4 Arctic species that depend on ice
Canada’s North is as unforgiving as it is stunning. This is never more apparent on film than in the “Frozen Worlds” episode of Netflix’s new docuseries, Our Planet.
The Canadian Arctic is home to unique — and universally adored — species, all of which depend on sea ice for survival; it’s where they hunt, socialize, rest and rear their young. But this critical habitat is in peril, and if it disappears, they will, too.
Sea ice is in steady decline — and it has been for 30 years now. That’s because the Arctic is warming at twice the rate of the rest of the Earth. Soaring temperatures due to climate change have caused sea ice to thin, shrink and melt earlier in the year. When sea ice recedes, wildlife habitats do, too.
Slowing climate change will ensure the long-term survival of these ice-dependent species.
When they’re not swimming in open sea, deep-diving narwhals get air from small cracks in the ice, which also keep them safe from predators. When cracks widen and ice disappears, narwhals become vulnerable to predation.
A warmer, ice-free Arctic is attractive to curious marine species. Killer whales are showing up in the region in increasing numbers, which means trouble for the whale. This population of killer whales likes to gorge on narwhal, so when the apex predator is around, narwhals tend to cower close to shorelines where food is scarce. Since this is a new phenomenon, scientists are still learning how the growing number of predators are affecting the overall health and behaviour of narwhals.
Ice has many uses for polar bears in Canada, but they primarily use it to hunt. When sea ice is plentiful in the winter, it gives them access to seals. Once ice melts and polar bears retreat to land, bears must use their energy reserves to survive until sea ice reforms. When ice forms late or is too thin for seals to make their dens, food becomes scarce and polar bears run the risk of starvation during summer months. And while many won’t necessarily starve, a lack of food could hinder a female’s ability to bring a cub to term.
Studies show that polar bears at the southern point of their range are giving birth less frequently and fewer cubs are surviving. In these areas it was quite common to see a mother with three cubs. Today, researchers are observing more and more mothers with a single cub.
The Pacific walruses showcased in the Netflix series prefer to spend their time on ice in groups known as haul-outs. It’s here they socialize, rest and reproduce. This ice-based habitat also provides access to food.
When sea ice shrinks or melts entirely, it forces walruses to haul out on land where food availability is limited. Instead of gathering in smaller groups, land-based haul outs are much larger. This can result in a stampede, which you can see in a shocking scene of Our Planet. Meanwhile, Atlantic walruses are found in Canadian haul outs on land in late summer and early fall, when sea ice is at its minimum. As the Arctic warms, the push for industrial development is on the rise, increasing the risk of disturbances to this critical habitat.
Arctic caribou are known for their epic long-distance migrations so it’s no surprise ice serves as a migratory habitat for some caribou in the North.
Peary caribou, found in the high Arctic Archipelago and Ellesmere Island, need to travel on ice in search of the limited amount of forage between high Arctic islands. The Dolphin and Union herd cross between Victoria Island where they give birth and rear their young, and their wintering habitat on the mainland of Nunavut and the Northwest Territories. The absence of sea ice would be disastrous for these groups, completely disrupting their migrations. Less reliable sea ice that is thin or forms later in the year could result in a population decline for both groups.
Our Planet is streaming on Netflix now.