Rare discovery of new freshwater pearl mussels population in river

A new population of critically endangered freshwater pearl mussels has been discovered in a Scottish river.

Kieran Leigh-Moy, a graduate on the Scottish Natural Heritage (SNH) placement scheme, found them unexpectedly while looking for a site where the species could be reintroduced.

Freshwater pearl mussels can live up to 280 years but the species is critically endangered as a large proportion of the populations across Europe have not been breeding successfully for several decades.

Mr Leigh-Moy said: “I’d already identified this river as potentially having good quality habitat so was visiting the site to conduct more in-depth surveys to see if it would be a suitable site for a reintroduction but was stunned to find juvenile freshwater pearl mussels already there.

“It’s really rare to find a new population of these mussels and especially one that is breeding successfully, so it was a really exciting moment.

“What’s particularly significant is that the juvenile mussels found were many miles away from the nearest known breeding population and that’s good news because it could help to prevent further range contraction of the species.”

Mr Leigh-Moy has been working on a project to understand why the declining populations of freshwater pearl mussels in the river were not breeding and locate sites where they could be reintroduced to help their recovery.

It is hoped the approach he has developed can be used to help prioritise conservation efforts and find good habitats for freshwater pearl mussels at other locations, as well as mitigate the shrinking range of the species in the river.

SNH said the presence of the mussels is likely to be a testament to sensitive land management in the area.

Along with Forestry and Land Scotland, SNH is working to promote this kind of land management, which includes reducing pollution and establishing riverside woodlands, through their support of the Spey Catchment Initiative.

Giles Brockman, from Forestry and Land Scotland, said: “This is really exciting news.

“Forest management is not just about trees and this is a strong indication that actions to protect water courses are effective and can help to sustain and nurture wildlife and rare species.”