DNA testing to locate endangered freshwater pearl mussels in northern Finland

Researchers will survey 14 sites along the Kemijoki river system this autumn to identify new populations of the critically endangered freshwater pearl mussel, using environmental DNA sampling to track their spread.

The project, led by Finland’s state-owned forest and park service Metsähallitus, aims to assess the health of known mussel populations in the Kemijoki and Tuuloma waterways while searching for undiscovered groups. Fieldwork will focus on tributaries with prior sightings of the species, which is classified as critically endangered in Finland.

Last summer, biologists confirmed a previously unknown, thriving population in the Ivalojoki river—a rare find for a species whose numbers have plummeted due to habitat loss and pollution. The current effort is part of Raakkuohjelma 2030, a nearly six-year conservation initiative funded by forestry company Stora Enso.

In addition to the 14 new survey sites, researchers will revisit three established populations to evaluate their status. Environmental DNA (eDNA) analysis will detect genetic traces left by the mussels in water samples, allowing non-invasive monitoring of their presence.