A new synthesis report, titled "Ecological Characterisation of Peatlands and Coastal Lagoons in Europe," has been published to support the assessment, monitoring, and restoration of European wetlands under EU environmental legislation. The report was prepared in response to a policy request submitted by the Directorate-General for Environment (DG ENV) to the European Commission's Knowledge Centre for Biodiversity (KCBD), and delivered by the Science Service for Biodiversity (SSBD), currently under development by the BioAgora project.

The report provides an ecological characterisation of two contrasting Annex I habitat groups under the Habitats Directive: inland peat-forming wetlands (Group 7, “Raised bogs, mires and fens”) and coastal lagoons (habitat type 1150). Its findings are intended to inform monitoring and condition assessment under the Habitats Directive (HD), the Water Framework Directive (WFD), and the Nature Restoration Regulation (NRR).

Extent and status of wetland loss

European wetlands have undergone substantial historical loss, with an estimated 80% of the wetland area present a century ago no longer extant, and more than half of remaining peatlands drained. Despite their comparatively limited spatial extent, peatlands are estimated to store nearly one-third of global soil carbon, while coastal lagoons account for approximately 13% of the global coastline and support disproportionately high levels of biological productivity and biodiversity.

Hydrology as the principal determinant of ecosystem condition

The report identifies hydrological regime as the dominant control on the functioning of both habitat groups. In peatlands, a persistently high and stable water table sustains the anoxic conditions that suppress decomposition and allow peat to accumulate. When the water table falls - most often through drainage – peat oxidises, subsides and compacts, vegetation and microbial communities shift, and fire risk increases. Because the structure of the peat is itself altered, much of this is effectively irreversible, and a long-term carbon sink can become a net source of greenhouse gases. In coastal lagoons, freshwater–marine exchange, hydrographic and associated biological connectivity and physico-chemical gradients, regulate hydrodynamics, sediment transport, nutrient availability, community structure, and biological productivity, and are associated with substantial natural variability and spatiotemporal heterogeneity independent of anthropogenic pressure.

Multiple interacting pressures

Degradation in both habitat groups is most attributed to combinations of pressures rather than to single causal factors. Drainage and land-use conversion, nutrient enrichment, peat extraction, contaminant inputs, coastal development, and climate change act together and rarely in isolation, reinforcing one another through feedback that are often non-linear and context-dependent. Because pressures compound in this way, ecological deterioration is difficult to detect, attribute, and reverse.

Indicator frameworks and assessment methodology

The report concludes that no single indicator is sufficient to characterize ecosystem conditions in either habitat group. It proposes tiered indicator frameworks distinguishing essential from complementary variables across hydrological, physico-chemical, biological, and functional dimensions. Assessment designs must account for the natural scales of spatial and temporal variability, and for historical trends in the context of ecological succession – without this, frameworks risk mistaking intrinsic ecosystem dynamics for anthropogenic impact. Earth Observation should be integrated with in-situ measurement, keeping in mind that it is most reliably applied to hydrological and vegetation-related metrics, and requires field-based calibration and validation.

Recommendations for future monitoring architecture

Wetland monitoring across Member States remains fragmented and inconsistent. The report sets out a transition pathway towards an integrated observation architecture combining Earth Observation, in-situ measurement, numerical modelling, and digital twin approaches. It recommends a dual design: standardised routine monitoring, designed to capture relevant spatial and temporal heterogeneity, alongside adaptive, event-specific monitoring able to respond to extreme events and unforeseen impacts. Such a system would reduce the reporting burden on Member States, improve comparability between regions, and distinguish early warning signals from indicators of consolidated change. The report identifies this architecture as a foundation for a future EU Wetland Watch service, built on local and national observation systems integrated into a European-scale network. The report is explicitly a scientific foundation rather than an operational assessment protocol. Calibration of habitat-specific condition thresholds - capable of distinguishing favourable condition from early and severe degradation across the range of peatland types and lagoon contexts present in the EU - is identified as the critical next step, requiring coordinated analysis of monitoring data and reference conditions across Member States.

About the report

The report was prepared by a multidisciplinary expert group coordinated by the BioAgora project and the Science Service for Biodiversity, in response to a policy request from the European Commission’s Directorate-General for Environment to the EC Knowledge Centre for Biodiversity (KCBD). It is published by the Publications Office of the European Union and is available under a Creative Commons Attribution 4.0 licence.

Access the report here.

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Funded by the European Union under grant agreement No. 101059438, BIO-Agora (Bio Knowledge Agora: Developing the Science Service for European Research and Biodiversity Policymaking). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the granting authority can be held responsible for them.

Citation: Cetinic, K.A., Pérez-Ruzafa, Á., Boix, D., Cravo-Laureau, C., Klimkowska, A., et al, Ecological characterisation of peatlands and coastal lagoons in Europe, Blasi, M., Korcheva, A., Vasilakopoulos, P. and Velasco Gomez, D.M. (editors), Publications Office of the European Union, Luxembourg, 2026, https://data.europa.eu/doi/10.2760/9963649, JRC146927.