While hiking the beach at Cape Scott in British Columbia last summer, I kept on seeing these weird pieces of organic flotsam. I'm familiar with kelp, dead jellyfish, sea urchin shells, etc... but these seemed really different. And I've never seen them before anywhere else in BC or elsewhere.
First, from a distance when wet, they look more like dead organs of some fish or sea mammal, because of the red and white coloring.
Yes, I can see how something like a plant or jellyfish may dry out to that texture. But I'd expect that to slime up/lose consistency as soon as it got wet again.