Wildlife experts discovered 113 dead freshwater pearl mussels in a river south of Lochinver at the weekend.
They have concluded that they were deliberately killed and the police’s wildlife crime officers are appealing for information.
Many rivers in Scotland hold large internationally important populations of the pearl mussels.
Police believe that those responsible for the crime have “killed a significant part of the river’s population”.
It is understood that mussels were taken from the bed of the river during the summer months and killed to see if there was a pearl inside.
The crime was discovered during a survey at the river.
Survey leader Dr Peter Cosgrove said: “I am appalled that someone deliberately broke the law and killed such a large number of this endangered species.
“It is very disheartening and distressing to discover this type wildlife crime when so many local people are trying to help conserve this important and protected species.”
Daniel Sutherland, North Divisions wildlife crime and environmental crime officer, added: ”The Scottish Fresh Water Pearl Mussels are a native species which are under serious threat of decline or worse extinction locally in the north of Scotland.
“These mussels are one of the wildlife crime policing priorities set out by government and police through the Partnership for Action against Wildlife Crime (PAW).
Iain Sime from Scottish Natural Heritage (SNH), explained that it is important pearl mussels continue to survive as they can act as the “livers of our rivers”.
“Through their filter feeding pearl mussels can help maintain clear water and remove some impurities. But they also require high quality water themselves. As such, they are important indicators of the health of our wider environment.
“It is therefore really disappointing to see our survey reveal the death of so many pearl mussels. As pearl mussels are so slow growing and can live for more than a century it that will take decades of undisturbed conditions for the population to recover. “
Police are appealing to anybody with information about this incident, particularly anglers and walkers in the area who have seen anything suspicious to come forward and contact Police on 101 or Crimestoppers on 0800 555111 if they wish to remain anonymous.
