http://lod.bco-dmo.org/id/dataset/944890
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2024-12-03
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Trace metal and organic iron ligand data collected during the PLUME RAIDERS cruise (RR2106) on the R/V Roger Revelle from 18 September – 6 November 2021 along the 16-18ºS section of the Southern East Pacific Rise.
2024-12-18
publication
2024-12-18
revision
Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)
2024-12-20
publication
https://doi.org/10.26008/1912/bco-dmo.944890.1
Randelle M. Bundy
University of Washington
principalInvestigator
Joseph A. Resing
National Oceanic and Atmospheric Administration
principalInvestigator
Nathan Buck
National Oceanic and Atmospheric Administration
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Moore, L., Buck, N., Resing, J. A., Bundy, R. M. (2024) Trace metal and organic iron ligand data collected during the PLUME RAIDERS cruise (RR2106) on the R/V Roger Revelle from 18 September – 6 November 2021 along the 16-18ºS section of the Southern East Pacific Rise. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2024-12-18 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.944890.1 [access date]
Trace metal and organic iron ligand data Dataset Description: Methods and Sampling: <p><em>Seawater collection</em></p>
<p>Seawater was collected using 10 L Teflon-coated GO-Flo bottles (General Oceanics) with the U.S. GEOTRACES trace metal rosette sampling system&nbsp;(Cutter and Bruland, 2012). The rosette was additionally outfitted with a miniature autonomous plume recorder (MAPR;&nbsp;(Baker, 1997)&nbsp;which included an oxidation reduction potential (ORP) and light scattering sensors, and an ultra-short baseline (USBL) transponder to ensure precise site locations on repeat casts. Two bottles were tripped at every depth to ensure adequate volumes of seawater were obtained for sample analysis. Samples were taken for dissolved gases, total dissolvable Fe (dtFe) and total dissolvable Mn (tdMn), dissolved Fe (dFe) and dissolved Mn (dMn), and total suspended particle analysis, all of which were sampled from even numbered bottles. All cleaning and sampling procedures were done according to GEOTRACES cookbook protocols&nbsp;(Cutter et al., 2017; Cutter and Bruland, 2012).</p>
<p><em>Dissolved and total dissolvable iron and manganese analyses</em></p>
<p>All samples for tdFe, dFe, tdMn, and dMn were measured shipboard using flow injection analysis (FIA) and analyzed within 6-8 hours of sample collection. The dFe, tdFe, dMn, and tdMn samples were measured using direct injection FIA with spectrophotometric detection modified from&nbsp;(Measures et al., 1995)&nbsp;and detailed in&nbsp;(Sedwick et al., 2008)&nbsp;for Fe and from&nbsp;(Resing and Mottl, 1992)&nbsp;for Mn. Detection limits for Mn and Fe were 1 nM and 1.5 nM, respectively.</p>
<p><em>Organic iron-binding ligand analyses</em></p>
<p>Samples for dFe-binding organic ligands were measured using competitive ligand exchange adsorptive cathodic stripping voltammetry (CLE-ACSV)&nbsp;(Abualhaija and van den Berg, 2014; Rue and Bruland, 1995). All titrations were performed on a controlled growth mercury electrode (CGME, Bioanalytical Systems Incorporated) equipped with an Ag/AgCl reference electrode and platinum auxiliary electrode, with a mercury drop size of 14 and acid-cleaned Teflon analytical cell (Bioanalytical Systems Incorporated). Samples for which dFe concentrations were less than 10 nM were first analyzed using the forward titration method using a 5 µM salicyladoxime analytical window&nbsp;(Abualhaija and van den Berg, 2014). Briefly, samples were thawed, and 10 mL were aliquoted into each of 15 acid-cleaned and conditioned Teflon vials (Savillex Corporation). Then 10 µL of 1.5 M boric acid buffer (boric acid, Alfa Aesar 99.99% metals basis, in 0.4 N Optima NH4OH, Fisher Scientific) was added to each vial for a final concentration of 5 µM to achieve a pH of 8.2. Next 12.5 µL of 4M salicylaldoxime (Fluka &gt; 98% assay in Optima MeOH, Fisher Scientific) was then added to each vial for a final concentration of 5µM. The dFe standards (Diluted from SpexCertiPrep in pH 2 HCl) were then added to each vial, ranging 0-10 nM for final concentrations. Aliquots were then equilibrated overnight prior to electrochemical analysis using differential pulse stripping voltammetry (0 to -800 mV), with a 120-180s deposition period with stirring at 0 mV. After the final aliquot was analyzed, 5 nM of dFe standard was added and the aliquot was re-measured to ensure complete titration of the ligands. Peak heights were obtained using ECD-Soft and ligand concentrations and binding strengths were calculated using ProMCC&nbsp;(Omanović et al., 2015)&nbsp;with an inorganic side reaction coefficient of&nbsp;logα<sub>Fe′</sub>&nbsp;= 10&nbsp;(Abualhaija and van den Berg, 2014).&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p>
<p>For samples where forward titrations showed no curvature, indicating excess ligands were present, or in the case where dFe in the sample was &gt; 10 nM, reverse titrations were completed, employing 1-nitroso-2-naphthol (NN) as the competing ligand. The procedure and theory are described in detail elsewhere&nbsp;(Hawkes et al., 2013). Briefly, samples were thawed and 10 mL were aliquoted into 10 acid-cleaned and conditioned Teflon vials (Savillex Corporation). Then 10 µL of boric acid buffer was added to each vial for a final concentration of 5 µM and pH of 8.2. The NN standard (Sigma Aldrich) was prepared in methanol (Optima, Fisher Scientific) and was then added to each vial to achieve final concentrations ranging 0-40 µM, and aliquots were left to equilibrate overnight. After equilibration, samples were analyzed electrochemically using linear sweep voltammetry (-150 to -650 mV) after a 5-minute nitrogen purge (ultra high purity, Airgas) and a 120 s deposition time at -50 mV. Three standard additions of dFe standard were added to the final aliquot and analyzed to calculate the amount of dFe that was exchangeable with NN under the analytical conditions. The estimates of exchangeable dFe often exceeded the ambient dFe concentrations in the samples. In these cases, all ambient dFe was assumed to be exchangeable. Peak heights were obtained using ECD-Soft, and ligand concentrations and binding strengths were calculated using publicly available R code&nbsp;(Hawkes et al., 2013)&nbsp;with the unsaturated Fe fit with&nbsp;logα<sub>Fe′</sub>&nbsp;= 9.8&nbsp;as the inorganic side reaction coefficient.</p>
<p><em>Siderophore analyses</em></p>
<p>At sea, four liters of 0.2 µm filtered seawater (Acropak 200, Pall Corporation) were collected for siderophore analyses. Prior to solid phase extraction, columns were activated with 2 column volumes of ultrapure methanol (Fisher, Optima grade) and rinsed with 2 column volumes of ultrapure Milli-Q water. Filtered seawater samples were then pumped continuously (~15-18 mL min-1) onto a Bond Elut solid phase extraction column (1g ENV, 6 mL, Agilent Technologies). After solid phase extraction, columns were again rinsed with at least 2 column volumes of Milli-Q water to flush remaining sea salts then stored frozen at -20ºC prior to analysis. In the laboratory, columns were thawed in the dark at room temperature and then rinsed with 2 column volumes of Milli-Q water to remove any additional salts. Columns were then eluted with 12 mL ultrapure methanol into 15 mL acid-washed and methanol-rinsed falcon tubes. Eluent was then concentrated to ~0.5 mL on a vacuum concentrator with a refrigerated vapor trap (SpeedVac, Thermo Scientific) and transferred to clean 2 mL low density polyethylene vials. Extracts were weighed to determine exact volumes then frozen at -20ºC until analysis.</p>
<p>Samples were analyzed using liquid chromatography (LC) coupled to an inductively coupled plasma mass spectrometer (ICP-MS) and an electrospray ionization mass spectrometer (ESI-MS). For each analysis, 100 µL of sample was combined with a spike of 15 µL of 5 µM cyanocobalamin internal standard then injected and separated using a Dionex 3000 LC system equipped with a ZORBAX-SB C18 trap column (0.5x35 mm, 3.5µm, Agilent technologies) and a ZORBBAX-SB C18 working column (0.5x150 mm, 5 µm, Agilent technologies) after the method of&nbsp;(Li et al., 2021). For each sample, a 62.5 µL injection was loaded onto the trap column at 25 µL/min with a 5-minute isocratic elution of solvent C (5% Optima methanol in 95% Milli-Q water, with 5 mM ammonium formate). Samples were then separated on working column using a flow rate of 40 µL/min at 30ºC beginning with a 5-minute isocratic elution of 95% solvent A (Milli-Q water with 5 mM ammonium formate) and 5% solvent B (Optima methanol with 5 mM ammonium formate buffer) followed by a 20 minute gradient from 95% solvent A to 90% solvent B, then a 10-minute isocratic elution at 90% solvent B, followed by a 5 minute gradient from 90% solvent B to 95% solvent B, then a 5-minute isocratic elution at 95% solvent B and a 13 minute conditioning step at 5% solvent B prior to the next injection. The same chromatography structure was used for both LC-ICP-MS and LC-ESI-MS&nbsp;(Boiteau et al., 2016; Bundy et al., 2018; Park et al., 2023).</p>
<p>Samples were introduced from the LC to the ICP-MS (iCAP-RQ; Thermo Scientific) via a PFA-ST nebulizer (Elemental Scientific) and spray chamber cooled to 2.7ºC. The ICP-MS was equipped with platinum sample and skimmer cones and a 10% oxygen flow was added to the sample chamber to prevent organic matter precipitation on the cones. Analyses were made in kinetic energy discrimination (KED) mode with a helium collision flow rate of 4.0-4.2 mL/min.&nbsp;<sup>56</sup>Fe peaks were identified using an in-house R code with a peak threshold of 700 counts above the large background of non-chromatographically resolved dFe-binding organic matter. All identified&nbsp;56Fe peaks were considered putative siderophores. Putative siderophore concentrations were calculated using a standard curve of ferrioxamine E (25-200 nM)&nbsp;(Boiteau et al., 2016; Bundy et al., 2018; Park et al., 2023). A 50 nM ferrioxamine E standard followed by a MilliQ blank were analyzed every six samples to adjust for instrument drift and ensure minimal carryover between samples.</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1756402 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1756402
completed
Randelle M. Bundy
University of Washington
209-543-8966
1492 NE Boat St.
Seattle
WA
98195-0001
USA
rbundy@uw.edu
pointOfContact
Joseph A. Resing
National Oceanic and Atmospheric Administration
206-526-6184
Joint Institute for the Study of the Atmosphere and the Ocean, PMEL/NOAA 7600 Sand Point Way NE, Building #3
Seattle
WA
98115
USA
Resing@uw.edu
pointOfContact
Nathan Buck
National Oceanic and Atmospheric Administration
nbuck2@uw.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
GT_number
Cruise
Station
Cast_number
Rosette
Site_Name
Station_ID
Bottle_Position
Nisken_number
Date
Time_GMT
ISO_DateTime_UTC
Pressure_dbar
Depth_m
Temp_degC
Salinity_PSU
Sigma_Theta_kg_m3
ORP_mv
Longitude
Latitude
tFe_nM
dFe_nM
dFe_nM_flag
tMn_nM
tMn_nM_flag
dMn_nM
dMn_nM_flag
Siderophores_pM
Siderophores_pM_flag
Free_Fe_pM
error_Free_Fe_pM
L_nM
error_L_nM
logK
error_logK
CTD profiler (Seabird Scientific)
theme
None, User defined
sample identification
Cruise identfier
station
cast
sample description
site
bottle
date
time of day
ISO_DateTime_UTC
water pressure
depth
water temperature at measurement depth
salinity
sigma-theta
Oxidation_Reduction_Potential
longitude
latitude
Iron
flag
Manganese
featureType
BCO-DMO Standard Parameters
CTD - profiler
instrument
BCO-DMO Standard Instruments
RR2106
service
Deployment Activity
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
Collaborative Research: Are Low-Temperature Hydrothermal Vents an Important but Overlooked Source of Stabilized Dissolved Iron to the Ocean?
https://osprey.bco-dmo.org/project/905705
Collaborative Research: Are Low-Temperature Hydrothermal Vents an Important but Overlooked Source of Stabilized Dissolved Iron to the Ocean?
<p><em>NSF Award Abstract:</em><br />
Hydrothermal vents are hot springs on the seafloor. They are often thousands of meters below the surface of the ocean along the large volcanic mountain ranges called the mid-ocean ridges. Relatively little is known about these hydrothermal vents because they exist so far from the ocean surface. Instead of lava, these vents emit warm to hot fluids (from several ºC up to 350 ºC) into the ocean, and contain high concentrations of a wide range of dissolved chemicals. One of these chemicals, iron, has been studied extensively by ocean scientists because of its importance as an essential nutrient for the microscopic photosynthetic algae called phytoplankton that grow in surface ocean waters. Scientists once thought that most of the dissolved iron coming out of hydrothermal vent fluids would quickly precipitate (form a solid and sink) near the vents, as a result of chemical reactions between the hot vent fluid and cold seawater, and therefore only small amounts of dissolved iron could be transported from the deep sea mid-ocean ridges to surface waters where phytoplankton grow. However, on a recent scientific expedition over one of the most active mid-ocean ridges called the southern East Pacific Rise (SEPR), scientists discovered that much of the dissolved iron discharged from the SEPR hydrothermal vents was in fact transported thousands of kilometers across the deep ocean. In addition, computer simulations suggest that a substantial amount of this 'hydrothermal iron' is transported as far as the surface waters of the Southern Ocean around Antarctica, where it could support the growth of phytoplankton.</p>
<p>Scientists from the University of Washington, Woods Hole Oceanographic Institution and Old Dominion University will return to the SEPR aboard a research ship and make additional measurements to better understand how hydrothermal vents add dissolved iron to the deep ocean. They will use specialized sampling equipment, including unmanned miniature submarines called autonomous underwater vehicles (AUVs), to map the distribution of hydrothermal vents in this region, and collect water samples from both high temperature (250-350 ºC) and low temperature (< 150 ºC) vents. These samples will be analyzed for chemicals that are enriched in the hydrothermal vent fluids, such as iron, manganese and helium-3, which will provide information on the chemical changes that occur as the hydrothermal vent fluids mix with surrounding seawater and are carried away from the SEPR. The scientists will use their observations and chemical analyses to address the following major questions: 1) are there more hydrothermal vents along mid ocean ridges than previously thought? and (2) are low temperature hydrothermal vents especially favorable for stabilizing dissolved iron, and ultimately transporting it to the surface ocean where it supports phytoplankton growth?</p>
<p>The project will contribute to the education and training of a graduate student and two senior undergraduate students, and outcomes will be incorporated into high school STEM curricula. The research activities will be communicated via public lectures and media releases, and project results will be disseminated to the scientific community by conference presentations, publications in peer-reviewed scientific journals, and freely available on-line archived data.</p>
<p>Along thousands of kilometers of the seafloor volcanic chains known as the mid-ocean ridges, hydrothermal vents discharge hot, acidic, metal-rich fluids into the deep ocean. These submarine hot springs are a major gateway for the exchange of heat and chemicals between the solid earth and the deep ocean, and have received intensive scientific study during the last 40 years. This research has overwhelmingly focused on high temperature (~200-350°C) hydrothermal vents. Lower temperature (<150°C) hydrothermal venting has received relatively little attention, although results from recent observational and modeling studies point to the greater abundance of low temperature discharge along the mid-ocean ridges, and its potential importance for the input of elements and chemical compounds into the deep ocean. Among the elements that are enriched in hydrothermal vent fluids, iron has received attention because of its role as an essential nutrient for primary production in the surface ocean. It has long been thought that most of the dissolved iron discharged by hydrothermal vents is lost from solution close to mid-ocean ridge sources, and thus of limited importance for ocean chemistry. But this view has been challenged by recent studies which suggest that chemical stabilization of hydrothermal dissolved iron may facilitate its long-range transport in the deep ocean. In particular, results from the US GEOTRACES program have revealed the lateral transport of a plume of hydrothermal dissolved iron over several thousand kilometers westward from its source region on the southern East Pacific Rise (SEPR).</p>
<p>In this project, investigators from the University of Washington, Woods Hole Oceanographic Institution and Old Dominion University will carry out a field research program on the SEPR to test the overarching hypothesis that diffuse low-temperature hydrothermal venting is a major a source of chemically-stabilized dissolved iron to the deep ocean, and hence plays an important but previously overlooked role in the ocean iron cycle. The ship-based field program will use an autonomous underwater vehicle equipped with in-situ optical and chemical sensors to identify plumes of both diffuse (low-temperature) and discrete (high-temperature) hydrothermal discharge along the SEPR. Emissions from multiple sites of both low and high temperature hydrothermal venting will be sampled for shipboard and post-cruise analyses of iron and other trace metals, and the inert hydrothermal "tracer" helium-3. The resulting data will be used to test two specific hypotheses: (1) the population of active hydrothermal discharge sites along mid ocean ridges is greater than previously estimated, (2) low temperature hydrothermal venting is conducive to the chemical stabilization of dissolved iron, thus facilitating its export to the ocean interior and ultimately to surface ocean where it supports primary production by phytoplankton. The information obtained in this research will facilitate inclusion of iron and other trace elements in numerical models of ocean biology and biogeochemistry, which will improve the ability to predict how the ocean will respond to and modulate future climatic and environmental changes.</p>
<p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p>
PLUME RAIDERS
largerWorkCitation
project
eng; USA
oceans
-113.5000833
-105.2501667
-17.883617
9.9008333
2021-09-24
2021-10-26
Southern East Pacific Rise
0
BCO-DMO catalogue of parameters from Trace metal and organic iron ligand data collected during the PLUME RAIDERS cruise (RR2106) on the R/V Roger Revelle from 18 September – 6 November 2021 along the 16-18ºS section of the Southern East Pacific Rise.
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
http://lod.bco-dmo.org/id/dataset-parameter/945233.rdf
Name: GT_number
Units: unitless
Description: <p>geotraces number for each sample</p>
http://lod.bco-dmo.org/id/dataset-parameter/945234.rdf
Name: Cruise
Units: unitless
Description: <p>cruise name</p>
http://lod.bco-dmo.org/id/dataset-parameter/945235.rdf
Name: Station
Units: unitless
Description: <p>station name</p>
http://lod.bco-dmo.org/id/dataset-parameter/945236.rdf
Name: Cast_number
Units: unitless
Description: <p>cast number</p>
http://lod.bco-dmo.org/id/dataset-parameter/945237.rdf
Name: Rosette
Units: unitless
Description: <p>rosette type, either trace metal or hydrothermal (regular CTD)</p>
http://lod.bco-dmo.org/id/dataset-parameter/945238.rdf
Name: Site_Name
Units: unitless
Description: <p>name of each process study site</p>
http://lod.bco-dmo.org/id/dataset-parameter/945239.rdf
Name: Station_ID
Units: unitless
Description: <p>extended number assocaited with each station (needed for NOAA)</p>
http://lod.bco-dmo.org/id/dataset-parameter/945240.rdf
Name: Bottle_Position
Units: unitless
Description: <p>bottle position on rosette</p>
http://lod.bco-dmo.org/id/dataset-parameter/945241.rdf
Name: Nisken_number
Units: unitless
Description: <p>Niskin bottle number</p>
http://lod.bco-dmo.org/id/dataset-parameter/945242.rdf
Name: Date
Units: unitless
Description: <p>date</p>
http://lod.bco-dmo.org/id/dataset-parameter/945243.rdf
Name: Time_GMT
Units: unitless
Description: <p>time</p>
http://lod.bco-dmo.org/id/dataset-parameter/945244.rdf
Name: ISO_DateTime_UTC
Units: unitless
Description: <p>Date Time in ISO format (UTC timzone)</p>
http://lod.bco-dmo.org/id/dataset-parameter/945245.rdf
Name: Pressure_dbar
Units: dbars
Description: <p>pressure</p>
http://lod.bco-dmo.org/id/dataset-parameter/945246.rdf
Name: Depth_m
Units: meters
Description: <p>depth</p>
http://lod.bco-dmo.org/id/dataset-parameter/945247.rdf
Name: Temp_degC
Units: degrees celsius
Description: <p>temperature</p>
http://lod.bco-dmo.org/id/dataset-parameter/945248.rdf
Name: Salinity_PSU
Units: psu
Description: <p>salinty</p>
http://lod.bco-dmo.org/id/dataset-parameter/945249.rdf
Name: Sigma_Theta_kg_m3
Units: kg/m3
Description: <p>density</p>
http://lod.bco-dmo.org/id/dataset-parameter/945250.rdf
Name: ORP_mv
Units: millivolts
Description: <p>oxidation reduction potential</p>
http://lod.bco-dmo.org/id/dataset-parameter/945251.rdf
Name: Longitude
Units: decimal degrees
Description: <p>longitude, west is negative</p>
http://lod.bco-dmo.org/id/dataset-parameter/945252.rdf
Name: Latitude
Units: decimal degrees
Description: <p>latitude, south is negative</p>
http://lod.bco-dmo.org/id/dataset-parameter/945253.rdf
Name: tFe_nM
Units: nanomolar
Description: <p>total dissolvable iron</p>
http://lod.bco-dmo.org/id/dataset-parameter/945254.rdf
Name: dFe_nM
Units: nanomolar
Description: <p>dissolved iron</p>
http://lod.bco-dmo.org/id/dataset-parameter/945255.rdf
Name: dFe_nM_flag
Units: unitless
Description: <p>flag for dissolved iron: ND = below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/945256.rdf
Name: tMn_nM
Units: nanomolar
Description: <p>total dissolvable manganese</p>
http://lod.bco-dmo.org/id/dataset-parameter/945257.rdf
Name: tMn_nM_flag
Units: unitless
Description: <p>flag for otal dissolvable manganese: ND = below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/945258.rdf
Name: dMn_nM
Units: nanomolar
Description: <p>dissolved manganese</p>
http://lod.bco-dmo.org/id/dataset-parameter/945259.rdf
Name: dMn_nM_flag
Units: unitless
Description: <p>flag for dissolved manganese: ND = below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/945260.rdf
Name: Siderophores_pM
Units: picomolar
Description: <p>siderophore concentration</p>
http://lod.bco-dmo.org/id/dataset-parameter/945261.rdf
Name: Siderophores_pM_flag
Units: unitless
Description: <p>flag for siderophore concentration: ND = below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/945262.rdf
Name: Free_Fe_pM
Units: picomolar
Description: <p>inorganic dissolved Fe</p>
http://lod.bco-dmo.org/id/dataset-parameter/945263.rdf
Name: error_Free_Fe_pM
Units: picomolar
Description: <p>95% confidence interval of inorganic Fe</p>
http://lod.bco-dmo.org/id/dataset-parameter/945264.rdf
Name: L_nM
Units: nanomolar
Description: <p>organic iron-binding ligand concentration, ND is below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/945265.rdf
Name: error_L_nM
Units: nanomolar
Description: <p>95% confidence interval of orgnaic Fe binding ligands</p>
http://lod.bco-dmo.org/id/dataset-parameter/945266.rdf
Name: logK
Units: unitless
Description: <p>conditional stability constant of Fe-binding ligands, ND is below detection limit</p>
http://lod.bco-dmo.org/id/dataset-parameter/945267.rdf
Name: error_logK
Units: unitless
Description: <p>95% confidence interval of orgnaic Fe binding ligand condtional stability constant</p>
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
34317
https://darchive.mblwhoilibrary.org/server/api/core/bitstreams/a3d91764-7476-4456-986d-a321bf6c7065/content
download
https://doi.org/10.26008/1912/bco-dmo.944890.1
download
onLine
dataset
<p><em>Seawater collection</em></p>
<p>Seawater was collected using 10 L Teflon-coated GO-Flo bottles (General Oceanics) with the U.S. GEOTRACES trace metal rosette sampling system&nbsp;(Cutter and Bruland, 2012). The rosette was additionally outfitted with a miniature autonomous plume recorder (MAPR;&nbsp;(Baker, 1997)&nbsp;which included an oxidation reduction potential (ORP) and light scattering sensors, and an ultra-short baseline (USBL) transponder to ensure precise site locations on repeat casts. Two bottles were tripped at every depth to ensure adequate volumes of seawater were obtained for sample analysis. Samples were taken for dissolved gases, total dissolvable Fe (dtFe) and total dissolvable Mn (tdMn), dissolved Fe (dFe) and dissolved Mn (dMn), and total suspended particle analysis, all of which were sampled from even numbered bottles. All cleaning and sampling procedures were done according to GEOTRACES cookbook protocols&nbsp;(Cutter et al., 2017; Cutter and Bruland, 2012).</p>
<p><em>Dissolved and total dissolvable iron and manganese analyses</em></p>
<p>All samples for tdFe, dFe, tdMn, and dMn were measured shipboard using flow injection analysis (FIA) and analyzed within 6-8 hours of sample collection. The dFe, tdFe, dMn, and tdMn samples were measured using direct injection FIA with spectrophotometric detection modified from&nbsp;(Measures et al., 1995)&nbsp;and detailed in&nbsp;(Sedwick et al., 2008)&nbsp;for Fe and from&nbsp;(Resing and Mottl, 1992)&nbsp;for Mn. Detection limits for Mn and Fe were 1 nM and 1.5 nM, respectively.</p>
<p><em>Organic iron-binding ligand analyses</em></p>
<p>Samples for dFe-binding organic ligands were measured using competitive ligand exchange adsorptive cathodic stripping voltammetry (CLE-ACSV)&nbsp;(Abualhaija and van den Berg, 2014; Rue and Bruland, 1995). All titrations were performed on a controlled growth mercury electrode (CGME, Bioanalytical Systems Incorporated) equipped with an Ag/AgCl reference electrode and platinum auxiliary electrode, with a mercury drop size of 14 and acid-cleaned Teflon analytical cell (Bioanalytical Systems Incorporated). Samples for which dFe concentrations were less than 10 nM were first analyzed using the forward titration method using a 5 µM salicyladoxime analytical window&nbsp;(Abualhaija and van den Berg, 2014). Briefly, samples were thawed, and 10 mL were aliquoted into each of 15 acid-cleaned and conditioned Teflon vials (Savillex Corporation). Then 10 µL of 1.5 M boric acid buffer (boric acid, Alfa Aesar 99.99% metals basis, in 0.4 N Optima NH4OH, Fisher Scientific) was added to each vial for a final concentration of 5 µM to achieve a pH of 8.2. Next 12.5 µL of 4M salicylaldoxime (Fluka &gt; 98% assay in Optima MeOH, Fisher Scientific) was then added to each vial for a final concentration of 5µM. The dFe standards (Diluted from SpexCertiPrep in pH 2 HCl) were then added to each vial, ranging 0-10 nM for final concentrations. Aliquots were then equilibrated overnight prior to electrochemical analysis using differential pulse stripping voltammetry (0 to -800 mV), with a 120-180s deposition period with stirring at 0 mV. After the final aliquot was analyzed, 5 nM of dFe standard was added and the aliquot was re-measured to ensure complete titration of the ligands. Peak heights were obtained using ECD-Soft and ligand concentrations and binding strengths were calculated using ProMCC&nbsp;(Omanović et al., 2015)&nbsp;with an inorganic side reaction coefficient of&nbsp;logα<sub>Fe′</sub>&nbsp;= 10&nbsp;(Abualhaija and van den Berg, 2014).&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p>
<p>For samples where forward titrations showed no curvature, indicating excess ligands were present, or in the case where dFe in the sample was &gt; 10 nM, reverse titrations were completed, employing 1-nitroso-2-naphthol (NN) as the competing ligand. The procedure and theory are described in detail elsewhere&nbsp;(Hawkes et al., 2013). Briefly, samples were thawed and 10 mL were aliquoted into 10 acid-cleaned and conditioned Teflon vials (Savillex Corporation). Then 10 µL of boric acid buffer was added to each vial for a final concentration of 5 µM and pH of 8.2. The NN standard (Sigma Aldrich) was prepared in methanol (Optima, Fisher Scientific) and was then added to each vial to achieve final concentrations ranging 0-40 µM, and aliquots were left to equilibrate overnight. After equilibration, samples were analyzed electrochemically using linear sweep voltammetry (-150 to -650 mV) after a 5-minute nitrogen purge (ultra high purity, Airgas) and a 120 s deposition time at -50 mV. Three standard additions of dFe standard were added to the final aliquot and analyzed to calculate the amount of dFe that was exchangeable with NN under the analytical conditions. The estimates of exchangeable dFe often exceeded the ambient dFe concentrations in the samples. In these cases, all ambient dFe was assumed to be exchangeable. Peak heights were obtained using ECD-Soft, and ligand concentrations and binding strengths were calculated using publicly available R code&nbsp;(Hawkes et al., 2013)&nbsp;with the unsaturated Fe fit with&nbsp;logα<sub>Fe′</sub>&nbsp;= 9.8&nbsp;as the inorganic side reaction coefficient.</p>
<p><em>Siderophore analyses</em></p>
<p>At sea, four liters of 0.2 µm filtered seawater (Acropak 200, Pall Corporation) were collected for siderophore analyses. Prior to solid phase extraction, columns were activated with 2 column volumes of ultrapure methanol (Fisher, Optima grade) and rinsed with 2 column volumes of ultrapure Milli-Q water. Filtered seawater samples were then pumped continuously (~15-18 mL min-1) onto a Bond Elut solid phase extraction column (1g ENV, 6 mL, Agilent Technologies). After solid phase extraction, columns were again rinsed with at least 2 column volumes of Milli-Q water to flush remaining sea salts then stored frozen at -20ºC prior to analysis. In the laboratory, columns were thawed in the dark at room temperature and then rinsed with 2 column volumes of Milli-Q water to remove any additional salts. Columns were then eluted with 12 mL ultrapure methanol into 15 mL acid-washed and methanol-rinsed falcon tubes. Eluent was then concentrated to ~0.5 mL on a vacuum concentrator with a refrigerated vapor trap (SpeedVac, Thermo Scientific) and transferred to clean 2 mL low density polyethylene vials. Extracts were weighed to determine exact volumes then frozen at -20ºC until analysis.</p>
<p>Samples were analyzed using liquid chromatography (LC) coupled to an inductively coupled plasma mass spectrometer (ICP-MS) and an electrospray ionization mass spectrometer (ESI-MS). For each analysis, 100 µL of sample was combined with a spike of 15 µL of 5 µM cyanocobalamin internal standard then injected and separated using a Dionex 3000 LC system equipped with a ZORBAX-SB C18 trap column (0.5x35 mm, 3.5µm, Agilent technologies) and a ZORBBAX-SB C18 working column (0.5x150 mm, 5 µm, Agilent technologies) after the method of&nbsp;(Li et al., 2021). For each sample, a 62.5 µL injection was loaded onto the trap column at 25 µL/min with a 5-minute isocratic elution of solvent C (5% Optima methanol in 95% Milli-Q water, with 5 mM ammonium formate). Samples were then separated on working column using a flow rate of 40 µL/min at 30ºC beginning with a 5-minute isocratic elution of 95% solvent A (Milli-Q water with 5 mM ammonium formate) and 5% solvent B (Optima methanol with 5 mM ammonium formate buffer) followed by a 20 minute gradient from 95% solvent A to 90% solvent B, then a 10-minute isocratic elution at 90% solvent B, followed by a 5 minute gradient from 90% solvent B to 95% solvent B, then a 5-minute isocratic elution at 95% solvent B and a 13 minute conditioning step at 5% solvent B prior to the next injection. The same chromatography structure was used for both LC-ICP-MS and LC-ESI-MS&nbsp;(Boiteau et al., 2016; Bundy et al., 2018; Park et al., 2023).</p>
<p>Samples were introduced from the LC to the ICP-MS (iCAP-RQ; Thermo Scientific) via a PFA-ST nebulizer (Elemental Scientific) and spray chamber cooled to 2.7ºC. The ICP-MS was equipped with platinum sample and skimmer cones and a 10% oxygen flow was added to the sample chamber to prevent organic matter precipitation on the cones. Analyses were made in kinetic energy discrimination (KED) mode with a helium collision flow rate of 4.0-4.2 mL/min.&nbsp;<sup>56</sup>Fe peaks were identified using an in-house R code with a peak threshold of 700 counts above the large background of non-chromatographically resolved dFe-binding organic matter. All identified&nbsp;56Fe peaks were considered putative siderophores. Putative siderophore concentrations were calculated using a standard curve of ferrioxamine E (25-200 nM)&nbsp;(Boiteau et al., 2016; Bundy et al., 2018; Park et al., 2023). A 50 nM ferrioxamine E standard followed by a MilliQ blank were analyzed every six samples to adjust for instrument drift and ensure minimal carryover between samples.</p>
Specified by the Principal Investigator(s)
<p><em>Organic iron-binding ligands</em></p>
<p>Peak heights were obtained using ECD-Soft, and ligand concentrations and binding strengths were calculated using publicly available R code&nbsp;(Hawkes et al., 2013)&nbsp;with the unsaturated Fe fit with&nbsp;logα<sub>Fe′</sub>&nbsp;= 9.8&nbsp;as the inorganic side reaction coefficient.</p>
Specified by the Principal Investigator(s)
* adjusted parameter names to comply with database requirements
* added ISO_DateTime_UTC to dataset
* Added flags (under detection limit) as separate column to preserve numeric column formats. Changed flag BDL (1 occurrence) to ND for consistency (in column dMn_nM_flag).
Specified by BCO-DMO Data Managers
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
CTD profiler (Seabird Scientific)
CTD profiler (Seabird Scientific)
PI Supplied Instrument Name: CTD profiler (Seabird Scientific) Instrument Name: CTD - profiler Instrument Short Name: Instrument Description: The Conductivity, Temperature, Depth (CTD) unit is an integrated instrument package designed to measure the conductivity, temperature, and pressure (depth) of the water column. The instrument is lowered via cable through the water column. It permits scientists to observe the physical properties in real-time via a conducting cable, which is typically connected to a CTD to a deck unit and computer on a ship. The CTD is often configured with additional optional sensors including fluorometers, transmissometers and/or radiometers. It is often combined with a Rosette of water sampling bottles (e.g. Niskin, GO-FLO) for collecting discrete water samples during the cast.
This term applies to profiling CTDs. For fixed CTDs, see https://www.bco-dmo.org/instrument/869934. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/130/
Cruise: RR2106
RR2106
R/V Roger Revelle
Community Standard Description
International Council for the Exploration of the Sea
R/V Roger Revelle
vessel
RR2106
Joseph A. Resing
University of Washington
R/V Roger Revelle
Community Standard Description
International Council for the Exploration of the Sea
R/V Roger Revelle
vessel