Fig 1.
Photographs of the selected P. astreoides coral colonies located adjacent to deployed coral ecosphere sampling devices (A-E) and a sampling diagram detailing seawater sampling locations from coral ecosphere and reef-depths (F). Diagram is not drawn to scale.
Fig 2.
Comparison of picoplankton cell abundances over three consecutive days for A) Prochlorococcus, B) Synechococcus, C) picoeukaryotes, and D) unpigmented cells (generally heterotrophic bacteria and archaea). Each point represents a sample. Point shape corresponds to sampling distance from the coral and point color reflects the colony adjacent to where sampling was conducted. Gray shading indicates samples collected at night. Lower and upper edges of the boxplot correspond to the first and third quartiles, the whiskers extend to the largest or smallest value at 1.5 times the interquartile, and the black bar across the box represents the median. Original, untransformed cell counts are presented.
Table 1.
Summary of 4-way ANOVA statistical tests presenting results for the four main factors and any significant interactions between factors.
Fig 3.
Comparison of inorganic nutrient concentrations over three days for A) phosphate (PO43-), B) silicate, C) nitrate (NO3-), and D) ammonium (NH4+). Each point represents a sample. Point shape corresponds to sampling distance from the coral and point color reflects the colony adjacent to where sampling was conducted. Gray shading indicates samples collected at night. Lower and upper edges of the boxplot correspond to the first and third quartiles, the whiskers extend to the largest or smallest value at 1.5 times the interquartile, and the black bar across the box represents the median. Untransformed concentrations and their outliers are presented.
Fig 4.
PCA biplots of picoplankton abundances, relative light, temperature, sampling depth, and inorganic macronutrient concentrations across A) all time-points, B) samples collected during the day, and C) samples collected during the night. Point color and shape reflect the day and time of sampling. Symbols outlined in black or with 1–2 black lines indicate ecosphere samples. Abbreviations are as follows: Syn. = Synechococcus cell abundance, Pro. = Prochlorococcus cell abundance, Pico. = picoeukaryote, Unpig. cells = unpigmented cells, and temp. = temperature.
Fig 5.
Alpha diversity metrics of the bacterial and archaeal community by sample type and time, based on SSU rRNA gene sequences grouped into ASVs and subsampled with replacement to 11,500 sequences per sample.
Observed richness is indicated in A) and Shannon’s diversity is presented in B). Each point represents a sample. The date of sampling is denoted by the shape and the point color reflects day or night. Gray shading indicates samples collected at night. Lower and upper edges of the boxplot correspond to the first and third quartiles, the whiskers extend to the largest or smallest value at 1.5 times the interquartile, and the black bar across the box represents the median.
Fig 6.
CAP of bacterial and archaeal SSU rRNA genes sequenced from reef-depth and coral ecosphere samples compared using the Bray–Curtis index.
Significant environmental variables (ANOVA, p < 0.05) are overlaid on the plot as vectors and labeled. Symbols outlined in black indicate coral ecosphere samples.
Table 2.
Results of PERMANOVA (ADONIS) test examining factors influencing amplicon-based reef-depth and coral ecosphere seawater microbial community dissimilarity, using 999 permutations.
Fig 7.
Relative abundances of bacterial and archaeal sequences from SSU rRNA gene sequencing that comprise >1% of the genus-type level community composition in A) reef-depth (RD), coral ecosphere (Eco) and surface seawater samples (*) and B) coral tissue samples. Colors indicate the taxonomic grouping at the genus-type level. Color legends are specific for each plot.
Fig 8.
Significantly differential enrichment of bacterial and archaeal SSU rRNA gene amplicon sequence variants (ASVs) across A) reef-depth and coral ecosphere samples collected during the day or night and between B) all bottom reef seawater (reef-depth and ecosphere samples) and surface seawater. Each point represents an individual ASV labeled at the genus-type taxonomic level and the color reflects the order. Only ASVs matched at the genus level are plotted. The number in parentheses indicates the unique number assigned to each ASV sequence.
Table 3.
Amplicon sequence variants (ASVs) that displayed rhythmic fluctuations in relative abundance over a period of 24 hours in reef-depth and coral ecosphere seawater.