Growth and survival of unattached Madracis mirabilis fragments transplanted to different reef sites, and the implication for reef rehabilitation

Unattached fragments of the branching scleractinian coral Madracis mirabilis were transplanted at four different fringing reefs over distances up to 27 km along the coast of the island of Curacao, Netherlands Antilles. Growth and survival of the different transplantations at a depth of 5-6 m was variable, but in general related to bottom sediment cover and movement of the fragments. Fragmentation had significant detrimental effects on growth and survival of the fragments. No difference was found between growth and survival of fragments which were fragmented/transplanted in situ on the reef and those which received a surface control treatment. Survival rates of M. mirabilis fragments at different sites were 20-49% after 4 mo. Although these rates were average to good, compared to other studies and compared to survival of hurricane-generated fragments, unattached fragments are unsuitable for reef restoration projects as mortality is likely to continue to increase over a longer time span.