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Does water management pay off? Introducing the DESSIN Ecosystem Services Approach framework

May 18, 2018

The Emscher River in Nordsternpark, a former mining site in Gelsenkirchen, Germany. Image: M. Knuth | Flickr Creative Commons

Two new studies on the potential of the ecosystem services approach in strengthening European water management have been published in the Ecosystem Services journal. Both studies were supported by the EU-funded DESSIN project.

The first study provides a practical guide for water managers to assess changes in ecosystem services as a result of different water management measures. Lead author Gerardo Anzaldúa and colleagues outline that innovative solutions to water quality and quantity problems – such as groundwater replenishment and combined sewage treatments – are continually advancing and improving. However, they argue that existing impact assessment methodologies for investigating their impacts are increasingly limited. An ecosystem services approach can help both the assessment and communication of the impacts and benefits of new water management approaches on human lives, the authors argue.

Anzaldúa and colleagues found that whilst there are already ecosystem services (or ESS) assessment frameworks available to help environmental decision-makers and managers, many existing approaches do not adequately link ecosystem changes to ecosystem service provision. In addition, these assessment frameworks are often data intensive, focus on single issues (such as water scarcity) or service types (such as provisioning services), and – importantly – don’t easily link to Water Framework Directive assessments (although, see the 2015 MARS ‘cookbook’ approach to assessment and valuation)

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The DESSIN Ecosystem Service Evaluation Framework – structured guidance for ecosystem service assessment. Image: Anzaldua et al. (2018)

The new DESSIN Ecosystem Services Approach framework outlined in their paper aims to address these gaps and shortfalls. The framework is designed to allow users to evaluate and account for the ecosystem service impacts of new and innovative water management approaches. It is intended to complement the implementation of Water Framework Directive River Basin Management, and incorporates a similar DPSIR approach to adaptive management.

The framework is designed to support local-scale evaluations of ecosystem service provision, which are intended to help make assessments more accessible and useful for both stakeholders and decision-makers, and can be scaled-up to river basin and national scales. You can read the full details of the framework in the open-access study here.


An unrestored (left) and a restored section (right) in Dortmund Aplerbeck in the Emscher catchment. Image: Emschergenossenschaft.

The second paper provides a case study of the DESSIN Ecosystem Services Approach framework in use relating the to the restoration of the Emscher River in Germany. Restoration management to improve the ecological health and status has intensified on the Emscher in recent years, in an effort to reverse decades of water pollution, habitat loss and riverbank alteration.

To assess the values of restoration efforts, Nadine Gerner and colleagues applied the new DESSIN framework to evaluate the provision of regulating (self-purification of water, nursery populations and habitats and natural flood protection) and cultural ecosystem services (aesthetic, recreational and educational values) along stretches of the Emscher.

The research team used economic assessment methods including damage costs avoided, contingent valuation and benefit transfer. They estimated that restoration efforts on the Emscher generated a direct economic impact or market value of over €21 million per year. Market value here means the direct economic benefits to local communities and businesses, such as increased house prices or recreational opportunities.

In addition, they calculated that the non-market value of restoration exceeded €109 million per year. Non-market values includes both willingness to pay and avoided cost calculations and include benefits such as reductions in flooding risk . You can read the full step-by-step application of the DESSIN framework to the Emscher case-study, and the methods and justifications of value calculation in the open-access study here.


Map of the Emscher catchment in Germany. Image: DESSIN

Gerardo Anzaldúa from the Ecologic Institute in Berlin says, “The attractiveness of the Ecosystem Services Approach resides in its potential to enable individuals with diverse backgrounds and interests to communicate in terms of the inherent value they see in nature. This does not refer only to the monetary worth of ecosystems and their outputs, but to the variety of benefits that humans in direct or indirect contact with them perceive. Unfortunately, this wide-ranging character of the approach is at the same time what has made it so elusive to put into practice, as different disciplines have their own set of rules to understand and solve problems.”

“In DESSIN we had the chance to bring together a core group of ecologists, economists, engineers and sociologists under a single common goal: developing a way to run locally relevant and practicable ESS evaluations,” Anzaldúa explains.


Before (left) and after (right) construction of Lake Phoenix and restoration of the Emscher in Dortmund. Image: City of Dortmund / Emschergenossenschaft.

Nadine Gerner from Emschergenossenschaft continues, “In this way, the DESSIN ESS Evaluation Framework was developed on the basis of three case studies where restoration projects and innovative solutions had already been implemented in the past. Therefore, it was possible to compare the status before and after the solutions were implemented. The case studies were distributed throughout Europe in order to cover a broad geographical range with diverse environmental conditions and social dimensions as well as a wide variety of ESS types.”

“Ongoing restoration measures as part of the reconversion of the Emscher River in Germany were evaluated with regard to their impact on ESS provision, use and benefit. Regulation and Maintenance ESS – such as the self-purification capacity, maintaining nursery populations and habitats and flood protection – were evaluated, as well as Cultural ESS describing aesthetic, recreational, educational and existence values.” Gerner says.


An art installation by Tobias Rehberger at Emscherkunst, an exhibition of contemporary environmental art along the banks of the Emscher. The river basin is increasingly a space for recreation and tourism. Image: Reinhard H | Flickr Creative Commons

Read the new open-access papers in full here:

Anzaldua, G., Gerner, N. V., Lago, M., Abhold, K., Hinzmann, M., Beyer, S., Winking, C., Riegels, N., Krogsgaard Jensen, J., Termes, M., Amorós, J., Wencki, K., Strehl, C., Ugarelli, R., Hasenheit, M., Nafo, I., Hernandez, M., Vilanova, E., Damman, S., Brouwer, S., Rouillard, J., Schwesig, D., Birk, S., 2018. Getting into the water with the Ecosystem Services Approach: The DESSIN ESS evaluation framework. Ecosystem Services 30, 318–326.

Gerner, N. V, Nafo, I., Winking, C., Wencki, K., Strehl, C., Wortberg, T., Niemann, A., Anzaldua, G., Lago, M., Birk, S., 2018. Large-scale river restoration pays off: A case study of ecosystem service valuation for the Emscher restoration generation project. Ecosystem Services 30, 327–338.

A new atlas of European caddisflies

May 10, 2018
Chaetopteryx rugulosa

Chaetopteryx rugulosa has a small distribution area in the Eastern Alps, and is split into several subspecies. Image: © Graf & Schmidt-Kloiber

A major new European atlas of the distribution of caddisfly species (or Trichoptera) has recently been published, providing the first comprehensive overview of their occurrence patterns across the continent. Based on data collected over 7 years from over 630,000 species occurrence records, the Distribution Atlas of European Trichoptera features 1,579 maps of a fascinating, diverse and ecologically-important insect order.

Whilst freshwater ecosystems are known to support a rich diversity of species – there are more than 14,500 caddisfly species, of which more than 1,700 occur in Europe – their distribution maps are often patchy and incomplete. Comprehensive species mapping – as carried out here by the Atlas team – is important in guiding future scientific research and environmental policy and management.

Atlas co-author Astrid Schmidt-Kloiber says, “The Atlas shows us the distribution ranges of every single caddisfly species in Europe, it reveals common species as well as rare ones and identifies Trichoptera hot spots. With the help of fellow caddisfly experts we compiled occurrence records from all over Europe into one single database, which now serves as a valuable base to establish a European IUCN Red List of threatened species.”

Limnephilus subcentralis

Limnephilus subcentralis – as many other Limnephilidae species – covers a huge range from Scandinavia to the Balkans and from Belarus to UK. Image: © Graf & Schmidt-Kloiber

The idea for the Atlas was first discussed in 2005 at the ‘First Conference on Faunistics and Zoogeography of European Trichoptera’ in Luxembourg. The Atlas project was kick-started in 2011 as part of the EU-funded BioFresh project, and includes data contributions from 83 Trichoptera experts (see this open-access Hydrobiologica article for more detail).

Co-author Wolfram Graf explains, “The Atlas is a milestone in Trichoptera research: up to now species distribution ranges were only indicated on country level – such as Fauna Europaea – or on an ecoregional level – such as through the portal. For the Atlas we collected point records. This, for the first time, reveals the real distribution range of a species. The Atlas serves to delimitate diversity spots and refuge areas for endemic species on different scales and is therefore an essential basis for any conservation issue.”

The Atlas shows that areas of southern Europe – particularly in Spain, Italy and the Balkans – and mountainous regions (such as the Alps and the Carpathians) support both high caddisfly biodiversity and endemism. In other words, these areas harbour a high biodiversity and support certain rare species which are not found anywhere else.

Limnephilinae map

Species of the family Limnephilidae are found all over Europe, but several genera have very limited distributions. Image: Distribution Atlas of European Trichoptera

Micrasema map

Micrasema morosum is a caddisfly species predominantly found in the Alps. Image: Distribution Atlas of European Trichoptera

In general, overall caddisfly species diversity decreases with increasing latitude. There is a similar drop in species diversity in the move from Western Europe to Eastern Europe, largely because caddisfly-rich mountainous areas are lacking on the eastern plains of the continent. In several cases, distinctive Atlantic and Siberian species – which underwent speciation processes in glacial ‘refugia’ in the last ice age – overlap in areas of Central Europe. These climate-induced speciation processes in ice-free parts of the content account for the increased present-day species diversity in Southern Europe.

Areas rich in caddisfly biodiversity and endemism such as the Mediterranean are particularly threatened by the ongoing effects of climate change and other anthropogenic pressures. The Atlas identifies these areas of conservation importance, which can subsequently help raise their visibility as an issue amongst environmental policy makers in Europe.

lept_inte1_b copy

Leptocerus interruptus is a delicate species with a wide distribution throughout Europe. Image: © Graf & Schmidt-Kloiber

Co-author Peter Neu outlines the value of the Atlas, “By delineating the distribution areas, the Atlas provides invaluable help in identifying species that are difficult to distinguish and therefore also serves as a quality control tool for all future identifications, for example, for people who identify specimens from regions whose fauna is not familiar to them, the Atlas is a great decision aid. Through the Atlas, we can further identify species for which there is still a research need.”

Wolfram Graf continues, “The Atlas enhances our knowledge on evolutionary theories as well as on zoo- and phylogeographic aspects. The depicted maps are just the beautiful surface but the basic data are the true treasure which will be analysed in-depth now. The Atlas may be an inspiration for us and others to continuously collect faunistic data in order to be able to analyse long-term developments of this fascinating insect order in a changing world.”

Astrid Schmidt-Kloiber concludes, “As the success of the Atlas very much relied on the willingness of our colleagues to contribute data, I want to take the opportunity to thank them once again for their enthusiasm and great work!”

The Distribution Atlas of European Trichoptera is published by Conch Books

The Water Framework Directive at 18: Future Directions and Emerging Challenges

May 4, 2018

Image: Jim Liestman | Flickr Creative Commons

The Water Framework Directive (WFD) is the foundation of European Union water policy. Adopted in 2000, the WFD provides a policy framework for European member states to monitor, assess and manage their aquatic ecosystems. However, despite widespread improvements in the monitoring, conservation and restoration of rivers and lakes across Europe, the WFD has not yet achieved its primary objective: the good ecological status of all European freshwaters.

Part of the rationale for the MARS project’s work over the last four years has been to assess the success of the WFD in addressing contemporary issues for European water management. When the WFD was designed and developed in the 1990s, the issues facing Europe’s rivers and lakes were somewhat different to today. Strong single stressors such as nutrient pollution and water abstraction were common across the continent. In the time since, the challenge of multiple stressors – where stressors act in tandem, causing complex interactions and ecological impacts – has emerged.

Similarly, new challenges such as the pollution of microplastics and synthetic chemicals into water bodies means that water managers need to stay alert to the possible impacts of emerging stressors. However, new water body monitoring techniques for both ecological health and stress – such as those used for dissolved chemical ‘cocktails’ in the SOLUTIONS project – are being developed, providing new opportunities for effective water management.


Microplastics. Image: Florida Sea Grant | Flickr Creative Commons

A formal EU ‘fitness check’ evaluation of the WFD in the context of these developments is due in Autumn 2019. Ahead of this assessment, MARS researchers have published a policy brief providing recommendations for the future implementation and evaluation of European water policy. They identify four key areas to be addressed:

Monitoring and assessment systems

The researchers argue that whilst the WFD has significantly advanced the environmental monitoring and assessment of European water bodies, there are a number of problems with the current approach. They suggest that the strategic design of monitoring networks can be improved across the continent, and that monitoring the ecological effects of restoration management can be enhanced, for example, by using ‘early responding indicator’ species and metrics.

They highlight the concern that the WFD assessment uses overly strict criteria to define success, in which the overall ecological status of a water body is determined by the lowest of its biological, physical and chemical quality elements – potentially obscuring a more nuanced picture of the ecosystem. Finally, they outline the value of incorporating new monitoring tools such as earth observation, genomics, automated monitoring platforms and citizen science into WFD assessment, where appropriate.

Management measures

River Basin Management Plans (RBMPs) are a key WFD management tool. They are based on ecosystem monitoring data and outline management plans for entire river basins, addressing not only water bodies but also the drivers of environmental stress such as agriculture, hydropower and flood protection. In their policy brief, MARS researchers suggest that RBMPs can be improved through more targeted planning and implementation of measures to manage the emerging impacts from multiple stressors across Europe.

They highlight the availability of data and diagnostic tools to identify stressors and their interactions (such as those developed by MARS), which can help design effective and cost-effective management measures. They outline the value of trait-based diagnostic tools which can help diagnose the mechanisms behind environmental degradation; and of ecosystem service indicators which can provide powerful messages to the public and policy makers about the benefits of freshwater conservation and restoration.


Agricultural terraces in the Douro River Basin, Portugal. Image: Malcolm Payne | Flickr Creative Commons

Policy integration

The MARS researchers argue that there is a need to harmonise and integrate the objectives and management of the WFD with other key European policy frameworks. One key policy relationship is with the Common Agricultural Policy (CAP). Diffuse pollution and habitat degradation as a result of agricultural activity are common pressures across the continent, and there is a need to make farming increasingly ‘water friendly’. A key aspect of this is in regulating pollution events, in terms of who should bear the cost of measures to restore ecological status and flood protection, when the source and impact of pollution events can be geographical dispersed.

The authors highlight the need to better account for climate change in the WFD, stating that drought and water scarcity are poorly addressed in the WFD. They suggest that the Floods Directive could be brought into the WFD, and synergies over natural flood protection measures could be emphasised. Finally, the MARS researchers suggest that bringing an ecosystem services approach into the WFD could help integrate land and water policy goals, and make explicit the costs and benefits of conserving and restoring natural capital.

Beyond 2027

A key message of the new policy brief is that whilst the WFD is the ‘most important step even taken towards sustainable water management in Europe’, there is the pressing need to make sure it is ‘future proof’ and can address new and emerging water management issues.

The third and final WFD River Basin Management Cycle ends in 2027. The authors suggest that it is unlikely that Europe’s water bodies will have reached good ecological status – a key aim of the WFD – by this date. This is largely because the ecological effects of ecosystem restoration can take many years to occur.

The authors argue that there is thus a pressing need to decide on the future of the River Basin Management mechanism beyond 2027. In short, there needs to be a framework in place to encourage European member states to continue to monitor, conserve and restore their rivers and lakes after 2027. They conclude that, ‘An extension of the River Basin Management mechanism, keeping the ambitious targets, and restricting the option to apply further time exemptions, is now required to make the WFD future proof.’


Read the new MARS policy brief, “Future of the Water Framework Directive: What have we learned and how do we adapt to new challenges?”

World Fish Migration Day – 21st April 2018

April 20, 2018


Events will be held across the world tomorrow to highlight the importance of free-flowing rivers and migratory fish. Hundreds of events are planned as part of World Fish Migration Day, involving groups of people and organisations on a diverse range of river and streams.

Migratory fish populations are threatened in many global rivers and streams. Often this is the result of multiple pressures such as barriers to migration (like weirs and dams), water flow alterations (such as agricultural abstraction) or damage to habitat (such as removal of spawning beds).

Migratory fish lifecycles can occur over very large geographic areas – with breeding, feeding and reproduction all potentially taking place hundreds of miles apart. This means that conservation and restoration actions often need to be coordinated over large areas. For example, for the Atlantic salmon in northern Europe, this includes managing fishing both at sea and in estuaries, alongside mitigating water pollution, conserving spawning grounds, and providing fish passes on weirs and dams.

Migratory fish often provide valuable sources of food and livelihood for local communities. They can also be important parts of large-scale nutrient cycles. For example, migratory Pacific salmon in North America and Canada carry nutrients upriver from the ocean, where they both provide food for predators such as bears, and also fertiliser for riparian ecosystems when their die and their bodies decay.


Pacific salmon migrating upstream. Image: World Fish Migration Day

The main goal of World Fish Migration Day is to improve public understanding of the importance of migratory fish, and to highlight the need for healthy rivers and the communities that depend on them. The events – co-ordinated by the World Fish Migration Foundation – aim to engage citizens around the world to take action on these topics. Through showcasing a global community of people and organisations passionate about conserving and restoring migratory fish populations, the World Fish Migration Day aims to agree lasting commitments from NGOs, governments and industry on safeguarding free-flowing rivers.

Clemens Strehl of the IWW Water Centre in Germany outlines the value of World Fish Migration Day, “I believe it is a great opportunity to raise awareness of this issue. Healthy rivers and fish migration mean increased biodiversity. However, it is a continual challenge to balance the need for rivers to provide services and benefits to humans – energy production and industry, hydropower, drinking water, agriculture, recreation, and so on – whilst at the same time achieving good ecological status. But fishes do not ‘scream’ in this struggle, so the World Fish Migration Day event is a nice opportunity to give them a symbolic voice.”

“There are many great opportunities to restore streams and waterways to encourage fish migration. See the examples from our area – Essen in Germany – where the Emschergenossenschaft took the challenge to restore a stream which had been degraded completely to an open wastewater channel. This former ‘sewer’ is now returning piece by piece to a healthy urban ecosystem. See our European water research DESSIN project and the latest open-access publication from Nadine Gerner and colleagues, which shows the many benefits of river restoration on the Emscher,” Strehl says.


The restored Lippe River in Germany. Image: Benjamin Kupilas | REFORM

“On the River Lippe in Germany,  the sighting of one migratory salmon in a previously degraded river triggered enthusiastic reactions in the local area (see here and here for coverage). The Lippe was nominated as ‘River of the year 2018/19’ in Germany, as a result of successful restoration actions. On the Lippe – which crosses a former coal mining and industrial area, much like the Emscher – measures were taken to connect former non-connected stream sections and reactivate floodplain areas. This enabled a local fish species called ‘Quappe’ (Lota lota) to return to the Lippe system. Fishes do not ‘scream’, but they can be ‘happy’ – appropriately the symbol of the World Fish Migration Day is a happy fish!” Strehl says.

Find a World Fish Migration Day event close to you.

The MARS Diagnostic Analysis Tool: diagnosing the causes of ecological degradation

April 5, 2018
DAT image

The MARS Diagnostic Analysis Tool visualises probable multiple stressor occurrence based on ecological data from a water body.

Rivers and lakes across Europe are subject to multiple human stressors, which can interact to impact freshwater ecosystem health and status. As a result, a key problem for environmental managers seeking to conserve and restore water bodies is identifying the multiple causes of ecological stress and degradation.

Modern ecological assessments are increasingly sophisticated and informative, but they generally do not give a picture of the causes of multiple human stressors acting on an ecosystem. This is because such assessments are generally ‘integrative’ and do not focus on individual stressors.

Over the last four years, the EU MARS project has developed a Diagnostic Analysis Tool (DAT) to help water body managers and policy makers to identify and rank potential causes of ecological degradation at the catchment, reach and water-body scale.

The DAT is freely accessible through the online Freshwater Information Platform. Users can enter values or ranges of biological metrics which indicate ecological status in a water body. Metrics that can be inputted into the DAT include community-based indices (e.g., percentage of EPT macroinvertebrate taxa), assessment indices (e.g., saprobic index) and ecological traits (e.g., feeding types).

DAT three steps

The DAT uses a Bayesian network to calculate the probability of different causes of ecological degradation being present in a water body. This probability can be visualised through graphs and tables. In effect, the DAT works like a doctor’s ‘health check’ for water bodies, in which the causes of illness are diagnosed based on a patient’s symptoms.

The DAT ‘diagnoses’ the probable causes of ecological degradation, based on their inputted ecological ‘symptoms’. Possible drivers of multiple stressors – arable and urban land use, riparian degradation, channel straightening, flow regulation, fine sediment pollution, habitat loss – are ranked in order of probability.

DAT information

Descriptions of each driver, and possible mitigation approaches, are then provided through the tool’s interactive interface. This provides potentially valuable information for water managers seeking to minimise biodiversity losses and ecosystem alterations in their water bodies.

The DAT has been developed based on MARS research and modelling for mid-sized sand-bottom lowland rivers of Central Europe. However, it can be tailored by interested users to work for other water body types. Full documentation on how to modify the DAT can be found here (pdf) and guidance can be given by MARS scientist Christian Feld by email.

Access the MARS Diagnostic Analysis Tool here.

Visualising multiple stressors on European river catchments: the MARS Scenario Analysis Tool

March 21, 2018
sat mars laptop

The MARS Scenario Analysis Tool

Over the last four years, the MARS project has been investigating the interactions and impacts of multiple stressors on Europe’s aquatic ecosystems. This is a topic at the cutting edge of freshwater science research, and MARS scientists have sought to understand how the multiple pressures humans place on the environment – nutrient pollution, habitat alteration, climate change, water abstraction, and many more – act together to cause stress on the continent’s rivers and lakes. As a result, this work is important for environmental managers and policy makers seeking effective options to mitigate multiple stresses, and conserve or restore Europe’s freshwaters.

MARS Scenario Analysis Tool

MARS has recently launched its Scenario Analysis Tool – an online, open-source mapping tool, which allows users to visualise and analyse multiple stressor conditions in European rivers. The tool can generate maps showing where different stressors occur, how many stressors co-occur, and their potential impacts on ecosystem status, at both the river basin and the continental scale.

The Scenario Analysis Tool shows that six stressor indicators – 1) dissolved inorganic nitrogen and 2) phosphorous concentrations; surrounding 3) urban, and 4) agricultural land; alterations to 5) annual and 6) base water flows – explain the majority of differences in ecological status across European rivers. MARS researchers also identified ecological thresholds when the impact of multiple stressors tips ecological status from good to moderate.

Current Stressor Patterns in European Rivers

The Scenario Analysis Tool illustrates a number of broad current European stressor patterns. It shows that Southern Europe is significantly more hydrologically stressed than the rest of Europe, particularly in Mediterranean countries as a result of water abstraction for agriculture. There are three or more stressors acting together in half of the European river catchments. Only 9% of European river catchments have no active human stressors acting on them.

Stressor ‘thresholds’ where ecological status is reduced were found in 60% of catchments for agricultural land use stressors, 50% of catchments for dissolved inorganic nitrogen, and 40% of catchments for total phosphorous. This is unsurprising, as nutrient modelling underpinning the tool shows that agriculture is a significant source of nutrient loadings into European rivers.


Visualisations of the multiple stressors impacting individual river basins can be created by users. This complex picture is for the Danube basin.

Storylines for Future Worlds

The Scenario Analysis Tool also allows users to visualise the multiple stressor picture for two future periods – 2026–2035 and 2056–2065 – under two different ‘storylines’ of possible climatic and social change. The two time-horizons have been chosen to inform the update of the Water Framework Directive in 2027 (2026–2035), and to show possible impacts of climate change (2056–2065). The two storylines have been designed by MARS researchers to outline possible future climatic, political and economic trajectories, based on forecasts in the IPCC Representative Concentration Pathways and Shared Socio-Economic Pathways.

The Techno World storyline is based on a scenario of high greenhouse gas emissions and rising global temperatures (Representative Concentration Pathway 8.5) in combination with a strong, carbon-based global economy in which many currently pressing social concerns, such as inequality and population growth, have been mitigated (Shared Socio-Economic Pathway 5).

The Consensus World storyline is based on a scenario where future development follows similar patterns to the recent past: the economy grows well in some countries and poorly in others, and inequality between rich and poor countries continues. Despite this disparity, the world tends towards being relatively politically stable (Shared Socio-Economic Pathway 2). This occurs alongside a stabilising and relatively low level of climatic change (Representative Concentration Pathway 4.5).

In addition to the future ‘storylines’, the Scenario Analysis Tool allows for the effects of three stressor mitigation management approaches – nutrient reductions, riparian buffer strips, and improved waste water treatment – to be modelled.

thames nitrogen

Forecasting dissolved inorganic nitrogen concentrations in the River Thames basin in SE England under the Consensus World scenario around 2060.

Future ‘Storyline’ Stressor Patterns

Both Techno and Consensus World storylines predict that river discharges are likely to increase, on average, across European catchments in the future. The highest increases will occur during high flow season, and the lowest increases during low flow season. However, in several rivers in Southern Europe, discharge in the low flow season will decrease in both storylines.

For both storylines, the probability of rivers reaching good ecological status falls by 3–5% in the future if mitigation strategies aren’t implemented to manage stressor effects. However, this prediction differs with river type. This finding emphasises the need for catchment specific stressor mitigation approaches, rather than a ‘one size fits all’ European water management approach.

Data and Models

The Scenario Analysis Tool is underpinned by two computer models using hydrological, ecological and meteorological data gathered between 2001-2010. The global hydrological model PCR-GLOBWB was used to simulate river flows and runoff across Europe. Water abstraction, reservoir management and domestic, industrial, livestock and irrigation water use are all included in this model. This feeds hydrological data to a second model, MONERIS, which quantifies nitrogen and phosphorus emissions to surface waters, along with their in-stream retention rates, and resulting loads and concentrations.

The results of both models are brought together with data on individual catchments, and the Water Framework Directive reporting data on ecological status by EU member states. The outputs of this computer modelling allows for climate, water availability, nutrient fluxes and management options to be analysed through quantifying and evaluating multi-stressor conditions and aquatic responses across Europe.

The tool was designed and developed by Markus Venohr and Judith Mahnkopf from IGB (DE), supported by Lidija Globevnik (Uni Ljubljana, SI), Yiannis Panagopoulos (NTUA, GR), and Marta Faneca Sanchez and Frederiek Sperna Weiland (Deltares, NL).

Explore the Scenario Analysis Tool

Read the MARS report on the methods, data and results of the Scenario Analysis Tool

Managing multiple pressures from recreational activities on freshwater ecosystems

March 4, 2018

A motorboat anchored on a Norwegian lake. Engine noise, water turbulence and fuel spills can all cause stress to aquatic ecosystems. Image: Henry Leirvoll | Flickr Creative Commons

Rivers and lakes are popular places for people to relax, play and exercise, and recreational activities like boating, bathing and angling are all well-documented to have positive effects on human well-being. But can the enjoyment of such freshwater ‘ecosystem services’ cause pressures on aquatic ecosystems? And how best can recreational activities be managed to minimise the harm they might cause?

A review of available data on the topic recently published in the Environmental Reviews journal shows that environmental quality is closely liked to recreational activities in many freshwater ecosystems. The ecological health and diversity of a river or lake can be an attractive draw for visitors, potentially causing tensions between tourist ‘hotspots’ and areas of conservation importance. This means there is a pressing need for effective management strategies to minimise ecological damage from visitor use in many places.

The new MARS-supported study, led by Markus Venohr from IGB Berlin and colleagues, outlines how recreational activities can cause a variety of physical, biological and chemical pressures to freshwaters. Physical pressures can include the noise and waves produced by boats, damage to riparian vegetation and stream banks and beds by human trampling, camping and wading, whilst boats and canoes can stir up bottom sediments, leading to increased water cloudiness (or turbidity).

Biological pressures can include the spread of non-native species due to angling or boating activities, and increased levels of coliform bacteria (e.g. E. coli), as a result of poorly-treated sewage run-off from nearby campsite toilets. Finally, chemical pressures largely stem from increases in nutrient pollution (e.g. from nearby tourist centres), but also include pollution impacts from soap, sunscreen, food particles, human and animal waste, and fuel discharges.


Campsite beside a Swedish lake. Fuel and waste disposal can cause lake pollution. Image: Jörgen Brouwer

Clearly, there is a geography to such pressures: some are direct and some indirect; some local-scale and others occurring over larger spatial scales. Some activities (e.g. power-boating) will likely create more pressures than others (e.g. wild swimming). Each individual water body will be subject to its own particular socio-ecological ‘cocktail’ of pressures as a result of recreational activities. As Venohr and colleagues put it, the challenge for managers of individual water bodies is to “develop solutions that maximise the well-being of as many people as possible while minimising ecological impacts and therefore reaching ecological quality standards.”

So how can recreational pressures impact ecosystem health and status? Such pressure-impact links are not always fully understood, but have been investigated by a number of recent studies. Motorboat noise has been shown to directly modify fish assemblages, as prey fishes were more easily caught by predators when exposed to noise. Waste water from boats moved between water bodies, and illegal releases of live angling bait and pet fish can both be significant routes for the spread of invasive species across ecosystems (see here (pdf), for example). Recreational angling can impact fish populations in some ecosystems, even after regulations seeking sustainable use, such as catch and release have been implemented (see here and here for example).

Venohr and colleagues propose a new framework for understanding relationships between recreational quality, demand and use, recreational impacts on ecosystem state and function, and ecological and social carrying capacities. They argue that current water management approaches rarely address these relationships, in part due to inadequate information on the dynamics and densities of recreation uses.

framework 1

The framework has two parts. The first, shown above, shows the relationships between ecosystem quality and recreational demand. It conceptualises that recreational demand will increase or decrease depending on the ecological quality of the freshwater ecosystem. It uses the idea of ‘carrying capacity’ – the limits to sustainable use of an ecosystem – to highlight where ecological damage or human overcrowding of a site may lead to decreasing recreational demand.

framework 2

The second part of the proposed framework is a ‘multi-loop’ concept, which links ecological quality and recreational quality with responsive ecosystem management. It illustrates how water managers should monitor visitor perceptions of their water body, and how these influence recreational use. These uses influence (and are influenced by) ecological quality, which should be monitored in tandem. Such a linked, responsive approach will allow managers to encourage sustainable recreational uses, which minimise ecological damage, the authors argue.

Markus Venohr outlines the benefits of such an approach, “This framework provides the basis of a next-generation water management approach. It brings together expertise from different disciplines to generate a joint ecosystem assessment attribute – the social-environment carrying capacity of a water body.”

Venohr and colleagues outline the need for novel assessment and monitoring methods to capture the short-term peak dynamics of freshwater recreational activities. They suggest that geotagged social media posts from Twitter, Facebook, Flickr and Instagram have the potential to illustrate recreational activity dynamics across large spatial scales. Geotagged data from social media posts could allow researchers and water managers to analyse how recreational uses of freshwaters varies depending on weather conditions, time of day, season, and site accessibility.

Whilst such digital mapping of human behaviour is increasingly used in business and political strategy, Venohr and colleagues suggest that it holds untapped potential for water management, providing that social media use can first be calibrated to ‘real world’ conditions through the use of interviews, surveys, cameras, flights or drones.

Markus Venohr concludes, “Our study has three key outcomes. First, we found that recreational peak uses of water-bound activities can potentially cause pronounced stress to aquatic ecosystems. Second, we argue that the links between water quality and recreational use has to better understood and conceptualised across larger geographical scales. Finally, we suggest that better assessment of recreation-induced pressures on aquatic ecosystems is needed, both to achieve water management goals and to increase ecological awareness amongst recreational user groups.”

Venohr, M, et al (2018). The underestimated dynamics and impacts of water-based recreational activities on freshwater ecosystems. Environmental Reviews. 10.1139/er-2017-0024. 

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