A coral ring mount device and method for the propagative culture of sessile benthic marine organisms (for example, stony corals) employing either a ring, washer or threaded nut or similar as a propagule mount upon which the coral is set in order to attach, grow and overgrow within a coral nursery system. In the preferred embodiment of the invention, once the coral is grown onto the ring mount and to its requisite size and condition, the ring mount becomes the washer through which passes a screw to secure the ring and coral to the seafloor.