Narwhals The new “canary” of the sea?
Affectionately known as the “unicorn of the sea,” the narwhal, Monodon monoceros, has long enthralled ocean-lovers over the centuries.
The stunning tusk – which is actually a modified tooth – that juts out of the center of their head is the key aesthetic feature that has grabbed the attention and stolen the hearts of wildlife observers around the world.
Yet, this may not be the only unique trait of this marine mammal.
Recent research has shown that the narwhal may be capable of indirectly alerting scientists to warming ocean temperatures.
Their extreme sensitivity to pockets of cold and warm water, along with their highly specific habitat preferences, illustrates that this animal can reliably signal changes in the underwater environment.
Narwhal’s ecological sensitivity
Although the narwhal is considered to be of “Least Concern” by the International Union for the Conservation of Nature (IUCN), it is still endemic to Arctic habitats.
With no other present habitats in the world, the decline of environmental stability in their current range could mean trouble.
This, along with the traits listed below, makes it especially vulnerable to climatic changes:
• Lack of flexibility in migration patterns and related population movements
• Relatively low population numbers
• Poor genetic diversity
• Stringent diet (their palates are not very adaptable)
Still, given that the species is not currently in danger of imminent extinction, their extreme climate sensitivity could serve a greater purpose.
The international team of researchers, led by Mads Peter Heide Jorgensen, were interested in just how deeply temperature fluctuations affect these whales, so they gathered telemetry equipment and journeyed to observe four narwhals in East Greenland.
The team discovered that, despite the narwhals’ preference for “dense, high salinity waters,” their desire to remain in areas between 0.5-2֯C was much stronger.
Further, when foraging for cod and squids, the whales favor depths between 300-600m above most other microhabitats.
These depths slightly differed between the summer and winter, yet the maximum temperature limit remained the same.
Due to the specificity with which narwhals react to their surrounding environment, their behavior could be a reliable indicator of the state of deep ocean habitats as climate change continues to warm polar landscapes.
The narwhal as a window into ocean climatic changes
As mentioned in the study, Arctic ice has been disappearing at an unnerving rate of 3-4% per decade, on average. Additionally, the vast ocean continued its ascension into higher temperatures at about 0.11֯C with each passing decade between the ‘70s and 2010.
Since narwhals’ lives are so particularly dictated by sea temperatures, watching their behavior may give marine researchers a peek into ocean degradation in real-time.
Though the inflow of cold waters into the narwhals’ habitat sustains their current ecological preferences, warming temperatures in the North Atlantic’s surface area may force them to change in the near future.
If and when these changes occur, marine experts may be indirectly alerted to climate-related anomalies in the deep sea.
These researchers set out to discover the ecological intricacies of narwhal life, and yet, they may have just unveiled a brand-new canary of the sea.