Hostile Mobs don't spawn in ocean biomes

Since the previous fix to not let mobs spawn in kelp and other blocks below the ocean, it also broke mob spawning completely under the ocean.

I tried making a dark area below ocean level around y=40, where previously mobs would spawn, they now don't. I suggest reverting the fix that lets mobs spawn in kelp, and refixing it by not allowing hostile mobs to spawn in waterlogged blocks or water, therefore mobs being able to spawn in dark dry areas under the ocean, but not in dark kelp areas or whatever.