Theoretically, yes. Glue is made of collagen, which is found in the skin and bones of most animals, fish included! I'm not sure that I've ever heard of it being made from fish, though. It could be an interesting experiment.

[ her mention of seaweed earns a brighter approval from him, however, his slippery skin turning orange as a red "O" marking fades into being on his face. Yes, he changes colors, too. ]

But seaweed is certainly a much better idea! Algae has certain polymers that are naturally adhesive. If we grind it down and combine it with other material, we could make a tough material to bind our metal together.