Microbial assemblages on a cold-water coral mound at the SE Rockall Bank (NE Atlantic): interactions with hydrography and topography

Abstract

Abstract. This study shows the microbial community composition over Haas Mound, one of the most prominent cold-water coral mounds of the Logachev Mound Province (Rockall Bank, NE Atlantic), outlining distribution patterns both vertically from the seafloor to the water column and laterally across the mound and coupling this to mound topography and hydrography. Samples were collected in 2012 and 2013 from biotopes that were partially chosen based on high definition video surveys that were conducted prior to sampling and included overlaying water (400 m depth and 5+10 m above the bottom (m ab)) collected with a CTD/Rosette system and near-bottom water, sediment, Lophelia pertusa mucus, and L. pertusa skeleton samples collected with a box-core. Furthermore, temperature and current measurements were obtained at two sites at the summit and foot of Haas Mound to study near-bed hydrodynamic conditions. Community composition was determined by next generation Roche 454 sequencing yielding high-resolution records of 16 S rRNA genotypes, improving our understanding of deep-sea microbial consortia. With the methods we employed we were able to report for the first time Archaea in association with L. pertusa. The pattern of similarities between samples visualized by multi-dimensional scaling (MDS), indicates a strong link between the distribution of microbes and specific biotopes. All biotopes share a number of taxa, but biotopes are distinct on basis of relative abundances and a small number of unique taxa. Similarity in microbes indicates that water is well-mixed at 400 m depth, but less so at 5 + 10 m above the bottom, where microbial communities differed between summit, slope and off mound. Even more variability was observed in the near-bottom water samples, which group according to sampling station. Likely the coral framework prevents the near-bottom water in between the branches to be vigorously mixed with the water overlaying the reef. The microbial consortium on Haas Mound appears strongly linked with the surrounding environment, making cold-water coral communities sensitive to outside environmental influences.

On the influence of cold‐water coral mound size on flow hydrodynamics, and vice versa

“…While the size of the CWC mounds has been shown to play a role in the hydraulic control of the flow over them, questions are raised regarding the influence of hydrodynamics on CWC ecosystem functioning and reef and mound growth. Recent video footage by our team (unpublished results) suggests that while healthy corals are found at the summit of smaller mounds, they are virtually absent from the summit of bigger mounds (although found on their flanks; see van Bleijswijk et al []). This may suggest that the Haas mound has reached its maximum height while the smaller mound still grows vertically.…”

Biogeographic Comparison of Lophelia-Associated Bacterial Communities in the Western Atlantic Reveals Conserved Core Microbiome

“…Our hypotheses were that (a) since van Bleijswijk et al (2015) only examined mucus, and it was previously shown by fluorescent in situ hybridization (FISH) that the mycoplamas were in the tissue component (Neulinger et al, 2009), that explained their absence in one dataset, and (b) perhaps the low number of sequences examined (446 per sample) by Meistertzheim et al (2016) was insufficient to detect mycoplasmas. With our greater sequencing depth, we did observe Tenericutes in 7 of 12 samples, but always at less than 1% relative abundance.…”

“…While these studies have been geographically diverse, including the Mediterranean Sea (Yakimov et al, 2006; Meistertzheim et al, 2016), Norwegian fjords (Neulinger et al, 2008, 2009; Schöttner et al, 2009; Emblem et al, 2012), Rockall Banks (Hansson et al, 2009; van Bleijswijk et al, 2015) and the Gulf of Mexico (Kellogg et al, 2009; Galkiewicz et al, 2011), the use of different methodologies prevents direct data comparisons in most cases. A key exception is 16S rRNA gene clone library studies conducted with almost identical methods on L. pertusa from the Trondheimsfjord in Norway (Neulinger et al, 2008) and the Gulf of Mexico (Kellogg et al, 2009).…”

Global diversity and distribution of close relatives of apicomplexan parasites

“…Illumina and 454 amplicon sequencing studies that targeted bacterial SSU rRNA genes in coral reefs (coral tissue, mucus and associated seawater and sediments), marine shallow and deep water column, hydrothermal vents, oceanic sediments and freshwater environments, were retrieved from the NCBI Sequence Read Archive (SRA: Leinonen et al ., ) (Agogue et al ., ; Amaral‐Zettler et al ., ; Andersson et al ., ; Brazelton et al ., ; Campbell et al ., ; Campbell et al ., ; Dove et al ., ; Eiler et al ., ; Foster et al ., ; Galand et al ., ; Gilbert et al ., ; Glasl et al ., ; Glasl et al ., ; Goodwin et al ., ; Hamdan et al ., ; Herlemann et al ., ; Huber et al ., ; Jorgensen et al ., ; Kellogg et al ., ; Kellogg et al ., ; Kerfahi et al ., ; Kirchman et al ., ; Lee et al ., ; Lema ; Li et al ., ; McCliment et al ., ; McNally et al ., ; Meistertzheim et al ., ; Meyer et al ., ; Morrow et al ., ; Ng et al ., ; Pavloudi et al ., ; Pavloudi et al ., ; Rogozin et al ., ; Ruff et al ., ; Shore‐Maggio et al ., ; Slapeta and Linares, ; Sogin et al ., ; Somboonna et al ., ; Spietz et al ., ; Staley et al ., ; Tripathi et al ., ; Van Bleijswijk et al ., ; Van De Water et al ., ; Vezzulli et al ., ; Walsh et al ., ; Welch and Huse ; Zhu et al ., ; Zinger et al ., ) The full list of studies and their corresponding environment type is available in Supporting Information Table 1. The SRA toolkit and fastq‐dump utility was used to extract the sequences (settings: ‐split‐files ‐skip‐technical) (Leinonen et al ., ).…”