‘The narwhals stop calling’: how the noise from ships is silencing wildlife in the Arctic | Whales

The delicate clicks and whistles of narwhals pass through Tasiujaq, known locally as Eclipse Sound, at the eastern Arctic entrance to the Northwest Passage. A hydrophone in this shipping corridor off Baffin Island, Nunavut, picks up their calls as tusked whales navigate their fall migration route to northern Baffin Bay.

But as the Nordic Odyssey, a 225-meter ice-class bulk carrier serving the nearby iron ore mine, approaches, the low rumble of its engine gives way to a wall of sound created by millions of bubbles crashing from its propeller. Narwhals’ acoustic signals, developed for one of Earth’s quietest environments, go silent.

“Narwhals stop calling or move away from approaching ships when they hear them,” says Alexander James Ootoowak, an Inuit hunter from Pond Inlet and field technician on the research team that deployed the hydrophone to study these acoustic overlaps.

The research, conducted in 2023 and published this year, adds to growing evidence that radiated underwater noise – the sound energy emitted by ships through their hulls, propellers and machinery – disrupts marine life. As the crescendo grows, so do calls to calm the seas by designing less noisy ships.

Michelle Sanders, general manager of Transport Canada’s Innovation Center in Ottawa, says: “We need to bring everyone together to work on a solution that will reduce noise in our oceans to protect marine species, regardless of where ships operate. »

This November, members will gather at the International Maritime Organization Assembly where a high-ambition Quiet Ocean Coalition – made up of 37 countries representing more than 50% of the world’s maritime fleet – will call for new policies focused on designing and operating quieter ships.

We can’t act soon enough, says Lindy Weilgart, a marine biologist based in Halifax.

“I have yet to find a marine species that is completely immune to noise or vibration of any kind,” she says. “Once you know, do something, now.”

SSound helps underwater organisms find food, communicate, navigate, avoid predators and mate. In Pacific waters, southern resident orcas lose their salmon-hunting echolocation clicks in the noise of ships off Vancouver. In Atlantic waters, North Atlantic right whales showed a measurable reduction in stress when shipping traffic ceased after 9/11, suggesting chronic physiological impacts of ship noise.

Shipping noise, unlike other major sources of anthropogenic ocean noise pollution, should be resolvable. While seismic surveys for oil and gas exploration require powerful pulses of sound to map seafloor geology, and offshore wind farm development uses pile driving to install turbine foundations, “ships don’t gain anything from making noise,” says Weilgart.

The maritime industry has long recognized that radiated underwater noise is a waste of energy, says Giorgio Burella, a naval architect at Robert Allan, a Vancouver-based boat design firm.

To reduce noise, ships can bypass sensitive marine areas or slow down. But through design, the industry can target key sources of ship noise, with advanced propeller designs that reduce cavitation bubbles, hull modifications that create smoother water flow, and engine isolation systems that prevent transmission of machinery vibrations through the ship to the surrounding waters.

However, implementing these solutions requires perseverance. “The maritime industry is a very conservative industry, so any change takes time,” says Burella, who highlights incremental progress so far, based on voluntary measures.

For example, the Enhancing Cetacean Habitat and Observation (Echo) program – a ten-year collaboration between the Vancouver Fraser Port Authority, government, Indigenous communities and shipping companies – has pioneered measures to reduce noise in critical orca habitats through voluntary slowdowns and vessel reroutings.

“We were able to get a 60% voluntary participation rate and cut the noise in half,” explains Melanie Knight, Echo program manager. As the message spread, that rate rose to 90 percent, she says, pointing to other related benefits: Slowdowns reduced air emissions by about a third and reduced collision risk for marine mammals.

Knight believes the future lies in designing quieter ships. “We know there is a longer-term solution that requires much more investment, time and design expertise. For the future of whales, we need quieter ships to start with,” she says.

Back in Eclipse Sound, the Baffinland Iron Mines Corporation, which relies on cargo carriers such as the Nordic Odyssey to service its Mary River mine, last year added a vessel designated Silent-E to its fleet. The Nordic Nuluujaak is the first bulk carrier in the world to receive this designation. The mining company has also implemented a series of measures including convoy operations – where ships travel in groups – speed limits of nine knots and fixed sailing routes to reduce cumulative noise exposure to marine life.

Mads Petersen, chief operating officer of Pangea Logistics Solutions – the company that owns the Nordic Odyssey and Nordic Nuluujaak – says it is working to reduce underwater noise in its fleet. “This includes working with our partners in the Arctic. With a vessel that has received the Silent-E rating, we are considering the impacts of our operations in areas where there may be wildlife of all kinds.”

But Joshua Jones, an oceanographer at the Scripps Institution of Oceanography at the University of California, San Diego, says that even when ships operate below quiet certification standards, noise can still disturb highly sensitive species such as narwhals.

“In order to determine what is quiet, you need to have some key definitions and understand calm. Silence is from a listener’s reference point,” he says.

Arctic waters also create unique acoustic challenges: colder temperatures and icy conditions require region-specific solutions. The Eclipse Sound research, led by the Mittimatalik Hunters and Trappers Organization in collaboration with Scripps and Oceans North, began with Inuit observations that narwhals are sensitive to ship noise. The research confirmed this vulnerability at distances of 20 km (12.4 miles), far exceeding the 3 km range predicted by previous studies.

“Having Western science to back up local people’s accounts has been instrumental in shaping the rules and regulations of the waters here,” says Ootoowak, who would like to see all ships entering Arctic waters make efforts to reduce their noise.

From cruise ships to fishing boats to pleasure boats, comprehensive noise management requires accountability across the entire maritime fleet, Ootoowak explains, because in the acoustic world of narwhals, every engine counts.