Background Coastal lagoon is a priority habitat of the EU Habitats Directive. Coastal lagoons are particularly well developed in the Baltic region. Together with various dune habitats, cliffs and stone beaches, salt meadows and various types of grasslands, the Baltic coastal lagoons form an extremely varied habitat complex, associated with high levels of biodiversity. The project focused on the most important Baltic coastal areas for breeding populations of the ruff (Philomachus pugnax) and of a distinct subspecies of dunlin (Calidris alpina schinzii), two wading bird species listed in the Birds Directive. The project area also covers many of the last Baltic strongholds for creeping marshwort (Apium repens), European green toad (Bufo viridis), natterjack toad (Bufo calamita) and avocet (Recurvirostra avosetta). Many coastal lagoons have either been destroyed already, or are still loosing their ecological distinctiveness because of hydrological changes, overgrowth, and eutrophication. The project provided an opportunity for testing and demonstrating restoration and management measures on a range of 34 Baltic coastal lagoons habitat complexes, located in Denmark, Germany, Sweden, Lithuania and Estonia. Objectives The overall goal of the BALTCOAST project was to contribute to securing a favourable conservation status of the Baltic coastal lagoon habitat complexes, as well as the species characteristic for its habitats in Denmark, Germany and Estonia. The project aimed to prevent the extinction of the ruff (Philomachus pugnax) and of the southern subspecies of dunlin (Calidris alpina schinzii) from the Baltic Sea region. In order to ensure the use of best practices, the project had established a reference site in Sweden and aimed to establish a strong coastal lagoon management network between the countries bordering the Baltic Sea. In order to restore the coastal lagoons, drainage trenches would be blocked. Additionally, eutrophic mud and dense reed vegetation would be removed from the lagoons. These actions would lead to the enhancement of habitat quality for wading birds and amphibians. Dry semi natural habitats would be restored by clearing overgrowth with bushes and trees including alien invasive species such as the wrinkled rose (Rosa rugosa). Appropriate grazing regimes with hardy sheep and cattle would be introduced on many areas to keep them free of overgrowth. To ensure a sustainable management, the socio-economic conditions would be taken into account while developing site management strategies. The methods for the restoration of the coastal lagoon habitat complex would be improved by co-operation between experts and managers from Denmark, Sweden, Germany, Estonia and Lithuania. Results The BALTCOAST project focused on the most important Baltic coastal areas for breeding populations of the ruff (Philomachus pugnax) and of a distinct subspecies of dunlin (Calidris alpina schinzii), two wading bird species listed in the Birds Directive. The project area also covered many of the last Baltic strongholds for creeping marshwort (Apium repens), European green toad (Bufo viridis) and natterjack toad (Bufo calamita). In order to restore the coastal lagoons, drainage trenches were blocked. Additionally, eutrophic mud and dense reed vegetation were removed from the lagoons. These actions have led to the enhancement of habitat quality for wading birds and amphibians. Dry semi natural habitats were restored by clearing overgrowth with bushes and trees including alien invasive species such as the wrinkled rose (Rosa rugosa). Appropriate razing regimes with hardy grazers were introduced on more than 2 800 ha to keep the area free of overgrowth. The establishment of whole-year grazing with robust cattle was one of the core activities of the project. On many sites, the establishment of winter grazing has led to a reduction of litter, dominant grass species, such as bush grass (Calamagrostis epigeios) and unwanted shrubs of invasive alien rose species (e.g. Rosa rugosa). As a result, typical species of sand dunes (Thymus vulgaris, Galium verum) and coastal meadows (various orchid species) could spread again. The changes in the vegetation of coastal meadows due to the introduction or improvement of grazing regimes have resulted in a significant increase of the habitat qualities for many meadow bird species. As a result of the project, the dunlin returned to the Saltholm (Denmark) and Teorehe (Estonia) sites. The blocking of ditches has helped to retain water in early spring and to maintain a certain water level in lagoons throughout the year. Moreover the restoration of depressions created additional temporary aquatic habitats in many coastal lagoons. These actions have created new habitats for green toad and Natternjack toad and for the ruff [e.g. in Syöstra Öland (Sweden), Ottenby (Sweden) and Saltholm (Denmark)]. Due to the international approach and the high variety of the applied restoration measures, the project has a high "demonstration value" for other projects that are focusing on coastal habitats. The project clearly shows that the establishment of a whole-year grazing regimes is a key strategy in order to put in place appropriate conservation strategies for habitats and species of coastal grasslands. Moreover, it demonstrated that the detailed analysis of the hydrological conditions on site and the re-establishment of the "natural hydrology" is crucial in order to provide the suitable abiotic conditions for a high species diversity of coastal habitats. Further information on the project can be found in the project's layman report (see "Read more" section).