Wetland restoration has been a key strategy in Denmark’s efforts to reduce agricultural nutrient runoff into aquatic systems over the past three decades. Beyond their primary function, these re-created waterbodies also benefit waterbird species. This study investigates the role of restored wetlands in supporting the national breeding population of the Black-necked Grebe Podiceps nigricollis. Drawing on spatial information on restoration efforts from the national monitoring programme and citizen science records from volunteer observers, we analysed breeding presence and abundance of the species across 651 freshwater sites. Our results revealed a strong preference for restored habitats; the proportions of breeding pairs observed in these wetlands increased from 6% in the early 1990s to 83% in the last ten years. Colonisation typically occurred within the first year following restoration but was short-lived, with most colonies persisting only a few years. In a modern Danish landscape largely devoid of hyper-saline and ephemeral arid-lands wetland ecosystems favoured by Black-necked Grebes, restored wetlands appear to function as temporary surrogate habitats for this pioneer species. Longer-term conservation of this species may require the continued creation of newly established wetlands, as well as the re-invigoration of wetland systems governed by natural hydrological processes.

The application of manure phosphorus at rates above crop uptake has resultedin water pollution for some regions. In response, new manure managementstandards will require some farms to match manure phosphorus applicationrates with crop uptake. For some regions, this will lead to more crop acresand a shift toward crops with greater nutrient uptake, both of which willincrease nitrogen runoff. The greater nitrogen runoff could offset the lowerphosphorus runoff to result in greater water pollution. This demonstratesthe law of unintended consequences, which results when policy does notconsider how economic agents respond to incentives.