How is climate change affecting Arctic char?

Inuit have been enjoying char—raw, cooked, dried, frozen, or fermented—for millennia. It's a dependable and delicious food that countless generations have been able to count on. Gratitude and respect for arctic char are tightly stitched into Inuit culture. It's a staple in most communities.

Arctic char provides employment in some communities through small commercial fisheries, and as Inuit experience the effects of climate change on their local environments and wildlife, they have questions about what the future holds for arctic char—and for their food security.

Scientists and Inuit knowledge holders have been working together to provide some of the answers. What have they learned?

Temperature and char behaviour

Sea ice conditions, salinity, prey, predators—and especially temperature— can all influence the health of char, and where they go in the ocean. As climate change shortens sea-ice seasons, sea-run Arctic char (char that migrate to the ocean in summer to feed and return to freshwater in fall) may migrate to the ocean earlier and spend more time feeding there.

Arctic char need less food in cold water than in warmer water. This may be why they move away from the shore in late summer to deep water, further out, where it's cold. As average ocean temperatures continue warming, we may see these fish move earlier in the season, staying in deeper cooler water longer.

The arrival of new fish species

On another note, warmer temperatures have been attracting southern fish like capelin and salmon north to parts of the Arctic where they were rare in the past. It is not clear how these new arrivals are affecting char. Inuit experts are monitoring them, and in Cumberland Sound, Nunavut, they've observed that the char are eating more capelin, which gives a paler shade to their orange flesh.

In southern parts of the eastern Arctic the northern ranges of Atlantic salmon overlap with char. The two species do not compete for spawning areas however, as they spawn in different kinds of habitat. More research is needed to find out exactly what effect southern fish species are having on char.

Persistent organic pollutants such as PCBs are declining in Arctic char, thanks to laws banning their use and cleanups of contaminated sites in the Arctic. Mercury, a pollutant that occurs naturally, can increase in the environment because of dams and mining. This is a concern in Nunatsiavut. Research shows that mercury levels in sea-run Arctic char are very low, well within commercial sale guidelines. Char that never migrate to the ocean, especially those living in smaller lakes, are more likely to have higher levels.

Conclusion

There is much to learn about the present effects of climate change on Arctic char, and what to expect in future. Inuit communities—who have the most at stake—are making major contributions to char research, working closely with biologists and sharing their perspectives and expertise.

Finding out what influences the health and abundance of Arctic char, and learning how to manage their populations effectively, will require continued collaboration between scientific and Inuit knowledge holders—so that these iconic fish continue to nourish Inuit families and communities far into the future.