Document Type

Article

Publication Date

2011

Abstract

A novel hydrothermal field has been discovered at the base of Lōihi Seamount, Hawaii, at 5000 mbsl. Geochemical analyses demonstrate that ‘FeMO Deep’, while only 0.2 °C above ambient seawater temperature, derives from a distal, ultra-diffuse hydrothermal source. FeMO Deep is expressed as regional seafloor seepage of gelatinous iron- and silica-rich deposits, pooling between and over basalt pillows, in places over a meter thick. The system is capped by mm to cm thick hydrothermally derived iron-oxyhydroxide- and manganese-oxide-layered crusts. We use molecular analyses (16S rDNA-based) of extant communities combined with fluorescent in situ hybridizations to demonstrate that FeMO Deep deposits contain living iron-oxidizing Zetaproteobacteria related to the recently isolated strain Mariprofundus ferroxydans. Bioenergetic calculations, based on in-situ electrochemical measurements and cell counts, indicate that reactions between iron and oxygen are important in supporting chemosynthesis in the mats, which we infer forms a trophic base of the mat ecosystem. We suggest that the biogenic FeMO Deep hydrothermal deposit represents a modern analog for one class of geological iron deposits known as ‘umbers’ (for example, Troodos ophilolites, Cyprus) because of striking similarities in size, setting and internal structures.

Publication Title

The ISME Journal

Volume

5

Issue

11

First Page

1748

Last Page

1758

DOI

10.1038/ismej.2011.48

Required Publisher's Statement

2011 Copyright the Authors and International Society for Microbial Ecology

Comments

Supplementary Information accompanies the paper on The ISME Journal website (http://www.nature.com/ismej)

Subjects - Topical (LCSH)

Hydrothermal vents--Microbiology--Hawaii; Microbial mats--Hawaii; Proteobacteria--Research

SuppMatsISMEj201148x1.pdf (12539 kB)
Supplemental Figures & Figure Captions

SuppTableISMEj201148x2 (1).xls (40 kB)
Supplementary Table S1

Genre/Form

articles

Type

Text

Rights

Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.

Language

English

Format

application/pdf

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