Decisions are still being made on just how the various fish in the world will move around but one possible option is for a node based AI system. This would work best with larger, feature creatures such as sharks which would allow them to explore key points of an undersea world.
This AI is based off a tutorial found online but has been completed and fixed to work with the latest UDK. It is also in its early stages and will be improved as the project continues – at the moment, the mini-mantas (standing in for fish) will move between nodes in a random order. As you can see in the video, some work still needs to be done on collisions between the fish among other things.