A £3.5 million project aimed at protecting the endangered freshwater pearl mussel has been launched by wildlife campaigners.
The four-year project will centre around 21 of Britain's key conservation sites, focusing on the conservation of remaining mussel populations which face extinction in many rivers.
Scottish Natural Heritage (SNH) said the sites in Scotland, England and Wales are designated as special areas of conservation under the EC habitats directive and are deemed to be the most important for pearl mussels' survival.
Central to the project will be a crackdown on wildlife crime, with riverwatch schemes helping to prevent the illegal persecution of the mollusc.
SNH's Dr Iain Sime said: "The freshwater pearl mussel has suffered a catastrophic decline across its former range. It is important and we need to care because it is an excellent indicator of good water quality, and we all need good quality drinking water.
"As part of the project we are aiming to restore river channels and plant trees along more than 70km of riverbanks to help provide the habitats which the pearl mussels need to flourish. We will also teach primary school children about the pearl mussel and its amazing life cycle.
"We are tremendously excited by this project which includes such a wide range of activities in so many places."
Britain, and Scotland in particular, contains around 50% of the known breeding populations of freshwater pearl mussel in Europe. Conservationists believe the loss of these populations would have a "catastrophic impact" on its survival in Europe.
The mussels are fully protected under the 1981 Wildlife and Countryside Act and whilst the pearls they can produce have long been used in jewellery, their exploitation is now strictly prohibited.
Their population sites can be vulnerable to illegal pearl fishing. A 2008/09 SNH study found that 75% of the internationally important sites they surveyed had suffered significant and lasting criminal damage. This ranged from illegal fishing to unauthorised river works which destroyed whole pearl mussel populations.