Fish
Arctic Char
Salvelinus alpinus · also called Arctic chars
In a lake trapped within the Arctic Circle since the last ice age receded, an Arctic char spawns in water cold enough to have frozen almost any other freshwater fish’s reproductive plans entirely, having spent thousands of generations isolated from any ocean-going relatives.
Overview
The Arctic char, Salvelinus alpinus, is a cold-tolerant fish found across circumpolar Arctic habitat spanning North America, Greenland, Scandinavia, and Russia. Its position as the northernmost freshwater fish on Earth, combined with the split between ancient landlocked populations and ocean-migrating relatives, make it one of the more geographically and evolutionarily distinctive salmonids in the world.
A fish holding the northern frontier alone
While most freshwater fish reach their limits well south of the Arctic Circle, the Arctic char keeps going, occupying lakes and rivers so far north and so cold that it effectively has the northernmost freshwater habitat on the planet entirely to itself.
Status
Least Concern — widespread across suitable cold-water habitat throughout the circumpolar Arctic, though some isolated landlocked populations are considered vulnerable.
Arctic Char: common questions
Is the Arctic char really the northernmost freshwater fish?
Yes, the Arctic char is found further north than any other freshwater fish species, occurring in lakes and rivers well within the Arctic Circle across its circumpolar range, an extreme cold tolerance that lets it occupy freshwater habitat no other fish species can survive in.
Why do some Arctic char never leave freshwater while others migrate to the sea?
Certain Arctic char populations became landlocked within isolated lakes thousands of years ago as the last ice age ended and ancient meltwater connections to the sea disappeared, while other populations retained access to the ocean and remain anadromous today, migrating between rivers and the sea much like salmon.
How cold can the water be when Arctic char spawn?
An Arctic char can spawn successfully in water temperatures close to freezing, an extreme cold tolerance that allows the species to reproduce in conditions that would be entirely unsuitable for the vast majority of other freshwater fish species.
Why is the Arctic char important to Arctic communities?
The Arctic char has long served as an important traditional subsistence food source for Indigenous communities across its circumpolar Arctic range, valued for its reliable availability in a region where many other food sources are scarce or highly seasonal.