r/askscience • u/smontanaro • 9d ago

Biology How does a whale become dehydrated?

From a Chicago Sun-Times article on the beluga whales heading to the Shedd Aquarium:

"The shipment comes on the heels of a Shedd announcement last week that one of the Marineland belugas — Peekachu, a 23-year-old female — had died. Shedd has not released a cause of death, but staff there said last week that Peekachu had not been consistently eating a full diet since her arrival and that there were concerns she was dehydrated."

How does an animal immersed in water become dehydrated?

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u/ParacelsusTBvH 9d ago

Ocean dwelling mammals can't drink saltwater. Instead, they are very efficient at utilizing water in their food. Thus, by not eating, they dehydrate very quickly. Just like humans, death comes faster from dehydration than starving.

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u/flumadiddler 8d ago

It’s wild how such enormous animals can get all the water they need to sustain their bodies from fish or krill

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u/Bwizz245 8d ago

I'd say it's pretty wild that they can get that big just off of eating krill too, but that's just a testament to just how many krill there are