FAI is the most powerful underwater AI system currently on the Unity Asset Store. It contains not only a system that can be used to simulate a broad underwater ecosystem (salmons, sharks, whales...) but also a powerful and deeply-optimized flocking system that can run +20,000 units at the same time at +100 FPS.
For more information please check the "Technical details" section.
Models, materials, and animations are from "Underwater life deluxe" asset by Janpec.