It’s not a dumb question. Wildlife in the game is something I thought about. You’re not going to see fishes underwater because I want to keep the game fairly realistic, and U-boats, once submerged, are blind. There’s no windows to see outside the submarine.
However it doesn’t mean that animals won’t be present at all. For instance I want to have sea birds near coasts. You will also get to encounter other marine life in very rare occasions and under special circumstances, but that’s as much as I’m going to say because I don’t want to spoil the surprise for future players.