Scientists are eavesdropping on whales -- and it could save their lives

‘This system could become like satellites in the ocean’

Audio shows humpback whales sharing songs across entire population

Scientists for the first time have developed a way to eavesdrop on the conversations of whales across vast expanses of ocean.

So-called Distributed Acoustic Sensing (DAS) uses an “interrogator” instrument to tap into existing, underwater fibre optic cables, and converts unused fibres into a long line of virtual hydrophones - essentially, underwater microphones.

The research project was carried out in Svalbard, a Norwegian archipelago between Norway and the North Pole, where baleen whales, like blue whales, forage in the summer months.

Whales are valuable indicators of ocean health, and following their underwater calls to each other is the best way to study the elusive large mammals.

For 40 days in summer 2020, researchers listened along 75 miles (120km) of cable buried beneath the seabed between the archipelago’s main town, Longyearbyen, and Ny-Ålesund, a research settlement.

Whale calls are normally monitored using satellite tracking, aerial surveys, sightings and individual hydrophones. However, studying a limited ocean area can make it challenging to understand whales’ migratory routes, for instance.

The difference with DAS is that it not only allows researchers to detect whale calls, but piggybacking on to a widespread fibre network allows scientists to locate where whales are in both space and time.

Dr Léa Bouffaut, a researcher at the K. Lisa Yang Center for Conservation Bioacoustics at Cornell University, described the significance of the innovation for the field of marine bioacoustics.

How Distributed Acoustic Sensing, or DAS, works

“Deploying hydrophones is extremely expensive. But fibre optic cables are all around the world, and are accessible,” she said in a statement on the study, published this week in journal Frontiers in Marine Science.

“This could be much like how satellite imagery coverage of the Earth has allowed scientists from many different fields to do many different types of studies of the Earth. To me, this system could become like satellites in the ocean.”

Researchers can also use DAS to “hear” other sounds carried through the water, from large tropical storms and earthquakes to ships passing by, said Martin Landrø, a geophysicist at the Norwegian University of Science and Technology, who co-authored the paper.

The scientists underlined the importance of the system in the Arctic region -- where the climate crisis is causing warming three times as fast as the global average.

Last month, a severe heatwave in Europe led to record-breaking temperatures including in the Arctic Circle where temperatures in the far north of Norway reached an unprecedented 32 degrees Celsius.

Dr Bouffaut noted that while blue whales aren’t currently seen in the Arctic year round, this could change as ice sheets further disintegrate. Less ice cover also opens the possibility of more shipping, fishing and tourism in the region.

More vessels increases the risk of ship strikes of whales but DAS could play a role in combatting this danger.

If DAS data could be analysed in real time, the information could be relayed to ships travelling in waters where whales are feeding or socializing, and also help protect them.

Hannah Joy Kriesell, one of the paper’s co-authors, said: “[If] we have a means to inform ships about the location of whales in real time, we could stop or at least reduce the risk for ship strikes.”

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Please enter a valid email
Please enter a valid email
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Must be at least 6 characters, include an upper and lower case character and a number
Please enter your first name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
Please enter your last name
Special characters aren’t allowed
Please enter a name between 1 and 40 characters
You must be over 18 years old to register
You must be over 18 years old to register
Opt-out-policy
You can opt-out at any time by signing in to your account to manage your preferences. Each email has a link to unsubscribe.

By clicking ‘Create my account’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in