Macro Algae Display Tank

I recently returned from a trip to Belize:dance:. I did a lot of fishing in the back bays, and I was amazed by the community's of fish established just within the mangroves and the variety of macroalgae that were growing. I would like to try to integrate this into my current 75g. I do not have much experience with macro algae in my DT. Can mangroves be fully submerged in the tank? I was looking on live aquaria and their mangroves dont have leaves so I would like to have them growing off my sand bed. Also, I would like to get other macro's like kelp and lettuce algae but I fear my angelfish would eat them, even though he doesn't eat my coral. Have anyone ever kept macro with anglefish before? Thanks in advanced.

-Cooper