Habitat Restoration

Since 1995, scientists have been trying to reestablish the fragile, slow-growing Oculina corals by deploying concrete substrate to encourage colonization. In 1996, they began by deploying clusters of concrete ìreef ballsî throughout the reserve, hoping that the corals would attach, settle and grow. Some were deployed with live coral already attached, and some were deployed bare. Three years later, the scientists discovered that live coral remained on some of the balls. On others, the coral was stripped off, and only one reef ball deployed without coral attached showed coral recruitment (NOAA, Ocean Explorer, 2001).

In September 2001, a grouper shows interest in one of 105 reef balls a year after they were deployed on Oculina Bank. On the right is an arm of the submersible Clelia, used by scientists to examine progress in this effort to reestablish Oculina habitat and the associated fish and invertebrate communities.

In 2000, a different type of reef ball—dome-shaped equipped with holes through which fish could swim—were deployed. The balls, which were similar in size and shape to an Oculina coral colony, were released with live coral attached. In the summer of 2001, explorers found that several fish species, including groupers, amberjacks, snappers, angelfish, butterflyfish and small basses, had colonized the structures—an encouraging sign of initial habitat restoration. Researchers also observed more gag and scamp grouper at the southern end of the EORR. Just 10 years ago, researchers saw no gag grouper, fewer than 10 scamp grouper, and very few amberjacks in the same area (NOAA, Ocean Explorer, 2001). Though too soon to tell how successful the coral reestablishment efforts will be, scientists are optimistic about their initial restorative efforts (NOAA, Ocean Explorer, 2001).