Greenland’s polar cod are declining and moving north as waters warm

Polar cod stocks have declined markedly in both West and East Greenland since the early 1990s and the species has shifted north as the waters around the country have warmed, according to a study by the Greenland Institute of Natural Resources and DTU Aqua published in February, KNR reports.

The Arctic is warming almost four times faster than the global average. Rising sea temperatures and shrinking sea ice are changing conditions for polar cod, a cold-water species that depends on ice, and the study found a clear correlation between less ice and fewer fish. In the species’ core areas in Disko Bay and Uummannaq Fjord, winter sea-ice cover fell 44 percent between the beginning of the study period and its final years.

Polar cod has little commercial value in Greenland, but it is a key food source for ringed seals, seabirds, other fish and some whales, which makes its decline a problem for the wider food chain.

The researchers analysed 13,158 trawl hauls from surveys conducted between 1993 and 2023 and combined the data with interviews with eight fishers from Tasiilaq, Tiilerilaaq, Kuummiut and Kulusuk in East Greenland.

The effects are already reaching people. Fishermen in East Greenland reported that polar cod, once caught close to settlements and used as bait, dog food and household food, is now found mainly near glacier fronts, and some have switched to capelin as bait. Ringed seal catches have fallen in the Disko area and risen around Upernavik, tracking the fish and the ice north.

“Our data speak very clearly,” Teunis Jansen, professor at the Greenland Institute of Natural Resources and DTU Aqua and a lead author of the study, told the Greenlandic broadcaster. He said the warming behind the changes is human-caused and global, and that the remedy lies with decision-makers in industrialised countries cutting emissions.