Data for coral distribution on bommies in Moorea—deployment of coral nubbins and clod cards on bommies in 2022

On shallow coral reefs, coral bommies create patchy communities where
interactions among patches are likely to affect a variety of ecological
features. Here, we describe bommies in the back reef of Moorea, French
Polynesia, and evaluate the role of select factors in determining their
size, shape, and distribution. We tested the hypothesis that the
distribution and growth of corals vary across the surface of bommies
(i.e., north, south, east, and west sides), and therefore might play a
role in determining bommie shape and their propensity for fission and
fusion. Bommies were elliptical in planar shape, with their long axes
parallel to the ambient flow and perpendicular to the direction of
offshore waves. Porites spp. and Pocillopora spp. were the most abundant
corals, and they were uniformly distributed over the surface of bommies.
During April 2022, small colonies (≤ 4 cm height) of Pocillopora spp. grew
at similar rates on the north, south, east, and west sides of the bommies,
among which integrated seawater flow during the experiment was similar.
These results suggest that the contemporary growth and distribution of
corals are unlikely to play a strong role in determining the features of
present-day bommie. Evaluating how environmental conditions mediate the
structure of coral bommies in shallow habitats will help to understand
whether habitat mosaics can mediate coral reef resilience in the
Anthropocene.