Background The river Odense (Odense Å) is one of the largest river systems in Denmark. Between 1944 and 1960 important sections of around 20 km in total, were canalised and straightened to provide more farmland. This, however, had serious consequences for wildlife, both in and near the river, which declined rapidly thereafter. Despite these losses, the River Odense is still the only river in Denmark that hosts a population of the thick-shelled river mussel (Unio crassus), a large freshwater mussel that has disappeared over much of its European range, as well as Annex II fish species such as the spined loach (Cobitis taenia) and brook lamprey (Lampetra planeri). Where the river drains into the Odense Fjord there is an area of Atlantic sea meadows and mudflats of high conservation potential. Within the framework of national programmes, originally based on HELCOM objectives (the governing body of the Convention on the Protection of the Baltic Sea Area), extensive efforts had been made to reduce the point sources of pollution. However, the river and its surrounding habitats still suffered from the combined effects of a lack of hydrological interactions, due to the rigid canalisation system, and of leaching from diffuse pollution sources. Objectives The overall objective of this LIFE project was to improve the ecological conditions of species and habitats along the river Odense and in the fjord. The main action was to restore meanders to a 12.2 km section of the river. All landowners along the river (79 in total) would be contacted with a view to receiving compensation for the partial loss or alteration of their land use, within the framework of a land consolidation process. Around 350 ha of riparian wetlands and meadows would be re-created, which should help to reduce the nutrient load in Odense Fjord by some 5%. Management agreements would be signed to restore 155 ha of neglected coastal meadows along the fjord. The project also aimed to explore the synergies between Natura 2000 designation and the implementation of the Water Framework Directive (WFD), as the river Odense was one of 13 pilot river basins selected by the European Commission to test the implementation of the WFD (2002-04). Results The REGAIN project was successful. Its main actions included: Restoring 350 ha of wetlands along the river Odense with increased retention capacity for nutrients and thereby reducing (by 3%), the nutrient load on Odense Fjord. Despite this relatively small decrease (i.e. less than the targeted 5%), it is an important step towards an improved biological status of the fjord; The Natura 2000 area was enlarged to include the whole project area. Improving the hydrological interplay between the river Odense and its riparian areas in the river valley, thus restoring the Habitat Directive Annex I types such as alluvial forest and petrifying springs, Re-meandering 12 km of the river Odense to obtain better physical conditions for the benefit of the thick-shelled river mussel and other targeted Annex II fish species; Obtaining proper management by grazing of over 155 ha of coastal meadows along the Odense Fjord shores, and 156 ha freshwater meadows along river Odense; Exchanging experience with a German LIFE project on the conservation of the Unio Crassus mussel to ensure good conservation status; Monitoring to follow the development of nature types and species over the short and longer- term. One of the key future challenges is to keep the areas under an appropriate grazing regime. The project provided the basic infrastructure to allow grazing to take place in the future. Agreements were signed between 72 landowners. Fences erected under the framework of the project can last for 20 years, so the beneficiary hopes that this will provide an incentive to the landowners to maintain the grazing beyond the 5-10 years or so, guaranteed by the project. Further information on the project can be found in the project's layman report(see "Read more" section).