European freshwaters are among the most intensively used and modified ecosystems. Rivers, streams, floodplains and wetlands are affected by overlapping pressures, including hydromorphological alteration, changes in flow, nutrient enrichment, toxic substances and broader land-use impacts. This talk addresses how such multiple stressors shape the ecological status of European waters, how different organism groups respond to these pressures, and what can be learned from recent restoration practice for large-scale recovery.

The first part of the talk synthesises evidence on freshwater degradation across Europe. Large-scale assessments of more than 52,000 functional elementary catchments show that ecological status is explained by a complex mix of stressors, including urban and agricultural land use in riparian areas, flow alteration, nitrogen and phosphorus inputs, and toxic substances. Overall, hydromorphological pressures account for a substantial share of stressor-induced variance, while water-quality-related pressures dominate the remaining effects. A recent meta-analysis further illustrates that organism groups differ markedly in their sensitivity: hydromorphological stress particularly affects macroorganisms, while benthic invertebrate diversity responds most consistently and negatively across stressors.

The second part turns to restoration and recovery, using the Emscher system as a regional example. Once shaped by industrialisation, flooding and the conversion of streams into open wastewater channels, the catchment has undergone one of Europe’s most ambitious river restoration programmes. Evidence from restored streams in the Boye catchment shows that recolonisation of formerly heavily polluted systems is a long-term process: good dispersers arrive first, while habitat development, species interactions and increasing proportions of sensitive taxa unfold over roughly a decade.

The final part broadens the perspective to landscape-scale restoration through the EU project MERLIN, which works across peatlands and wetlands, small streams and basins, and large transboundary rivers. The talk discusses how restoration can move beyond isolated projects by building on existing “cores” of successful action, developing regional scalability plans, recognising environmental, social and economic co-benefits, cooperating with economic sectors, and strengthening learning within communities of practice. In doing so, it links ecological evidence on degradation and recovery with practical lessons for implementing the EU Nature Restoration Regulation and for advancing freshwater restoration at the scale required by the biodiversity and climate crises.