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Spatial scales of bacterial diversity in cold-water coral reef ecosystems.

Schöttner S, Wild C, Hoffmann F, Boetius A, Ramette A - PLoS ONE (2012)

Bottom Line: Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types.Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity.It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has fundamental implications for the monitoring of microbial diversity and function in those ecosystems.

View Article: PubMed Central - PubMed

Affiliation: HGF-MPG Joint Research Group on Deep-Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, Bremen, Germany.

ABSTRACT

Background: Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning.

Methodology/principal findings: Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA), was investigated with respect to (i) microbial habitat type and (ii) coral species and color, as well as the three spatial components (iii) geomorphologic reef zoning, (iv) reef boundary, and (v) reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus) and ambient microbial habitats (seawater, sediments). This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity.

Conclusions/significance: This study presents the first multi-scale survey of bacterial diversity in cold-water coral reefs, spanning a total of five observational levels including three spatial scales. It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has fundamental implications for the monitoring of microbial diversity and function in those ecosystems.

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Number of ARISA-derived OTUs in distinct microbial habitats at each reef site.Top, middle, and bottom lines of the boxes represent the 25th, 50th (median), and 75th percentiles, respectively, while the end of the whiskers represent the 5th and 95th percentiles, respectively; box height and symmetry around the median indicate the degree of dispersion and skewness in the data, respectively; outliers above and below the whiskers denote extreme values.
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pone-0032093-g003: Number of ARISA-derived OTUs in distinct microbial habitats at each reef site.Top, middle, and bottom lines of the boxes represent the 25th, 50th (median), and 75th percentiles, respectively, while the end of the whiskers represent the 5th and 95th percentiles, respectively; box height and symmetry around the median indicate the degree of dispersion and skewness in the data, respectively; outliers above and below the whiskers denote extreme values.

Mentions: From a pool of 440 different operational taxonomic units (OTUs) occurring in the whole data set (104 samples), between 9–223 OTUs were obtained per sample. OTU number was strongly related to microbial habitat type (KW, P<0.001), and to the reef site (P = 0.05; Fig. 3). The most pronounced difference occurred between coral-generated surfaces and the ambient environment, with branch (34±15 OTUs) and mucus (58±22 OTUs) featuring 30–80% lower mean OTU numbers than water (135±16 OTUs) and sediments (192±19 OTUs). At Røst, mean OTU numbers showed a slight increase (P = 0.0398; Fig. 3) between reef center (Røst-in, 86±11 OTUs) and reef periphery (Røst-out, 116±62 OTUs), which was mainly related to branch and mucus variability. When studying local trends at Røst-in and Røst-out separately, however, neither geomorphologic reef zoning (P = 0.098), nor gradual distance away from the apparent reef margin (P = 0.956) resulted in any significant variation of OTU numbers. These were also not significantly related to coral species (L. pertusa and M. oculata with 36±13 and 35±17 OTUs, respectively; P>0.05) or to coral color (white and red colonies with 34±14 and 38±14 OTUs, respectively; P>0.05).


Spatial scales of bacterial diversity in cold-water coral reef ecosystems.

Schöttner S, Wild C, Hoffmann F, Boetius A, Ramette A - PLoS ONE (2012)

Number of ARISA-derived OTUs in distinct microbial habitats at each reef site.Top, middle, and bottom lines of the boxes represent the 25th, 50th (median), and 75th percentiles, respectively, while the end of the whiskers represent the 5th and 95th percentiles, respectively; box height and symmetry around the median indicate the degree of dispersion and skewness in the data, respectively; outliers above and below the whiskers denote extreme values.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3293894&req=5

pone-0032093-g003: Number of ARISA-derived OTUs in distinct microbial habitats at each reef site.Top, middle, and bottom lines of the boxes represent the 25th, 50th (median), and 75th percentiles, respectively, while the end of the whiskers represent the 5th and 95th percentiles, respectively; box height and symmetry around the median indicate the degree of dispersion and skewness in the data, respectively; outliers above and below the whiskers denote extreme values.
Mentions: From a pool of 440 different operational taxonomic units (OTUs) occurring in the whole data set (104 samples), between 9–223 OTUs were obtained per sample. OTU number was strongly related to microbial habitat type (KW, P<0.001), and to the reef site (P = 0.05; Fig. 3). The most pronounced difference occurred between coral-generated surfaces and the ambient environment, with branch (34±15 OTUs) and mucus (58±22 OTUs) featuring 30–80% lower mean OTU numbers than water (135±16 OTUs) and sediments (192±19 OTUs). At Røst, mean OTU numbers showed a slight increase (P = 0.0398; Fig. 3) between reef center (Røst-in, 86±11 OTUs) and reef periphery (Røst-out, 116±62 OTUs), which was mainly related to branch and mucus variability. When studying local trends at Røst-in and Røst-out separately, however, neither geomorphologic reef zoning (P = 0.098), nor gradual distance away from the apparent reef margin (P = 0.956) resulted in any significant variation of OTU numbers. These were also not significantly related to coral species (L. pertusa and M. oculata with 36±13 and 35±17 OTUs, respectively; P>0.05) or to coral color (white and red colonies with 34±14 and 38±14 OTUs, respectively; P>0.05).

Bottom Line: Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types.Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity.It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has fundamental implications for the monitoring of microbial diversity and function in those ecosystems.

View Article: PubMed Central - PubMed

Affiliation: HGF-MPG Joint Research Group on Deep-Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, Bremen, Germany.

ABSTRACT

Background: Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning.

Methodology/principal findings: Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA), was investigated with respect to (i) microbial habitat type and (ii) coral species and color, as well as the three spatial components (iii) geomorphologic reef zoning, (iv) reef boundary, and (v) reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus) and ambient microbial habitats (seawater, sediments). This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but weak microbe-host specificity.

Conclusions/significance: This study presents the first multi-scale survey of bacterial diversity in cold-water coral reefs, spanning a total of five observational levels including three spatial scales. It demonstrates that bacterial communities in cold-water coral reefs are structured by multiple factors acting at different spatial scales, which has fundamental implications for the monitoring of microbial diversity and function in those ecosystems.

Show MeSH
Related in: MedlinePlus