Agriculture is the largest anthropogenic source of nutrients (N and P) enhancing eutrophication of the Baltic Sea. The reduction of agricultural nutrient load depends on the reduction of emissions from animal and crop production as well as on the enhancement of nutrient retention in the watershed. Available evidence suggests that improving retention processes have a greater potential for reducing nutrient load than emission management. Constructed wetlands are recognized as a powerful tool to reduce nutrient run-off from arable land. However, the popularity of wetlands among farmers and landowners has been small, mainly due to the large demand of area and high construction costs. The proposed project aims to work out and promote methods and techniques to enhance nutrient retention in wetlands (hereby entitled "active wetlands"), model biological and economical efficiency of wetlands, and increase awareness of the importance of wetlands in decreasing the nutrient load from agriculture. Different approaches are available for improving nutrient retention processes. These include construction and treatment of artificial wetlands, as well as conservation and management of natural wetlands. In WP2, the different methods to increase efficiency of wetlands are surveyed and the most promising ones are tested in small pilot wetlands. Chemical precipitation of dissolved inorganic P with ferric sulphate is one way to increase the retention efficiency of small wetlands. In WP3, the effect of active wetlands on nutrient emissions is modelled from small drains to large watersheds. This work connects the watershed modelling in Estonia and Finland. In addition, the cost-effectiveness of wetlands in retaining nutrients is economically modelled. In WP4, the positive effects of wetlands are promoted with the aim to increase the number of wetlands in Estonia and Finland. This campaign is directed to farmers, landowners, authorities and policy makers. In addition, WP4 also aims to enhance co-operation in wetland management between Estonian and Finnish wetland managers. The main results expected from the project are improvements in the design and management of constructed wetlands leading to improved nutrient retention. This in turn will support the development of effective policy measures to reverse the ongoing trend of draining natural wetlands (in Estonia). In addition, the project will result in cross-border cooperation in wetland management, including the sharing of information. Through media coverage, the general level of awareness of the issues involved will be developed among landowners and the public at large. Achievements: The Active Wetlands project identified possible solutions for how to reduce agricultural nutrient load by enhancing nutrient retention in the watersheds. Constructed wetlands are recognised as a powerful tool in reducing nutrient run-off from arable land to the Baltic Sea. Such wetlands preserve soil and nutrients from incoming water and increase biodiversity by creating plant and animal habitats different from neighbouring fields. During the project, Estonian and Finnish farmers, rural advisors and decision-makers learnt more about how wetlands can be used to reduce the nutrient load from agriculture. By establishing small pilot wetlands, the project established practical designs and methods to increase the efficiency of agricultural wetlands.