Arctic char as their name suggests, have a circumpolar distribution. This means that they are only found in the most northerly parts of the world (Arctic and subarctic, in upland places where water temperatures are lower).
Arctic char are a relict species, which means that they are a remaining population of what was once a more widespread species thousands of years ago. Unfortunately, the Arctic char is now one of the rarest fish species in Ireland and is only found in a small number of upland, post-glacial lakes.
A threatened species
The current distribution of Arctic char in Ireland depends on the maximum depth of the lake and whether other fish species are present. Because Arctic char are confined to lakes, they are vulnerable to human pressures such as pollution, acidification and water abstraction. Arctic char come under pressure when other fish species (for example, roach and perch) gain access to their lake and squeeze them out of their habitat through competition. While Arctic char may be able to co-exist with other fish communities when a lake is deep enough to provide some shelter (refuge), their survival in shallower lakes is at greater risk. As a cold water species, the Arctic char is vulnerable to the effects of climate change. Sadly, recent Inland Fisheries Ireland research shows an overall decline in this species.
This research programme was designed to monitor this special species and explore its habitat, distribution and genetics. It also helped develop new methods such as hydroacoustic sampling for Arctic char.