Ecological Approaches to Coral Restoration

Removal of Coral Predators

NOAA scientists have been testing various novel, low-cost ecological approaches to coral restoration. To improve habitat quality and restore ecosystem functions, these approaches emphasize coral recruitment, reduction of competing algae, and control of corallivorous predators. To evaluate the efficacy of removing targeted predators to mitigate tissue loss to elkhorn coral (A. palmata) populations, researchers conducted a pilot experiment in FKNMS involving the removal of coral-eating snails (Coralliophila abbreviata) from elkhorn coral colonies. Removing the corallivorous snails preserved 75 percent more live tissue than treatments that left the snails in place, suggesting that predator removal may be an effective conservation measure in situations where the natural system is out of balance.

Reintroduction of Herbivores

The reintroduction of wild-caught and laboratory-cultured herbivorous long-spined black sea urchins (Diadema antillarum) to a wide variety of habitats in FKNMS is being tested by NOAA scientists and partners to control macroalgae that has proliferated since urchin die-off in 1983–84. The primary factor limiting sea urchin reintroduction and recovery appears to be predation pressure by fish and large crabs with the laboratory-cultured urchins being more vulnerable. However, surviving urchins are contributing to the successful removal of algae through grazing pressure. Other research is evaluating the differences between structural restoration approaches in FKNMS and the ability to enhance recovery through the natural recruitment of corals, survival and growth of seeded coral larvae, and survival of transplanted fragments.

Return to main restoration page.