Fish sausages are sold in Japan, and these are a finely emulsified sausage of fish with pork fat.

Run the Japanese Wikipedia page through a translator for more background: https://ja.m.wikipedia.org/wiki/%E9%AD%9A%E8%82%89%E3%82%BD%...

This is a graph of fish sausage production 1953-2020 https://www.jca-can.or.jp/~sausage/tokei-htm/ in Japanese, left axis is tons.

I've translated a 1939 paper on fish sausage and whale ham production methods, comment if interested.