title: Volcanic ash supports a diverse bacterial community in a marine mesocosm.
abstract: Shallow-water coral reef ecosystems, particularly those already impaired by anthropogenic pressures, may be highly sensitive to disturbances from natural catastrophic events, such as volcanic eruptions. Explosive volcanic eruptions expel large quantities of silicate ash particles into the atmosphere, which can disperse across millions of square kilometres and deposit into coral reef ecosystems. Following heavy ash deposition, mass mortality of reef biota is expected, but little is known about the recovery of post-burial reef ecosystems. Reef regeneration depends partly upon the capacity of the ash deposit to be colonised by waterborne bacterial communities and may be influenced to an unknown extent by the physiochemical properties of the ash substrate itself. To determine the potential for volcanic ash to support pioneer bacterial colonisation, we exposed five well-characterised volcanic and coral reef substrates to a marine aquarium under low light conditions for 3 months: volcanic ash, synthetic volcanic glass, carbonate reef sand, calcite sand and quartz sand. Multivariate statistical analysis of Automated Ribosomal Intergenic Spacer Analysis (ARISA) fingerprinting data demonstrates clear segregation of volcanic substrates from the quartz and coral reef substrates over 3 months of bacterial colonisation. Overall bacterial diversity showed shared and substrate-specific bacterial communities; however, the volcanic ash substrate supported the most diverse bacterial community. These data suggest a significant influence of substrate properties (composition, granulometry and colour) on bacterial settlement. Our findings provide first insights into physicochemical controls on pioneer bacterial colonisation of volcanic ash and highlight the potential for volcanic ash deposits to support bacterial diversity in the aftermath of reef burial, on timescales that could permit cascading effects on larval settlement.
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.|MWM-Museum Witt München, Munich, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Witt
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: P M
authors.initials: PM
authors.lastname: Ayris
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.|United States Geological Survey, Menlo Park, CA, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Damby
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Cimarelli
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Kueppers
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: D B
authors.initials: DB
authors.lastname: Dingwell
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität, Munich, Germany.|GeoBio-CenterLMU, Munich, Germany.|SNSB-Bavarian State Collections of Palaeontology und Geology, Munich, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Wörheide
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000254:growth & development*; D044822:Biodiversity; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D018707:Volcanic Eruptions
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer