Humpback whales enjoy ‘spa’ time together on the ocean floor

'They were both rolling on the ground together and having a great time'

Scientists researching the marine mammals off of Australia's God Coast found they were drawn to a sandy, shallow area of the ocean floor where they appeared to be removing dead skin.

Researchers from Australia's Griffith University likened the deep-sea retreat to visiting a "day spa".

The discovery was made after scientists attached tracking tags to three humpback whales, -that could also take video - as they migrated south between August 2021 and October 2022.

Video footage captured during their journey showed both tagged and untagged whales rolling around on the sea bottom on multiple occasions.

“They were doing these bizarre rolls, going fully on their back and on their side,” Griffith University marine ecologist and lead study author Dr. Olaf Meynecke told The Australian Associated Press.

The researchers determined they were exfoliating their skin, with Meynecke saying that they could "actually see the skin flying off".

And that provided a little snack for someone else: “And then fish would come in and eat it. The fish were also picking skin off the whale, not just the floating skin.”

Meynecke added that the rolling sessions all took place in the same general area off the coast of Main Beach in Queensland.

The study was published in the Journal of Marine Science and Engineering in March.

Researchers considered “the possibility” that the tagged whales were rolling around were attempting the devices, but that was discounted as whales, not tagged, were also exhibiting the behaviour.

And, the rolling, did not target the places where the tags were placed.

Researchers said that in addition to dead skin, the whales were removing barnacles, which often attach themselves in warmer waters. If they aren’t removed, the crustaceans can inhibit humpbacks' movements.

Meynecke told the AAP that for some whales, the sand rolls appeared to be a social occasion.

“We had two whales that were swimming with each other for several hours,” he said.

“They clearly had a very good relationship, and they were both rolling on the ground together and having a great time.”

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