Fig 1.
Images of the study reef and hollow corals in 2024.
The fore reef of Moorea at 10-m depth showing the high coverage of live Pocillopora coral before (A), during (B), and after (C) the 2019 bleaching. Only a few live Pocillopora remained on the reef by 2024 (e.g., center foreground of (C)), and the reef was spatially dominated by dead corals encrusted by the macroalga Lobophora variegata and tufts of the red macroalga Asparagopsis taxiformis. (D) Naturally fractured branches of Pocillopora showing the internal hollowing and the profusions of encrusting taxa hypothesized to provide a scaffolding effect allowing the internal dissolution to proceed.
Table 1.
Taxonomic rank of associated invertebrates with live and dead Pocillopora.
Fig 2.
Invertebrates associated with dead and live Pocillopora colonies from 10-m depth.
Bar graph shows mean raw abundances (± SE, n = 4 per colony condition) of invertebrates collected from Pocillopora from the fore reef in 2022–2023. The y-axis is displayed on a logarithmic scale to better visualize differences across taxa with large differences in mean abundances. To ensure visibility of low abundance values (e.g., < 1 animal colony-1), a constant (1) was added to all abundance values. Taxonomic groups with only one observation per condition do not have error bars.
Fig 3.
Structure and composition of remnant hollowed out Pocillopora skeleton branches.
(A) Field photograph of hollowed out eroded and encrusted skeleton branches at 10-m water depth. (B) Circular polarization (CPOL) microscopy image of the area of heavily eroded and encrusted remnant skeleton shown in white box in A. (C) Super resolution autofluorescence (SRAF) microscopy enlargement image of the area of heavily eroded and encrusted remnant skeleton shown in white box in (B). Note that the original coral skeleton is dark and exhibits no SRAF emissions other than from organic matter preserved within fungal hyphae borings and sediments adjacent to the skeleton margin.
Fig 4.
Structure and composition of scalloped inner margin of remnant hollowed out Pocillopora skeleton branches.
Microscopy images are enlargements of remnant skeleton area shown by white box in Fig 3C. (A and B) Paired circular polarization (CPOL) and super resolution autofluorescence (SRAF) images of the inner scalloped margin of the remnant hollowed out skeleton. (C and D) Paired bright field (CPOL) and super resolution autofluorescence (SRAF) microscopy images of the areas of scalloped inner margin of the remnant skeleton shown by white boxes in A and B. Note that the original coral skeleton is dark and exhibits no SRAF emissions in B and D other than from organic matter preserved within fungal hyphae borings and sediments adjacent to the skeleton margin.
Fig 5.
Comparison of changes in community structure 5 years after two major disturbance events.
Benthic community structure at 10-m depth on the north shore fore reef of Moorea following corallivory by Acanthaster spp. and cyclone Oli in 2010 (A) and bleaching in 2019 (B). Both graphs show mean (± SE, n = 77–80 year-1) percentage cover over a 5-year period for all corals and Millepora sp. (pooled among taxa), Pocillopora, and macroalgae.