Underwater noise in a busier Arctic: what narwhal silence suggests and what can reduce harm

The Arctic Ocean is getting louder—more ships, more industrial activity, more tourism—and narwhals appear to be responding by getting quieter. Reporting summarized by Ars Technica (from Inside Climate News) points to field research in Canada’s Eclipse Sound suggesting that narwhals reduce vocal activity and change feeding behavior when ships pass nearby. That matters because narwhal sound isn’t just “communication”; it’s a critical part of how these animals navigate, coordinate, and forage in an environment where visibility is limited and sea ice is changing.

What makes this story feel urgent is that it’s not a single noisy event. It’s the slow build of traffic along emerging Arctic routes and resource corridors, plus local industrial shipping, producing a background level of disturbance that can reshape habitat use over time.

Why underwater noise is a real form of pollution

On land, we think of noise as an annoyance. Underwater, sound behaves differently and tends to travel farther, especially in cold, dense water. Many marine species rely on sound in ways that terrestrial animals don’t, because:

light availability is seasonal and often low
visibility can be poor (turbidity, ice, depth)
sound propagates efficiently in water

That means sustained noise can function like a “habitat tax.” Even if an area still has prey, the cost of staying there rises if animals can’t hear properly or if they respond by reducing feeding or moving away.

This is why conservation groups and some regulators treat underwater noise as a pollutant: it alters behavior, changes where animals can effectively live, and can accumulate as traffic increases.

What the study in Eclipse Sound suggests

The reporting references a multi-year study of narwhals’ responses to shipping traffic in Eclipse Sound, a summer calving ground in Nunavut, Canada.

The reported findings are straightforward and sobering:

narwhals “went silent” when ships were passing
they were detected responding at distances farther than expected
one researcher said narwhals go quiet or move away when a ship is within about 20 kilometers
they also stopped eating during ship transits, including pausing deep feeding dives

Even if the details vary by vessel type, speed, or local conditions, the pattern aligns with a common ecological concern: if an animal repeatedly interrupts feeding in a short seasonal window, the energy consequences can be meaningful.

Where the noise is coming from: a mix of industry and tourism

Eclipse Sound is not just a “shipping lane” in the abstract. The reporting points to specific drivers of vessel traffic:

industrial shipping linked to the Mary River Mine on Baffin Island
increasing numbers of tourism vessels, including cruise ships, private yachts, sailboats, and smaller boats

One local hunter, Alex Ootoowak, described a rise to about 30 cruise ships a year in the region and said, “Our waters are a lot louder than they traditionally were.”

That combination matters because noise isn’t only about the loudest ships. It’s also about frequency and predictability. A few massive ships can be disruptive; frequent transits can turn disruption into a constant condition.

What “going silent” might mean biologically

It’s tempting to anthropomorphize silence as fear. In animal behavior terms, silence can be a strategic response to risk and interference.

Possible mechanisms include:

Avoiding detection or stress responses: If sound is associated with danger, animals may reduce vocalization.
Masking: If ship noise overlaps with the frequencies narwhals use, vocalizing becomes less effective. Imagine trying to have a conversation next to a running engine.
Behavioral displacement: If ships cause narwhals to move away, you’ll record fewer calls simply because the animals are not where they normally would be.

The feeding component is especially important. The story notes that animals stopped doing deep feeding dives during ship transits. If those dives are the core way narwhals take in calories, repeated interruption can reduce overall intake, with knock-on effects for reproduction and survival.

Why this is happening now: the Arctic “opening up”

Two broad forces are pushing more activity into Arctic waters:

Climate change and sea ice loss: Longer ice-free seasons make transits more feasible and expand the windows for tourism and industrial shipping.
Resource and infrastructure projects: Mines and extraction projects require transport, which can mean regular shipping schedules.

The result is a feedback loop: more infrastructure enables more shipping; more shipping normalizes the route; more normal routes draw more operators.

Even if global shipping routes don’t suddenly shift overnight to the Arctic, local and regional increases can still matter intensely for specific animal populations that depend on particular breeding and calving areas.

What mitigation looks like in practice (and why it’s hard)

“Reduce underwater noise” sounds like a single goal, but it breaks into practical levers:

Speed reductions: Lower speeds can reduce noise and also reduce collision risk. The reporting notes that lower speeds can lower the risk of ship strikes, which is particularly relevant for some whale species.
Routing changes: Avoiding sensitive habitats during key times (calving, migration) can reduce harm.
Operational planning: Better awareness of “where and when whales are likely to be present” allows shipping companies to plan routes and schedules accordingly.
Ship design: Quieter propellers, better maintenance, and hull design can reduce noise, but changes are slow and expensive.

The challenge is that the benefits are often distributed (ecosystem health, food security for local communities, biodiversity), while the costs are concentrated (shipping time, fuel trade-offs, scheduling complexity). That makes regulation and standards-setting—through bodies like the IMO—an important part of the story.

Why this matters for people, not just whales

The reporting ties underwater noise impacts to Indigenous communities that rely on marine ecosystems for food security. In regions with high costs of living and limited alternatives, changes in the availability or predictability of marine life are not abstract environmental concerns.

If narwhals abandon traditional calving grounds or change migration patterns, hunting practices and local knowledge built over generations can become less reliable. Ootoowak described concern that narwhals may be leaving Eclipse Sound for quieter waters, with neighboring Greenland communities reporting what they see as “foreign narwhals.”

That kind of redistribution—animals moving, ecosystems shifting—can create cross-border governance issues and can intensify pressure on “quieter” refuges.

Bottom line

Underwater noise is becoming a defining environmental pressure in a more trafficked Arctic. If narwhals respond to ships by going silent and pausing feeding, then the growth of industrial shipping and tourism isn’t just changing the soundscape—it may be changing where and how these animals can successfully live.

The Arctic is getting louder and narwhals are getting quieter: why underwater noise matters