In a fantasy world (a D&D setting, basically), how would an open underwater town populated by an assortment of mer-people deal with waste disposal? A few details: the town in question is a part of a larger above-ground settlement. They mainly trade fish for tools and other surface products. The dwellings are mostly carved/shaped into the coral reef in the shallow waters. The population is relatively low, around two thousand people, and likely spread-out - less an urban center and more a farming village.
Technology is, again, D&D-like, which is to say pseudo-medieval, as useless as that statement is. This being a fantasy world, "magic" could be the answer to everything, of course, and I suspect it will be needed to some extent. But I'm more interested in low-magic, somewhat natural solutions to the simple question: where does a merman poo?