Thousands of river pearl mussels found dead due to logging activities in Hukkajoki River, Finland

A dark brown shell has cracked, revealing the tragedy beneath—a once-thriving freshwater mussel, the endangered river pearl mussel, which swayed gently in the waters of the Hukkajoki River in Suomussalmi, now lies dead in a container. It is not alone; thousands of its counterparts have met a similar fate after being crushed by logging machinery.

This environmental disaster was discovered last week, spurring police investigations into severe violations of nature protection laws. Since then, experts from Metsähallitus have been working tirelessly to save as many mussels as possible. Those that remain alive are being relocated upstream to escape the sludge spread by the heavy machinery.

In just four days, over 4,000 critically endangered river pearl mussels have been moved from the devastated area, although their survival in the new habitat remains uncertain. If they begin to thrive, it will be seen as a sign of hope, according to experts.

The damage to Hukkajoki was accidentally revealed while researchers were studying the local mussel population. The riverbed has been contaminated with mud, sand, and logging debris, severely disrupting the mussels’ habitat.

It is estimated that Hukkajoki was home to over 120,000 river pearl mussels, accounting for about five percent of the species’ population in Finland, most of which resides in Lapland and Kainuu. The cleaning of the river, which has already seen contamination spread over several hundred meters, will require significant effort and time. Next week, additional specialists will join the cleanup, ensuring the safe handling of the vulnerable mussels.

The destruction occurred at a logging site run by Stora Enso, where the environmental impacts have been described as shocking. Despite prior instructions from the Environmental Authority regarding the mussel populations, these guidelines were not observed during the logging activities.