So I was recently doing some exploring, and came across a Warm Ocean biome. While browsing the coral wiki page, I learned about sea pickle farming. They have some interesting growth mechanics, which I think could add a fun challenge for players who just keep building the same kind of farm. They require bone meal to spread to other nearby blocks, but this only be done underwater. In addition, they must be on a coral block, and only spread to other coral blocks. The only issue I can think of is that there currently aren't any drugs that need bone meal in order to farm. I don't know if there's a reason behind that.