Orcas play in Chatham Sound near Prince Rupert, B.C., Friday, June, 22, 2018. A hush has blanketed the waters off the British Columbia coast as the pandemic has marked a significant reduction in sea traffic, which scientists say is an opportunity to study how noise affects southern resident killer whales. THE CANADIAN PRESS Jonathan Hayward

Quiet Salish Sea gives scientists chance to study endangered killer whales

Noise levels have dropped by about 75%

A significant drop in sea traffic brought on by the COVID-19 pandemic has created what scientists call a rare opportunity to study how quieter waters affect southern resident killer whales off the British Columbia coast.

Ocean Networks Canada, which has been monitoring noise from ships and sounds made by marine mammals such as orcas, said it believes the change will be a boon for the animals.

“The anticipation is that the quieter environment will help the killer whales in communicating, in socializing, in navigating and most importantly, in finding food,” said Richard Dewey, the organization’s associate director of science.

A paper published last month in the Journal of the Acoustical Society of America said there has been about a 30 per cent decrease in commercial shipping traffic into the Port of Vancouver from China due to COVID-19 in just the first four months of the year.

Dewey said it’s not just commercial traffic that’s gone down – there’s also been a pause in whale watching boats, cruise ships, recreational vessels and tankers. That’s led to a noise reduction of about 75 per cent, he said.

“What we are seeing in the Salish Sea is levels of shipping noise that haven’t been present for three or four decades,” he said. “So we would have to go back to the 1980s before we would have heard such a quiet environment.”

READ MORE: Young killer whale untangles itself from trap line off Nanaimo shore

One of the major concerns for the endangered southern resident killer whales is that shipping noises have been increasing and almost doubling every decade, he said.

These mammals have a hearing that is similar to that of humans, and they communicate in a frequency band similar to ours, Dewey said.

They use vocalizations to communicate within the pod, to navigate and most importantly to find their prey, he said.

“They echo-locate to find their salmon. It’s a very sophisticated sort of acoustic capability and the quieter the environment, they would have more success in finding prey.”

In the ocean, Dewey said whales use sound “continuously and all the time.”

Their eyesight helps them see up to a distance of about five to 10 metres while using sounds helps them scope out kilometres, he said, adding that the Salish Sea is a “very murky environment.”

Scientists believe the loud noises caused by humans increase stress hormones in orcas because they have to shout and cannot communicate over large distances, Dewey said.

He compared it to someone going into a loud club and having to pause until noise passes, to speak more loudly or give up. He noted that unlike people in a club, orcas can’t just leave for a quieter space.

Scientists will be using 30 hydrophones to record sounds made by the killer whales when they come into the Salish Sea, which should be any time now, Dewey said. Hydrophones are underwater recording devices that record how loudly the whales talk when it’s noisy or if they just give up.

The team is hoping this study will yield much-needed data to make policy and regulation changes to help the animals survive, he said.

“If we see them returning and staying in their critical habitat for longer periods … if we have evidence of successful feeding on the salmon, then those are all good signs and in some sense the quieter environments can only have helped their survival,” he said.

The director of the University of British Columbia’s marine mammal research unit said that in the past, killer whales would be seen in the Salish Sea in May and June, but for the past four years they have been coming in much later, sometimes as late as September.

Andrew Trites said one of the reasons could be that there is not enough salmon, although mathematically there is enough fish for the 72 remaining southern resident killer whales.

This has left scientists wondering whether the trouble is that the whales cannot hunt because of disruption from vessels, he said.

“And there is an opportunity to see whether or not the behaviour of whales is different with fewer boats on the water and less noise.”

Hina Alam, The Canadian Press


Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

CoronavirusWhales

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Kaslo art exhibit invites you to play in the forest

Hide and seek on the Kaslo River Trail

Two men killed in Hwy 3 collision west of Castlegar

The single-vehicle incident happened Thursday morning

Nelson considering new Hall Street pier as part of COVID-19 economic stimulus plan

Pier needs replacing, with possible designed public space added

Central Mountain Air to offer flights out of Castlegar

The company will be offering Castlegar to Vancouver flights October 1.

Health ministry to hire 33 new practitioners for Kootenay Boundary

Over 15,000 people in the region don’t have access to a primary care provider

VIDEO: B.C. to launch mouth-rinse COVID-19 test for kids

Test involves swishing and gargling saline in mouth and no deep-nasal swab

70-year-old punched in the head in dispute over disability parking space in Nanaimo

Senior’s turban knocked off in incident at mall parking lot

CHARTS: Beyond Metro Vancouver, COVID-19 cases in B.C. haven’t increased much recently

COVID-19 case counts outside of Metro Vancouver have been level since July

Record-breaking 165 new COVID-19 cases diagnosed in B.C. in 24-hour period

Fifty-seven people are in hospital battling the novel coronavirus

B.C. teachers file Labour Relations Board application over COVID-19 classroom concerns

The application comes as B.C.’s second week of the new school year comes to a close

Young Canadians have curtailed vaping during pandemic, survey finds

The survey funded by Heart & Stroke also found the decrease in vaping frequency is most notable in British Columbia and Ontario

Interior Health reports four new cases of COVID-19

First hospitalization since mid-August announced

B.C.’s COVID-19 economic recovery plan: Top 5 things you need to know

Jobs training, tax incentives for employers to hire staff and more

March to protect old growth, stop industrial logging coming to B.C. Legislature

Organizers say they want to give frontline communities a bigger say in nearby logging

Most Read