Background The freshwater pearl mussel (Margaritifera margaritifera) is declining dramatically throughout its range and is under grave threat in the UK, as in other areas of its EU distribution. The British populations of the freshwater pearl mussel, which is highlighted for conservation under Annex II of the Habitats Directive, have been adversely affected by multiple issues, including wildlife crime (removal in order to sell the pearls), habitat degradation and declining water quality. Objectives This overall project objective is to safeguard the future of the most important pearl mussel populations (M. margaritifera), in Great Britain (i.e., in 21 Natura 2000 sites across England, Scotland and Wales) by tackling the main threats to this and by implementing best practice conservation methods. Specific project goals are: Restoring the habitat of freshwater pearl mussels and their host fish (brown trout and Atlantic salmon) in selected UK river catchments. This will be achieved by improving instream and riparian (river) habitats for freshwater pearl mussels and their host fish; Securing the long-term survival of existing mussel populations and preventing their further degradation, by carrying out artificial ‘infection’of host fish with mussel larvae in three Natura 2000 sites (Ehen, Moriston, North Harris). This action will also include monitoring the existing levels of ‘natural’ infection; and Carrying out communications activities aimed at local, national and international audiences to raise awareness of pearl mussel conservation issues. Activities will include events within each project site, as well as presentations, seminars and conferences with national and international audiences. Expected results: A reduction of nutrient and sediment input from diffuse sources by improving the riparian land management in at least five river catchments (Dee, South Esk, Ehen, Evelix and Afon Eden). This will include the promotion of enhanced riparian land management techniques with at least 120 land-managers; The promotion of tree planting will take place in at least the five catchments (Dee, Spey, S. Esk, Ehen and Naver). This will include working with at least 60 land-managers; The physical restoration of natural in-stream processes will take place in at least five catchments (Dee, S Esk, Naver, Eden, Ehen). This will include the identification of degraded sites throughout each catchment and the delivery of practical restoration work at over 25 individual locations. It will also include the installation of large woody debris and restoring access for Atlantic salmon in the Mingarry Burn catchment; A reduction in silt input in at least seven catchments (South Esk, Borgie, Mingarry Burn, Oykel, Eden, Ehen, Evelix) by blocking ditches and establishing riparian wetlands as well as the establishment of extensive areas of native riparian woodland. It will also include identifying opportunities and planning for the implementation of subsequent riparian woodland improvements in the River Moriston catchment; A ‘riverwatch’ programme will be developed and delivered in 16 Natura 2000 sites. This will include raising awareness of freshwater pearl mussel conservation issues with at least 20 stakeholder groups; and A “pearls in the classroom” programme will be developed and delivered in 20 Natura 2000 network sites. Delivery of the programme will involve at least 150 school visits.