MERLIN Academy launches free course on freshwater restoration
The EU MERLIN project has today launched a new, open-access learning module on implementing freshwater restoration. Across 62 lessons, the module – hosted on the MERLIN Academy – guides visitors through the policy, management and assessment of the restoration of rivers, lakes and wetlands.
The new learning module includes a range of fact-sheets, videos and quizzes produced by leading restoration scientists. It begins by introducing the key policies – including the EU Green Deal and Nature Restoration Law – that structure and guide restoration efforts in Europe. Central to this theme is the idea of using natural processes to implement restoration projects – a set of approaches known as nature-based solutions.
The module continues by outlining the key concepts – such as River Basin Management and Regional Scalability planning – which underpin how freshwater restoration is planned and implemented. A vital component of this theme is the challenge of ‘scaling up’ restoration from individual sites to whole river basins.
“MERLIN learns a lot from close collaboration with restoration cases on the ground,” says MERLIN coordinator Dr Sebastian Birk from UDE in Germany. “These experiences have shaped the design of the Academy, resulting in knowledge that is robust and actionable.”
This learning theme leads into a series of resources around designing and implementing effective restoration monitoring programs which can track the progress of a restoration project. This is an important process, not only for monitoring how nature recovery is taking place, but also tracking the benefits it produces to people.
This feeds into the final theme of the new learning module, which offers resources to help users assess the impacts of restoration on both people and nature. In particular, this theme highlights environmental criteria such as biodiversity, free-flowing rivers and climate resilience which are designated by European policies.
“Nature restoration is not just about biodiversity benefits,” says module coordinator Dr Laurence Carvalho from NIVA in Norway. “This module provides you with the knowledge to measure the co-benefits, and trade-offs, for society and the economy.”
The MERLIN Academy offers free, cutting-edge learning resources to help support and train new generations of restoration managers and scientists. The new module follows another released earlier this year which explores the economics and financing of freshwater restoration.
The MERLIN Academy instructors are experts with deep experience of freshwater ecology, restoration, nature-based solutions, policy and economics. Drawn from academic institutions, NGOs and private companies, their expertise is offered freely as a means of supporting positive change through freshwater restoration, both in Europe and globally.
“Something I really appreciate is that this tool is freely accessible, which makes education and the MERLIN knowledge inclusive for any person with an internet connection,” says Joselyn Arreaga Espin, developer of the MERLIN Academy.
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This article is supported by the MERLIN project.
Signalling the path towards healthy freshwaters in Europe
Europe’s freshwaters are under increasing pressure from human activities. For centuries, rivers, lakes, streams and wetlands across the continent have been altered, abstracted and polluted. And as floods and droughts across Europe intensify, we are seeing the real-time effects of climate change directly impacting both our freshwaters and our everyday lives.
In recent years there has been a groundswell of activity promoting freshwater conservation and restoration across the continent. Large EU projects like MERLIN and WaterLANDS are rigorously testing the potential of so-called ‘nature-based solutions’ to help restore rivers, streams and wetlands.
These schemes – which harness the power of natural process – aim to highlight how healthy freshwaters are not only vital habitats for a dizzying range of biodiversity, but also the vital scaffolding to sustainable and prosperous human societies.
These topics are at the heart of a new report by the European Environment Agency (EEA). In Signals 2024, the EEA state that despite ongoing attempts to safeguard European freshwaters, urgent action is needed to safeguard water security and build resilience to every-growing pressures.
“Climate change is making water management more challenging than ever. Rising temperatures, changing rainfall patterns, and extreme weather events are putting unprecedented pressure on water resources,” says Leena Ylä-Mononen, the EEA Executive Director.
“Water stress already affects 30% of Europe’s population each year, a trend that is set to worsen as climate change intensifies. Across Europe, shifting rainfall patterns have led to both more frequent droughts and more intense rainfall events and floods,” Ylä-Mononen continues.
These trends are evident in this year’s EEA assessment of Europe’s water bodies. The study shows that as of 2021, only 37% of Europe’s surface waters achieved ‘good ecological status’ whilst just 29% met ‘good chemical status’.
Ongoing agricultural and industrial pollution into freshwaters creates ‘cocktails’ of pressures on freshwaters increasingly impacted by climate change. As the figures show, this means that around two-thirds of European freshwaters are in unfavourable condition.
“Our existing systems are poorly adapted to cope with these rapid changes, threatening both water security and the health of people and nature,” Leena Ylä-Mononen continues. “As weather extremes become more common, our management of water must adapt too. We need decisive action to protect communities and preserve the health of our natural environments.
“To improve resilience, we must focus on reducing water use and enhancing efficiency. This includes cutting water leakage, investing in water-efficient technologies, and increasing water reuse. In addition, expanding the use of nature-based solutions, such as restoring wetlands and increasing green infrastructure, can improve water retention, reduce flood risks, and restore biodiversity,” Ylä-Mononen states.
The report highlights the need for better data and monitoring systems which offer real-time information on water quality and quantity to allow better decisions to be made about managing freshwater systems. This is particularly the case when negotiating water use with other stakeholders from agriculture and industry.
In this spirit, the report emphasises that building water resilience is a shared responsibility, requiring open collaborations between policy makers, scientists, industry and citizens to help reduce water consumption, reduce pollution and restore freshwater ecoystems.
The report features four key articles on water management in Europe. The first highlights the pressing need to restore European freshwaters to protect their rapidly dwindling biodiversity. The second explores why water pollution persists across the continent despite decades of action to curb it.
The third highlights how climate change poses increasing risks to water quality and freshwater supplies for people and nature across the continent, and how there is an urgent need to build resilience into our freshwater systems. The final article offers a good news story: highlighting how – thanks to effective environmental management – 96% of designated European bathing waters now meet safety standards.
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Read EEA Signals 2024 – Towards healthy and resilient waters in Europe
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This article is supported by the MERLIN project.
Notes from the water’s edge: how MERLIN is helping bring Europe’s freshwaters back to life
Plans for environmental restoration are gathering pace across Europe as we move closer to the adoption of the EU Nature Restoration Law. This planning is supported by four major European projects which aim to develop new approaches to help restore the continent’s freshwaters, forests, wetlands and coastlines.
These four projects – MERLIN, SUPERB, WaterLANDS and REST-COAST – were funded by the EU’s big environmental policy, the Green Deal. As they all have around a year left to run, the four projects are rapidly producing guidance, tools and support to help environmental managers bring Europe’s environments back to life.
The four Green Deal projects will present their work at an EU webinar next month – sign up here.
MERLIN Academy and Innovation Awards
MERLIN has been particularly busy in recent months. The latest newsletter showcases the breadth of work taking place across the project, including the developments of the MERLIN Academy, an online platform which aims to support practitioners, students, and policymakers in implementing effective restoration projects.
The MERLIN Academy – which consists of free online modules covering both theoretical and practical themes around freshwater restoration – is now looking for people to help shape its future. An online survey is available for the rest of the month, asking how the Academy can be better tailored to meet the needs of those implementing the Nature Restoration Law. You can access it here.
The annual MERLIN Innovation Awards are now open for submissions. The awards celebrate the products and services which are making ground-breaking contributions to global freshwater restoration. You can read about the past winners here, and make your entry by 13th December 2024 here.
Exploring case studies and deliverables
MERLIN’s work is based on the experiences and findings from 18 restoration case studies across Europe, from large rivers to tiny streams; from urban wetlands to remote peatlands. Stories and data from these amazing places can now be explored through the Case Study portal.
If you haven’t been keeping up with the MERLIN podcast, you can explore all our episodes here. The latest episode, released earlier this month, focuses on the crucial role of communities in driving positive change. From Israel to Germany, we learn how diverse groups of people are coming together to restore their local waterways.
A key part of big projects like MERLIN is publishing so-called ‘deliverables’, which provide cutting-edge information to policy makers, environmental managers and scientists to help share new findings. Four new deliverable reports have been published this autumn, covering topics including just transformations in implementing nature-based solutions, economic value analysis, and how to ‘upscale’ restoration from small sites to entire landscapes. You can read them all here.
Simulating ‘digital twins’ of real-world environments
One particularly fascinating deliverable covers the stories from the four ‘digital twin’ case studies in MERLIN. Digital twins are dynamic, virtual copies of real-world systems. Essentially, they are computer models of real environments which look and behave like a natural system.
Following the boom in ‘big data’, digital twins have become increasingly popular in replicating complex human-made systems like aircrafts and buildings. In so doing, they allow designers to predict their behaviour under different scenarios.
The MERLIN scientists saw significant potential for this approach to be applied to freshwater restoration. As we well know, freshwaters are hugely complex systems which change over seasons and years, and are vulnerable to human-made pressures. Being able to better predict their dynamics over long timescales is thus a valuable opportunity for environmental managers and policy makers seeking to mainstream their restoration.
In an engaging ‘StoryMap’, the MERLIN team lead viewers through four key elements of digital twinning: big data, computer modelling, supporting decision making, and boosting wider engagement. You can explore the world of digital twinning here.
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This article is supported by the MERLIN project.
It’s increasingly recognised that restoring damaged ecosystems is not only about improving habitats for wildlife, it is also vital to consider the needs of the people who live and work in a restoration landscape.
In the new episode of the MERLIN podcast we hear stories about how community has been placed at the heart of freshwater restoration projects. We hear from Tal Marciano Ratner about how the restoration of the Tzipori watershed in Israel offers a meeting place for people from different religions and ethnicities to come together in a time of great unrest and conflict.
Ruben Rocha from Dam Removal Europe talks about the challenges of communicating the benefits of dam removal to local communities, and describes how he is beginning to see the demand for removal projects coming from communities themselves. Roland Bischof and Julia von Gönner from iDiv in Germany tell us about the innovative citizen science work in the FLOW project, where the public can help scientists generate valuable data about the health of their streams.
Robert Arlinghaus from IGB and Humboldt University in Germany describes his long-standing work with angling communities, outlining how a productive form of aquatic stewardship can emerge from their interactions with nature. Finally, María Sánchez from ECOLISE outlines how community-led initiatives across Europe are helping give people a stronger voice in shaping environmental restoration.
You can also listen and subscribe to the podcast on Spotify, Amazon, and Apple Podcasts. Stay tuned for the next episode soon!
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This article is supported by the MERLIN project.
2023 was the driest year for global rivers in 33 years, according to a major new report released this week. The World Meteorological Organisation’s (WMO) State of Global Water Resources 2023 report highlights the severe stresses on global water supplies, starkly indicated by five consecutive years of below-normal river flows across the world.
The report draws from global meteorological and hydrological data to offer a planetary assessment of water resources. It highlights that 2023 was the hottest year on record, with widespread floods and prolonged droughts globally, driven by the ongoing climate emergency, which has made the global water cycle more erratic and extreme.
Melting glaciers suffered the largest loss of ice mass ever recorded over the last five decades. 2023 is the second consecutive year in which all regions of the world with glaciers recorded ice loss.
“Water is the canary in the coalmine of climate change,” says WMO Secretary-General Celeste Saulo. “We receive distress signals in the form of increasingly extreme rainfall, floods and droughts which wreak a heavy toll on lives, ecosystems and economies. Melting ice and glaciers threaten long-term water security for many millions of people. And yet we are not taking the necessary urgent action.”
The report illustrates that global rivers are being significantly affected by the effects of the climate emergency. Over half of global river catchments had abnormal conditions in 2023, with most of them running at lower levels than normal.
Large areas of Northern, Central and South America experienced severe droughts in 2023, as the Mississippi and Amazon basins suffered record low water levels. Similarly, the Ganges, Brahmaputra and Mekong basins experienced lower than normal water level conditions.
Other areas were deluged with rain and flooding. The East coast of Africa, North Island of New Zealand and the Philippines experienced regular river flooding, as did the UK, Ireland and Finland in Europe.
“As a result of rising temperatures, the hydrological cycle has accelerated,” Saulo continues. “It has also become more erratic and unpredictable, and we are facing growing problems of either too much or too little water. A warmer atmosphere holds more moisture which is conducive to heavy rainfall. More rapid evaporation and drying of soils worsen drought conditions.”
The trend of widespread low river levels translated into lower inflows into reservoirs across the world, particularly across India, Northern, South and Central America and parts of Australia. For example, low water levels in Lake Coari in the Amazon led to extreme peaks in water temperatures, with negative effects for its biodiversity.
However, the report highlights that water management approaches heavily influence reservoir inflows, as areas of the Amazon and Parana kept water levels topped up despite low river flows.
Glaciers across the world lost more than 600 gigatonnes of water in 2023, largely due to extreme melting across western North America and the European Alps. Snow cover across the Northern Hemisphere has been decreasing in spring and summer, reflecting a cold season shortened by climate change.
“And yet, far too little is known about the true state of the world’s freshwater resources,” Saulo adds. “We cannot manage what we do not measure. This report seeks to contribute to improved monitoring, data-sharing, cross-border collaboration and assessments. This is urgently needed.”
The report highlights the significant changes happening to the global water cycle as a result of the climate emergency. As a result it has important implications for freshwater managers across the world seeking to conserve and restore their ecosystems under increasingly erratic and extreme conditions.
Water supplies are also vital for human health and equitable development. However, 3.6 billion people currently experience inadequate access to water for at least one month a year, according to UN Water. This figure is expected to increase to more than 5 billion by 2050.
As Celeste Saulo argues, there is a need for better monitoring and assessment of global freshwaters in order to adapt to rapidly changing conditions. The report cites the United Nations’ Early Warnings for All and Operational Global Water Information System as valuable tools for this task to help inform better freshwater planning and policy making.
Restoring Europe’s landscapes to tackle the effects of the climate emergency
Devastating flooding has killed at least 24 people as more than five times the average monthly rainfall for September has fallen across Austria, the Czech Republic, Hungary, Poland, Romania and Slovakia in the past week. At the same time, the Portuguese government has declared a ‘state of calamity’ as wildfires have torn through forests across the north of the country.
Through these floods and wildfires, we are witnessing the effects of the climate emergency in action. “Make no mistake. This tragedy is not an anomaly. This is fast becoming the norm for our shared future,” the EU’s crisis management commissioner Janez Lenarčič told MEPs last week. “Europe is the fastest warming continent globally and is particularly vulnerable to extreme weather events.”
In the same debate, Terry Reintke, co-president of the Greens/EFA Group in the European Parliament, highlighted the need for an ambitious Green Deal to continue to reduce emissions to fight climate change across the continent. Allied to this, Reintke emphasised the need to invest in nature restoration programmes to mitigate the effects of climate change, and to further build solidarity between member states to work together on delivering restoration.
A few weeks before, environmentalists from across Europe met in Estonia to tackle the issues highlighted by Reintke. A key session at the European Conference on Ecological Restoration addressed strategies for restoring Europe’s ecosystems at a landscape scale under the EU Green Deal.
Historically, ecosystem restoration has been largely split into approaches that focus on individual ecosystem types: rivers, forests, wetlands, urban green spaces, and so on. Despite the growing agreement for the need for ambitious restoration across Europe to tackle the climate emergency and biodiversity crisis, this ‘siloing’ of approaches is still dominant.
The discussions brought together representatives from each of the EU Green Deal restoration projects, the Endangered Landscape and Seascape Programme, the UNEP World Conservation Monitoring Centre and other institutions focused on restoration.
Together, they asked the question: what knowledge is needed to effectively restore entire landscapes across Europe? Given the recent adoption of the Nature Restoration Law, and the growing awareness of the need for nature-based solutions to tackle the climate crisis, these discussions are timely and vital.
MERLIN project co-ordinator Sebastian Birk took part in the discussions, and helped to convey four key themes for fostering landscape-scale restoration in Europe. “The session highlighted the complexities and challenges of working at a landscape scale,” Birk reflects, “but it also presented several opportunities.”
Bringing people into the conversation
First, Sebastian stresses the importance of stakeholder engagement and co-produced solutions in designing and carrying out restoration programmes. This means understanding local people, conflicts and cultures in restoration landscapes, and finding effective communication strategies to foster engagement and participatory governance.
In short, it’s important to remember that people are an inherent part of nature restoration, and their voices and perspectives need to be heard in its implementation. Across wide areas, it is likely that these perspectives will be diverse, and so creating spaces for conversation and conflict resolution are critical.
The complexities of restoring entire landscapes
Second, Sebastian emphasises the complexities of implementing and monitoring restoration projects across entire landscapes. Here, restoration planning must content with complex land tenures and boundaries, different government ministries, and data gaps in the condition of habitats. Moreover, there is the need to consider restoration as a long-term process, which can need adaptive planning and management over time.
So a key challenge is to bring diverse stakeholders together across wide areas to cooperate on long-term plans for restoration. The session highlighted the potential for better cooperation between bottom-up (e.g. community groups) and top-down (e.g. EU legislation) stakeholders, and the opportunities offered by creative engagement techniques to bring these groups on board.
In addition, the session highlighted the value of adaptive pilot projects which show the value of restoration to different communities, and allow environmental managers to make adjustments based on monitoring results.
Finding new funds to finance restoration
Third, Sebastian identifies the key theme of financing restoration. For ambitious restoration projects to be successful, there is a need for significant funding to support them. Here, the discussions highlighted the need for more public-private partnerships in raising long-term, stable funding. The need for better communication of the value of restoration – for example through demonstration sites and multimedia content – is identified as vital in fostering these partnerships.
Participants at the meeting discussed the value of aggregator organisations which can help pool smaller-scale funding into larger, more impactful and consistent funds for restoration. Similarly, they identified the need for ‘matchmaker’ services which can help bring together restoration organisations with fundraising and investor engagement.
Promoting nature-positive economies in restoration landscapes
Finally, Sebastian highlights the relationship between landscape restoration and local economies. Here, discussions focused on the need to help foster nature-positive economic opportunities – such as eco-tourism or sustainable farming – in restoration landscapes. There is the potential to help promote markets for such restoration economies, for example by helping producers scale their production and gain access to markets across the continent.
“By integrating local communities and mainstreaming nature-positive businesses,” Birk concludes, “these strategies can help overcome barriers and foster long-term success in landscape restoration efforts.”
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This article is supported by the MERLIN project.
Online marketplaces create new routes for the spread of invasive crayfish species
Growing global networks of online trade are creating new pathways for invasive crayfish species to spread across Europe, a new study has found. Freshwater crayfish are popular pets amongst aquarium hobbyists, but their release into rivers and lakes can cause significant damage to the health and functioning of ecosystems.
Writing in Conservation Biology, Julian D. Olden and Francisco A.C. Carvalho highlight how national biosecurity measures which tackle such invasive alien species widely struggle to keep pace with the growth of online platforms for buying and selling exotic species. This ‘clicks-not-bricks’ transition away from physical retail outlets has created opportunities for new long-distance trade routes for live organisms, and in so doing increased the potential for the spread of invasive species.
The authors’ study provides the first global assessment of the online trade in ornamental crayfish. “By systematically examining e-commerce marketplaces in multiple languages, we show that the online global crayfish pet trade involves hundreds of online marketplaces and thousands of sale listings in thirty-three countries across five continents, involving sixty different species and representing a selling value of around US$1.5 million,” explains Professor Olden. “We found that close to half of the listings were selling species considered globally invasive, and we subsequently map the geography of invasion risk across the world.”
One species highlighted by the study is the marbled crayfish. This remarkable creature – Procambarus virginalis – did not exist three decades ago. The original marbled crayfish was born in a German pet shop to a male and female slough crayfish, but had an additional set of chromosomes. This mutation gave the marbled crayfish the extraordinary ability to reproduce without a mate, leading to a population which now consists entirely of females. The species is highly prized by aquarium owners, not least for its diversity of colouration: individuals raised alone in captivity are blue, whilst those raised with others tend to be more grey.
Now found in waterways across Germany, the rapidly-reproducing marbled crayfish can outcompete native crayfish species for habitat, and help spread a fungal disease often called the “crayfish plague”. Despite the European Union instituting a total ban of the possession and trade of the marbled crayfish in the wild, the authors found the species widely available online to be shipped to Europe. They highlight research which suggests that the spread of the marbled crayfish across Europe is entirely driven by demand from the aquarium trade, increasingly facilitated by online trade.
Olden and Carvalho’s study – part of a wider special issue on the global wildlife trade – prompts significant questions for the conservation and restoration of Europe’s freshwaters. In particular, it highlights the need for joined-up policy decisions to monitor and regulate the online trade of invasive species across borders. The authors demonstrate that whilst the EU has a strategic coordinated joint plan across all Member States to reduce the availability of high-risk invasive species, two of the prohibited species (red swamp crayfish and marbled crayfish) are widely available in European-based online marketplaces.
“Importantly the internet is not purely the cause of the problem; rather it also offers solutions that help prevent trade-related invasions of crayfish,” states Professor Olden. “Internet public forums and discussion groups provide opportunities for regulators to track consumer preferences, including through surveying popular social media platforms. The internet may also lend insight into how often and where illegal dumping of aquarium animals occurs, such as through the monitoring of online video postings.”
“Early warning systems can leverage the massive amounts of data on the Internet to support real-time surveillance of online marketplaces to detect new non-native species in trade, Olden continues. “Internal retailers represent the major, and perhaps the only, point of contact between the supply chain and the hobbyist. Online marketplaces are uniquely positioned to influence and educate ornamental owners about what to do with unwanted aquarium organisms, although forging these new relationships to increase awareness of the risks associated with invasive species remains uncommon.”
“Our work illustrates how continued growth in international trade and the burgeoning transition from brick-and-mortar stores to online marketplaces to purchase pets may necessitate a paradigm shift in the way in which nations seek to safeguard their borders against alien invasive species, both today and in the future,” Olden concludes.
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This article is supported by the MERLIN project.
Freshwater restoration is growing in popularity across Europe, increasingly backed by better scientific knowledge, practical experience and political support. However, as work in the EU MERLIN project shows, there is still a need to demonstrate how successful restoration can be mainstreamed across the continent.
A new survey aims to help advance freshwater restoration in Europe by identifying the factors that make restoration projects successful. The EcoAdvance project – funded by the EU Horizon scheme – has designed the survey to gather the perspectives of freshwater scientists, academics, managers, community organisers and policy makers across Europe.
The results of the survey will contribute to a tool which supports freshwater restoration projects by showcasing best-practice examples and case studies, at both continental and national scales. This work is extremely timely given the adoption of the EU Nature Restoration Law – and its commitment to restoring 25,000km of free flowing rivers across Europe – earlier this year.
“Success inspires success, and when you hear these people, when you see the varieties of paths they followed to be successful, when you read their insights into how to deal with barriers, it is nothing short of inspiring,” says EcoAdvance partner Phyllis Posy. “You understand that Europe really has the people and resilience to achieve the Green Deal.”
“The survey will help us understand country differences – the diversity of stressors and climates – and what factors make restoration projects prone to success,” adds EcoAdvance coordinator Mark Morris. “This includes the tools people use to adapt to specific technical and social challenges that could derail a project.”
For EcoAdvance partners Helmut Habersack – voted the Austrian of the Year in Research 2023 for his work on river restoration – the work is important to help bring people together, recalling years when “engineers and ecologists were colliding, and no one could go forward.” Habersack explains: “there is only one river – and we have no choice but to come to the table and work together.”
The EcoAdvance survey is open until 10th September and can be completed here.
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This article is supported by the MERLIN project.
Making the Seine swimmable for the Paris Olympics
This summer’s Olympic Games in Paris saw swimmers compete in the River Seine, a waterway that had been closed to public bathers for more than a century due to high levels of water pollution.
The Seine, which flows 481 miles from Burgundy to the sea in Normandy, has long defined the architecture and culture of Paris. However, before this summer, centuries of domestic and industrial wastewater coupled with Paris’s complex and antiquated sewage system had made the river highly polluted and unsafe to swim in.
When Paris won their Olympic bid in 2016, Anne Hidalgo – the city’s current mayor – promised that athletes would be able to safely swim in the Seine during the 2024 Games, as they did when Paris first hosted the Olympics in 1900. City authorities hope that the Games will revive public swimming in the Seine, and 26 new swimming pools – walled off from heavy boat traffic – are due to be opened along the river in Paris.
Over the last eight years, significant investments into reducing the amount of untreated wastewater reaching the Seine have been made. Ahead of this summer’s Olympics, French authorities invested around €1.4 billion in measures across the Seine basin, including a giant stormwater storage tank in Paris. The tank – which has a capacity equivalent to 20 Olympic-sized pools – is designed to store untreated wastewater during heavy rain storms, and prevent it from directly entering the Seine.
The water is then slowly released back into the sewer system and treated downstream in the city’s sewage-treatment plants, before being released back into the river. The storage tank system is accompanied by disinfection systems to treat sewage more effectively and the redirection of wastewater from more than 10,000 homes and houseboats that used to dump directly into the Seine. Together, this work has resulted in untreated wastewater levels reaching the Seine being 90% lower in 2022 than 2002.
In July, shortly before the Olympics started, Paris mayor Anne Hidalgo donned goggles and a wetsuit to swim in the Seine in central Paris, accompanied by swimmers from local clubs. However, heavy rain at the start of the Games caused concerns over water quality in the river, and multiple training swims were cancelled as a result.
The organisers carried out daily water quality tests for the fecal bacteria E. coli and enterococci – which can lead to sickness and diarrhoea if ingested – in the Seine. These tests allowed both triathlon and marathon swimming events to go ahead in river water which was deemed ‘good quality’ by international standards. Under World Triathlon guidelines, E. coli levels up to 1,000 colony-forming units per 100 milliliters can be considered ‘good’ enough for competitions to take place.
Urban swimming: a growing trend
The initiatives in Paris are part of a wider movement, with urban swimming steadily growing in popularity in many European cities – including Copenhagen and Zurich – in recent years. There are now ongoing efforts to make Berlin’s Spree canal and Amsterdam’s canals swimmable for the public.
Urban swimming brings many benefits to the wider city. Plainly, it requires clean waterways where pollution levels have been limited. In many cases, this is both good for people, and the aquatic ecosystem too. For example, clean-up efforts in the Seine have increased the number of fish species inhabiting urban Paris from three in the 1970s to more than thirty now.
Many urban waterways have been polluted for decades by overflows of sewage from combined sewer overflows, or CSO’s as they’re often known. During periods of heavy rainfall, these underground sewers are designed to overflow directly into urban waters, carrying with them cocktails of pollutants, bacteria and microplastics.
One powerful solution is to turn to nature to reduce the amount of polluted water reaching sewer systems. The ‘sponge city’ concept – in which green urban architecture helps absorb and slow the flows of water through the city – is rapidly growing across the world. Originally coined in China in the early 2000s, the sponge city model emphasises green infrastructure such as urban parks, wetlands, tree planting, green roofs, permeable paving and rainwater reuse to help alleviate flooding and pollution.
These different nature-based solutions are brought together in cities to form sustainable urban drainage systems (or SuDs), which harness natural processes to filter pollutants and buffer floodwaters. Many of these approaches also help create valuable biodiversity habitat to boost the health of urban ecosystems, and their resilience to the ongoing heat effects of the climate emergency.
Paris’s success in making the Seine swimmable for the Olympics this summer provides a beacon of hope for our urban rivers. Despite the multitude of challenges the clean-up operation has faced, it shows that even the most polluted urban rivers can be made safe for people to swim and bathe, and boost the health of the wider aquatic ecosystem in cities.
Allan Water restoration project wins major Scottish award
The Forth Rivers Trust has won the Climate Impact award at the recent Scottish Council for Voluntary Organisations (SCOV) Scottish Charity Awards 2024 for their work in restoring the Allan Water in Central Scotland.
The Trust, supported by the MERLIN project and other funders, has been working with land managers and communities for the past eight years to restore degraded habitats along the Allan Water.
The Trust have implemented a range of nature-based solutions to help build resilience to ongoing climate changes along the catchment. These include measures to slow water flows to help buffer flooding, riparian tree planting to help keep the river cool under increasing air temperatures, restoring degraded peatland to lock in carbon, and creating new wetlands to help boost wading bird populations.
“This award is testament to the collective efforts and hard work of our staff, land managers, partners, contractors and steering group It underscores our shared commitment to delivering a resilient catchment for future generations,” said Charlotte Neary from the Forth Rivers Trust.
“The project wouldn’t be possible without the support of our funders, including The Scottish Government, European Union via the MERLIN Project, Nature Scot Nature Restoration Fund and Network Rail,” Neary continued.
“Recognition of the project through winning this award has given us even more momentum to carry on developing and delivering work on the Allan Water in the future. We extend our heartfelt thanks to each and every one who has been a part of this journey, supporting the project in various ways. Your contributions have been instrumental in its success,” Neary said.
You can find out more about the Allan Water restoration project through the MERLIN factsheets, and on our most recent podcast, which features an interview with Charlotte Neary.
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This article is supported by the MERLIN project.
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