Concentrations of anions, cations, and trace elements/metals from vents near Milos Island, Greece. from May 2012 (Hydrothermal Autotrophic Carbon Fixation project)

Website: https://www.bco-dmo.org/dataset/474322
Version: 2014-01-08

Project
» Autotrophic carbon fixation at a shallow-water hydrothermal system: Constraining microbial activity, isotopic and geochemical regimes (Hydrothermal Autotrophic Carbon Fixation)

Program
» Center for Dark Energy Biosphere Investigations (C-DEBI)
ContributorsAffiliationRole
Foustoukos, DionysisCarnegie Institution for Science (CIS)Principal Investigator
Copley, NancyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Dataset Description

Data from samples collected at the shallow-water hydrothermal vent sites at Paleochori Bay, Milos Island, Greece, and includes the chemical composition (anion, cation, trace elements/metals) of vent fluids sampled.


This is also available at http://people.gl.ciw.edu/dfoustoukos/Site/Data_Repository.html


Acquisition Description

Fluid samples were collected from the water column close to the shallow-water venting sites and from the interstitial waters of all cores at 2 cm intervals. Fluids and gases were also sampled from the subaerial sites. Samples returned to the Geophysical Lab were analyzed to determine dissolved concentrations of: organic acids and a range of major anions/cations species (e.g. SO42-, PO42-, SNH3, NO3-, Cl-, Na+, K+, Ca2+, and Mg2+) including trace elements and metals. We used ion chromatography (Metrohm "MIC-3 Advanced IC, Metrosep A supp 7-250/16-250; C4- 250 columns). Fluids were analyzed for metal and trace element concentrations at the MC-ICP-MS facility of Prof. Michael Bizimis at the University of South Carolina. 
 

Relevant References:

Mustafa Yücel, Stefan M. Sievert, Costantino Vetriani, Dionysis I. Foustoukos, Donato Giovannelli, Nadine Le Bris. Eco-geochemical dynamics of a shallow-water hydrothermal vent system at Milos Island, Aegean Sea (Eastern Mediterranean). Chemical Geology 356 (2013) 11-20.


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Parameters

ParameterDescriptionUnits
datesampling date mm/dd/yyyy
yearyear of sampling yyyy
monthmonth of sampling 1 to 12
dayday of sampling 1 to 31
yrdayyearday of sampling; e.g. 1.5 means January 1 at 1200 hours (noon time) 1 to 365
sitesample location identification unitless
latlatitude; north is postive decimal degrees
lonlongitude; east is postive decimal degrees
distancedistance from the vent site centimeters
depth_cmsampling depth centimeters
sample_descripbrief description of the sample name text
sample_idsample code alphanumeric
temptemperature at sampling location degrees Celsius
activityvent or subaerial text
LiLithium ion concentration as measured by the ICW lab millimoles
NaSodium ion concentration as measured by the ICW lab millimoles
NH4Ammonium ion concentration as measured by the ICW lab millimoles
KPotassium ion concentration as measured by the ICW lab millimoles
Mg_ICMagnesium ion concentration as measured by the ICW lab millimoles
Mg_USCMagnesium ion concentration as measured by the USC lab millimoles
Ca_ICCalcium ion concentration as measured by the ICW lab millimoles
Ca_USCCalcium ion concentration as measured by the USC lab millimoles
ClChloride ion concentration as measured by the ICW lab millimoles
BrBromide ion concentration as measured by the ICW lab millimoles
FFlouride ion concentration as measured by the ICW lab millimoles
NO3Nitrate concentration as measured by the ICW lab millimoles
PO4Phosphate concentration as measured by the ICW lab millimoles
SO4Sulphate concentration as measured by the ICW lab millimoles
SrStrontium ion concentration as measured by the USC lab micromoles
CsCesium ion concentration as measured by the USC lab micromoles
RbRubidium ion concentration as measured by the USC lab micromoles
BaBarium ion concentration as measured by the USC lab micromoles
MnManganese ion concentration as measured by the USC lab micromoles
FeIron ion concentration as measured by the USC lab micromoles
NiNickel ion concentration as measured by the USC lab micromoles
CuCopper ion concentration as measured by the USC lab micromoles
SiSilicon ion concentration as measured by the USC lab micromoles


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Instruments

Dataset-specific Instrument Name
temperature probe
Generic Instrument Name
Water Temperature Sensor
Dataset-specific Description
Hand-held temperature probe
Generic Instrument Description
General term for an instrument that measures the temperature of the water with which it is in contact (thermometer).


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Deployments

Milos_vents_2012

Website
Platform
shoreside Milos_vents
Start Date
2012-05-21
End Date
2012-05-30
Description
Vent fluids and sediment cores were were collected at shallow-water hydrothermal vent sites at Paleochori Bay, Milos Island, Greece, and analyzed for their chemical composition (anion, cation, trace elements/metals).


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Project Information

Autotrophic carbon fixation at a shallow-water hydrothermal system: Constraining microbial activity, isotopic and geochemical regimes (Hydrothermal Autotrophic Carbon Fixation)

Coverage: Shallow-water hydrothermal vents, Paleochori Bay, Milos Island, Greece


In this project we studied the shallow-water hydrothermal vent sites at Milos Island (Greece) to better understand the extent of autotrophic carbon fixation and its chemical and isotopic signature along environmental (redox/thermal) gradients. This was a 12-day long expedition (May 18 to 30, 2012) to sample vent fluids, gases and retrieve sediment cores at Paleochori Bay by using SCUBA diving at 8-10 m depth. In addition to the submarine vent sites, two subaerial locations of venting were identified at 36o 40' 28"N - 24o 31' 14" E and 36o 40' 25" N - 24o 30' 44" E. Both the subaerial and submarine sites are located on the same fracture zone that likely controls the hydrothermal circulation of evolved meteoritic water and seawater within the magmatic zone of Milos Island. To this end, the geochemistry of the fluids and gases emitted from subaerial sites provide important information towards identifying the linkage between the subaerial and submarine magmatic activity and provide insights on the metabolic functions (e.g. H2 oxidation, Fe(III) reduction, C and S cycling) of the subsurface microbial community. 

Abstract:
Currently, there is only limited information on the identity and activity of the microorganisms carrying out CO2-fixation in situ, despite the fact that these organisms form the basis of their respective ecosystems. Representatives that are able to grow autotrophically are known to exist in almost all major groups of prokaryotes, and these organisms play essential roles in ecosystems by providing a continuous supply of organic carbon for heterotrophs. Microorganisms present in extreme environments utilize CO2- fixation pathways other than the Calvin-Benson-Bassham (CBB) cycle. At present, five alternative autotrophic CO2 fixation pathways are known. Different carbon fixation pathways result in distinct isotopic signatures of the produced biomass due to the isotopic discrimination between light (12C) and heavy (13C) carbon by the carboxylating enzymes. Thus, inferences about the carbon fixation pathway predominantly utilized by the microbial community can also be made based on the stable carbon isotopic composition of the organic matter, in extant systems as well as in the geological record. However, at present little is known about the systematics and extents of fractionation during carbon fixation by prokaryotic organisms, and to our knowledge no studies exist that have systematically studied the relationship between the operation of different carbon fixation pathways and how this is reflected in the stable carbon isotopic composition in a natural system. This is a 2-year interdisciplinary, international research program that employs a powerful combination of cutting-edge research tools aiming to improve our understanding of autotrophic carbon fixation and its chemical and isotopic signature along environmental gradients in a natural hydrothermal system. The following hypotheses are addressed:

1. The diversity of microorganisms present along a thermal and redox gradient, and rates of CO2 fixation, will reflect adaptation to in situ temperatures and geochemical conditions

2. Microorganisms utilizing the CBB cycle for autotrophic CO2-fixation will represent a smaller percentage of the chemolithoautotrophic community at higher temperatures, where microorganisms utilizing alternative CO2-fixation pathways dominate

3. Isotopic values of biomass and specific biomarker molecules will vary along a thermal and redox gradient from zones characterized by a higher hydrothermal fluid flux and thus higher temperatures to the surrounding, cooler areas, corresponding to the physiology of the microorganisms utilizing different pathways for carbon fixation

The PIs will use a multidisciplinary approach to delineate the relative contribution of the different carbon fixation pathways along an environmental gradient by combining metagenomic analyses coupled with: 1) an assessment of the frequency and the expression of specific key genes involved in carbon fixation, and 2) with the measurement of carbon fixation rates. These data will be integrated with the determination of stable C isotopic composition of biomass, DIC, and specific hydrocarbons/lipids. Due to its easy accessibility, well-established environmental gradients, and extensive background information, the shallow-water vents off Milos (Greece) will be used as a natural laboratory to perform these studies.

Intellectual Merit. The data generated in this study will allow constraints on the relationship between autotrophic carbon fixation and the resulting isotopic signatures of biomass and specific biomarker molecules (e.g. CH4, C2+ alkanes, lipids) in a natural system. This has implications for assessing the importance of carbon fixation in extant ecosystems, and it will also provide a tool to improve the interpretation of isotopic values in the geological record.



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Program Information

Center for Dark Energy Biosphere Investigations (C-DEBI)


Coverage: Global


The mission of the Center for Dark Energy Biosphere Investigations (C-DEBI) is to explore life beneath the seafloor and make transformative discoveries that advance science, benefit society, and inspire people of all ages and origins.

C-DEBI provides a framework for a large, multi-disciplinary group of scientists to pursue fundamental questions about life deep in the sub-surface environment of Earth. The fundamental science questions of C-DEBI involve exploration and discovery, uncovering the processes that constrain the sub-surface biosphere below the oceans, and implications to the Earth system. What type of life exists in this deep biosphere, how much, and how is it distributed and dispersed? What are the physical-chemical conditions that promote or limit life? What are the important oxidation-reduction processes and are they unique or important to humankind? How does this biosphere influence global energy and material cycles, particularly the carbon cycle? Finally, can we discern how such life evolved in geological settings beneath the ocean floor, and how this might relate to ideas about the origin of life on our planet?

C-DEBI's scientific goals are pursued with a combination of approaches:
(1) coordinate, integrate, support, and extend the research associated with four major programs—Juan de Fuca Ridge flank (JdF), South Pacific Gyre (SPG), North Pond (NP), and Dorado Outcrop (DO)—and other field sites;
(2) make substantial investments of resources to support field, laboratory, analytical, and modeling studies of the deep subseafloor ecosystems;
(3) facilitate and encourage synthesis and thematic understanding of submarine microbiological processes, through funding of scientific and technical activities, coordination and hosting of meetings and workshops, and support of (mostly junior) researchers and graduate students; and
(4) entrain, educate, inspire, and mentor an interdisciplinary community of researchers and educators, with an emphasis on undergraduate and graduate students and early-career scientists.

Note: Katrina Edwards was a former PI of C-DEBI; James Cowen is a former co-PI.

Data Management:
C-DEBI is committed to ensuring all the data generated are publically available and deposited in a data repository for long-term storage as stated in their Data Management Plan (PDF) and in compliance with the NSF Ocean Sciences Sample and Data Policy. The data types and products resulting from C-DEBI-supported research include a wide variety of geophysical, geological, geochemical, and biological information, in addition to education and outreach materials, technical documents, and samples. All data and information generated by C-DEBI-supported research projects are required to be made publically available either following publication of research results or within two (2) years of data generation.

To ensure preservation and dissemination of the diverse data-types generated, C-DEBI researchers are working with BCO-DMO Data Managers make data publicly available online. The partnership with BCO-DMO helps ensure that the C-DEBI data are discoverable and available for reuse. Some C-DEBI data is better served by specialized repositories (NCBI's GenBank for sequence data, for example) and, in those cases, BCO-DMO provides dataset documentation (metadata) that includes links to those external repositories.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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