Arctic charr is called Rautu in Lapland. Fish has clear and unclear multicoloured dots on it's sides which have greenish grey background. Colouring varies among populations, for example wandering populations have much lighter sides with silver and steely blue. Fins of bottom side are white bordered on front. Especially in spawning time, male fish's stomach is red. Arctic charr have no dots on fins, unlike lake trout.
Arctic charr is an arctic specie. In Finland it exists also in south, Vuoksi-waters as a relic.
Fish of cold
Arctic charr get along well in cold, oxygen rich and clear waters. Depth is not an issue, arctic charrs exist in also shallow lakes. It don't tolerate acidity. Koli (1990) states that lowest pH in Finnish charr-lakes is 6,2. Requirement of cold water is so absolute that warming climate will most likely abolish first arctic charr from Finland, if it continues.
There can be divergent populations of arctic charr even in the same watercourse. People talk commonly about small and big arctic charr. Small fishes are slow growing and reside in deep and big fishes are predators. Also wandering form is known: in Finland wandering arctic charrs ascend the river Teno and it's offshoots. There is no mutual understanding, but arctic charr is considerably one specie that just varies a lot.
Food taking
Young charrs and midget populations eat zooplankton and bottom fauna. Big fish are almost complete predators and eat e.g. vendace, smelt, minnow and small whitefish. Arctic charrs take also food from the surface. In lakes that have small and slow grown populations the situation is alike to perch, so those who have reached size big enough start to eat smaller fellows.
Spawning
Arctic charr spawn in autumn. In Saimaa it takes place in September and in Lapland in October-November.
Spawning areas are in 1-10 m - usually in 3-5 m - deep with clear stony or rough grit bottom. Small charrs of lake Inari spawn much deeper. Wandering charrs that ascend river Teno spawn offshoots with cold water which won't do for salmons or sea trouts.
Like graylings arctic charr males occupy their own territory for spawning ceremonies, that they also aggressively defend.
Catch, records and specialties
In 2003 catch of arctic charr from lake Inari was 8500 kilos. It is feeble indeed, because in 1930s before rationing by hydroelectric plants in Paatsjoki river started to affect very negatively to lake's ecosystem the catch was 20 tonnes yearly.
Official record (from 20th century) is 6,4 kg arctic charr that was somewhat surprisingly caught from Saimaa. Presently unofficial old records were dominated by 8,6 kg charr trolled from lake Inari and 9,8 kg charr caught with a net from lake Sevettijärvi.
Flesh of arctic charr is red coloured, fatty and absolutely delicious. With hook in the mouth, arctic charr puts up a good fight. So it is highly desirable and distinguished among fishermen. Ice fishing of arctic charr is its own art. Charrs are ice fished with special jigs "charr-flaps".
Sources:
- Koli, Lauri, Suomen kalat
