Skeletal form and growth in Acropora aspera (Dana) from the Pulau Seribu,Indonesia

Linear extension and calcium carbonate accretion were measured in the branching coral Acropora aspera (Dana) from shallow-water sites around Pulau Pari, Pulau Seribu, Indonesia, during both wet and dry monsoon periods. Skeletal density and corallite form were also monitored in specimens collected from sites, variously affected by wave energy resulting from the monsoonal influence. Although the reversing monsoon appeared to exert the greatest effect on skeleton growth (by influencing temperature and possibly number of “sun-hours”) wave energy was also shown to affect skeletal extension, skeletal accretion, and skeletal density. The scale of differences between growth rate measurements was greatest for weight of skeleton accreted between monsoon period (8-fold), followed by between site differences (maximum 3-fold during west monsoon) and finally between station differences (maximum 3-fold during west monsoon at an outer reef flat and reef edge station). Skeletal extension did not appear to be as sensitive to the reversing monsoon influence as skeletal accretion.