They paint this as the grooviest thing since fake meat:
https://www.chefsresource.com/what-is-upcycled-salmon/
Sources and Significance of Upcycled Salmon Byproducts
The primary sources of salmon byproducts used in upcycling are:
Salmon Skin: Rich in collagen, omega-3 fatty acids, and protein, salmon skin can be transformed into crispy snacks, collagen peptides for supplements, or added to pet food.
Salmon Bones: These bones are a valuable source of calcium, phosphorus, and other minerals. They can be ground into bone meal for human consumption or used in pet food formulations.
Salmon Trim: These are the smaller pieces of flesh that are removed during processing. While they might not be aesthetically pleasing for prime cuts, they are perfectly edible and can be used in fish cakes, burgers, pâtés, or fish stock.
Salmon Heads: Often overlooked, salmon heads contain a surprising amount of edible flesh and are rich in omega-3 fatty acids. They can be used to make delicious fish stock or broth.
There was a salmon skin potato chip-like product on the market and then it was gone. Bummer. I waould have eaten iy raw.
Cats with their tiny kidneys and ureters can get deadly or expensive-to-treat urinary tract disorders from fishbone meal. Speaking from experience.