ABSTRACT
Corals growing on Biorock reefs typically grow 2–6 times faster than controls and have 16–50 times higher survival after severe bleaching (Goreau and Hilbertz 2005, 2008). Nevertheless, sponge overgrowth of some species of corals by certain sponges has occurred on some electrical coral-reef restoration projects in the Maldives and in Bali and Lombok Indonesia. This project determined the growth rates of corals and sponge overgrowth as a function of distance from the electrical field to determine whether electricity affected the sponge–coral interaction. Due to the higher levels of sponge overgrowth on some structures than on nearby natural reefs, it was initially hypothesized that sponge growth might be stimulated more than coral growth, favoring sponge overgrowth (Figures 8.1 through 8.3).
