Collaborative knowledge-gathering about migration can help us understand species’ adaptability

Many Arctic species migrate to cope with drastic seasonal differences in environmental conditions and food availability—and as the climate crisis alters Arctic landscapes, many are adjusting their patterns. Narwhal were once thought to migrate predictably throughout their ranges. But Courtney Shuert wonders: as other species show signs of adjusting to the changing Arctic environment, how flexible may narwhal turn out to be—and what might the answer tell us about other species’ adaptability?

Conservation efforts have made great strides in protecting Arctic ecosystems. When multiple species inhabit an area year-round or seasonally, conservation targets are relatively easy to figure out. But it’s less straightforward when species move around more.

Migration can make conservation management more challenging because entire populations may move out of protected areas for periods of time, sometimes across vast distances or geopolitical boundaries. However, some migrating species may offer clues as to how Arctic wildlife will fare in the future. Scientists are studying narwhal—which may live upward of 100 years—to understand the ability of long-lived species to cope with the impacts of climate change by altering their migratory patterns.

What’s behind migration?

Species migrate for different reasons: to find food, mate and breed, or escape harsh winters. Many travel vast distances to the Arctic to take advantage of the plentiful food available in summer. Some of the most iconic Arctic species are year-round residents, yet they still exhibit strong migratory behaviours. For example, polar bears, narwhal and beluga move seasonally between near-shore and offshore regions to cope with the extreme seasonality of life in the North.

Migratory patterns in the Arctic are often tied to sea ice. While some species, such as seals and polar bears, depend on the presence of sea ice, other marine mammals may be limited by it because they must be able to access the water’s surface to breathe. But sea ice is becoming less predictable, and this variability is having an impact on both year-round residents and seasonal visitors. Rising temperatures and less predictable weather patterns are threatening species’ ability to move through, use and interact with their environments across the entire food web, from microscopic plankton to the largest whales.

Scientists are studying narwhal—which may live upward of 100 years—to understand the ability of long-lived species to cope with the impacts of climate change by altering their migratory patterns.

Lifespan and adaptive capacity

We are beginning to understand how well species can cope with these changes and how these changes may impact migration. While we anticipate that many short-lived species—like the small passerine birds that seasonally visit the Arctic—will be able to adjust their migration strategies through mechanisms of evolution, many long-lived species (which have long generation times) may be limited to adjusting their behaviours to match the rate of climate change.

Over the past few decades, narwhal equipped with satellite transmitters have offered researchers important insights into how they may be coping with change. Narwhal typically spend summers in the fjords and sounds of Greenland and the Canadian Arctic before changing sea-ice conditions force them to deeper waters offshore for the winter. Like many whales, narwhal are thought to follow culturally learned migratory routes.

The satellite tags have revealed that narwhal that summer in the north of Baffin Island are departing the area later for their autumn migration. The difference in the average departure timing amounts to about two weeks over a 21-year period.

This variability in timing is closely linked to changing sea-ice conditions: narwhal stay later in their summering areas when Arctic sea ice is low. Although their migration route remains generally the same, these narwhal have been observed to use a variety of routes to reach their wintering areas, with some staying close to the coast and others preferring deeper waters offshore. Individual narwhal that use the near-shore route also appear to stop over at productive deep-water fjords along the coast of Baffin Island, possibly to rest or refuel.

Other Arctic species known to exhibit migratory behaviours, such as Greenland halibut and shark, show affinity to these same regions and migrate at the same time.

Making use of collaborative knowledge

When populations or communities follow similar areas of use during the migratory period, we refer to the areas as migratory corridors, and these may offer achievable targets for conservation. However, migratory corridors sometimes cross international boundaries or important shipping lanes, highlighting the need for collaborative knowledge-gathering to track migration and mitigate future impacts through adaptive management.

The fact that narwhal show flexibility in their migration timing despite their long life spans highlights the possibility that many other marine species may also be able to adjust their behaviours to changing conditions in the Arctic. As interest in the region grows—and as species’ migration timings and use of space shift in response to climate change—it will be crucial to bring together prior research, traditional knowledge and current observations to develop the adaptive management tools to help species survive.

Evidence continues to mount that many species use similar migratory corridors. Making use of collaborative knowledge from all levels of Arctic ecosystem organizations will be paramount to our ability to forecast community-level effects and best protect the Arctic ecosystem.