Black reefs: Iron-induced phase shifts on coral reefs

Kelly, Linda Wegley, Barott, Katie L., Dinsdale, Elizabeth, Friedlander, Alan M., Nosrat, Bahador, Obura, David, Sala, Enric, Sandin, Stuart A., Smith, Jennifer E., Vermeij, Mark J. A., Williams, Gareth J., Willner, Dana and Rohwer, Forest (2012) Black reefs: Iron-induced phase shifts on coral reefs. ISME Journal, 6 3: 638-649. doi:10.1038/ismej.2011.114


Author Kelly, Linda Wegley
Barott, Katie L.
Dinsdale, Elizabeth
Friedlander, Alan M.
Nosrat, Bahador
Obura, David
Sala, Enric
Sandin, Stuart A.
Smith, Jennifer E.
Vermeij, Mark J. A.
Williams, Gareth J.
Willner, Dana
Rohwer, Forest
Title Black reefs: Iron-induced phase shifts on coral reefs
Journal name ISME Journal   Check publisher's open access policy
ISSN 1751-7362
1751-7370
Publication date 2012-03
Year available 2011
Sub-type Article (original research)
DOI 10.1038/ismej.2011.114
Volume 6
Issue 3
Start page 638
End page 649
Total pages 12
Place of publication London, United Kingdom
Publisher Nature Publishing Group
Collection year 2012
Language eng
Formatted abstract
The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the shipwreck debris are characterized by high benthic cover of turf algae, macroalgae, cyanobacterial mats and corallimorphs, as well as particulate-laden, cloudy water. These sites also have very low coral and crustose coralline algal cover and are call black reefs because of the dark-colored benthic community and reduced clarity of the overlying water column. Here we use a combination of benthic surveys, chemistry, metagenomics and microcosms to investigate if and how shipwrecks initiate and maintain black reefs. Comparative surveys show that the live coral cover was reduced from 40 to 60% to <10% on black reefs on Millennium, Tabuaeran and Kingman. These three sites are relatively large (>0.75 km2). The phase shift occurs rapidly; the Kingman black reef formed within 3 years of the ship grounding. Iron concentrations in algae tissue from the Millennium black reef site were six times higher than in algae collected from reference sites. Metagenomic sequencing of the Millennium Atoll black reef-associated microbial community was enriched in iron-associated virulence genes and known pathogens. Microcosm experiments showed that corals were killed by black reef rubble through microbial activity. Together these results demonstrate that shipwrecks and their associated iron pose significant threats to coral reefs in iron-limited regions.
Keyword Coral reef
Iron
Metagenomics
Microbes
Phase shifter
Shipwreck
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online 1 September 2011

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
Australian Centre for Ecogenomics
School of Chemistry and Molecular Biosciences
 
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Created: Thu, 20 Oct 2011, 08:58:23 EST by Dana Willner on behalf of School of Chemistry & Molecular Biosciences