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Managing and restoring fragmented Anthropocene rivers

October 19, 2021
Altered flows on the River Reuss, Switzerland: a new study offers suggestions for managing fragmented Anthropocene rivers. Image: Kurt Stocker | Flickr Creative Commons

Rivers are hotspots for global biodiversity, and bring a host of benefits to both humans and the catchments through which they flow. However, river systems across the world are increasingly fragmented by dam and hydroelectric construction, and by droughts exacerbated by climate change.

Healthy river systems depend on environmental processes taking place across entire landscapes: from wetlands, springs and sources through tributaries and channels as waters flow towards an estuary. Scientists increasingly recognise that the health of river system depends on these catchment processes being connected and free-flowing.

“Flows of water, nutrients, sediment, fish and insects through catchments all require well-connected river courses,” says Dr. Thibault Datry, a freshwater scientist at INRAE. “To adequately consider this connectivity in management, monitoring or restoration plans for rivers requires a broad, so-called river-network, approach. However, the majority of practices and policies for freshwater ecosystem management are based on local scale processes.”

Dr. Datry and a team of colleagues led by Dr. Núria Cid Puey, have published a new study seeking to address this issue. Writing in Frontiers in Ecology and the Environment, the research team argue that sustainable management of rivers in the Anthropocene – the present global epoch in which humans cause wide-scale changes to Earth environments – requires approaches which span entire catchments.

“The scientific understanding of how biodiversity and ecosystems are organised in dynamic river environments has progressed substantially in the past decade,” says Dr. Datry. “In particular, meta-system theory tells us how local populations, communities and ecosystems are connected by gene flows, the dispersal of individuals, and flows of resources across a landscape.

“Our paper proposes that this metasystem approach can, and should, be better integrated into conservation, restoration and biomonitoring of rivers,” says Dr. Datry. “We recommend a series of measurements and indicators that could be integrated into European and national biodiversity and water governance to make management of river networks fit for the Anthropocene.”

The research team, supported by the ALTER-Net High Impact Action initiative, outline that river fragmentation – for example, through dam construction – doesn’t only affect local biodiversity and water flows, but can have cascading impacts on wider catchment ecosystems. For example, fragmentation can isolate populations of species which live across a river system, meaning that gene flows and biological interactions are reduced.

This fragmentation of a river system can have significant effects on how its ecosystems function, and the benefits they can bring to people. For example, the decomposition of leaf litter – a key source of nutrients to river ecosystems – is particularly impaired by fragmentation, so altering nutrient cycling across catchments.

The research team propose three recommendations for river policy and management in the Anthropocene. First, they suggest that conservation management needs to identify how ‘metapopulations’ of species are spread across river catchments, and design protected areas which ensure their ongoing health.

Second, they identify the need to develop methods for monitoring the connectivity and fragmentation of river systems in order to understand how species move across catchments. This work could allow the identification of key sites for species to recolonise river systems through restoration initiatives.

Third, the team advocate for adaptive ecosystem-based management which is based on an understanding of the flows of water, sediment, nutrients and species through a river system. They outline the need for management which addresses biodiversity and ecosystem processes, and the benefits they provide, across entire catchments.

In so doing, the team suggest that fragmented Anthropocene rivers might be better protected and restored, so contributing to the implementation of major environmental policies such as the European Biodiversity Strategy, the US Endangered Species Act and the Aichi Biodiversity Targets.

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Cid, N, et al (2021), “From meta-system theory to the sustainable management of rivers in the Anthropocene”, Front Ecol Environ; doi:10.1002/fee.2417

Mainstreaming freshwater restoration in Europe through MERLIN

October 1, 2021
Beaver reintroductions are restoring natural processes to the Torringen area of Sweden. Image: MERLIN

Europe’s environments are in an alarming state. Despite decades of environmental action and policy, human activities continue to alter, degrade and destroy ecosystems across the continent. All of this comes with a cost, not only to the rich biodiversity European ecosystems support, but also to the human communities who rely on nature for food, water, jobs and well-being.

As a result, there is a pressing need for damaged ecosystems to be brought back to life through ecological restoration across Europe. Freshwaters are key to such transformative change. As this blog has documented, freshwaters are vital ‘life support systems’ for both humans and wildlife alike.

Rivers, lakes, peatlands and wetlands create a host of benefits for people: drinking water, flood protection, water filtration, carbon storage, food supplies, tourism, and mental well-being, amongst numerous others. However, when freshwater habitats are degraded and destroyed, their ability to provide such benefits to people is impaired.

This was seen recently in the flood disasters across Germany and Belgium, where decades of heavy river engineering coupled with extreme rainfall as a result of climate change created the conditions for catastrophic flooding. These floods are stark evidence of how the ongoing impacts of climate change are being intensified by the degradation of natural freshwater habitats.

Wildflowers bloom on the banks of the Emscher River, Germany. Image: MERLIN

MERLIN: supporting innovative freshwater restoration in Europe

But what can we do about the situation? MERLIN, a major new EU-funded project, launched today, has ambitious goals to kick-start the restoration of Europe’s freshwater environments over the coming years.

The MERLIN project involves 44 partners from across Europe, including universities, research institutes, nature conservation organisations, and stakeholders from business, government, and municipalities. One of four flagship restoration projects in the EU Green Deal, the project will invest €10 million into restoring rivers, lakes, peatlands and wetlands across the continent.

“Water bodies and their floodplains need more space – they have to be renaturalised,” says MERLIN co-ordinator Prof. Daniel Hering from the University of Duisburg-Essen (UDE), Germany. “One focus is on cooperation with industries that can benefit from restoration, for example agriculture, drinking water production and insurance companies,” Prof. Hering outlines.

MERLIN will support 17 ongoing freshwater restoration projects across Europe. These include the restoration of heavily modified rivers, such as the Emscher catchment in Germany; wetland restoration, such as in Kampinos, Poland; the reconnection of natural floodplains, such as on the Danube River across Austria and Hungary; and dam removal, such as on the Oulujoki Iijoki catchments in Finland.

The location of the 17 MERLIN restoration case studies across Europe. Image: MERLIN

Nature-based Solutions bring benefits to humans and ecosystems

A key theme across all the case studies is that freshwater restoration can bring about multiple benefits, both for humans and ecosystems. The MERLIN project seeks to learn from these sites to develop best practice approaches for innovative environmental restoration management. It will also examine how these approaches can be scaled-up across catchments and the continent.

More broadly, the project aims to use evidence from these sites to place freshwater restoration at the heart of contemporary environmental policy and management aiming for sustainable, low-carbon futures. The benefits of freshwater restoration will be quantified, both ecologically and economically, as a means of strengthening arguments for its implementation.

Nature-based Solutions are an important part of the tool-kit for achieving this goal. Nature-based Solutions are actions to manage and restore ecosystems which simultaneously provide human well-being and biodiversity benefits. For example, reconnecting rivers to their floodplains has the potential to both restore lost habitats, and provide enhanced natural flood protections.

“Many social groups benefit from restoration, and it requires the contribution of many actors,” says MERLIN co-ordinator Dr. Sebastian Birk of the UDE Aquatic Ecology Working Group. “Restoration contributes to improving residential environments and creates local recreation areas,” Dr. Birk continues.

The River Forth, Scotland flowing through heavily modified agricultural landscapes. Image: MERLIN

Placing freshwater restoration at the heart of European environmental policy and management

MERLIN will bring together new communities of scientists, policy makers, conservationists, environmental managers and the public across Europe to develop Nature-based Solutions for contemporary freshwater restoration. Through training, knowledge-sharing and engagement, these results will be shared extensively with new networks of restoration practice across the continent.

In so doing, the project will support the new EU Green Deal, which states that climate change and environmental degradation present a stark, existential threat, both to Europe and globally. Over the coming years and decades, the Green Deal aims to transform the EU into an economy with no net emissions of greenhouse gases by 2050, and where economic growth is decoupled from resource use. MERLIN’s focus on freshwater restoration will support such goals, particularly those around zero pollution, ecological recovery and circular economies.

“MERLIN is an ambitious project which will demonstrate the importance of transformative freshwater restoration for people and biodiversity across Europe,” says Dr. Birk. “This is the beginning of a positive and productive plan to bring freshwater habitats across the continent back to life, sparking a host of benefits for all our lives,” Dr. Birk states.

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MERLIN – Mainstreaming Ecological Restoration of freshwater-related ecosystems in a Landscape context: INnovation, upscaling and transformation

MERLIN on Twitter

Restoring Danube sturgeon populations through ex-situ conservation

September 28, 2021
A juvenile Russian sturgeon is stocked into the Danube River as part of the MEASURES ex situ conservation programme. Image: Thomas Friedrich | MEASURES

Sturgeon are remarkable fish, sometimes called ‘living fossils’ with a slow evolutionary heritage spanning millions of years. Many sturgeon species are large and long-lived, with a so-called ‘anadromous’ lifespan traced by migrations between fresh- and saltwater environments.

Sturgeons are thus sensitive to a range of environmental pressures, and as a result, are often termed ‘flagship’ species for the wider health and connectivity of freshwater ecosystems. However, many sturgeon species are significantly threatened by human impacts, particularly the harvesting of their roe for caviar. This is often coupled with wider threats around habitat loss and the fragmentation of migration routes in river systems, for example through the construction of hydropower dams.

The Danube River has six native species of sturgeon, all of which are threatened by human activities. The European sturgeon (Acipenser sturio) and Ship sturgeon (A. nudiventris) are locally extinct, Beluga sturgeon (Huso huso), Russian sturgeon (A. gueldenstaedtii) and Stellate sturgeon (A. stellatus) are on the very brink of extinction, with the sterlet (A. ruthenus) being endangered.

Restocking sturgeon bred in ex situ conservation projects in the Danube River, Romania. Image: George Caracas | WWF Romania

To address widespread declines in Danube sturgeon populations, the MEASURES project has implemented a series of conservation and restoration measures across the basin. A key element of this work is the ex-situ conservation of Danube sturgeon. Ex-situ (or ‘off-site’) conservation is the process of protecting an endangered species by maintaining and breeding captive populations in an artificial environment, reflecting the genetic diversity in the wild.

The MEASURES project used ex-situ conservation techniques to strengthen the populations of two Danube sturgeon species: the sterlet and the Russian sturgeon. The project developed facilities where eggs harvested from autochthonous broodstock could be incubated in Danube river water where natural conditions such as temperature fluctuations and food sources could be replicated and imprinting of the fish on their natal waters can take place.

This initiative was based on the latest recommendations for ex-situ conservation by experts from the Danube Sturgeon Task Force and World Sturgeon Conservation Society affiliated with the MEASURES project. The use of natural river conditions in ex-situ sturgeon conservation has already been demonstrated on a small scale in the Austrian-Slovakian LIFE-Sterlet project.

Design for an ex situ sturgeon conservation facility. Image: BOKU

Key to this process was the conservation of the native genotypes in the captive sturgeon populations. MEASURES researchers undertook generic analysis of the captive sturgeon broodstock in order to ensure that their offspring maintained the genetic diversity of native populations.

This analysis also allowed MEASURES researchers to better understand genetic connectivity of sturgeon populations across the Danube basin. This mapping of the ‘living gene banks’ of Danube sturgeon is a key element of the Pan European Action Plan for Sturgeons, released in 2018.

“Sturgeons are important natural heritage in the Danube River Basin and it is our responsibility to preserve them for future generations,” says Dr Thomas Friedrich, sturgeon expert at BOKU, Vienna. “While ex situ actions are at this point of utmost priority to safe the remaining gene pool, the future of our sturgeons lies in the Danube.

“Therefore, we also have to target the restoration of the ecological corridor in order for the releases to be sustainable and enabling natural reproduction and recovery in the wild,” continues Dr Friedrich. “The cooperation between the MEASURES and LIFE-Sterlet projects, as well as the WePass project, the DTF, WSCS and other stakeholders ultimately led to the implementation of necessary steps on the path to sturgeon recovery in the Danube River Basin.”

The young sturgeons reared in hatcheries are tagged and released back into the river. Their tags will give researchers new information on their migratory journeys to sea and back, which will in turn help shape future conservation and restoration planning in the Danube basin.

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Funded by the EU as part of the Danube Transnational Programme, MEASURES aimed to improve habitat quality and connectivity along the Danube in order to support populations of threatened sturgeon species, as well as other migratory fish and wider aquatic biodiversity in the basin.

Troubled Waters: pollution threatens the health and status of UK freshwaters

September 21, 2021
The River Teifi in Wales, one of the case studies in the new Troubled Waters report. Nutrient pollution and sediment run-off in the Teifi catchment threatens its biodiversity. Image: Robert Haandrikman | Flickr Creative Commons

Poor water quality as a result of widespread pollution is threatening UK freshwater habitats and biodiversity, according to a newly published report. This is despite a significant proportion of the UK population stating that freshwater habitats are a ‘national treasure’ in need of improved protections.

The Troubled Waters report, released last week, was commissioned by a partnership of environmental charities including the RSPB, the Rivers Trust and the National Trust. It outlines how rivers, lakes, ponds, wetlands and streams across England, Wales and Northern Ireland are being significantly affected by agricultural waste, raw sewage, chemical pollution from mines, plastic and pharmaceutical waste.

The report states that the majority of water bodies across the UK fail to reach EU standards for good ecological status. In England and Wales, only 14% and 46% of rivers respectively are rated as having good ecological status, whilst only 31% of Northern Irish waterbodies are classified as good or high quality.

The good ecological status standards are set through the EU Water Framework Directive, which aims to focus environmental policy and management on improving the health and diversity of freshwater ecosystems. However, the new report states that despite concerted efforts many UK freshwaters remain in poor and declining ecological states.

“It is no surprise so many people think of our waterways as a national treasure and revel in the magical sight of otters playing in our streams, dragonflies hovering like jewels above our lakes and the vibrant flash of kingfishers in flight,” says Jenna Hegarty, RSPB Deputy Director of Policy.

“But  nature is in crisis and  the incredible freshwater wildlife people marvelled  at  as they explored our countryside this summer  is a fraction of what should be there,” Hegarty continues. “It is disturbing how it has become so normal for our waterways to be polluted and contaminated, and that  many people do not realise there is something wrong.”

Poor water quality in UK freshwaters has numerous negative effects for both wildlife and human communities. Through a series of case studies, the report highlights issues including biodiversity losses as a result of eutrophic algae blooms and pollution incidents, reductions in the structure and stability of freshwater food chains, and the dangers to human health, particularly in waters which are used for bathing and wild swimming.

“Freshwater biodiversity is declining at an accelerated rate when compared with marine and terrestrial organisms,” says Gail Davies-Walsh, CEO of Afonydd Cymru. “This decline in freshwater life is accompanied by  the  widespread  eutrophication of many of our rivers. 

“Eutrophication gives rise to algal blooms which  occur when too many nutrients enter the water column,” continues Davies-Walsh. “These blooms deplete the oxygen in the water to a degree that aquatic life are suffocated. Algal blooms are only one of the many pressures on our precious water resources that need addressing.  Immediate action is required to protect and enhance our blue spaces for current and future generations.” 

Birds in flight over Leighton Moss, a case study in the report where diffuse pollution is causing water quality issues. Image: Ian Livesey | Flickr Creative Commons

The report authors commissioned a YouGov survey to understand UK public perception of freshwater habitats and the issues they face. The majority of respondents (88%) agreed that UK freshwaters are a ‘national treasure’, and similarly (87%) that there is a need to better protect them.

“This report helps to quantify what those of us working closely with rivers have suspected for a while: the public’s appreciation of rivers as natural heritage has grown in recent years, especially as they have become an important refuge and recreational space during Covid, and our shared concern about the pressures rivers are facing is growing even faster,” says Mark Lloyd, CEO of The Rivers Trust. “This should send a  clear signal to government and businesses to start prioritising nature based solutions to improve the state of our rivers.”

The report concludes with six recommendations to help improve the health and status of UK freshwaters. First, it advocates for a systemic change to the UK planning approval system, in order to promote catchment-based approaches to freshwater management. Second, it highlights the need to shift towards ‘nature-friendly’ farming practices which generate significantly less pesticide and fertiliser pollution run-off.

Third, the report states that an improved set of long-term, legally-binding targets is needed for UK governments to drive improvements in freshwater quality and biodiversity. Fourth, it highlights the need for water companies to stop untreated sewage from reaching rivers, particularly through the use of combined sewer overflow systems.

Fifth, the report outlines that environmental agencies should be supported to carry out water quality monitoring and policy enforcement to better hold polluters to account. Finally, it highlights the need to better monitor protected sites across the UK to effectively implement environmental management schemes.

“Our rivers are facing a range of pressures, some of which are new and some of which have been causing pollution for decades, says Karen Whitfield, Joint Director of Wales Environment Link. “Impacts that local people might not have been aware of previously are now so bad that they are visible to communities, who can see and smell the pollution and have noticed the loss of wildlife.

“We need serious leadership from our regulators in tackling this pollution urgently, so that wildlife and local communities can benefit from clean rivers and lakes,” Whitfield states. 

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Read the Troubled Waters report.

Rights of Rivers at the IUCN World Conservation Congress 2021

September 10, 2021
The Whanganui River in New Zealand, the first river to be granted ‘legal personhood’ rights in 2017. Image: Tim Proffitt-White | Flickr Creative Commons

Today is the final day of the IUCN World Conservation Congress 2021, held in Marseille. The Congress has brought together over a thousand participants from government, academia, public and indigenous peoples’ organisations to set priorities for global conservation and sustainable development.

Freshwater ecosystems are one of the seven key themes addressed by sessions at this year’s Congress. Alongside numerous freshwater events, two plenary sessions (here and here) and a forum outlined the key pressures facing global freshwaters, and discussed how they could be managed under policy frameworks such as the Convention on Biological Diversity 2021, held next month in Kunming, China.

The Congress programme states that environmental rights and equitable governance are crucial in protecting freshwater ecosystems, and supporting the human communities that depend on them. It asks, “How can existing laws, policies, and institutions be strengthened and adapted to ensure the more effective and sustainable management of water resources at the local, national and transboundary levels? How can we effectively strengthen governance and stewardship to maintain healthy watersheds, and address pollution and contamination?”

One response to these questions comes in the form of the Rights of Rivers movement, highlighted at the Congress. The movement states that all rivers should be regarded as living entities that possess legal standing in a court of law. This means that ‘fundamental rights’ of rivers – such as free flows, protection from pollution, biodiversity habitat and ecological functioning – are given strong legal protections.

A Rights of Rivers session at the Congress marked the one year anniversary of the launch of the Universal Declaration of the Rights of Rivers, which sets out the basic rights to which rivers should be entitled. This outlook contrasts with established environmental legal frameworks, which recognise ‘nature’ as human property to be managed. Instead, the Rights of Rivers movement states that rivers and their watersheds are living entities with inherent rights to be conserved and restored.

“It is obvious that effective river management works best at the basin scale, and ‘river rights’, as described in the Declaration, is a very important way of achieving this and ensuring protection of ecosystem integrity,” says Angela Andrade, Chair of IUCN’s Commission on Ecosystem Management.

Five years ago we covered the landmark ‘legal personhood’ designation of the Whanganui River in New Zealand. The legislation gives the right for the indigenous Whanganui tribe to speak for the river in the country’s courts, and to file lawsuits on its behalf when environmental protections are not upheld. This approach can be seen as a type of co-management, through which the rights of the river, and its health and diversity, are upheld through decision-making involving local Maori tribes.

Passed in 2017 by the New Zealand parliament, the legislation named the Whanganui as the first river in the world to be recognised as an indivisible and living being. In essence, this outlook shifts the management frame from seeing freshwaters as a resource to be exploited towards understanding them as living entities which should be sustainably guided towards ecologically healthy futures, for both humans and non-humans alike.

Communities on the banks of the Atrato River, Colombia, which was awarded legal rights in 2017. Image: Agencia Prensa Rural | Flickr Creative Commons

“Western law and culture often treat rivers as a human resource instead of recognising the reality that they are living systems,” says Jessica Sweidan, Co-founder and Trustee of Synchronicity Earth and IUCN Patron of Nature. “An important step towards correcting this falsehood is for rivers and other natural entities to be recognised in law as legal entities with intrinsic rights.” 

“The playbook for protecting rivers and watersheds must evolve beyond the traditional environmental law approaches we’ve been using since the 1960s, as such laws are helpful but grossly inadequate,” says Grant Wilson, Executive Director of Earth Law Center. “The Declaration is a useful legislative starting point for those wishing to promote new, Earth-centred legal protections for fresh waters.”

Since the Whanganui legislation was passed, a number of other global rivers have been granted similar declarations of rights. In 2017, broadly similar legislation was passed for the Atrato River in Colombia and the Ganga and Yamuna Rivers in India. In the last year alone, examples include Boulder Creek and the Boulder Creek Watershed ( USA), the Magpie River (Canada), waterways in Orange County, Florida (USA), the Alpayacu River (Ecuador), and the Paraná River and Wetlands (Rosario, Argentina).

The Universal Declaration of the Rights of Rivers has been gaining global support since its release last year. Last week, 16 IUCN members co-sponsored a motion calling on the IUCN to endorse the Declaration, although it did not pass. However, advocates for the Rights of Rivers approach suggest that the Declaration offers a powerful and customisable legal model for global governments to strengthen their freshwater conservation and restoration policies.

Can such a model be embraced by policy makers attempting to manage rivers in complex and dynamic contemporary environments? How can it fit with, and even enhance, existing freshwater conservation and restoration schemes? It will be fascinating to trace the development of these debates over the coming years.

“Globally, rivers have enormous social, cultural, environmental, and economic value, but are becoming progressively more threatened,” says Kristen Walker, Chair of IUCN’s Commission on Environmental, Economic and Social Policy. “The Rights of Rivers approach is becoming increasingly important for ensuring that they can continue to provide these essentials to benefit nature and the people who rely on them.” 

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Find out more about Rights of Rivers

Read the Rights of Rivers: A global survey of the rapidly developing Rights of Nature jurisprudence pertaining to rivers report.

Shout Trout Workout: creative methods for communicating fish migration

August 23, 2021
Frame from the Shout Trout Workout cartoon. Image: FIRE Lab

The threats to freshwater ecosystems can sometimes be difficult to recognise. Aquatic life going on beneath the water’s surface is often hard to see, and pressures such as pollution can often be tricky to observe through opaque and murky waters.

The impacts of other key issues, such as habitat fragmentation, may not even register in public awareness of freshwater ecosystems. And, given the ongoing series of calls from conservationists for urgent action to halt the loss of global freshwater biodiversity, being able to engage people with the multiple threats faced by freshwaters is a key contemporary issue.

In this context, an international team has developed creative ways of engaging young people with issues around fish migration. The Shout Trout Workout is a lyric poem, comic and music video designed for 8–14 year olds. It uses artistic methods to communicate complex issues around declining migratory fish populations.

“We’re very passionate about fresh waters here at FIRE Lab.” says project lead Dr. Merryn Thomas, part of Swansea University’s Freshwater Interdisciplinary Research and Engagement Laboratory (FIRE Lab) which explores young peoples’ relationships with freshwater environments.

“We wanted to explain about fish migration in an educational and informative way, and think we achieved this through our interdisciplinary collaboration with passionate creatives and academics,” Dr. Thomas continues.

Frame from the Shout Trout Workout cartoon. Image: FIRE Lab

The project was developed in 2020 through a collaboration involving an environmental scientist, social scientist and artist from the FIRE Lab, alongside a fish scientist, illustrator and media production company.

The Shout Trout comic, designed by American illustrator Ethan Kocak, tells the story of a migratory sea trout’s lifecycle, through birth, migration and spawning. It highlights the habitats the sea trout passes through in its lifecycle, and the threats it faces at each stage. The lyric poem and video sets the comic themes to music.

“We learned a lot about co-creation along the way, which we hope will be useful for others who are interested in collaborating across boundaries to design inspiring engagement materials for young people about our natural environments,” says Dr. Thomas.

The research team have recently published an open-access journal article reflecting on the production of the project in the British Ecological Society’s People and Nature journal. The article discusses how their interdisciplinary collaborations required an openness to co-creation in shaping how key themes were communicated.

Significantly, they highlight the role of scientists in project contributing creative input to the production process to shape how scientific research is translated into artistic outputs. Here, as in other creative freshwater communication projects such as Water Lives…, the team highlight the need to balance scientific accuracy with artistic licence.

The team suggest that it is vital to engage young people with issues such as threats to fish migration in order to develop their environmental literacy for the future. They highlight how such projects have the potential to travel widely through online channels, through educational use in schools, and through workshops and events such as World Fish Migration Day.

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 Swansea University Freshwater Interdisciplinary Research and Engagement Laboratory (FIRE Lab)

IPCC Climate Change Report: Three Key Themes for Freshwaters

August 9, 2021
Extreme events including floods and droughts are predicted to increase due to climate changes over coming decades. Image: IPCC

Humans are altering Earth’s climate in unprecedented and potentially irreversible ways, according to the latest Intergovernmental Panel on Climate Change (IPCC) Report, released today.

The report is the sixth assessment of global climate science published by the IPCC since 1988, and is based on the collaborative review of peer-reviewed science by hundreds of experts across the world. It states that global climate change is widespread, rapid and intensifying, and that many ongoing observed climate changes are unprecedented in thousands, if not hundreds of thousands of years.

“This report reflects extraordinary efforts under exceptional circumstances,” says Hoesung Lee, Chair of the IPCC. “The innovations in this report, and advances in climate science that it reflects, provide an invaluable input into climate negotiations and decision-making.”

“This report is a reality check,” says IPCC Working Group I Co-Chair Valérie Masson-Delmotte. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”

The report states that climate change will increase globally in coming decades, bringing multiple potential impacts such as heat waves, droughts and flooding to different regions. “It has been clear for decades that the Earth’s climate is changing, and the role of human influence on the climate system is undisputed,” says Masson-Delmotte.


The complex impacts of multiple climate change pressures on aquatic systems are increasingly well-documented. In this context, the IPCC report highlights three overarching impacts on freshwater ecosystems arising from its assessment.

Intensification of the water cycle

The report states that ongoing climate change will cause the global water cycle to continue to intensify as global temperatures rise over coming decades. This means that some regions will experience more intense rainfall, and associated flooding, whilst others will experience intensified droughts. Overall, the impacts of such extreme events on freshwater systems are likely to increase in the future.

Increased variation in rainfall patterns

Precipitation patterns are also expected to alter globally over coming decades. The report suggests that precipitation will increase over high latitudes, the equatorial Pacific and parts of the monsoon regions, but decrease over large parts of the subtropics. Average annual global land precipitation is projected to increase under each scenario of future greenhouse gas emissions by 2100. Additionally, regional changes to monsoon rainfall patterns are predicted.

Impacts of warming on snow and ice melt

The report suggests that ongoing increases in air temperatures will amplify permafrost thawing, the loss of seasonal snow cover and the melting of glaciers and ice sheets. This has the potential to significantly affect water flows and habitat quality in freshwater ecosystem at high latitudes and altitudes, and potentially cause flooding issues downstream.

The message from the report is clear: act now to restrict global carbon emissions to minimise the harmful effects of future climate change. “Climate change is already affecting every region on Earth, in multiple ways. The changes we experience will increase with additional warming,” says IPCC Working Group I Co-Chair Panmao Zhai. “Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net zero CO2 emissions. Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate,” Zhai states.

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Read the IPCC Sixth Assessment Report, Climate Change 2021: The Physical Science Basis

IUCN survey suggests that almost half of Caribbean freshwater fish are threatened with extinction

July 31, 2021
The Zapata swamp in Cuba, home to the critically endangered ‘living fossil’ Cuban gar, which is increasingly threatened by the spread of non-native catfish. Image: Marjon Melissen | Flickr Creative Commons

The Caribbean islands are home to a rich diversity of freshwater life, including 79 species of fish which are unique to the region’s shallow streams, lakes and wetlands. However, a new IUCN survey suggests that 41% of Caribbean freshwater fish are threatened with extinction.

The survey represents the first comprehensive assessment of freshwater fish populations in the Caribbean. It shows that fifty-four of the region’s fish species are endemic to the two largest islands, Cuba and Hispaniola, with fewer other endemics found on smaller islands.

“Freshwater fishes are one of the most threatened groups of vertebrates on the planet,” says Tim Lyons, Species Survival Officer at the ABQ BioPark and project coordinator for the assessment. “When you think of the Caribbean, the first thing that comes to mind are visions of beaches and coral reefs, but freshwater fishes are just as important. We depend on them and the watersheds they live in for everything from food to energy.”

The survey suggests that freshwater fish populations in the Caribbean are subject to multiple pressures, including habitat loss, pollution and the spread of invasive non-native species. Whilst its findings are stark, it is hoped that the survey will provide a basis for conservationists and local communities to develop plans to conserve and restore freshwater ecosystems across the region.

“This new assessment sheds light on the critical need for directing more resources to conserving the unique freshwater fishes of the Caribbean, given they face a risk of extinction higher than the global average and include many species found nowhere else on Earth,” says Dr. Harmony Patricio, Conservation Programme Manager for Shoal.

A Jumbie Teta (Ancistrus trinitatis) on a shallow streambed in Trinidad. The species was assessed as Near Threatened due to its limited range and continuing habitat decline associated with human pressures. Image: Amy Deacon.

“Beyond the species known so far, the insular Caribbean holds an incredibly valuable diversity of freshwater fishes still to be discovered, described and understood,” adds Dr. Jose Ponce de Leon from the IUCN freshwater fish working group. “This IUCN report shows the overwhelming need of protecting Caribbean freshwater habitats and educating ourselves and others about their values and threats. This project is an important step in identifying conservation priorities in the Caribbean and highlights the value of collaborative research and inclusive strategic alliances for conservation biology.”

The spread of invasive non-native species was highlighted by the survey as a significant threat to freshwater fish populations in the Caribbean. Native to the Zapata swamp in Cuba, the Cuban gar can reach over two metres in length. Known as a ‘living fossil’, barely changed since the late Jurassic period, the Cuban gar plays an important apex predator role in wetland food webs. 

However, the spread of the African walking catfish (or ‘claria’) to the island following aquaculture introductions has significantly impacted populations of Cuban gar and other fish species. The catfish are large, mobile and predatory, and can outcompete gar and other species. As a result, the Cuban gar is now listed by the IUCN as critically endangered.

A juvenile Cuban gar. Image: Erik Garcia-Machado

Another key pressure highlighted by the survey is ongoing habitat loss and pollution. For example, Lake Miragoane is a coastal freshwater lake on the Tiburon Peninsula of southwestern Haiti. The lake supports 10 critically endangered fish species from the genus Limia – tiny livebearing fish – which are found nowhere else in the world. However, their populations are increasingly threatened by water pollution and deforestation around the lake.

“The primary threats to freshwaters in the Caribbean are consistent with the threats that are driving extinction in other parts of the world, and the extinction risk that these species face is a clear indicator of an ecosystem in distress,” suggests Tim Lyons. “The IUCN has declared 80 species of freshwater fishes extinct, with hundreds more likely to have gone extinct before their formal description or assessment on the IUCN Red List. We must act now to prevent unique Caribbean species from joining them.”

“These assessments are a critical step towards the conservation of freshwater fishes in the Caribbean,” says Dr. Yolanda León, President of Grupo Jaragua, an organisation based in the Dominican Republic which works on biodiversity conservation on Hispaniola.

Grupo Jaragua led the recent submission of an IUCN Resolution which recognises the Caribbean as a significant biodiversity hotspot, and calls for increased regional and international action to halt biodiversity loss. “The results of these Red List assessments will help identify freshwater conservation priorities that can address the objectives of that IUCN Resolution,” Dr. León suggests.

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IUCN Freshwater Fish Specialist Group

Rivercide: live-streamed documentary investigates river pollution in England and Wales

July 16, 2021

Earlier this week a new live-streamed documentary, Rivercide, was broadcast. The documentary, presented by environmentalist George Monbiot, investigates the impacts of pollution on British rivers.

“Our rivers should be beautiful, complex ecosystems,” says Monbiot. “But on our watch, they’ve become open sewers, poisoned by sewage and farm slurry. They’re dying before our eyes.”

Broadcast live from the banks of the River Wye, which runs between England and Wales, Rivercide features interviews with conservation scientists, wild swimmers, anglers, politicians, local residents and citizen scientists to document the ecological impacts of rising agricultural and urban pollution in the river catchment.

“Last year raw sewage was released into English rivers over 400,000 times, for over 3 million hours,” says Monbiot. “The Mogden Sewage Treatment Works in Twickenham spewed 3.5 billion litres of raw sewage into the Thames last year. On one day in October, they spilled over a billion litres, which is the equivalent of over 400 Olympic-sized swimming pools of raw sewage.

“As well as releasing faecal bacteria and other nasty chemicals into our water, untreated sewage includes pollution in the form of wet wipes and sanitary towels, leading to build-up of microplastics. And yet, nationally, sewage isn’t even the biggest polluter of our rivers. Agriculture is the sector responsible for most river pollution,” says Monbiot.

The documentary highlights how the regulatory bodies responsible for environmental regulation in rivers in England and Wales – the Environment Agency and Natural Resources Wales, respectively – have been subject to significant budget cuts in the last decade.

“Rivercide shows how the agencies charged with protecting our rivers have been progressively under-funded and under-resourced and are failing to adequately monitor water quality and enforce action against polluters,” says Monbiot. “For example, at current rates, the average farm can expect to be inspected by the Environment Agency once every 263 years.

“Rivercide investigates who’s polluting our rivers and why we’re allowing them to get away with it. We examine acute pollution incidents too – for example the tragic pollution of the Afon Llynfi in Wales which occurred last July, killing over 10,000 fish,” says Monbiot.

The Rivercide Emergency Rescue Plan. Image: Rivercide.

The documentary, produced on a limited Kickstarter-supported budget using mobile phone and drone streaming techniques, also features contributions from singer Charlotte Church and poets Owen Sheers and Benjamin Zephaniah.

“Rivercide is the antithesis of those deathly Zoom calls we’ve all had to endure this last year,” says award-winning director Franny Armstrong. “Yes, it’s using the same technology, but in spirit it’s the anarchic offspring of Springwatch and Challenge Anneka.

“You’d be hard pressed to find a single person in this country who actively wants dirty rivers. And yet every single one of the rivers, lakes and streams that’s monitored in England is now polluted. How can that be? That’s the mystery which Rivercide is setting out to solve – live, in real time.”

The documentary is produced in support of the River Action organisation’s ‘Give Us Back Our Rivers’ campaign, which calls for a doubling of funding for the Environment Agency in England and Natural Resources Wales in Wales.

“It’s madness that we live in a time of cars that drive themselves and fitbits for dogs and yet we put raw sewage into our rivers and allow 20 million chickens to poo into a single river catchment,” says Armstrong. “After a year of lockdown, we’re now a nation of wild swimmers and nature lovers – just imagine how much more fun we’d all be having if our rivers were safe and healthy again, both for wildlife and for people?”

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Rivercide website

Give us Back our Rivers campaign

An eBioAtlas of global freshwater biodiversity

July 1, 2021
Water sampling for eDNA using the eBioAtlas test kits. Image: eBioAtlas

Freshwater habitats are vital for biodiversity and human communities around the world. Covering only 1% of Earth’s surface, freshwaters support 10% of all known animals, 30% of vertebrates and over 50% of fish. However, as a series of recent reports have documented, freshwaters are amongst the world’s most threatened habitats.

At present, freshwater conservation and restoration projects are limited in many parts of the world by limited scientific knowledge about the status and distribution of species. Such incomplete mapping of freshwater biodiversity – and the threats it faces – makes effective conservation funding, management and policy difficult.

A major new project seeks to address this issue through the use of environmental DNA (or eDNA) techniques. Together, the International Union for Conservation of Nature (IUCN) and DNA-based monitoring organisation NatureMetrics announced the eBioAtlas project earlier this month.

The project will supply easy-to-use water pump sampling kits to conservationists and citizen scientists in areas of critical freshwater conservation importance, including the Amazon, Ganges, Mekong Delta, and the Niger Delta. Their aim is to collect 30,000 water samples over the first three years, which can then be analysed for eDNA – the traces of DNA left in water by species of fish, birds, amphibians and land animals.

The eDNA technique thus allows conservationists to detect the presence of freshwater biodiversity which might otherwise be difficult or expensive to monitor. As a result, it is intended that the eBioAtlas monitoring will allow local communities to participate in freshwater monitoring over wider areas than ever before.

“eDNA is a game changer because it allows surveys to be done much faster and it has the potential to pick up much more information than through conventional sampling,” says Dr. Will Darwall, Head of IUCN’s Freshwater Biodiversity Unit.

“A third of the world’s freshwater fish are threatened. If nothing changes in the way we manage freshwater environments these species are headed for extinction. We need a full-scale bio-blitz using eDNA to rapidly get new and updated information about where freshwater fish live all over the world so we can bring it into the mainstream of conservation and environmental management and policy efforts,” Dr. Darwall states.

The eBioAtlas monitoring work will result in a freshwater biodiversity database freely available for research and conservation. It is intended that the results will inform species assessments on the IUCN Red List of Threatened Species, and identify sites in need of protection as Key Biodiversity Areas.

“eDNA’s usefulness will only grow over time, as more and more data become available to allow comparisons and cross-referencing between scientists around the world,” says Angelique Todd, Senior Programme Manager, West and Central Africa at eBioAtlas partner Flora & Fauna International.

“We face a biodiversity crisis and we’ve been running blind,” says Dr. Kat Bruce, NatureMetrics founder and Chief Technology Officer. “We know we have to act to protect threatened species and their habitats, but the lack of data makes it hard to set tangible targets and monitor progress, or to incentivise businesses and governments to take meaningful action. We end up spinning in circles and going nowhere, while the loss of nature continues to accelerate.

“eDNA is totally transformative. It’s a tool we can put in the hands of ordinary people all over the world to capture biodiversity data at a previously unthinkable scale – and from those simple water samples, we will generate the knowledge base that can underpin effective action for the protection and restoration of nature. Nothing is more important.”

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eBioAtlas website