Restoration work is planned for a Highland river to help safeguard the future of a species as endangered as the giant panda.
Scottish Natural Heritage (SNH) wants to appoint experts to carry out a study on rivers in Sutherland with the aim of improving the habitat of the freshwater pearl mussel.
It is one of the most critically endangered molluscs in the world.
Rivers in Scotland, including many in the Highlands, are a stronghold for the species and contain about half of the world’s population.
The rivers Naver and Mallart in Sutherland form a Special Area of Conservation but SNH said the conservation status of the freshwater pearl mussels has been classed as “unfavourable”.
Now, as part of the four-year UK-wide Pearls in Peril LIFE project to safeguard the mussel, SNH is tendering for consultants to carry out a feasibility study of the impact of restoring parts of the rivers in the largest river restoration carried out in Scotland.
Smaller studies are also being carried out on the Dee and South Esk river
Jackie Webley, Pearls in Peril project manager, said: “The River Naver and its tributary the Mallart hold a sizeable population of freshwater pearl mussels. We don’t want any deterioration in the population and what we want to do is secure the future of the population. In places boulders have been removed and that has removed habitat for the mussels which the mussels depend on.”