Eco-geochemical dynamics of a shallow-water hydrothermal vent system at Milos Island, Aegean Sea (Eastern Mediterranean)

Date

2013-10-09

Author

Yücel, Mustafa
VETRİANİ, Costantino
Foustoukos, Dionysis I.
Giovannell, Donato
LE BRİS, Nadine

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

244
views

0
downloads

Shallow-water hydrothermal vents are extreme environments that share many characteristics with their deep-sea analogs. However, despite ease of access, much less is known about the geochemical dynamics of these ecosystems. Here, we report on the spatial and temporal geochemical dynamics of a shallow-water vent system at Paleochori Bay, Milos Island, Greece. Our multi-analyte voltammetric profiles of dissolved O-2 and hydrothermal tracers (e.g. Fe2+, FeSaq, Mn2+) on sediment cores taken along a transection in hydrothermally affected sediments indicate three different areas: the central vent area (highest temperature) with a deeper penetration of oxygen into the sediment, and a lack of dissolved Fe2+ and Mn2+; a middle area (0.5 m away) rich in dissolved Fe2+ and Mn2+ (exceeding 2 mM) and high free sulfide with potential for microbial sulfide oxidation as suggested by the presence of white mats at the sediment surface; and, finally, an outer rim area (1-1.5 m away) with lower concentrations of Fe2+ and Mn2+ and higher signals of FeSaq, indicating an aged hydrothermal fluid contribution. In addition, high-frequency temperature series and continuous in situ H2S measurements with voltammetric sensors over a 6-day time period at a distance 0.5 m away from the vent center showed substantial variability in temperature (31.6 to 46.4 degrees C) and total sulfide (488 to 1329 mu M) in the upper sediment layer. The analysis of these data suggests that tidal and wind forcing, and abrupt geodynamic events generate intermittent mixing conditions lasting for several hours to days. Despite substantial variability, the concentration of sulfide available for chemoautotrophic microbes remained high. However, the availability of electron acceptors originating from seawater might be more intermittent, which in turn has an effect on the reestablishment of the white mats after wave-induced disturbances. Our results emphasize the importance of transient events in the development of chemoautotrophic communities in the hydrothermally influenced sediments of Paleochori Bay.

Subject Keywords

Voltammetry, Sulfide, Hydrothermalism, Time series, Redox

URI

https://hdl.handle.net/11511/31084

Journal

CHEMICAL GEOLOGY

DOI

https://doi.org/10.1016/j.chemgeo.2013.07.020

Collections

Graduate School of Marine Sciences, Article

Suggestions

OpenMETU
Core

Physical control of the spatial and temporal diversity of microbial mats at a shallow water hydrothermal vent Giovannelli, Donato; Foustoukos, Dionysis; Le Bris, Nadine; Sievert, Stefan; Yücel, Mustafa; Dalessandro, Valerio; Ricci, Renato; Vetriani, Costantino (null; 2016-07-01) Shallow-water hydrothermal vents are ubiquitous but poorly studied geothermal environments. The active hydrothermal emissions of the Milos hydrothermal system support complex microbial mats, which are fundamental in engineering the environmental niche in which extremophiles thrive. Because of the shallow depth, the mat community is wiped out during every major storm, when swell and wave action increase, and then it reconstitutes itself over a brief period of time (days). Here we report the results of a join...
Seismic isolation of foundations by composite liners Kalpakçı, Volkan; Özkan, M. Yener; Department of Civil Engineering (2013) In this research, the dynamic behavior of a seismic isolation system composed of high strength geotextile placed over an ultra-high molecular weight polyethylene (UHMWPE) geomembrane (together called as composite liner) beneath the structure is investigated experimentally. The results of the shaking table experiments which were performed on model structures both under harmonic and modified earthquake motions with and without the seismic isolation (composite liner system), are presented in the thesis. The ma...
Chemistry, Temperature, and Faunal Distributions at Diffuse-Flow Hydrothermal Vents Comparison of Two Geologically Distinct Ridge Systems Luther, George W.; Gartman, Amy; Yücel, Mustafa; Madison, Andrew S.; Moore, Tommy S.; Nees, Heather A.; Nuzzio, Donald B.; SEN, Arunima; Lutz, Richard A.; Shank, Timothy M.; Fisher, Charles R. (2012-03-01) Diffuse-flow, low-temperature areas near hydrothermal vents support life via chemosynthesis: hydrogen sulfide (and other reduced chemical compounds) emanating from the subsurface is oxidized with bottom-water oxygen through bacterial mediation to fix carbon dioxide and produce biomass. This article reviews the in situ diffuse-flow chemistry (mainly H2S and O-2) and temperature data collected in 2006 and 2009 along the Eastern Lau Spreading Center (ELSC), and from 2004 to 2008 at 9 degrees N along the East P...
Down the thermodynamic ladder: A comparative study of marine redox gradients across diverse sedimentary environments Yücel, Mustafa (2013-10-10) The thermodynamic succession of electron acceptors used in microbial oxidation of organic matter and associated redox products lead to the vertical chemical zonation in diffusion-controlled marine sediments. The structure of this gradient is a key player in the recycling of organic carbon and nutrients in the marine environment. However, little attention has been given to the advection-dominated sedimentary systems where the co-existence of different reduced and oxidized chemical species is expected. In thi...
Biodegradation of Chlorobenzene, 1,2-Dichlorobenzene, and 1,4-Dichlorobenzene in the Vadose Zone Kurt, Zöhre (2013-07-02) Much of the microbial activity in nature takes place at interfaces, which are often associated with redox discontinuities. One example is the oxic/anoxic interface where polluted groundwater interacts with the overlying vadose zone. We tested whether microbes in the vadose zone can use synthetic chemicals as electron donors and thus protect the overlying air and buildings from groundwater pollutants. Samples from the vadose zone of a site contaminated with chlorobenzene (CB), 1,2-dichlorobenzene (12DCB), an...

Citation Formats

M. Yücel, C. VETRİANİ, D. I. Foustoukos, D. Giovannell, and N. LE BRİS, “Eco-geochemical dynamics of a shallow-water hydrothermal vent system at Milos Island, Aegean Sea (Eastern Mediterranean),” CHEMICAL GEOLOGY, pp. 11–20, 2013, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31084.