Okay, I know what people are going to think of this initially (ew...), but I'm sure people had the same reaction to cow and goat leather way back when.
Fish skin actually makes a great binding material for books as an alternative for leather and also gives a book (or box, etc) a very different look. They can also be dyed easily and are fairly available.
This is a look into what some bookbinders have been doing around the country with fish skin bindings (covering books and things) from one of my fav info sites for book artists and bookbinders: http://www.philobiblon.com/bindorama20/index.html
These are some of the Wolffish fish leather that we auctioned this year at our 2020 Online auction!