This is a work in progress version of Iron Fish's new mining algorithm FishHash. It was created by community member Lollidieb. It is a modified version of the Ethash mining algorithm that uses the blake3 hashing algorithm as well as some other customizations.
Lollidieb has created a specification for the algorithm.
Discussion has been happening in the IronFish Discord mining channel. There is also a post for the proposal on the IronFish Discourse website.