Salmon lead really fucking hard lives. They're the Enemy at the Gates Soviets of the animal kingdom. That being said, all of em were gonna die real soon anyway, if they're in a river and it's spring they're headed back to the lake or pond from which they came and then having more babies and immediately dying. The babies take the same rout with the same beers the other way to the ocean, vibe there until they're horny and then see above. They are here for one specific good time and not a long time.

If it's any consolation they've already transformed from lil fishes into horrifying lovecraftian monsters.