Pielinen, also Pielisjärvi, ranks as Finland’s fourth largest lake with a catchment area of 12,823 km². It is equally divided between eastern Finland and Russia. The formation of the lake and its outlet is attributed to postglacial isostatic rebound, which led to the uplift of the land. As is usual for Finnish lakes, the colour of the lake is dark. This is due to the high proportion of peat bogs present in the catchment area, which shed humic substances.
Lake Pielinen is located in the northernmost part of Finnish Karelia. It’s called the land of the Karelian peoples. A northern European region historically important not only for Finland, but also for Russia and Sweden. It is adjacent to Koli National Park. It is known for its scenic beauty in summer and winter skiing. Is close to the rafting centres in the tourist centres of Ruunaa, Lieksa and Nurmes.
Klima
Climatic data has been recorded in the two main towns in the lake basin. Lieksa and Juuka, between 1931 and 1960. In Lieksa, average annual rainfall of 583 mm and average minimum and maximum temperatures of -7.1 °C (December) and 16.4 °C (July) were recorded. During the same period, an average of 544 mm of precipitation fell in Juuka. Minimum and maximum temperatures of -7.1 °C (19.2 °F) (December) and 16.1 °C (61.0 °F) (July) were recorded. Records from 1960 to 1980 indicate that the lake averages a freeze-up between November 21 and May 14.
Lake Pielinen fauna
The fauna of the lake consists of eight species of benthos and ten species of fish, nine of which are economically important.
The following benthos have been recorded in the lake: Insects – Dicrotenipeds pulsus, Glyptotendipens spp., Polypedilum pullum, Chaoborus flavicans, Stictochironomus spp., Tanytarsus spp. and Oligochaeta – Limnodrilus hoffmeisteri.
Salmon, formerly endemic to the lake, have long since been extirpated. Other fish species still present include Perca fluviatilis, Esox lucius, Rutilus rutilus, Coregonus albula, C. mulesum, C. lavaretus, Lota lota, Abramis brama, Stizostedion lucioperca and Salmo trutta lacustris.
The lake is classified as mesotrophic.
