A new study published in Ecological Engineering sheds light on the effects of coastal wetland restoration on the climate, particularly on carbon dioxide (CO₂) and methane (CH₄) fluxes — two greenhouse gases whose exchanges with the atmosphere play an important role in regulating the Earth’s climate.
Conducted as part of the European RESTORE4Cs [1] project, in which Tour du Valat is a partner, the study brought together around fifty researchers across six pilot wetlands covering a wide range of European ecological contexts: Ria de Aveiro (Portugal), the Eastern Scheldt Estuary (Netherlands), the Camargue (France), the Marjal dels Moros (Spain), the Danube Delta (Romania) and the Curonian Lagoon (Lithuania).
Over four seasons, the teams simultaneously measured CO₂ and CH₄ fluxes at preserved, degraded and restored sites using static chambers. The goal was to determine the extent to which restoration measures, encouraged by European policies, translate into a measurable climate benefit in terms of CO₂ equivalents (CO₂-eq).
Results vary depending on the type of gas and wetland
CO₂ fluxes depend primarily on vegetation cover and the flooding regime at the landscape scale, whilst CH₄ emissions respond more sensitively to factors such as water quality, salinity, and hydrological dynamics.
Among the measures studied, the restoration of seagrass meadows through replanting shows the clearest positive climate signal, with a significant reduction in the CO₂-eq. balance, whether the effect of methane is considered over the short term (20 years) or the longer term (100 years). Reducing lagoon eutrophication through improved water treatment also showed a positive effect, but only in the short term (over a 20-year horizon). In contrast, other restoration measures modified CO2 and CH4 fluxes in opposing directions, with no significant effect on the overall balance.
Restoration strategies need to be adapted to each context
This work provides useful insight for wetland managers: the climate benefits of restoration are neither automatic nor uniform. They depend on the greenhouse gas in question, the type of wetland, and the specific restoration measure undertaken. This makes a case for restoration strategies tailored to each context, and for rigorous monitoring of several greenhouse gases — particularly CO₂ and CH₄ — to accurately detect and quantify potential climate benefits.
These results form part of the work carried out by the European RESTORE4Cs project, which develops knowledge, data, and decision-support tools to support the conservation and restoration of European coastal wetlands. They contribute, in particular, to the European Coastal Wetlands Interactive Platform [2] and its Decision-Support Toolbox [3], which enable users to explore the project’s results and support the prioritisation of restoration actions.
Publication reference
📄 Cabrera-Brufau M. et al. 2026. Ecological Engineering 232:108080. doi.org/10.1016/j.ecoleng.2026.108080 [4]