Elephant seals used researchers’ deep sea sonar equipment as ‘dinner bell’

By The Canadian Press on September 4, 2024.

VICTORIA – Scientists say new research shows how northern elephant seals used sonar from a deep sea research facility off the British Columbia coast like a “dinner bell” as they hunted for prey.

University of Victoria researchers say their study provides a rare glimpse into the species’ underwater behaviour, as the animals learned to associate sonar noise from the research instruments, 645 metres deep, with the presence of food.

Lead author Heloise Frouin-Mouy says in a University of Victoria news release that the phenomenon is known as the “dinner bell effect,” and the seals appeared to have used the sonar to find an area with prey, particularly their favoured sablefish.

The research observatory operated by Ocean Networks Canada in the Barkley Canyon was conducting unrelated research on the effects of light and bait on fish and invertebrate behaviour.

But when video of the site was reviewed, the surprised researchers saw at least eight elephant seals repeatedly visiting the site to hunt, suggesting they used the sonar to locate the area.

The university says the seals were also observed “power napping” on the sea floor, another new and never-before-seen behaviour.

The study was conducted in 2022 and 2023 and published in the peer-reviewed journal PLOS ONE on Wednesday.

This report by The Canadian Press was first published Sept. 4, 2024.

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