Just doing this bc I'm curious/research reasons

Mammals normally shed their skin in small flakes all the time when their skin cells die off, but because whales are living in the ocean -AKA, Bacteria Stew- flaking off like that would cause microabrasions (really tiny cuts) that would mean the whale is continually fighting off infections.  So, when a whale needs to replace it’s dead skin cells, it preps it’s new skin underneath, then sheds all it’s dead skin cells at once, like a lizard:

but not having hands makes it hard to remove this gross film, so molting brings many whales clsoe to shore where they can roll around on rocky/sandy coastal seabeds to scratch it off.  Here’s a bunch of Beluga coming in for a mass scratch:

And THIS is what a chunk of Sperm Whale Molt looks like, floating in the water before it’s devoured by pelagic microfauna, because you take what calories you can get in the open ocean: