In the rivers Koutajoki and Savinajoki, flowing next to the northern part of the Karhunkierros trail, there have been sightings of Cyanobacteria!
Cyanobacteria is a toxic alga that can cause stomach symptoms, skin irritation and flu like symptoms. Please do not swim or take drinking or cooking water from Koutajoki and Savinajoki (from Hautajärvi to Savilampi) and avoid taking water from Oulankajoki (from Savilampi downward). Take water with caution from Kitkajoki.
You can take clean water from Ruka, Juuma (Basecamp Oulanka or Retki-Etappi), Oulanka Visitor Center, Oulanka Camping Ground and Hautajärvi.
Water with Cyanobacteria cannot be used even after boiling!