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International polar year

Sea life snapshot

A changing climate is affecting polar oceans and run-off from the land. What will happen to the Arctic’s top predators that depend on sea ice for survival?

Arctic marine species – polar bears, sharks, seals and whales – have long since adapted to environmental features such as constant cold, almost complete ice cover, and long seasons of light and dark. But their resilience will be tested as the water warms, sea ice disappears, new species invade and contaminants arrive from lower latitudes.

The orca whale, for example, is an unusual visitor to Northern waters, but it could soon become one of the Arctic’s leading predators, replacing polar bears. This is a sign of how dramatically the fortunes of species in the polar marine ecosystem may be affected by the growing amount of open ocean.

Consider the case of the beluga whale. These whales are important to the traditional culture of the Inuit. They spend their summers in freshwater estuaries and over-winter in ice-covered waters. Climate change might have an impact on their migration corridors, the food they eat, even the kinds of animals that compete for their food. An International Polar Year (IPY) project, in partnership with communities along the Hudson Bay coast, is using traditional Inuit knowledge and satellites to better understand the whales and their movements.

Another IPY project is examining the role the Greenland shark plays in Arctic ecosystems. Measuring in at up to seven metres long, the Greenland shark is the largest fish in the Arctic seas. It is not particular about what it eats: virtually every marine organism, including ringed seals, have been found in the stomach of these large sharks. We know little about how changing climate or ice conditions will affect them.

IPY researchers are also studying how the diets, reproductive habits and movements of seabirds such as Thick-billed Murres and Northern Gannets have changed since the 1970s and 1980s. Using novel technologies such as remote-controlled and bird-borne tracking devices, they are studying the timing and movements of seabirds and comparing the data with weather, sea ice and other oceanographic conditions.

As IPY investigators will tell you, food webs are complex networks composed of several interconnected food chains. By learning more about the the impacts of climate change on maine mammals, researchers hope to gain insights to the larger food webs. As well, community-based monitoring practices will provide northerners with the information needed to adapt cultural practices to the changing availability of marine mammals.


This piece features a video that delves into the implications of climate change to sea ice formations and marine mammals’ habitat. It explains how ice patterns are an extremely significant part of their ecosystem, and scientists are attempting to predict how their way of life will be impacted in the future.


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Human health

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Quiz :

What characterizes Arctic freshwater systems?

Predictable freeze-thaw cycle
Predictable level of flooding