NEWS: Around the Arctic July 06, 2018 - 11:00 am

Narwhals, bowheads at risk from Arctic shipping, says study

“There has not been a circumpolar assessment of vulnerability for these species”


There could be a direct link between increased shipping in the Arctic and the access Nunavummiut have to yummy maqtaq—and this isn’t a good thing.

That’s according to a new study that says narwhals are the northern marine mammal most vulnerable to vessel traffic along marine routes like the Northwest Passage and the Northern Sea Route.

The study looks at 80 subspecies of seven kinds of Arctic marine mammals, to assess risks those species face when ships travel through their habitats during the navigable, or ice-free, season.

Researchers with the University of Alaska Fairbanks and the University of Washington conducted the study, which was published July 2 in the Proceedings of the National Academy of Sciences of the United States of America.

Besides narwhals, the other mammals studied are bowhead whales, beluga whales, ringed seals, bearded seals, walruses and polar bears.

Polar bears and seals are the least vulnerable to shipping impacts, researchers found.

All the animals studied “range widely across international boundaries, use regional habitats, are critical and traditional resources for Indigenous communities, and are at the forefront of climate change,” the study reads. 

And, while these species are “presumed” to be most at risk because of declines in sea ice and increases in commercial shipping, “there has not been a circumpolar assessment of vulnerability for these species,” the study states.

Species of marine mammal that spend a lot of their time in “geographic bottlenecks,” like the Bering Strait and areas of the Eastern Arctic like Lancaster Sound, are even more at risk than animals that keep to more remote northern regions. That’s why conservation efforts should focus on these high-traffic areas, scientists suggest.

Over half of the 80 subspecies are exposed to shipping in at least one Arctic sea route, even beyond those choke points, researchers said.

“Of the subpopulations that overlap with the sea routes, the Eclipse Sound narwhal subpopulation was the most vulnerable to vessel traffic,” the study reads.

This is because of regular exposure to ships transiting the Northwest Passage, and because the species has natural traits that make it more vulnerable. 

Beluga, bowhead and walrus are also vulnerable to shipping in the Northwest Passage and the Northern Sea Route.

That’s because the routes overlap with foraging areas and migration routes of the marine animals.

Whales, the study found, are especially sensitive to “vessel disturbance, acoustic effects, and in the case of bowhead whales, ship strikes.”

A ship strike is when a whale collides with a vessel during transit.

Lessening noise levels put out by ships in high-risk areas have proved helpful, but the study says that “understanding knowledge gaps” will help cut down on risks.

“We found a disproportionate focus on cetacean sensitivity to vessel effects, whereas few studies examined vessel effects on ice seals and polar bears,” researchers said.

A cetacean is a scientific name for marine mammals like whales, dolphins and porpoises.

Ice-breaking vessels are not included in the research, but the scientists suggest that breeding patterns for ice seals, along with feeding mothers and young seal pups, could be disturbed by icebreakers.

The study focused on vessel traffic in the Northwest Passage and the Northern Sea Route because those routes have ample and recent traffic data. Outside those areas, there are more unknowns.

“Vessel traffic in much of the Arctic is not well documented,” researchers said.