You still can't kill fish in Subnautica 2, but starting tomorrow you can at least stun them

They will also have "good flinches" if you bonk them with a hammer.
IGN

Subnautica 2 Players Are Discovering Ways to Defend Themselves From Predatory Fish

Subnautica 2 developer Unknown Worlds is still talking internally about what to do in response to the game’s big killing fish debate, but players have taken the matter into their own hands, diving ...
IGN

Subnautica 2 Dev Gives Players Hope Amid the Game's First Hot Topic Following Launch

Fresh from its huge early access launch, underwater survival and crafting adventure game Subnautica 2 has sparked a significant debate among fans: to kill or not to kill the fish. Currently, you can’t ...

Subanutica 2 major update adds the ability to shoot fish

Subnautica 2 has been a massive success, but its player base remains divided on how much violence should be in the game.