I think the reason so many marine organisms have such a huge reproductive capacity is because so many are lost in the larval and early juvenile phase. And I don't think that it is a "weakness" in the early juvenile that prevents survival as much as the hand of "fate" in the time and place in which the juvenile finds itself. According to this theory, juveniles produced by human culture, assuming that the larvae culture parameters produced healthy late larvae, are capable of a huge percentage survival if the environmental conditions are optimum for the juveniles of the cultured species. And it is up to the human culturist to research, develop, and provide these conditions. Sometimes this is easy and sometimes very hard, but for all organisms these conditions exist somewhere, sometime, and all that needs to be done is to identify them and provide them. Then the late larvae, early juveniles, will do the rest. So this all you have to do with your octopus and all I have to do with my Diadema. Somehow that old saying, "Easier said than done" comes to mind.