Alkalinity enhancement for improved grow-out in ex-situ tanks of priority coral species for restoration

The goal of this project was to determine the degree to which the growth rate of massive coral species, identified as a priority for coral restoration projects, can be increased by adding alkaline chemicals (sodium carbonate and bicarbonate) to the water in which they are raised. The study was conducted over a six-month period. The five species tested were Colpophyllia natans (CNAT), Siderastrea siderea (SSID), Orbicella faveolata (OFAV), Montastraea cavernosa (MCAV) and Pseudodiploria strigosa (PSTR). The study found that growth rates can be increased by 1.8 to 1.9-fold. The management significance is that it may be possible to raise sexually propagated corals to outplantable size in less time, thereby allowing land-based nurseries to produce more corals for restoration projects.