Integrating public health into wetland nature-based solutions (NBS) in Southern Europe
Nature-based solutions (NBS) have evolved from peripheral components of conservation practice to a pivotal tenet of climate adaptation and resilience policy across Europe. Wetlands in particular are receiving renewed attention as multifunctional infrastructures that store water, support biodiversity, sequester carbon, and buffer the social and economic impacts of droughts and floods.
Bridging drought resilience and disease risk
In the context of this evolving landscape, two EU-funded initiatives in which GERICS plays a key role, serve as exemplars of the dual promise and practical complexity inherent in the large-scale implementation of wetlands and green-blue infrastructure. The first initiative, NBS4Drought, aims to demonstrate and expand the use of wetland-based NBS for enhancing drought resilience. The second initiative, IDAlert, focuses on the development of climate-sensitive infectious disease indicators and early-warning tools within a One Health framework.
These initiatives highlight the potential benefits and the challenges associated with the large-scale deployment of such green-blue infrastructure in a landscape context. NBS4Drought is an initiative that aims to address the gaps in rigorous, transferable evidence on the cost-effectiveness and hydrological performance of wetland NBS. The objective is to enable practitioners and policymakers to make defensible investments. The project’s mandate is to pilot and evaluate wetland interventions across diverse European contexts, with a view to facilitating wider adoption.
In contrast, IDAlert prioritises the human and animal health dimensions of environmental change by developing indicators and decision-support tools that integrate climatic, ecological and epidemiological data. These tools enable local governments and public health authorities to anticipate and respond to the health risks that occasionally coincide with NBS deployment. In doing so, IDAlert emphasises the importance of co-creation with relevant stakeholders, including practitioners, community representatives, health agencies and environmental managers.
This collaborative approach has been developed and implemented by María Máñez from GERICS. This implementation is undertaken to ensure that the developed tools are fit for purpose and sensitive to the governance realities of each specific location.
The wetlands: Ecological benefits and vector suitability
The interplay between these objectives and the ecological conditions that wetlands engender, particularly in relation to the life cycles of disease vectors, is a critical consideration. Wetlands and constructed ponds naturally host standing or slowly moving water, dense emergent vegetation, and diverse microhabitats. The ecological services that wetlands provide, including water retention, filtration, and habitat for birds, amphibians, and invertebrates, as well as carbon storage, are contingent on these conditions. However, if the design, management, and monitoring of wetland sites do not explicitly account for vector ecology, these conditions can also increase environmental suitability for certain mosquito species and other vectors.
Recent surveillance studies and targeted research have highlighted the capacity of Culex pipiens, Aedes albopictus and other opportunistic mosquito species to establish themselves in wetland-edge habitats, sewage-fed ditches, irrigation ponds and peri-urban marshes, where water is persistent and temperatures rise in response to climate change. Consequently, a net benefit from wetland NBS is not automatic; whether an intervention reduces, leaves unchanged, or increases disease risk depends on local hydrology, species composition, management regimes, and the interplay of temperature and rainfall trends.
Integrating surveillance and conservation in Empordà, Spain
The Natural Park of Aiguamolls de l’Empordà in Girona serves as a tangible illustration of the potential benefits and challenges associated with wetland ecosystems. These ecosystems offer significant opportunities for research, yet they also necessitate diligent surveillance to ensure the integrity of their biodiversity and ecological functions. Aiguamolls represents the second largest wetland area in Catalonia and has long been valued for its biodiversity, traditional land uses and tourism.
In recent years, researchers and citizen-science networks have begun to treat the Empordà wetlands as an “open-air laboratory” for understanding the transmission dynamics of West Nile virus and other flaviviruses. Entomological monitoring in and around the park has captured seasonal changes in the composition and abundance of mosquito species. Targeted sampling of Culex mosquitoes has been used to test for the presence of viruses. These efforts have illuminated how local habitat structure and water management shape vector populations. It has been demonstrated that shallow pools, irrigation canals, residual floodplain ponds and man-made lagoons can all support mosquito larval development under the right conditions, especially when summer temperatures are higher and precipitation patterns are more erratic.
Of particular note is the Empordà initiative, which has not merely monitored vector movements, but rather facilitated collaborative endeavours among wetland managers, epidemiologists and community groups. This collaborative effort has culminated in the co-design of monitoring strategies and the utilisation of data to refine management actions. The overarching objective of these actions is the preservation of biodiversity in conjunction with the reduction of human exposure to infected mosquitoes. This co-produced approach, which combines ecological restoration, targeted surveillance and public communication, serves as a prime example of the integrated practice that projects such as IDAlert are promoting.
Harmonising wetland management and disease control in Attica, Greece
In the Attica region of Greece, the interaction between wetlands, urbanisation and the dynamics of mosquito-borne diseases has yielded a distinct set of lessons. Attica’s landscape is distinguished by the presence of peri-urban wetlands and coastal lagoons, which are recognised as being of significant value in terms of biodiversity and the provision of ecosystem services, including flood attenuation and groundwater recharge. Concurrently, the region has undergone changes in mosquito diversity and abundance that are pertinent to disease transmission, including the seasonal proliferation of Culex pipiens and the persistent presence of Aedes albopictus in suburban and urban environments. Recent entomological surveys, spanning a two-year period and conducted in collaboration with local health authorities and research institutions, have revealed a diverse array of mosquito species across urban and rural environments.
These surveys have also identified that species associated with flavivirus transmission exhibit a seasonal abundance in wetland-adjacent locations. The surveillance results have informed integrated mosquito control strategies in the region, prompting targeted larval source management, strategic timing of control activities, and enhanced coordination between public health agencies and local municipalities. IDAlert has engaged directly with regional authorities in Attica through workshops and knowledge-exchange events to share indicator tools and to support capacity building for surveillance and integrated vector management. The Attica example demonstrates that when entomological data are combined with targeted governance actions, such as mapping of high-risk habitats, community outreach, and harmonised surveillance, wetland management can be adapted to reduce vector habitat while preserving the ecological functions that wetlands perform.
Lessons for adaptive management: Hydrology, monitoring, and governance
A number of recurring themes were identified in the course of the studies. Firstly, the ecological heterogeneity of wetlands leads to the spatial and temporal variability of risk. It is important to note that shallow, ephemeral pools have been observed to be inhospitable to vectors for extended periods. Conversely, these pools have been known to experience a marked increase in mosquito production following prolonged periods of warm weather. Conversely, deeper ponds with limited emergent vegetation tend to support fewer mosquitoes. Consequently, the morphological and hydrological configuration of wetland characteristics is of significance: slope, depth, flow regimes, connectivity to other water bodies, and vegetation composition can be managed to minimise long-term standing water pockets that favour mosquito reproduction. Secondly, the implementation of active, science- based monitoring is imperative. Entomological traps, larval sampling, and pathogen screening provide the empirical foundation for adaptive management and for ensuring that interventions do not yield unintended public health outcomes. Thirdly, cross- sector governance must be institutionalised so that environmental managers, public health practitioners, and local communities share information and responsibilities.
Workshops and co-creation processes, as promoted by IDAlert, are effective mechanisms for developing shared indicators and response protocols. The themes under discussion are not merely theoretical in nature; rather, they are grounded in empirical work carried out in Girona and Attica, and they are also reflected in broader European guidance on wetlands monitoring and NBS implementation.
In practice, the management of the vector risk aspect of wetland NBS necessitates an integrated toolkit that encompasses design, management, surveillance and communication (see figure 3). From a design perspective, incorporating variability into wetland hydrology can discourage prolific mosquito breeding without compromising habitat value for birds and aquatic plants, e.g. creating zones that dry periodically, ensuring through-flow in key basins, and engineering margins that reduce stagnant microhabitats. Vegetation management is also of significance in this context; dense mats of emergent plants can provide shelter for larvae and adult resting sites. To this end, planners often utilise a mosaic of vegetation types and maintain open water patches, thereby balancing biodiversity goals and vector control. From a management perspective, routine inspections for emergent standing water in peripheral infrastructure (ditches, culverts, irrigation furrows) enable rapid remedial action such as mechanical clearing, source reduction, or targeted biological larviciding where appropriate. Surveillance is the cornerstone of these actions: adult and larval monitoring enable managers to detect increases in vector populations early and to test for pathogen presence so that public-health advisories can be issued only when justified. The final element is public communication, the purpose of which is to inform residents and visitors about peak mosquito seasons, encourage personal protective behaviours, and involve local stakeholders in habitat stewardship.
The outcome of this is that it builds social licence for NBS projects and reduces community-level transmission risk. The IDAlert experience in Greece and the surveillance collaborations in Catalonia demonstrate that such elements are most effective when they are co-designed and when responsibilities are clearly delineated.
It is imperative to recognise the trade-offs inherent in this process. Wetlands have been shown to deliver measurable benefits in terms of water regulation, biodiversity and cultural value. However, these environments are located within social-ecological systems where competing demands are created by land use, agriculture, tourism and urban pressure. In Aiguamolls, for instance, the pressures of tourism, shifting agricultural practices, and sea-level rise complicate management choices; any action to reduce mosquito habitat must be balanced against biodiversity objectives and the livelihoods of people who depend on the landscape. A similar situation is observed in Attica, where peri-urban development pressures and limited local capacity for maintenance render the adoption of complex, maintenance-intensive designs at scale challenging without additional funding and institutional support. These trade-offs underscore the indispensability of rigorous economic analysis in projects of this nature, as it is essential for policymakers to see quantified evidence of the benefits and maintenance costs of different wetland NBS designs in order to prioritise investments and to make the case for the sometimes hidden costs of ongoing management.
It is evident that there are several practical takeaways that emerge for practitioners, municipalities and funders. Firstly, vector-risk appraisal should be integrated into the earliest stages of NBS planning. This should include the selection of sites, the establishment of design specifications and the mapping of stakeholders, with entomological expertise being a key component of this process. Secondly, priority should be given to designs that favour hydrological dynamism and through-flow over static pools. In cases where static features are deemed necessary, active management and monitoring must be planned for. Thirdly, the institutionalisation of surveillance is to be encouraged through the provision of funding for entomological capacity within regional authorities, or through partnerships with research institutes and citizen science networks. The empirical data generated by such partnerships is invaluable for adaptive management and for maintaining public trust. Fourthly, the integration of ecological and social objectives through a collaborative approach is imperative. Local communities frequently serve as the primary observers of changes in mosquito nuisances and can function as effective collaborators in the domains of maintenance, reporting, and outreach. The case studies conducted in Girona and Attica demonstrate that the integration of co-created monitoring and participatory governance practices significantly enhances the efficacy of ecological and health outcomes management.
From a policy perspective, Europe’s growing portfolio of wetland restoration and NBS projects suggests an urgent need for harmonised guidance that brings together climate resilience, biodiversity conservation and public health. It is imperative that this guidance is grounded in empirical evidence, with a focus on the findings from pilot demonstrations and surveillance activities. Moreover, it is essential to emphasise financing models that encompass not only the initial capital costs but also the recurrent expenses associated with monitoring and maintenance.
It is asserted that instruments of funding which establish a correlation between the enhancement of restoration and the development of capacity for the purpose of disease surveillance will be of particular value, insofar as they serve to mitigate the risk that well-intentioned interventions, once implemented, become neglected liabilities. Projects such as IDAlert are already progressing in this direction by producing transferable evidence, facilitating stakeholder engagement, and developing indicator systems that help decision-makers weigh multiple objectives. Empirical evidence from Empordà wetlands and Attica demonstrates the efficacy of a multifaceted approach encompassing ecological restoration, entomological surveillance, adaptive management, and cross-sector governance. This strategy has been shown to yield numerous advantages, including the mitigation of vector-related harms, thereby underscoring the potential for integrated, comprehensive management of wetlands.
In the context of a changing climate, characterised by increasingly hotter and drier summers and shifting rainfall patterns, the importance of wetlands in resilient water management strategies is paramount. The task ahead is not to choose between ecosystems and health, but to design, monitor and govern nature-based solutions in a manner that explicitly accounts for the full spectrum of ecosystem services and disservices. In order to achieve this, there is a requirement for sustained investment in multidisciplinary science, practical design standards that embed public health safeguards, and the social processes that enable collaboration across sectors.
The Aiguamolls and Attica case studies demonstrate the feasibility of these elements in practice, illustrating that wetlands can function as both biodiversity hotspots and components of climate-resilient infrastructure, provided that a management approach incorporating entomological surveillance and adaptive measures to mitigate mosquito breeding opportunities is employed. The adoption of these integrated strategies by policymakers and practitioners is likely to result in the delivery of resilient, equitable and health-conscious outcomes for communities across Europe.
Sources:
- NBS4Drought: Demonstrating and Upscaling Wetland-based Nature-Based Solutions for Droughts in Europe (CORDIS, European Commission, 2023); https://cordis.europa.eu/project/id/101181351
- IDAlert. Infectious Disease Decision-Support and Alert System for Climate Change Resilience in Europe (CORDIS, European Commission, 2022); https://cordis.europa.eu/project/id/101057554
- IDAlert. Including Health Risks in Nature-based Solutions (Webinar summary, 2024); https://idalertproject.eu/events
- IDAlert. Building Indicators for Climate-Sensitive Infectious Diseases: One Health Approach and Stakeholder Co-Creation (Policy brief, 2023); https://idalertproject.eu/publications
- European Environment Agency. Wetland Restoration and Nature-based Solutions: Monitoring and Governance Challenges in Europe (EEA Report, 2023); https://www.eea.europa.eu
