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.
Mosquito nets designed to prevent malaria transmission are used for fishing which may devastate tropical coastal ecosystems, according to a new scientific study. The researchers found that most of the fish caught using mosquito nets were smaller than a finger and potentially collect hundreds of individuals. Malaria is a serious global health issue, killing nearly half a million people every year worldwide. Aid organisations like the Bill and Melinda Gates Foundation have invested in solutions to solve the crisis such as distributing hundreds of thousands of bed nets to protect people from mosquito bites carrying the virus. “Distributed mosquito nets are intended to be used for malaria protection, yet communities living in poverty use them for fishing, providing fresh concerns for already overfished coastal ecosystems, says,” Benjamin Jones, a director of Project Seagrass and PhD researcher at Stockholm University Department of Ecology, Environment and Plant Sciences. There are few studies that investigate how much fish mosquito-net fishing potentially harvests, although the use of mosquito nets for fishing is not a new phenomenon: “No evidence on the sheer amount of fish that these fisheries extract has been published that we are aware of. Gaining an understanding of these catches is vital if we are to manage such fisheries,” says Benjamin Jones. In Mozambique, each sweep of the mosquito net caught more than half of the average daily catch (2.4 kg a day) using traditional nets, by weight. But many of the fishes were very small, which means mosquito net fishers who cast their nets many times each day are removing a huge number juvenile fish to eat. Many of the species caught are important for food in the region when adults or help keep the seagrass ecosystems where they are found healthy. “The use of mosquito nets for fishing may contribute to less food availability, greater poverty and the loss of ecosystem functioning,” concludes Dr Richard Unsworth, a co-author and Lecturer in Marine Biology at Swansea University. Finding a solution to the problem is incredibly hard, but the researchers suggest the need for marine scientists, social scientists, health professionals and fishing communities to all work together. Laws imposed from governments make the use of mosquito nets for fishing illegal in some localities, however, such mechanisms are evidently insufficient because people still need food and “need re-thinking” according to the study. “We need to know why communities aren’t using these nets for intended use, and therefore we have to involve them, so they can be part of developing solutions to these challenges,” says Richard Unsworth. The team collected data at seagrass meadows by ten coastal villages in northern Mozambique. Identifying each fish species, the researchers recorded the weight of each fish group and the total catch, as well as age and where they are positioned in the food web. The open access paper – “The perverse fisheries consequences of mosquito net malaria prophylaxis in East Africa” – is published on Monday 11th November at https://doi.org/10.1007/s13280-019-01280-0
Seafood consumption is both a love and a necessity for hundreds of millions of people all across the world. And the supply of seafood is a key part of maintaining food security for the whole planet. But as demand for seafood is increasing, stocks of wild fish and invertebrates (such as mussels and prawns) are declining. A major problem is that policies and plans designed to ensure the sustainability of our fisheries almost exclusively target fishing activity. But we also need to protect the critical habitats that these fisheries also depend on. Most species that are fished require more than one habitat to complete their lifecycles. For example Atlantic cod (Gadus morhua) spends its adult life shoaling in deep water, but juveniles require more stable habitat where they can hide such as seagrass meadows. So, if we want to manage stocks for sustainability, it is essential to protect the supporting habitats of targeted species. Seagrass meadows are a critical habitat supporting biodiversity and in turn the productivity of the world’s fisheries. Seagrass meadows are not only suitable for juvenile fish but also for larger fish of different species. As seagrass meadows occur in shallow, clear waters, they are an easily exploitable fishing habitat. Today, we published the first quantitative global evidence on the significant roles that seagrasses play in world fisheries . Seagrass as nursery grounds: provide a safer, less exposed, environment for eggs to be laid and young animals to find food and protection from predators as they grow. This includes commercial species such as tiger prawns, conch, Atlantic cod and white spotted spinefoot. In fact, one-fifth of the world’s most landed fish — including Atlantic Cod and Walleye Pollock benefit from the persistence of extensive seagrass meadows. Seagrass as a fishing area: it is not just large scale fishing industries that benefit from the presence of seagrass meadows. They are an easily accessible fishing ground used by small scale artisanal and subsistence fisheries around the world. Seagrass gleaning: seagrass is also essential habitat for gleaning activity, fishing for invertebrates such as sea cucumbers in water that is shallow enough to walk in. This is often done by women and children, and provides a source of essential protein and income for some of the most vulnerable people in tropical coastal communities. It is a common and increasingly visible activity, but it is not usually included in fishery statistics and rarely considered in resource management strategies. Seagrass supports other fisheries: seagrass also provides trophic support to other fisheries. They do this by creating expansive areas rich in fauna, from which there are vast quantities of living material, organic matter and associated animal biomass that supports other fisheries. Seagrasses also promote the health of connected habitats (like coral reefs), and have the capacity to support whole food webs in deep sea fisheries. Threats to seagrass, fisheries and food security: the coastal distribution of seagrass means that it is vulnerable to a multitude of land and sea derived threats. These include land runoff, coastal development, boating activity and trawling. On a global scale, seagrass is rapidly declining and when seagrass is lost associated fisheries and their stocks are likely to become compromised with profound and negative economic consequences. Seagrass meadows support global fisheries production Pdf Supporting policy and action is needed now! The importance of seagrass meadows for fisheries productivity and hence food security is not reflected by the policies currently in place. Urgent action is needed if we want to continue enjoying the benefits that healthy and productive seagrass meadows provide. Fisheries management must be broadened from just targeting fishing activity to also targeting the habitats on which fisheries depend. Awareness of the role of seagrass in global fisheries production, and associated food security, must be central to policy, and major manageable threats to seagrass, such as declining water quality, must be dealt with. Action is urgently needed to protect the worlds seagrass meadows if we are to continue to enjoy the benefits they provide.
At least 7.3m tons of fish (usually dead or dying) are thought to be discarded each year from marine fisheries around the world. But these estimates come mostly from observations of large-scale industrial fisheries. Limited attention has been paid to small-scale fisheries, which are assumed to have low discard rates – some estimate as little as 3.7% total catch, compared to more than 60% for some large-scale shrimp trawlers. Small-scale or artisanal fisheries – for which there is no universal definition – are generally considered more sustainable than their large-scale industrial counterparts, but there is increasing evidence that shows this is not always the case. They employ more than 99% of the world’s 51m fishers and likely account for more than half of the total global fisheries catches. A Sri Lankan fisherman. One of the biggest problems for both large and small-scale fisheries around the globe is bycatch – fish and other marine organisms caught when the fishers are targeting something else. Powerful images of turtles and dolphins caught in fishing gear have caught the sympathy of the general public, but unintentional landings of fish aren’t as evocative. The truth is, however, that fish bycatch is a big issue. Progress is being made in Europe within large-scale fisheries thanks to campaigns such as the Fish Fight. But small-scale fisheries – though there is increasing recognition outside that they are “too big to ignore” – are only just beginning to recognise the fish bycatch and discard problem. Catch and bycatch. Our newly published research has found that artisanal fisheries in Sri Lanka are throwing away more marine species than they keep. For every fishing trip in one of Sri Lanka’s largest lagoons, Puttalam Lagoon, fishermen could be throwing away more than 50 fish. What’s more, of the 62 species recorded in the survey, more than 80% were routinely discarded. The reasons for this practice are unclear but sometimes it is because the individual fish are too small – or they are species without a high market value. We found that fishers targeting shrimp in particular caught more non-target species and had higher discards than those targeting fish. This is particularly worrying at a time when Sri Lankan shrimp exports are increasing, after the EU granted the country improved access to its market. Fishers in Puttalam Lagoon discard non-target catch onshore. Potentially 90% of the world’s fish stocks are threatened by over-fishing – when more fish are caught than the population can replace. And the “tell-tale” signs of over-fishing are now being observed in Sri Lanka and across other research sites in the Indo-Pacific region. Fishers in these locations have told us and other researchers that they are catching much less fish than they were five years ago. But this is not just an ecological issue, it is a social one too. In this era of increasing food insecurity, our findings highlight a serious concern for Sri Lanka. This unwanted seafood could be used to provide protein for the poorest in society. Instead, we found that fish with high nutritional value is being eaten by feral dogs and birds. Unwanted fish end up as quick and easy meals for animals. Billions of people worldwide rely daily on fish for protein, while 50m people also rely on catching fish for work. But, if the levels of bycatch and discard continue, the livelihoods and food security of the people that depend on these fisheries will be under threat. If the problem is not managed, there won’t be any fish left in the waters. There is one ray of hope for Sri Lanka, however. There are some small-scale fishery cooperatives which maximise long-term community benefits by dealing with the threats of fisheries mismanagement, livelihood insecurity and poverty. Communities with successful and inclusive cooperatives are better off than those without. Cooperatives have the potential to empower small-scale fishers against environmental and socioeconomic shocks, but the problem in Puttalam Lagoon is that these cooperatives are not operating across all levels of society. Fishing cooperatives do exist, but there could be more. If the bycatch and discards issue is going to be solved over the long-term, we need to look at combining sustainable management practices with community schemes to reduce unnecessary seafood waste all over the world. Together the millions of small-scale fishers all over the world have an immense amount of power, they just need to realise it. This article was originally published on The Conversation. Read the original article.
Britain’s seagrass is a refuge for numerous species of fish, stabilises sandy beaches, and helps to lock away the carbon which humans produce. The meadows that surround the country’s coast have been called the “canaries of the sea”, due to their sensitivity to a changing environment. And like a canary in a coal mine, their health can be used as an indicator of the condition of coastal areas. We know that the seagrass meadows surrounding the UK are in a perilous state of decline, and our recently published research has now uncovered one of the biggest causes. Our study suggests that a major driver of seagrass decline is nutrient pollution from sewage and livestock waste. Though a new finding, it sadly comes as no surprise, given that about 40% of rivers in England and Wales are polluted with sewage. This nutrient pollution puts the long term viability of seagrass meadows in doubt. Over-enrichment results in the suffocation of seagrass. The nutrients cause microscopic algae – called epiphytes – to smother the seagrass leaves, decreasing their ability to capture light, ultimately killing them, and destroying the habitat for fish and other marine animals. Â The seagrass, Zostera marina, covered in epiphytes. In addition to this environmental impact, we found that several areas, including the Thames waterway seagrass, and a meadow in Studland Bay, Dorset – which are popular with swimmers and boaters – were considerably enriched in nutrients from sewage, livestock effluent and/or human waste. Despite this, neither location, nor any other we identified with the same problem, were classed as unsuitable for swimmers. Outdated treatment Clearly, we have a massive problem at hand – but water companies, farmers and the government have not done and are still not doing enough to prevent it. Though efforts have been made to develop a British marine protected area network, and EU legislation has improved water quality in the last few decades, we have found these initiatives to be insufficient. Ten of the 11 sites we studied were in areas with designated EU protection, but most of these seagrass meadows were still polluted with nutrients derived from urban sewage and livestock waste. So how has this happened? Analysis of the seagrass tissues points to constant sewage exposure. Old and outdated water treatment facilities are one of the likely culprits, resulting in discharges of untreated sewage during times of heavy rainfall. These are legal, but evidently the capacity of these facilities is insufficient to handle the country’s needs, and waterways are suffering because of it. There is also the problem of livestock waste. Farming is now one of the UK’s leading causes of water pollution, and inefficiencies in storage and disposal of slurry mean that it ends up in rivers and coastal waters. Local and national Evidently, in addition to national and international initiatives, we need to start quickly identifying and understanding all local threats to seagrass. Especially if we are going to harmonise conservation goals with sustainable economic development. Only by finding out specifically where the nutrients affecting seagrass areas have come from can we really start to think about a targeted solution for each meadow. Unfortunately, to date, the conservation of specific seagrass meadows is rarely based on the explicit consideration of local threats and drivers. Instead, projects focus on conserving seagrass as part of a broader plan, incorporating other specific habitats or species. While this may be effective at dealing with problems such as fisheries impacts, and is certainly a step forward for the marine environment, it doesn’t deal with the persistent and chronic problem of pollution – which can go largely unnoticed. Poor water quality isn’t just a problem for seagrass in the British Isles, it’s a global concern. But if we want to solve it, we must look beyond “protecting” seagrasses with legislation, and challenge the way we think about marine protection overall. Serious infrastructure changes and better management of river catchments – for example, restoration of riverbanks – are vital if we are going to develop long term waste water management plans that span both land and sea. You can read the study, Tracking Nitrogen Source Using δ15N Reveals Human and Agricultural Drivers of Seagrass Degradation across the British Isles, here. This article was originally published on The Conversation. Read the original article.
Fishing in seagrass occurs around the globe; if there is seagrass (and people) there is fishing. Still, the nature and extent of fisheries in seagrass is poorly understood. It is a prerequisite for natural resource management to understand resource exploitation, therefore we decided to investigate this further. Seagrasses are plants that grow in the shallow ocean. The seagrass attracts many different types of animals, to live, forage, or seek shelter. These animals are collected by humans for subsistence (food), commercial and recreational purposes. Across the globe the reasons for fishing differs, it is more common to fish for recreational purposes in countries where the economic situation is better, while in countries with more challenged economies fishing for subsistence is very important. Interestingly, because seagrasses grow in nearshore environments, almost all types of fishing gears are used. Close to shore in many areas of the world the seagrass gets exposed during spring low tides making it possible to walk in the seagrass meadows. Many people take advantage of the low tide and walk across the seagrass meadows collecting invertebrates, such as mussels and sea cucumbers, often with bare hand or simple fishing gear like sticks. This type of fishery is commonly referred to as gleaning or invertebrate harvesting and is conducted by men, women and children. Gleaning is especially common and important for people with limited resources. Static nets are also used in the intertidal zone, the area where the tides raise and fall, catching fish when the tides come in. It is very common to use hook and line and fishing nets in seagrass. Unfortunately, very destructive fishing gears such as bottom trawls, poison, dynamite, and rakes are also occasionally used. Women and children walk across seagrass meadows at low tide in indonesia collecting resources that they can eat (Photo: Benjamin Jones) On a global scale, anything found in the seagrass that can be eaten, sold, used as bait or sold as a curio is targeted. Globally, the most commonly targeted invertebrates in seagrass appear to be crabs and bivalves (mussels). The most commonly exploited finfish from seagrass are mullet, herring, and snapper. The target species varies greatly across the globe, for example in areas with high biodiversity (many types of species), the number of target species is often higher than in areas with low biodiversity. This pattern often corresponds with colder water fewer species, warmer water more species. Species groups that are least commonly targeted are sea cucumbers, small fish for drying, aquarium trade species, seahorses, and sharks. People access the seagrass fishing grounds by walking, swimming, snorkelling, free diving, use of canoes, scuba diving, use of sailboats and motorboats. Crabs and bivalves appear to be the most commonly targeted invertebrates across the globe (Photo: Benjamin Jones) Seagrass meadows receive limited management attention compared to other nearshore marine habitats. Fisheries management does not yet target seagrass. But seagrass fisheries are diverse and important to people the world over. We, authors, hope that these findings, now systematically and scientifically investigated, will highlight the importance of seagrass for fisheries around the globe. Source: ‘Global significance of seagrass fishery activity’ by Lina Mtwana Nordlund, Richard K.F. Unsworth, Martin Gullström, Leanne C. Cullen-Unsworth. Published in Fish & Fisheries 2017. Arial footage of a nearshore environment with patchy seagrass, in the upper left corner there is a fishing boat and along the right edge there is a long fishing net deployed (blue in color), Tanzania. Drone pilot and photo LM Nordlund.
