Download URLhttps://www.bco-dmo.org/dataset/630314/data/download
Media Type text/tab-separated-values
Created December 29, 2015
Modified August 19, 2016
Brief Description

Net oxygen consumption rates of the fluids recovered from the CORKs installed at the North Pond in 2014.

Acquisition Description

To determine potential rates of oxygen consumption, 20 mL of freshly sampled fluids were incubated in sterile, combusted serum vials. For this, fluids were injected into the butyl stoppered serum vials using a 60 mL syringe and hypodermic needle using sterile technique. Overpressure was released by insertion of a second hypodermic needle. Oxygen was monitored optically via optical sensor spots (Presens) mounted to the inner wall of the vials. Fluids not containing particles >3 um diameter and sterile controls were set up as described above but with an additional filter (3 um and 0.2 um pore size respectively) inserted between the syringe outlet and the hypodermic needle. Tubes were incubated in the dark at 5 degrees C.

Processing Description

BCO-DMO Processing:
– Transposed original table so that parameter names are columns, rather than rows;
– Modified parameter names to conform with BCO-DMO naming conventions;
– Replaced blanks (missing data) with ‘nd’ to indicate ‘no data’;
– Added year and cruise id numbers;
– Corrected longitude value of bottom seawater sample from positive to negative.


Presens optical sensor spots [Optode]
Instance Description (Presens optical sensor spots)

Oxygen was monitored optically via optical sensor spots (Presens) mounted to the inner wall of the vials. 

An optode or optrode is an optical sensor device that optically measures a specific substance usually with the aid of a chemical transducer.


cruise_id [cruise_id]
Cruise identifer.
cruise designation; name
year [year]
4-digit year of cruise.

year, reported as YYYY, e.g. 1995

site [site]

Site identifier. The nomenclature refers to the IODP hole and formation horizon.  For example, U1383C-shallow means the fluids came from IODP CORK drillhole 1383C in the shallowest accessible porewater horizon.

Sampling site identification.
dive_num [unknown]
Dive number.
association with a community-wide standard parameter is not yet defined
date [date]

date; generally reported in GMT as YYYYMMDD (year; month; day); also as MMDD (month; day); EqPac dates are local Hawaii time. ISO_Date format is YYYY-MM-DD (http://www.iso.org/iso/home/standards/iso8601.htm)

lat [latitude]
Latitude of sample. Positive = North.

latitude, in decimal degrees, North is positive, negative denotes South; Reported in some datasets as degrees, minutes

lon [longitude]
Longitude of sample. Negative = South.

longitude, in decimal degrees, East is positive, negative denotes West; Reported in some datsets as degrees, minutes

O2_consump_no_particles [unknown]
Oxygen consumption; no particles (<3 um).
association with a community-wide standard parameter is not yet defined
O2_consump_whole_fluids [unknown]
Oxygen consumption; whole fluids.
association with a community-wide standard parameter is not yet defined

Dataset Maintainers

Peter R. GirguisHarvard University
Julie A. HuberHarvard University
Brian T. GlazerMarine Biological Laboratory (MBL)
Beate KraftMarine Biological Laboratory (MBL)
Shannon RauchUniversity of Hawaii at Manoa (SOEST)
Shannon RauchUniversity of Hawaii at Manoa (SOEST)
Shannon RauchWoods Hole Oceanographic Institution (WHOI BCO-DMO)

BCO-DMO Project Info

Project Title Collaborative Research: Characterization of Microbial Transformations in Basement Fluids, from Genes to Geochemical Cycling
Acronym North Pond Microbes
Created April 3, 2015
Modified August 29, 2019
Project Description

Description from NSF award abstract:
Current estimates suggest that the volume of ocean crust capable of sustaining life is comparable in magnitude to that of the oceans. To date, there is little understanding of the composition or functional capacity of microbial communities in the sub-seafloor, or their influence on the chemistry of the oceans and subsequent consequences for global biogeochemical cycles. This project focuses on understanding the relationship between microbial communities and fluid chemistry in young crustal fluids that are responsible for the transport of energy, nutrients, and organisms in the crust. Specifically, the PIs will couple microbial activity measurements, including autotrophic carbon, nitrogen and sulfur metabolisms as well as mineral oxide reduction, with quantitative assessments of functional gene expression and geochemical transformations in basement fluids. Through a comprehensive suite of in situ and shipboard analyses, this research will yield cross-disciplinary advances in our understanding of the microbial ecology and geochemistry of the sub-seafloor biosphere. The focus of the effort is at North Pond, an isolated sediment pond located on ridge flank oceanic crust 7-8 million years old on the western side of the Mid-Atlantic Ridge. North Pond is currently the target for drilling on IODP expedition 336, during which it will be instrumented with three sub-seafloor basement observatories.

The project will leverage this opportunity for targeted and distinct sampling at North Pond on two German-US research cruises to accomplish three main objectives:

1. to determine if different basement fluid horizons across North Pond host distinct microbial communities and chemical milieus and the degree to which they change over a two-year post-drilling period.

2. to quantify the extent of autotrophic metabolism via microbially-mediated transformations in carbon, nitrogen, and sulfur species in basement fluids at North Pond.

3. to determine the extent of suspended particulate mineral oxides in basement fluids at North Pond and to characterize their role as oxidants for fluid-hosted microbial communities.

Specific outcomes include quantitative assessments of microbial activity and gene expression as well as geochemical transformations. The program builds on the integrative research goals for North Pond and will provide important data for guiding the development of that and future deep biosphere research programs. Results will increase understanding of microbial life and chemistry in young oceanic crust as well as provide new insights into controls on the distribution and activity of marine microbial communities throughout the worlds oceans.

There are no data about microbial communities in ubiquitous cold, oceanic crust, the emphasis of the proposed work. This is an interdisciplinary project at the interface of microbial ecology, chemistry, and deep-sea oceanography with direct links to international and national research and educational organizations.

Data Project Maintainers
Julie A. HuberMarine Biological Laboratory (MBL)Lead Principal Investigator
Peter R. GirguisHarvard UniversityPrincipal Investigator
Brian T. GlazerUniversity of Hawaii at Manoa (SOEST)Principal Investigator