Loch Doon is the last known location in south-west Scotland to have a population of Arctic charr, which once inhabited at least four lochs in the region. Consequently it is a designated Site of Special Scientific Interest (SSSI). The Arctic charr is closely related to the Atlantic salmon and brown trout. Originally it migrated between the sea and fresh water but after the last Ice Age it populated inland freshwaters where it lives its entire lifecycle. Its disappearance throughout the southern edge of its range is thought to be due to increasing acidification.

Environment