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Bringing back the UK’s ‘royal’ fish from the brink of extinction

May 4, 2023
An ambitious new action plan seeks to bring back sturgeons to UK waters after decades of habitat loss and overfishing. Image: ZSL

Sturgeons were once so highly prized in the UK that in 1324, King Edward II declared them a ‘royal fish’. However, decades of overfishing, habitat loss and blocked migration routes have caused sturgeons to almost completely disappear from UK rivers and coastlines.

This population decline is not an isolated trend: the International Union for the Conservation of Nature (IUCN) considers sturgeons the most critically endangered group of species on Earth. Across Europe, conservationists are seeking to implement large-scale plans to bring back sturgeon populations from the brink along major rivers such as the Danube.

This week, a team of conservationists led by the Zoological Society of London have launched an ambitious plan to restore populations of Atlantic and European sturgeons to UK waters. The UK Sturgeon Conservation and Action Plan aims to help restore sturgeon habitat and migration passages whilst reducing accidental bycatch. It forms part of major Europe-wide restoration initiatives to help save critically endangered European sturgeons from the brink of extinction.

“Growing up to 5m in length, with long whisker-like barbels and diamond-shaped armoured plates along their backs, sturgeons look like they’ve swum straight out of a palaeontologist’s textbook,” said Hannah McCormick from ZSL. “These impressive and ancient animals were once common in UK rivers and along our coastline, so it’s hardly surprising that they were declared ‘royal fish’ by King Edward II back in the 14th Century.

“Fast-forward seven hundred years, and sturgeons have all but disappeared from our waters, after dam construction in rivers blocking their migration routes and overfishing caused numbers to plummet in the latter half of the 20th century,” McCormick explained.  

Both species of sturgeon native to the UK – European and Atlantic – are migratory. They are born in rivers, before migrating downstream to the sea, where they live most of their lives – which can stretch more than 60 years – returning to freshwater every few years to reproduce. This means that restoration efforts need to take into account the wide range of habitats that they pass through, and the numerous people and organisations responsible for their management.

As a result, the new action plan has five key goals. First, to map essential sturgeon habitats and migration routes across UK marine, estuarine and freshwaters to identify areas for restoration and protection from threats. Second, to boost European sturgeon restoration projects – particularly the Pan-European Action Plan for Sturgeons – by supporting UK sturgeon population recovery. Third, to minimise accidental sturgeon bycatch by working with marine fishers.

Fourth, the action plan aims to engage political and public audiences to actively support sturgeon restoration efforts. It highlights the role of sturgeons as ‘flagship species’ which draw attention to wider aquatic conservation issues. Finally, it aims to close evidence gaps around sturgeon populations by supporting scientific research which helps underpin conservation decision-making.

The action plan was created by the UK Sturgeon Alliance – a group of research organisations and NGOs formed in 2020 which works to restore native sturgeon populations. The Alliance have set up a website – Save the Sturgeon – where the public can report sturgeon sightings to help researchers better understand their population dynamics.

A ‘royal’ sturgeon caught in the Hundred-Foot River in East Anglia, UK in 1906. Populations of sturgeon dramatically declined through the 19th and 20th century in UK waters. Image: ZSL

“The development of this Action Plan has been an exciting first step that contributes to the European efforts of restoring sturgeons,” said Jenny Murray from the Blue Marine Foundation, a member of the UK Sturgeon Alliance. “This has been a truly collaborative approach that has highlighted the interest and need to see habitats in a good enough condition for their return. The public can support sturgeons return by raising awareness of this beautiful species and reporting any sightings to the Save the Sturgeon website.”

“We now have over 5,200 records of sturgeon in rivers, estuaries and coastal waters all around the UK, since at least 1700, added Steve Colclough from the Institute of Fisheries Management, another member of the member of the UK Sturgeon Alliance. “Our waters clearly formed part of the natural range of these great migrators.  Until recently, the numbers visiting us have been so low that these were only recognised as occasional vagrants. In the 18th and 19th century many fish were captured in our rivers and in some cases where they were not offered to the crown, they were removed and destroyed as strange exotic sea monsters. Now we know better, we can help conserve these flagship species for future generations to see.”


 This article is supported by the MERLIN project.

Turning the tide on the ‘triple’ global water crisis

April 20, 2023
Climate breakdown, biodiversity loss and human health are all impacted by a crisis in water management, according to a new report. Image: Jose Antonio Alba | Flickr Creative Commons

Decades of neglect of the global hydrological cycle have led to a triple water crisis which needs to be urgently addressed, according to a major report published last month.

Human water needs are not being met across the world, whilst global environmental change is causing increasingly extreme droughts, floods, storms and wildfires. Human actions are beginning to alter the global hydrological cycle and threaten the source of freshwater – precipitation – in many areas, the report warns.

Published by the Global Commission on the Economics of Water, “Turning the Tide: A Call to Collective Action” argues that urgent attention is needed to tackle these issues. The report states that a global transformation of the economics and governance of water is required to help sustain humans and nature in a rapidly changing world.

The report places water at the heart of the ongoing climate and biodiversity crises. “Every view of climate change that excludes water is incomplete,” says Johan Rockström, Director of the Potsdam Institute for Climate Impact Research and co-chair of the Commission. “For the first time in human history, we can no longer count on the source of all freshwater, our precipitation.

“We are changing the entire global hydrological cycle,” continues Rockström. “Each 1°C of global warming adds about 7% moisture to the water cycle, supercharging and intensifying it, leading to more and more extreme weather events.”

The climatic and biodiversity impacts of the water crisis have significant impacts on human life. The report highlights the stark figures that more than two billion people still lack access to safely-managed water globally, whilst one child under five dies every 80 seconds from diseases caused by polluted water. The water crisis has pushed communities and regions across the Global South into acute food insecurity.

These impacts are not the consequences of freak events, population growth or economic development, the report argues. Instead, they are the product of decades of mismanagement of water – including pollution, over-abstraction and habitat destruction – which has pushed the global water cycle out of balance for the first time in human history. The report highlights the prospect of a 40% shortfall in freshwater supply by 2030, with acute shortages in water-stressed regions.

The Commission outlines the need to transform the economics and governance of water in ways which recognise and manage the water cycle as a global common good. This means bold collective action across political borders to restore and safeguard rivers, streams, lakes, groundwater and wetlands across catchments, countries and continents.

“We need new economic thinking to help move from reactively fixing to proactively shaping economies to become inclusive and sustainable,” says Mariana Mazzucato, Professor in the Economics of Innovation and Public Value at University College London and co-chair of the Commission. “Moving from sectoral to mission-oriented innovation policies with a common good approach can help us put equity and justice at the centre of water partnerships and bring multiple sectors together to tackle our biggest water challenges,” Mazzucato adds.

The report sets out seven points to structure a more sustainable and just water future. First, it stress that water is a global common good which connects communities and nations across borders. This means that collective action to protect the water cycle is highlighted as being in the interests of all. Second, there is the need to mobilise public and private bodies alongside local communities to apply and scale-up innovative new approaches to providing clean and safe water. The report emphasises the need to shape markets, direct investments and design policies towards positive water goals.

Third, the report argues that our economic systems underprice the value of water, which leads to unsustainable use of freshwater resources, and a lack of access to water for the poor and vulnerable in many areas. In other words, the multiple benefits that water provides must become visible on public and private balance sheets through better accounting of their natural resource values. This should be coupled with targeted subsidies to ensure low-income communities have access to clean water, the report states.

Fourth, there is the need to phase out government subsidies – which are estimate to total more than USD 700 billion annually – to the agriculture and water industries which encourage excessive water consumption and environmental damage. Fifth, Just Water Partnerships (similar to the Just Energy Transition Partnerships launched at COP26) which enable investments in water access, resilience and sustainability in low- and middle-income countries should be more widely established across the world.

Sixth, the report states that we are in a critical window of time to to shift the economics and governance of the global water systems to help tackle human, climate and biodiversity crises. The authors identify the need to upscale and mobilise finance towards innovative new technologies which can help store and recycle water, tackle inefficiencies in water infrastructure, and incentive water-friendly farming systems.

Finally, the report argues that there is a need for more joined-up and co-ordinated global governance of water. This process would require better dialogue and collective action across governments, to help strengthen existing environmental policies, make trade policies more sustainable, encourage better data collection to track water systems, and strengthen partnerships with global financial institutions. In the longer-term this could involve the establishment of a new Water Convention or Global Water pact which encourages greater collaboration across nations and communities.

“Solving the water challenge requires higher ambition, but it’s an ambition that is actually achievable if we work collectively and accelerate actions in the current decade,” says Tharman Shanmugaratnam, Senior Minister in Singapore and co-chair of the Commission.“We have the scientific expertise, we know what the basic policy reorientations should be, and there is no real lack of finance globally. The task is to organise these resources for a sustainable and globally-equitable future – that’s in every nation’s interest.”


This article is supported by the MERLIN project.

Nature-based solutions and economic sectors in freshwater restoration: four themes to strengthen collaboration

April 5, 2023
Peatland restoration in Scotland: how might such nature-based solutions help support economic sectors? Image: MERLIN

Protecting natural environments has long relied on co-operation between the different people and organisations who live and work in them. As such, it is widely recognised that biodiversity conservation and restoration are inherently social activities. Accordingly, they require careful consideration of the cultural, political and economic contexts of the landscapes in which they take place.

The nature-based solutions concept offers emerging opportunities to navigate these contexts to help strengthen freshwater restoration efforts. Nature-based solutions aim to use natural processes to help tackle socio-environmental challenges such as climate change, biodiversity loss and flooding.

At the core of the nature-based solutions concept is a belief that ecological restoration can bring significant benefits to both society and biodiversity. The EU-funded MERLIN project explores how these benefits can act as a focus for collaborations between different economic sectors to help mainstream freshwater restoration.

MERLIN works with representatives from six economic sectors – agriculture, hydropower, insurance, navigation, peat extraction, and water supply and sanitation to mainstream nature-based solutions in their activities across Europe. Project partners recently released a briefing exploring how nature-based solutions are understood across these sectors in Europe, and – vitally – how they might help encourage collaborations which strengthen restoration efforts.

The team learnt four valuable lessons from talking to sectoral representatives which have wider implications for ecological restoration initiatives elsewhere.

Demonstrating the value of nature-based solutions

First, whilst sectoral representatives were largely aware of nature-based solutions in freshwater restoration, they were not always persuaded of the need for radical change or transformation. Crucially, representatives were not yet convinced that they could rely on nature-based solutions to deliver their sectoral objectives.

A key challenge is to illustrate how nature-based solutions can help sectors advance EU Green Deal goals. Adopted in 2019, the Green Deal has wide-ranging ambitions to support environmental protection, green economies, sustainable agriculture and technological innovation across Europe. The MERLIN briefing suggests that sectoral representatives were broadly supportive of its vision, and the task is to demonstrate how nature-based solutions can help achieve it.

Communicating and providing evidence

Second, whilst the language of nature-based solutions is not yet widely used across these sectors, there is an understanding of concepts of sustainability and ‘working with nature’. The MERLIN researchers suggest that this provides a strong basis to foreground the potential social and economic benefits offered by nature-based solutions in restoration.

Third, sectoral representatives seek clear evidence that nature-based solutions can bring tangible benefits to their own initiatives. In particular, this involves demonstrating how nature-based solutions can work effectively across entire catchments. Moreover, there is a need for clarity over how the ‘burden-sharing’ of restoring nature will be coordinated and governed.

The Tzipori basin in Israel: water in such pressurised ecosystems is often vital to multiple economic sectors. Image: MERLIN

Managing synergies and trade-offs

Finally, the MERLIN researchers identify strong synergies between the different sectors. However, these are balanced by potential trade-offs and challenges, for example over the location and scale of benefits generated. Through initiatives such as the MERLIN Academy, the project seeks to build new communities of practice around nature-based solutions to help communicate their potential for economic sectors, and manage these trade-offs and tensions.

Co-author and co-lead of research Kirsty Blackstock from the James Hutton Institute said, “It has been extremely instructive to talk to, and learn from, representatives from these economic sectors. Through this discussion, we’ve identified cooperation points where we can start our journey of transformation together. We don’t always agree – there are often difficult trade-offs to resolve – but through knowledge sharing, solutions can be found.”

Co-author and co-lead of research Anna Bérczi-Siket from WWF added, “Putting a focus on freshwater restoration and nature-based solutions in the six economic sectors’ actions requires a paradigm shift.

“Our first briefing introduces the starting point of our formulating community of practice which includes the six MERLIN sectors. Side by side with this community we will draw up a cross-sectoral route map to the change we want to achieve together.

“Our cooperation is a good example of how the integration principle of the environmental policy can be put into practice – which also requires that environmental and sustainability considerations become an integral part of the decision-making processes and actions of other sectors,” Bérczi-Siket said.

Overall, the briefing suggests that there is significant potential for nature-based solutions to help address social and biodiversity goals through strengthened collaborations across economic sectors. The challenge over the coming years is to provide clear evidence and recommendations to help sectors mainstream nature-based solutions in their everyday practices.


Read the MERLIN briefing: Mainstreaming aquatic restoration using Nature-based Solutions: Briefing on national / EU sector perceptions, workshops, and tailored briefings per sector

Read briefings on how nature-based solutions are being integrated into individual economic sectors through MERLIN.

“A rapidly closing window”: the urgent need for meaningful climate action for people and nature

March 21, 2023
Floods, drought, food and water security are all disrupted by climate change. Image: Internets Daily | Flickr Creative Commons

Climate change poses a significant threat to both human wellbeing and global ecosystems, but “there is a rapidly closing window of opportunity to secure a liveable and sustainable future for all,” according to the latest Intergovernmental Panel on Climate Change (IPCC) report, released this week.

The IPCC AR6 report emphasises that whilst the situation is increasingly serious, there are, “multiple, feasible and effective options” available to reduce greenhouse gas emissions and help societies adapt to human-caused climate changes.

“Mainstreaming effective and equitable climate action will not only reduce losses and damages for nature and people, it will also provide wider benefits,” said IPCC Chair Hoesung Lee. “This Synthesis Report underscores the urgency of taking more ambitious action and shows that, if we act now, we can still secure a liveable sustainable future for all.”

Five years ago, the 2018 IPCC report outlined the challenges of restricting global warming levels to 1.5°C above pre-industrial levels. However, continued increases in greenhouse gas emissions has already led to current global temperatures around 1.1°C higher than those around 1850–1900.

The new report stresses that every increment of warming escalates hazards such as heatwaves and heavier rainfall. As a result, increasingly extreme climate-related risks around drought, flooding and water security place increasing pressure on the health and livelihoods of global communities, particularly those in developing nations.

“Climate justice is crucial because those who have contributed least to climate change are being disproportionately affected,” said co-author Aditi Mukherji from the International Water Management Institute. “Almost half of the world’s population lives in regions that are highly vulnerable to climate change. In the last decade, deaths from floods, droughts and storms were fifteen times higher in highly vulnerable regions,“ she continued.

As we regularly highlight on this blog, freshwater ecosystems are significantly impacted by a changing climate. The IPCC report highlights the interdependencies of climate change and water. It outlines how increasingly extreme climatic events have left many global communities vulnerable to floods, droughts, reduced water and food security, and water-borne diseases. Moreover, it highlights the substantial, and increasingly irreversible, losses of plants and animals in freshwater ecosystems driven by heat extremes and changes in the water cycle.

The report also highlights the potential of freshwater nature-based solutions in helping mitigate the effects of climate change. Such measures include wetland restoration, reforesting river catchments and natural water management and storage in agricultural landscapes. These approaches can help buffer floods and droughts, and offer biodiversity habitat. The report states that 30–50% of global land, freshwater and ocean areas need to be effectively conserved in order to maintain their ecosystem resilience to climate change.

Image: IPCC AR6 2023

The report emphasises the need for governments to rapidly implement ‘climate resilient’ development strategies which shift our global reliance on fossil fuels towards clean energies and technologies. These include wind and solar power, energy efficiency schemes, ‘green’ low-carbon cities, transport and agriculture, alongside halting deforestation.

The report states that at the moment global governments are not doing enough to mitigate the impacts of current climate change, let alone to achieve the targets of the Paris Agreement on emissions. Indeed, IPCC models suggest that without a strengthening of global climate policies, global warming of 3.2°C is projected by 2100.

The message is clear, humanity is at a climate crossroads. “The choices and actions implemented in this decade will have impacts now and for thousands of years,” state the report authors.

The report argues that increasing finance to climate investments is a key step to achieve the rapid cuts in carbon emissions needed to slow down global warming. It calls on governments, investors and central banks to help scale up deep emissions cuts through ambitious policy and governance.

“Transformational changes are more likely to succeed where there is trust, where everyone works together to prioritise risk reduction, and where benefits and burdens are shared equitably,” Hoesung Lee said. “We live in a diverse world in which everyone has different responsibilities and different opportunities to bring about change. Some can do a lot while others will need support to help them manage the change.”


Read the Synthesis Report of the IPCC Sixth Assesment Report (AR6)

Nature conservation in the bio-metaverse

March 6, 2023
Pivansuo Bog in Finland: could biodiversity conservation in such places be strengthened through the bio-metaverse? Image: Mikko Muinonen | Flickr Creative Commons

Technological advances offer significant potential for environmental engagement and biodiversity conservation, say guest authors Kristian Meissner and Kristiina Valtanen.


Biodiversity is disappearing at an unprecedented rate. Protecting biodiversity through rapid and effective action is essential to secure the future of both humanity and ecosystems. There is an urgent need for new forms of financing for environmental protection, because traditional funding is not growing fast enough.

The choices of individual citizens can play an important role in halting biodiversity loss. It is important to make everyone understand that their own actions to preserve biodiversity are meaningful. Individual actions are a central part of the needed systemic shift towards a more sustainable society.

Increasing knowledge can help us understand the significance of our own actions. However, it is not realistic to rely on knowledge alone, as not everyone has the interest or time to delve deeper into biodiversity topics. How can the potential of dormant citizens who are largely estranged from nature be harnessed to maximise the protection of biodiversity?

The world’s largest companies, Google, Amazon, and Facebook (GAFA), could serve as a model. In just a couple of decades, they have succeeded in radically changing our everyday habits. GAFA are incredibly skilful at exploiting people’s basic social needs for their own ends on their digital platforms.

At the end of last year, Facebook announced its next development goal: the internet of the future. According to CEO Mark Zuckerberg, the purpose of this ‘metaverse’ is to make all online interactions more natural by providing a “sense of presence.” In addition to Facebook, many other companies are heavily involved in the development of the metaverse. Soon, applications will no longer open in front of us only through screens, but we will be able to immerse ourselves into the internet.

The metaverse uses Non-Fungible Tokens (NFTs) to assign ownership and trade digital things. NFTs are a type of digital certificate of authenticity. Indeed, unique digital skins have real monetary value, which many parents of teenagers already have come to realise, given NFTs have been exploited in the gaming world for a long time.

Interestingly, the promotional language around the metaverse is filled with words that refer to nature: universe, ecosystems and naturalness. Could nature and the metaverse share more than just terms with each other? With smart integration of the physical and digital worlds, unique natural objects, ecosystems and conservation measures could be tied to NFTs.

A rare orchid could be acquired and put on the wall of your study in the metaverse, and the funds from its purchase could be invested in the conservation work of its natural habitat. In the same way, you could buy a piece of Amazonian rainforest, or even a piece of a traditional Finnish biotope, such as a meadow, bog or wooded land. Your purchase could be the virtual background of your next Fortnite game.

Of course, the equivalence of NFTs and their corresponding real-world objects should be objectively verified, so that a sound basis for the value of tokens can be established.

Environmentally friendly measures undertaken by individual citizens that rapidly promote biodiversity, such as extending the intervals between mowing grasses, replacing grasslands, and encouraging plant-based diets could also be tokenised in the same way. This would not only create new forms of incentives, but would also make the importance of grassroots action as part of environmental protection more visible.

The metaverse has been said to be the embodiment of the internet. It could also offer a valuable embodiment of nature for an urbanite who has distanced themselves from nature, and provide novel means for reconnecting with it.

In the bio-metaverse, the expulsion of mosquitoes from your porch could be handled by buying a few NFT birdhouses for swallows instead of cans of insecticides. Alternatively, one could invest even more extensively in the market of insectivorous species. The bio-metaverse could serve as a platform for the most diverse work to protect biodiversity.

Of course, there is still a long way to go before all the necessary information about biodiversity can be brought into the bio-metaverse. This requires, for example, strengthening actual biodiversity research. Monitoring of conservation measures should also be stepped up to avoid mistakes and greenwashing. Despite these obvious challenges, no stone – not even digital ones – should be left unturned when looking for ways to make nature conservation more effective and affordable.


Translated and edited from an article first published in the Finnish language in the Talouselämä newpaper in October 2022.

This article is supported by the MERLIN project.

MERLIN Innovation Awards celebrates innovative approaches to freshwater restoration at 2023 ceremony

February 18, 2023
The Plastic Fischer TrashBoom collects plastic waste in polluted rivers. Image: Plastic Fischer

Last week, the EU MERLIN project announced the winners of its annual Innovation Awards, which highlight cutting-edge solutions for modern freshwater restoration. Entries from organisations across the world were assessed by an expert panel, and shortlists for the two categories – Service of the Year and Product of the Year – were drawn up. Two winners were announced at a busy and energetic ceremony on Wednesday.

The winners of the Service of the Year are Plastic Fischer, a social enterprise which collects and manages river plastic to prevent it entering the oceans. The organisation was founded in 2019 in response to its founders witnessing the continuous stream of plastic, styrofoam and other waste that floated down the Mekong River in Vietnam, towards the ocean. The idea was formed to build a waterwheel that automatically collects plastic waste from rivers, and lifts it to shore to be disposed of.

Plastic Fischer aim to share their open source technology to help other NGOs curb plastic pollution in global rivers. Image Plastic Fischer.

Further work on the Citrus River in Indonesia – one of the world’s most polluted waterways – then led the Plastic Fischer team to develop a floating fence which collected rubbish – the TrashBoom. Now working across India and Indonesia, the organisation has collected over 500,000kg of plastic waste since April 2021, and created over 70 local jobs. Plastic Fischer make their river cleaning technology open source and available for free on the website, with the intention that other NGOs can adopt their approach to help reduce plastic waste in global rivers using simple technology.

“I am very proud that we have been awarded the Merlin Innovations Award for Service of the Year,” said Karsten Hirsch, CEO and Co-Founder of Plastic Fischer. “Thank you so much for recognising the hard work of our entire team and the impact we create.”

The Ecocean artifical rafts and nurseries bring back valuable habitat to aquatic environments where it has been lost. Image: Ecocean.

The winner of the Product of the Year is Ecocean, a French company which specialises in developing new technologies to support the sustainable use of aquatic environments. One of the organisation’s flagship innovations is FLOLIZ – a series of artificial floating rafts which help boost biodiversity, both above and below the water’s surface.

The FLOLIZ rafts are made from recycled (and recyclable) materials, and can be introduced into rivers, canals and lakes to help compensate for habitat loss due to human activity. The rafts are planted with local vegetation species to offer habitat for birds, bees, insects and amphibians.

The Ecocean nurseries act as important spawning grounds and nursery areas for fish species. Image: Ecocean

Underneath the rafts, the Ecocean team install artificial nurseries, called Biohut. These nurseries are made from recyclable materials, including steel, wood and oyster shell, and help provide spawning grounds, nurseries and feeding areas for fish populations. Together, the FLOLIZ and Biohut approaches help bring back biodiversity habitat in aquatic ecosystems where it has been lost.

“Ecocean is very honoured to receive the Product of the Year 2023 award of the MIA awards, for the solutions that we developed with Biomatrix Water to enhance the ecological functions of littoral zones in freshwater,” said a project spokesperson. “The award acknowledges all our efforts to provide functioning habitats to urban and artificial waterbodies, in order to bring back ecological functions, complex ecosystems and biodiversity in habitat-depleted areas.”

The MERLIN Innovation Awards celebrates new and widely-applicable solutions for restoring freshwater ecosystems. The awards – organised by project partner Connectology – recognise the need for restoration projects to better engage with economic markets to support transformative ecological improvements.

You can find out about the ten shortlisted projects, and the expert jury who selected them.

This article is supported by the MERLIN project.

We all need freshwater biodiversity

February 10, 2023
Fishers on the Orinoco River, Colombia. Freshwaters across the world support human lives in diverse and important ways. Image: WWF

We are in a crucial ‘window’ of time to protect and restore global freshwater biodiversity, according to a major new journal article. The authors – a group of scientists from across the world – write that there is growing public and political recognition of the need to ‘mainstream’ biodiversity conservation across all areas of everyday life.

Writing in the WIRES Water journal, the authors highlight the vital roles that freshwater biodiversity plays in supporting human lives: from food and materials; to cultural and recreation; and climate regulation to water purification. As a result, conserving and restoring freshwater habitats offers a path towards achieving what the UN term the ‘future we want’: a more sustainable future for people and nature.

Reflecting on the opportunities offered by the recent IPBES and UNFCCC biodiversity and climate policy conferences, the authors identify the critical ecosystem services which depend on freshwater biodiversity. Resulting from collaborations between scientists across the world, the paper highlights the diverse ways in which ‘people need freshwater biodiversity’.

“Our author team came together across disciplines, career stage, and geography because we were all in need of a clear, simple resource that demonstrated why freshwater biodiversity is so important for people,” explains lead author Dr. Abigail Lynch from the US Geological Survey.  “In a series of coordinated, structured, rich discussions, we distilled down an enormous list to the nine key ecosystem services and functions in the manuscript.”

The paper highlights a varied set of global examples of ecosystem services across material, non-material and regulating categories. The authors focus on indigenous freshwater biodiversity, that is, the species which are native to the habitats in which they are found. They argue that whilst freshwater conservation, human livelihoods and sustainable development are closely linked, there is still need to mainstream freshwater biodiversity in international policy and water management.

“Some of these services are very tangible, like fish or plants used as food or swimming in a pristine lake for recreation,” says lead author Prof. Sonja Jähnig from Leibniz Institute of Freshwater Ecology and Inland Fisheries in Germany. “Others are hidden below the surface as they are run by microorganisms too small to be seen such as water purification or might only be important in the future, for example genetic resources.”

Freshwater species are some of the most fascinating creatures on Earth and they play vital roles in supporting human livelihoods. Image: WWF

The paper takes us on a tour of the diverse ways that freshwater biodiversity helps support human lives across the world. Materially, it explores the food fisheries of the Lower Mekong River Basin, the health benefits of frog species in the Hindu-Kush region, and the products – including fish skin shoes and notebooks – made from freshwater biodiversity across the Amazon basin. Non-materially, it documents the importance of freshwater crayfish in European culture, the value of dragonflies in environmental education in South Africa, and the varied recreational activities supported by the North American Great Lakes.

Freshwater biodiversity is also vital in regulating many of the environmental processes that support humans. The paper highlights the value of catchment integrity in the un-fragmented Parana-Paraguay corridor, the climate regulation provided by riparian regrowth in Southwestern Australia, and the water purification and nutrient cycling processes supported by wetland ecosystems in Uganda.

This global tour of freshwater biodiversity focuses attention on local, site-specific interactions between people and nature, whilst drawing out broader-scale themes about the value of freshwater life. As a result, the paper serves as a timely and convincing reminder to policy makers of the pressing need to conserve and restore freshwater ecosystems in the face of growing human pressures and climatic breakdown.

“We need a broader understanding that we are critically dependent on important ecosystem provided by biodiversity in freshwater ecosystems,” continues co-author Dr. Dave Tickner from WWF UK. “We urgently need to slow down the loss of biodiversity.”

“Freshwaters have been managed primarily as an important resource rather than as the special and sensitive habitat for an extraordinary variety of organisms that provide all these functions,” concludes Dr. Abigail Lynch. “Policymakers can integrate biodiversity conservation more fully into water management.”

The nine key things we need from freshwater biodiversity 

Food: Although we usually think of fish when we think of food from freshwater, the list is large and ranges from animals to plants to microorganisms.

Other animal and plant products: Materials from freshwater are used to make utilitarian and ornamental items, such as clothes made from fish leather, nail files from fish scales and scissors from piranha teeth. Aquatic plants are used as building materials and furniture.

Health and genetic resources: Algae, aquatic plants and animal products – from collagens from fish to secretion products from frog skin – are used in medicine and pharmacology.

Recreational opportunities: The recreational activities enabled by freshwater biodiversity are considered cultural services. Swimming and boating take place where the water quality is considered good. This is directly related to the living organisms in the water body, which can prevent algal blooms, for example.

Importance for culture, religion and spirituality: Almost all cultures around large lakes or rivers have rituals and traditions linked to the creatures who live there.

Opportunities for education and technological advancement: From formal curricula in primary schools to targeted extracurricular activities for youth – education schemes help to build connections and foster a lifelong commitment to freshwater conservation and responsible stewardship.

Climate regulation: Freshwater ecosystems are critical for the storage and sequestration of carbon and methane.

Catchment integrity: Riparian and aquatic plants reduce water velocity, improve bank stability, retain sediments, and filter nutrients and pollutants.

Self-purification of water and nutrient cycles: Billions of microorganisms, plants, algae and animals clean freshwater ecosystems by filtering excess nutrients, pathogens and pollutants. This is crucial for drinking water production.


Lynch, A. J., Cooke, S. J., Arthington, A. H., Baigun, C., Bossenbroek, L., Dickens, C., Harrison, I., Kimirei, I., Langhans, S. D., Murchie, K. J., Olden, J. D., Ormerod, S. J., Owuor, M., Raghavan, R., Samways, M. J., Schinegger, R., Sharma, S., Tachamo-Shah, R.-D., Tickner, D., Jähnig, S. C. (2023). People need freshwater biodiversity. WIREs Water, e1633.

Ecosystem restoration and nature-based solutions: how do they differ and why does it matter?

January 17, 2023
Freshwater catchments across the world are increasingly being restored using nature-based solutions. Image: Alexander Cahlenstein | Flickr Creative Commons

Awareness of the need to restore Earth’s ecosystems has become increasingly mainstreamed in recent years. The UN Decade on Ecosystem Restoration began in 2021, marking the start of increased efforts to halt the degradation of global ecosystems, and restore them to mitigate the effects of climate change and stop the collapse of biodiversity.

More recently still, the concept of nature-based solutions has entered the global environmental conversation. Nature-based solutions aim to manage natural processes to bring benefits to both people and ecosystems. For example, planting native forests in watersheds can help naturally filter water supplies, and reintroducing beavers can create the floodplain environments which buffer flooding.

As a result, the terms ecosystem restoration and nature-based solutions are often used interchangeably. And, of course, there is significant overlap between them: nature-based solutions are an increasingly central part of many restoration projects globally. But given the rapid growth of both approaches, it is useful to ask: how do they differ, and why does it matter?

Defining ecosystem restoration and nature-based solutions

As a starting point, it’s helpful to look at globally-agreed definitions of each approach. According to the International Standard for Ecological Restoration, restoration means, “assisting in the recovery of ecosystems that have been degraded or destroyed, as well as conserving the ecosystems that are still intact.”

On the other hand, the International Union for Conservation (IUCN) defines nature-based solutions as, “actions to protect, sustainably manage, and restore natural and modified ecosystems that address societal challenges effectively and adaptively, simultaneously benefiting people and nature.”

As these definitions suggest, the two concepts are similar and mutually supportive. However, the starting point of restoration is nature itself, whereas the starting point of nature-based solutions is societal needs and goals. Restoration’s focus on healthy ecosystems can, and often does, have benefits for society, but traditionally such benefits have not been the primary aim. This can make it harder to communicate the relevance of restoration actions to individuals and institutions who are not engaged in biodiversity conservation.

As a result, nature-based solutions represents a paradigm shift to a focus on how restoring ecosystems creates benefits for human well-being, economies and societies, particularly in terms of building resilience to environmental and climatic changes. It is often suggested that this focus on the human benefits of restoration projects can motivate more sectors of society, including economic bodies that affect, or are affected by, ecosystem degradation.

Restoration and nature-based solutions in a freshwater catchment

An hypothetical catchment helps imagine the impacts of restoration activities on freshwater ecosystems. Image: MERLIN

The MERLIN project supports the use of nature-based solutions in ambitious freshwater restoration projects across Europe. The diagram above shows a hypothetical freshwater catchment with many of the characteristics of the project’s real-life sites. These include rivers, streams and wetlands impacted by agriculture, hydropower and urban development. The hypothetical catchment helps us outline the subtle differences between ecosystem restoration and nature-based solutions approaches to management.

A restoration project in this catchment might aim to improve the extent and quality of wetland habitats by focusing on ecological connectivity through a range of activities to improve water quality, biology, morphology and hydrology. Actions that slow the flow of water through the landscape – such as upland rewetting – may also reduce downstream flood risks and provide some cultural ecosystem services such as increased landscape amenity. However, these are unlikely to be the main aims of the intervention. Restoration work in the catchment would not entirely ignore human activities in the landscape, but would seek to reduce the human impacts and pressures, as a means of restoring healthy, functional ecosystems.

On the other hand, a nature-based solutions approach in this catchment would start with a societally defined problem, such as flood risk management, and tailor its environmental management accordingly. For example, the use of Natural Water Retention Measures to protect communities and settlements would also consider other ecosystem services delivered by the catchment system, such as improving recreational access, or drinking water quality. Regulating extreme flooding events would likely benefit other economic sectors in the catchment, including agriculture, hydropower, navigation and water supply. Improvements to hydrological connectivity would benefit wetland habitats, but there is likely to be less attention paid to conservation issues such as tackling non-native invasive species.

Restoration and nature-based solutions in practice: planning, implementing and monitoring

These differences can often be seen in the way that projects are planned, implemented and monitored. Ecosystem restoration typically aims to restore ecosystem functioning, often through removing or mitigating significant human impacts. Interventions often aim to restore functional ecosystem units: in freshwater projects this can mean entire catchments, but in practice is often confined to smaller rural sub-catchments. Restoration is often planned, funded and carried out through public sector partners, and monitoring often prioritises ecological, biophysical and hydrological parameters.

Nature-based solutions, on the other hand, aim to support sustainable development by responding to societal challenges such as climate change mitigation, food security and flood risk. Each intervention is planned based on the scale of the challenge and the benefits required, and involves the collaboration of groups from across public and provide sectors. In this way, nature-based solutions have the potential to unlock more diverse sources of funding than traditional restoration approaches, such as through corporate investment and crowdfunding. Project monitoring often focuses on how well societal goals have been achieved through the use of nature-based solutions.

Balancing social and environmental needs in times of crisis

Nature-based solutions offer valuable tools to address the urgent need to achieve sustainable development and societal needs in the face of the climate and biodiversity crises. By responding to pressing social and economic needs they can potentially provide stronger arguments for environmental interventions than those based solely on the need for ecosystem restoration.

However, this utilitarian and human-centred framing brings inherent risks. Echoing previous debates over ecosystem services, nature-based solutions may focus attention largely on aspects of nature that are obviously useful, predictable and commodifiable. However, nature is inherently complex and dynamic: there are tradeoffs in what services it generates and for whom, and many of these services are irreplaceable even if they are not understood to be immediately responding to societal challenges. More broadly, nature has significant intrinsic value, and is worthy of conservation and restoration in its own right.

The eight criteria in the IUCN global standard for nature-based solutions. Image: IUCN

The IUCN global standard for nature-based solutions holds the potential to help mitigate these risks. Its eight criteria and associated indicators reflect insights from conservation practice and restoration ecology. Each criteria is equally important for guiding and evaluating action. For example, the standard requires all nature-based solutions to maintain and enhance biodiversity. It also highlights the likelihood of tradeoffs, and specifies the need for adaptive management in response to unpredictable changes in complex socio-ecological systems.

Whilst ecosystem restoration and nature-based solutions are sometimes used interchangeably, it is important to consider the different goals and scopes of the two approaches. The IUCN global standard for nature-based solutions offers a framework to help navigate the challenges of working with a wide range of societal actors – such as businesses – who may not be traditionally involved in environmental management. What matters is finding ways of living and working with nature that benefits both ecosystems and people.


Adapted from:

Kerry Waylen, Kirsty Blackstock, Alhassan Ibrahim, Esther Carmen, Keith Marshall, (2022), “Restoration or Nature-based Solutions: What’s the difference and why does it matter?”, Briefing Note, November 2022, MERLIN Project, James Hutton Institute, Aberdeen, Scotland.

This article is supported by the MERLIN project.

Top Posts of 2022

January 4, 2023
Image: Sonja und Jens | Flickr Creative Commons

In these early days of the new year we continue our annual tradition of looking back on the top posts of the previous year. 2022 was a big year for freshwater ecosystems, with increasing public and political attention focusing on the urgent need for their protection and restoration.

In mid-December, the UN Biodiversity conference COP15 in Montréal, Canada produced the Kunming-Montreal Global Biodiversity Framework, which outlines a series of global goals and targets for nature conservation and restoration. Crucially, the Framework highlights the need to protect ‘inland waters’ alongside land and sea environments.

Target 2 of the Framework commits governments to ensure that 30% of land, inland waters and sea are restored by 2030, whilst Target 3 states that 30% of land, inland waters and sea should be effectively conserved and managed by 2030. The targets are ambitious, and the timelines are relatively short, but the explicit role of freshwaters in the Framework is a significant moment, and follows years of concerted campaigning and advocacy.

Thank you to everyone who read our articles in 2022, we’re looking forward to another busy year, and are grateful of your support. Here’s our top posts from last year – happy 2023!


What are nature-based solutions and why do they matter? (January)

Catskill Mountains over Ashokan Reservoir: the watershed provides New York City with the “champagne of drinking water”. Image: John Cudworth | Flickr Creative Commons

Open a tap in New York City and flows what many locals call the “champagne of drinking water”. New York is one of the few cities in the USA with a public drinking water supply that doesn’t rely on expensive filtration plants. And the reason for this “champagne” supply? The network of forests, streams, lakes and reservoirs in Catskill Mountains watershed to the north of the city. Estimates suggest that if it wasn’t for the natural filtration processes occurring in the watershed the city would have to invest more than $10 billion in water filtration facilities.

The natural processes occurring in the Catskill watershed thus provide a range of environmental, social and economic benefits to local communities. Such aspirations are at the heart of a recent turn in environmental management towards so-called “nature-based solutions”, which aim to use natural processes to help tackle socio-environmental challenges such as climate change, biodiversity loss and flooding. (read more)


What is the European Green Deal and what does it mean for freshwater life? (February)

The European Green Deal has ambitious goals to transform European economies towards a low-carbon future. Image: Symbolique 2006

In December 2019, the European Commission presented its European Green Deal, a new set of policy initiatives aimed at making the EU climate-neutral by 2050. Described by Ursula von der Leyen, the president of the European Commission, as Europe’s “man on the moon moment,” the Green Deal has wide-ranging ambitions to support environmental protection, green economies, sustainable agriculture and technological innovation across the continent. But what exactly does the Green Deal aim to do, and how might it impact Europe’s freshwater ecosystems? (read more)


IPCC Climate Change 2022: Six Themes for Freshwater Ecosystems (March)

Flooding on the Santa Fe River, Florida. The new IPCC report suggests that extreme flooding and drought events will become increasingly frequent under ongoing climate change. Image: Florida Fish and Wildlife | Flickr Creative Commons

Human-induced climate change is causing significant disruption to global ecosystems and the lives of billions of people who depend on them, according to the latest Intergovernmental Panel on Climate Change (IPCC) Working Group Report, released this week.

The Working Group Report suggests that assessments of climate change impacts on freshwater systems have been limited in previous reports. As a result, this report devotes significant space to assessing how freshwater systems are responding to ongoing climate change, and the potential opportunities for mitigation and adaptation. These assessments build on reviews of cutting-edge freshwater science and management, from which six key themes are highlighted here. (read more)


Restoring Wild Haweswater: an interview with Lee Schofield (March)

Wild Haweswater in the English Lake District. Image: Wild Haweswater

Restoration is rarely a straightforward process: its ecological trajectories can be slow and uncertain, and often require the collaboration of numerous different people and organisations across a landscape. As a result, there is real value in finding out about how successful restoration projects have been planned and carried out.

Wild Haweswater is one such project. Located in the Lake District National Park in north-west England, the restoration of the Haweswater valley has been carried out alongside traditional hill farming, as a means of benefiting biodiversity, water and local communities. We spoke to Lee Schofield, RSPB Site Manager at Haweswater, to find out more. (read more)


‘Risky habitats’: managing disease risk in wetland restoration (May)

Beaver reintroduction site in Sweden: research suggests that environmental managers need to be mindful of the potential disease risks posed by wetland restoration. Image: Frauke Ecke

The emergence of infectious diseases is an inherently environmental process. Evidence shows that the majority of diseases (such as Ebola) and almost all pandemics (such as COVID-19) are zoonoses, caused by microbes of animal origin. These microbes can ‘spill over’ into humans through contact with wildlife and livestock. Moreover, environmental degradation, agricultural expansion and biodiversity loss can all drive the emergence of disease through the disruption of ecological networks, and the creation of new ones.

Could ecological restoration help reduce disease risk, then, by supporting healthy ecosystems with natural checks on zoonosis transmission? Not necessarily, according to Dr Frauke Ecke, speaking in a MERLIN webinar last month. Dr Ecke’s work challenges the view that ecosystem restoration necessarily mitigates disease risk. Instead, she argues for a more nuanced understanding of the potential outcomes of restoration. She asks, can wetland restoration actually cause ‘ecosystem disservices’, which are harmful to human health? (read more)


Fantastic Freshwater: 50 landmark species for conservation (May)

Starry night harlequin toad. Image: Fundacíon Atelopus

A dappled ‘starry night’ toad, lost to science for decades, but recently documented on indigenous lands in Colombia. An iridescent blue-banded kingfisher native to tropical streams on the island of Java. A West African tree-climbing crab which makes its home in tree holes filled with rainwater. These are some of the wonderful, but highly threatened, freshwater species highlighted in a new report authored by some of the world’s leading conservationists.

Released last week by the Shoal organisation, the Fantastic Freshwater report showcases fifty unique freshwater species threatened with extinction. These include a giant catfish, almost three metres in length, which migrates huge distances through the Mekong Delta, and a microscopic star-shaped fungi known from only two sphagnum bogs in Wisconsin, USA. Other wonders include a nocturnal Japanese firefly which flashes and buzzes through evergreen riverside forests, and a reclusive hairy-nosed otter native to wetland forests across southeast Asia. (read more)


Major new Nature Restoration Law proposes restoring 20% of European ecosystems by 2030 (June)

Removing barriers such as weirs and dams which fragment European rivers is a key focus of the new Nature Restoration Law proposal. Image: Keith Gallie | Flickr Creative Commons

The European Commission published a proposal for a major new European Nature Restoration Law yesterday. The proposal suggests a series of new binding targets to restore 20% of the EU’s land and sea by 2030, alongside deadlines for the restoration of important natural habitats. Further, it suggests that all European ecosystems in need of restoration should be restored by 2050.

The proposed Nature Restoration Law is an indication of the vital contemporary importance of ecological restoration, both in Europe and worldwide. The proposal is intended to build on existing environmental policy such as the EU Green Deal and Biodiversity Strategy for 2030 to ensure that Europe’s ecosystems are restored, resilient and adequately protected. (read more)


Creativity and conservation: a Red List of creatures of Scandinavian folklore (July)

‘The fairies’. Image: © Linnéa Jägrud / Tore Hagmans

Linnéa Jägrud is a limnologist based in Gothenburg, Sweden. Her work in MERLIN addresses peatland restoration in Sweden. Over the course of a year, Linnéa travelled with photographer Tore Hagman across Sweden to trace the landscapes of Nordic folkloric creatures called ‘vaesen’. As Linnéa explores in this guest article, their search for vaesen reveals the deeply-rooted cultural and historical connections to nature in Swedish landscapes. These connections can, in turn, deepen our modern-day understandings of ecological conservation and restoration. (read more)


MERLIN: Bringing Europe’s freshwaters back to life (September)

The MERLIN project held its first all-partner meeting last week in Fulda, Germany. Scientists, restoration managers and industry stakeholders all took part in valuable discussions over how best to mainstream freshwater restoration in Europe.

A new video exploring the key issues around the project was premiered at the meeting. A collaboration between the Schneeaufmoss creative agency and MERLIN partners, the video outlines five key challenges for contemporary freshwater restoration, and how the project is tackling them. Packed with beautiful footage of the continent’s waterways, the video is narrated by Christian Cummins of FM4 Radio.

The new video follows the recent launch of the first MERLIN podcast. A second podcast was recorded at the meeting, exploring ideas around transformation, disruption and inspiration as drivers of freshwater restoration. (read more)


Restoring Europe’s ecosystems to reverse biodiversity loss and build resilience to climate change (November)

A partnership of four major EU funded projects aims to restore European ecosystems. Image: WaterLANDS

Recent major reports on the state of the world’s climate and biodiversity clearly show the need for urgent, large-scale ecosystem restoration. Across the world, ecosystems are being degraded at rates faster than efforts to protect them, whilst ongoing climate change places increasing pressures on their health and functioning.

An awareness of the need to urgently restore healthy, resilient ecosystems underpins a partnership of major EU funded projects: WaterLANDS, SUPERB, REST-COAST, and MERLIN. Addressing the restoration of wetlands, forests, coastlines and freshwaters respectively, the projects have been funded to support the European Green Deal’s aspirations of a low-carbon, climate resilient future.

Each project aims to demonstrate how best-practice approaches for ecosystem restoration can be applied and upscaled across the continent. They are each developing innovative ways of implementing nature-based solutions in restoration to benefit ecosystems, societies, and even economies. Central to this work is the need to effectively monitor and share the results of ecosystem restoration to help wider global communities plan effective restoration strategies. (read more)


You can read all of 2022’s posts here. Thank you for reading!

Tracking the ecological, social and economic benefits of freshwater restoration in Europe

December 14, 2022
The MERLIN case study portal helps track the ecological, social and economic benefits of freshwater restoration across Europe. Image: MERLIN

The MERLIN project has recently launched its online case study portal. The portal provides interactive access to the seventeen freshwater restoration sites supported by the project. These sites include small streams and basins, large transboundary rivers, and peatlands and wetlands.

The portal offers in-depth information on each case study, including details of restoration activities and key stakeholders involved in their implementation. It outlines innovative approaches to restoration management, governance and financing across each case study.

The portal will help illustrate how each restoration project progresses over the coming years. In so doing, it will show how restoration helps contribute to European Green Deal goals. Further, it will help track and evaluate how new nature-based solutions are applied across the restoration projects.

The seventeen MERLIN freshwater restoration case studies are located across Europe. Image: MERLIN

In order to monitor progress towards Green Deal goals, the MERLIN team have identified indicators relating to seven key goals. These include biodiversity gains, climate regulation, flood and drought resilience, sustainable food systems, participatory governance, restoration financing, and green growth.

A key theme is that these indicators are broader in scope than traditional ecosystem-focused approaches for evaluating restoration projects. Biodiversity is still a vital part of restoration ambitions: for example, MERLIN researchers monitor trends such as conservation status of threatened species and ecosystems.

However, the focus for restoration goals in MERLIN is much broader. Greenhouse gas emissions are monitored to assess the role of restoration projects in climate regulation, whilst the water storage capacity of rivers and wetlands indicates their role in mitigating floods and droughts.

Each case study page features detailed information on the management, governance and financing of restoration activities. Image: MERLIN

This broader focus also extends into food production and governance. MERLIN researchers monitor how land is used in restoration catchments, as a means of assessing their role in sustainable food systems. They also track the participation of public and stakeholder groups in having a voice in the governance of the restoration projects.

Finally, the relationships between restoration and economics are increasingly at the forefront of environmental management and policy. MERLIN researchers document how innovative – and often private – streams of restoration financing may be mobilised, and their potential role in fostering green growth in the case study areas.

The intention is that case study portal will provide detailed insights into the real-world impacts of freshwater restoration projects across Europe. By highlighting the ecological, social and economic benefits of restoration activities, it is hoped that the portal will provide a beacon of inspiration for others seeking to undertake similar projects across the world.


This article is supported by the MERLIN project.