WISRD Research & Engineering Journal

Ex situ coral growth: A technical report on development of 3D printed ceramic substrates for growth of small polyp stony (SPS) coral microfragments in a marine aquarium 3 T. Albano, Dr. K. Griffs, J.A. Wise 1. Introduction This paper stems from a larger research question regarding microfragmentation of coral as a means to restore reef populations. This endeavor is a joint collaboration between the Mariner Oceanographic Research Institute (MORI) and the Wildwood Institute for STEM Research and Development (WISRD), under the project name Restoration of Corals using Ceramic Substrates (RoCCS). The central aspect of our research is quantifying growth rates of microfragments that are of differing initial sizes. The overarching goal of our research is to determine the smallest size of fragment that gives the greatest growth rate. In concert with this, we are investigating the use of ceramics as a substrate upon which fragments can be grown and placed in nature to restore damaged reefs. 1.1 Why a Ceramic Platform? A common method of propagating coral fragments in marine tanks for profit or research is to adhere them to off-the-shelf ceramic plugs and support them in a “frag rack” constructed out of a plastic egg crate. Our frag rack construction and use of ceramic plugs are described in a technical paper by Luca G., MORI Chief Technical Officer. As we were searching for an alternative to setting out a typical plastic frag rack and adding more plastics to the ocean, we were inspired by an innovative rack solution created by a group out of Hong Kong University (Lang et al., 2020) were investigating the use of terra cotta platforms to which coral fragments were adhered. Their platforms were produced by a robotic, 3D ceramic printer. Lang et al. prototyped several platform shapes (Figure 1) that they dubbed “biomimetic,” or similar in shape to natural corals such as the brain coral, in that the platforms have many ridges and valleys. They stated this was to attract local marine life over other platform types. We decided that the ceramic bases were desirable because they were suitable for growing coral, able to be repeatedly printed, and were made of an environmentally friendly material.

Figure 1. Prototype, biomimetic, 3D printed ceramic platforms created by Lang et al.

3 Sponsored by the Wildwood Institute for STEM Research and Development (WISRD) and the Mariner Ocean Research Institute (MORI)

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