Does the noise of live-fire training harm marine life? A new study says there are still many unknowns

A B.C. scientist wants the Canadian Armed Forces to do more to protect wildlife from the noise of live-fire training.

In a study published by Marine Policy this month, Kieran Cox with Simon Fraser University reviews a report commissioned by the Canadian Armed Forces (CAF) to determine and mitigate the effects of noise pollution from military small-arms munitions training within "Whiskey Hotel," a 330-square-kilometre area in the Strait of Juan de Fuca off Vancouver Island.

"I think there's a real urgency to this … a call to action," said Cox. "Noise pollution, in many regards, is the most pervasive and unregulated pollutant we have in the marine environment."

Studies have shown that loud marine environments reduce the ability of marine mammals to travel, communicate and find food.

"The impacts of [human-made] noise on Canada's marine ecosystems occur largely unimpeded, as no existing federal or provincial legislation regulates this pollutant and activities that pertain to national security are largely exempt from legislation that considers pollutants," Cox says in his study.

The Juan de Fuca Strait — part of the Salish Sea between Vancouver Island and Washington state's Olympic Peninsula — is habitat for many large marine mammals such as killer whales, humpback whales, minke whales, grey whales, porpoises, seals, sea lions and sea otters.

The CAF announced in January it would resume training in Whiskey Hotel involving firing guns from ships and planes after a three-year pause for a study it commissioned, which was conducted by Vancouver's Golder Associates Ltd.

The study found the noise was most likely to affect marine mammals known to often forage in the area, but that "masking of underwater communications" was expected to be limited.

Still, it called for further studies, such as the effects of in-air gunfire, especially when marine mammals were at surface levels.

Changes to CAF activities following the study include mitigation measures such as avoidance zones, cease-fire procedures and marine-species awareness training.

Cox, who is known for his examination of the growls, grunts and even farts of thousands of species of fish, commends the CAF for undertaking its study of the effects of its training activities on marine mammals in the area.

But he wants the CAF to further study how the noises affect other wildlife in the area and what role military vessels might play in disturbing them in the Juan de Fuca Strait.

"Subsequent examinations would benefit from integrating evaluations of vessel-generated underwater noise and the inclusion of [non-mammals], especially those that sustain marine mammal populations," reads the study, referring to fish, invertebrates and seabirds.

The study said at least 400 fish species, 1,900 invertebrate species and 170 species of seabirds are present in B.C.'s marine ecosystems, "a notable portion of which inhabit the Juan de Fuca Strait."

A U.S. study from 2011 listed 172 bird and 37 mammal species that depend on the Salish Sea marine ecosystem.

In a statement to CBC News, the Department of National Defence (DND) said it was committed to marine mammal welfare during on-water activities and thanked Cox and his colleagues for further study of the topic.

"DND remains dedicated to continuous assessment and refinement of mitigation procedures, adapting to evolving scientific research and emerging technologies as they arise," it said.

It said current mitigation aligns "with current scientific research, relevant legislation, and government commitments."

Canada is currently working on an Ocean Noise Strategy that will identify and understand ecological stressors, such as human-produced underwater noise. 

The eventual policy, though non-binding, is meant to develop and improve measures to mitigate the impacts of human activities "on the health and quality of our oceans, including impacts to whales and other marine species," says a government website.

Cox hopes for the policy to be made public in 2024 and that studies like his will help inform it.

He cautions that activities related to national security will most likely be exempt from any regulations, so CAF should continue to pursue mitigation efforts on its own.

"Commissioning an investigation and implementing mitigation measures is a conservation success story, one that I'm keen to see improved upon and used in the future," he said.