Skjern River Valley, Northern Europe’s most expensive wetland restoration project: benefits to breeding waterbirds

Abstrakti

After circa 35 years of drainage and intensive arable tillage, the lower Skjern River, Den-mark was re-engineered to its original meanders and flooding regime, creating 22 km 2 of lakes, shallow wetlands and seasonally flooded grazed wet grassland costing €38 million. The primary motivation was to restore the sediment/nutrient retention capacity of the river valley to reduce eutrophication of Ringkøbing Fjord at its efflux. Secondary objectives were to (i) restore breeding and staging bird habitat, (ii) enhance the self-sustaining Atlantic Salmon Salmo salar population and (iii) improve recreational and tourist activities. Despite lack of specific success criteria, breeding waterbird numbers increased from 134 ± 22.9 SE (n = 3) pairs before to 1,744 ± 153 SE (n = 5) after restoration (although on average 1,004 of these were Black-headed Gulls Chroicocephalus ridibundus), species richness and diversity also increased. Twenty-nine waterbird species returned to breed, 10 of national or international significance (Danish Red List/European Union Birds Directive Annex 1 species) now ranking Skjern River amongst the top 10 most important breeding waterbird sites in Denmark. Currently, agriculture supports cost-neutral management of the restoration area, but whilst most expected wet meadow and marsh species had returned, lack of goal-orientated management targets resulted in some additional rare and threatened species remaining absent. Breeding pair density and diversity of other species could have been greatly improved by prior planning and management intervention but at additional cost.