A noisy tomorrow for the Arctic Ocean without underwater noise regulation

By Melanie Lancaster, Senior Specialist, Arctic species for WWF’s Global Arctic Programme

A new report by the Arctic Council reveals that the Arctic Ocean, once pristine and filled with the clicks, trills and songs of whales and seals and the cracking of sea ice, is facing a future polluted by rising levels of ship noise unless new policy and management steps are taken.

The report, Underwater Noise in the Arctic – Understanding impacts and defining management solutions Report — Phase II, was welcomed last month at the 14th meeting of the Arctic Council.

Findings of the report were also submitted to the International Maritime Organization’s Marine Environment Protection Committee meeting in April.

A troubling rise in noise across the board

Four years in the making, due to the pause in most Arctic Council activities between March 2022 and February 2024, this new report follows on from phase I, which mapped underwater noise for the first time across the Arctic Ocean from 2013 to 2019. That work showed a surprisingly fast increase in underwater noise. What took just six years in the Arctic Ocean took over 30 years to occur in other oceans.

Phase II forecasts shipping and associated underwater noise to the near-future timepoint of 2030. Across almost all areas of the Arctic, underwater noise is predicted to jump substantially compared to now, because of planned growth in shipping and associated sectors like fisheries and mining, together with diminishing sea ice. Even the Central Arctic Ocean, still likely to be free from most industrial activities in 2030, will be affected as underwater noise from vessels operating in national waters spills into the high seas. In several areas, noise will also be present for more time, increasing exposure for marine species and putting them under greater pressure.

What more noise means for ocean life

We are still learning how noise-sensitive species such as bowhead whales, narwhals, walrus, fish and other marine life are being impacted by new noisy neighbours like tankers, fishing trawlers and container ships. But the rise in underwater noise expected by 2030 gives us some insights.

Underwater noise can shrink the area over which animals can hear and sense their environment. In general, a 3 decibel (dB) increase in noise reduces the amount of “communication space” by a quarter for marine mammals such as whales. The predicted 5 dB jump by 2030 represents an almost quadrupling of underwater noise intensity and a reduction in communication space to half its original size.

This makes it harder for whales and other marine mammals to find food, navigate and avoid predators, all of which they do primarily through sound. It is especially concerning for Arctic endemic species–those that live only in the Arctic–as over thousands of years, their senses have evolved to be perfectly suited to the dark Arctic Ocean. Since sea ice blocks light from penetrating into the water for much of the year, visual cues are lost within a few metres, and sound is vital.

Exploring shipping solutions for quieting the ocean

WWF, together with Governments of Canada and the United States, has co-led this research. Alongside mapping underwater noise trends, the project assesses how effective different shipping measures could be at lessening ship noise.

The measures included implementing speed limits for ships to 10 knots, re-routing ships away from sensitive marine areas, and making ships quieter through retrofits, better maintenance or other technological measures at the “source” of the noise – the ship. While some of these measures are already in place to improve maritime safety and reduce environmental risks of shipping, they weren’t originally designed with the goal of reducing underwater noise.

Diving deep and emerging with learnings

The research revealed how complex underwater sound is in the Arctic and reiterated the Arctic Ocean as a special case. Re-routing ships to offshore corridors, slowing speeds to 10 knots, or reducing noise at the source did not always result in the level of quieting expected. Digging deeper helped explain this and revealed important nuances in ship and underwater sound behaviour that can have profound effects on underwater noise in the Arctic and must be considered in management.

Several key lessons emerged that, while seemingly simple, are crucial. These should serve as practical guidelines for decision-makers, ship operators and the rest of the industry in managing underwater noise.

Speed restrictions are most effective if many ships are travelling substantially faster than the speed limit, something that varies across the Arctic. Re-routing ships shifts associated underwater noise, so can reduce it in one place but increase it in another, especially if ships are moved to deeper water, where sound travels farther.  Modifying ship behaviour within important habitats for noise-sensitive species needs buffer zones, otherwise noise from directly outside those habitats can seep in.

Action is needed now

While some progress has been made in other parts of the world, the Arctic still lacks effective management of underwater noise. The only regional approach being taken is by EU countries after the European Commission introduced binding targets for healthy oceans as part of its Marine Strategy Framework Directive that include underwater noise management. Globally, in 2023, the International Maritime Organization (IMO) updated its Guidelines for minimizing the impacts of underwater noise from shipping. The shipping industry is now in an “Experience Building Phase” to implement them. Yet, these guidelines are not mandatory or tailored to Arctic waters. Despite ongoing expansion of ship traffic and growing evidence that Arctic species are especially sensitive to underwater noise, regulation remains minimal.

Two lifelines exist. First, the Inuit Circumpolar Council has proposed Guidelines for reducing underwater noise in Inuit Nunaat and the Arctic, which were accepted by the IMO in 2023.  They highlight the unique nature of the region and the need for special shipping measures. WWF will work to ensure the findings from this new report are included in that guidance and make them available to ship operators. But guidelines only work if they are heeded, and so far, commitment from the shipping industry has been weak.

This leaves regulation by IMO, with leadership from Arctic states. While generally not popular with industry, enforceable rules may be the only way to safeguard the special and sensitive Arctic region — for less noise, and more life.