Figure 1.
Effects of treatments on coral growth.
Comparisons of growth rates (means ± SE) between corals competing with one of five macroalgal species vs. control corals. Each algal treatment in the block design had its own paired controls that had no algae. The number of controls were constant among treatments except when lost due to storm damage; in that instance the corresponding control was removed from the analysis. Statistics are from paired t-tests. P-values are based on Bonferroni-Holm correction for multiple comparisons with the controls. * p<0.05.
Figure 2.
Comparisons of relative bacterial diversity among macroalgal species and among coral-algal competition treatments.
The presence of individual TRFs were used to determine bacterial species richness (black bars) and CHAO 1 estimates (grey bars) were used to predict the relative number of taxa (means ± SE) in macroalgae (A) and on corals challenged with macroalgae (B). Letters represent significant differences (p<0.05) in CHAO1 estimates among sample types; richness was not found to be significantly different among samples. Differences among macroalgae are denoted by uppercase letters A-D while difference among coral-algae treatments and controls are denoted by lowercase letters w-z. *Galaxaura obtusata macroalgae data were not included in statistical analysis due to low replication.
Figure 3.
Microbial communities on algal thalli.
Multidimensional ordination of Bray-Curtis similarity of microbial communities found on macroalgae (A) and on corals in competition with different macroalgal species (B).
Figure 4.
Significant Changes in Individual TRFs.
Individual TRFs were compared between control corals and corals exposed to different macroalgal species. The relative total number of TRFs changed (A), the number of relative increases and decreases in individual TRFs (B), and the combined mean change in relative TRF abundance (C) compared to control TRFs.
Figure 5.
Contribution of Individual TRFs to Changes in Relative TRF Abundance.
Changes in mean individual peak heights for specific TRFs for macroalgal competition treatments relative to control corals. Positive/negative values indicate an increase/decrease of a bacterial TRF on coral fragments in competition with a given macroalgal species, compared to TRFs on control corals.