Study looks at how ship noise affects Arctic marine mammals
A research study is painting a fuller picture of how ship noise affects Arctic marine mammals in the eastern Beaufort Sea.
"Whales are swimming faster when ships are close by ... and we're finding changes in the sound that they're making in their vocalizations," said William Halliday, the lead researcher for the study.
He said the study found whales vocalize less when there's more ship noise.
Ships have propellers that create bubbles that explode and create noise.
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Underwater noise can have negative consequences for animals, and can affect their ability to hear and communicate with each other.
"It can cause them to stop foraging or to leave an area, to maybe even change their migration route," he said, adding if noise levels are high enough, it can affect the animal's hearing, as well.
More ships, more noise
The number of ships in the Arctic have increased over the past 20 years, and are expected to continue increasing in the future.
The study, which began in 2014, aims to examine how ships are affecting animals and establish a baseline of underwater noise levels right now, to help track how underwater noise levels are changing over time as more ships pass through the area.
A map of where the underwater recorders were placed, marked with yellow pinpoints. (submitted by William Halliday)
Researchers placed underwater microphones to record sound in the eastern Beaufort Sea and Amundsen Gulf. The study is being conducted by the Wildlife Conservation Society Canada.
Halliday said it's important to do this type of research because there's a knowledge gap and more research needs to be done to fully understand how underwater noise is affecting Arctic marine mammals, some of which have experienced a decrease in their population.
He said it's also important because it affects local people who depend on those animals.
David Kuptana, an elder and hunter in Ulukhaktok who hunts animals like belugas and seals, said he's noticed ships are causing animals in the area to move away.
He said that makes it difficult for hunters who rely on the animals as a source of food and income.
"If more ships are going to keep coming, then they are going to be scaring all the animals away from this area," he said.
He said in the future, if there are more ships in the area, hunters would have to travel farther away to go hunting — which costs more and uses more gas.
"It's going to affect us a lot," he said.
A look at sound levels
Some people might think it's quieter underneath water — but there is plenty of noise. A dominant sound underwater is waves crashing at the surface. There are also the sounds of raindrops falling, sea ice cracking and glaciers melting.
Halliday said sound levels under solid sea ice in the winter are typically at 80 or 85 decibels.
In the summer, on a calm day, it could be around 90 decibels — and on a really windy day it could be up to around 110 decibels.
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When a loud ship is two or three kilometres away, that rises to 120 decibels.
"That kind of distant ship is like being at a loud rock concert," said Halliday.
When the ship passes right over the underwater microphone, it can be as loud as 140 or 150 decibels, which is like a jet going over your head.
The project is still ongoing at the moment, and Halliday said it will take several years before it's completed.
Thumbnail image courtesy of William Halliday via CBC.
The story was originally written by Mah Noor Mubarik and published for CBC News.
