The same with nuclear plants dumping warm water in the ocean after using it to make steam and for cooling. Perhaps in both cases the waste water could be stored and evaporated in a salt flat or something.
IMO the solution to both of these is a ~5km perforated pipeline going out to deep ocean. Im no marine biologist, but I know life finds a way, and I’d bet my life that the stretch of slightly warmer/saltier water would end up facilitating a vibrant biome of some sort. It may not be identical to whats there today, but it’s unlikely to be “worse”, just different.