http://lod.bco-dmo.org/id/dataset/995970
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
2026-04-04
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Dissolved iron and iron isotopes for SGD well, river, and estuary samples collected between November 2022 and March 2024 along the West Florida Shelf
2026-04-06
publication
2026-04-06
revision
Woods Hole Oceanographic Institution (WHOI BCO-DMO)
2026-04-22
publication
https://doi.org/10.26008/1912/bco-dmo.995970.1
Timothy M. Conway
University of South Florida
principalInvestigator
Hannah Hunt
University of South Florida
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: Conway, T. M., Hunt, H. (2026) Dissolved iron and iron isotopes for SGD well, river, and estuary samples collected between November 2022 and March 2024 along the West Florida Shelf. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-04-06 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.995970.1 [access date]
STING river, estuary, and SGD well Fe and Fe isotopes Dataset Description: Methods and Sampling: <p><strong>Sample Collection</strong></p>
<p><em>SGD Wells</em></p>
<p>Submarine groundwater samples were collected by U.S. Geological survey (USGS) small boat from three offshore well transects, each with three well location. Samples were taken from well head (GWd) and from surface (SB) and bottom waters (BW). Divers, using acid-cleaned Teflon tubing attached to a trace metal clean diaphragm pump. First, bottom waters were collected, then the well uncapped, adequately purged, and sampled. All samples were filtered through 0.2 um Acropak Supor Cartridges (Pall, USA) into acid-cleaned LDPE bottles. NC5, NC10, NC15 = Nature Coast Transect, IRB25, IRB30, IRB35 = Indian Rocks Transect, VH45, VH50, VH55 = Venice Headlands Transect. More details are provided in Hunt (2025).</p>
<p><em>Rivers and Estuaries</em></p>
<p>River Sample sites were located on land and samples were collected from five rivers (Hillsborough, Alafia, Manatee, Peace, and Caloosahatchee), using trace metal clean protocols. Estuary samples were collected in collaboration with Mote Marine Laboratory via small boat (RV Eugenie Clark), also using trace metal clean protocols. All water samples for dissolved Fe and d56Fe were syringe filtered using acid-cleaned 50 mL Henke Jet HDPE syringes and 0.2 um PVDF membrane Titan3 syringe filters into acid-cleaned LDPE bottles. AR1-2 = Alafia River, HB1-2 = Hillsborough, MR1-2 = Manatee, PR1 = Peace River, CR1 = Caloosahatchee, CS and E= Estuary sample locations. More details are provided in Hunt (2025).</p>
<p><strong>Sample Processing</strong></p>
<p>Samples were acidified back on shore at the University of South Florida (USF) using 2.4 mL 10 M Teflon-distilled HCl per liter of sample and stored for at least 6 months before processing.&nbsp;Samples were then processed for dissolved Fe isotope and concentration analysis at the University of South Florida following Sieber et al. (2019), modified from Conway et al (2013). Briefly, an Fe double-spike was added prior to batch extraction using Nobias PA-1 chelating resin, followed by purification by anion-exchange chromatography using AG-MP1 resin. Concentration and isotope analyses were performed on a Thermo Neptune Plus MC-ICPMS (Multicollecter Inductively Coupled Plasma Mass Spectrometer)&nbsp;in the Tampa Bay Plasma Facility at the University of South Florida using the double spike technique via a ~100 uL min<sup>-1</sup>&nbsp;PFA nebulizer and Apex Ω introduction system, Pt Jet Sampler cone and an Al X skimmer cone.</p>
<p><strong>Sample Analysis</strong></p>
<p>Dissolved Fe stable isotope ratios are expressed in delta notation (δ<sup>56</sup>Fe) relative to the IRMM-014 standard. A secondary Fe standard, NIST-3126, was analyzed over 56 sessions to provide an estimate of long-term instrumental precision. We obtain a value of +0.36 ± 0.06‰ (2SD, n = 772; runs = 56), in agreement with consensus values (Hunt 2025; Conway et al., 2013). Therefore, we consider a 2SD uncertainty of 0.06‰ as an estimate of analytical precision, and have applied it to all samples, except for low concentration samples where the larger internal error is considered a more conservative estimate of uncertainty. Dissolved Fe concentrations were calculated using the isotope dilution technique based on on-peak blank, interference and mass-bias corrected&nbsp;<sup>57</sup>Fe/<sup>56</sup>Fe ratios measured simultaneously with isotope analysis. We express uncertainty (1SD) on Fe concentrations as 2%, based on Conway et al. (2013).</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2148836 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2148836
onGoing
Timothy M. Conway
University of South Florida
727-258-1081
College of Marine Sciences 830 1st St SE
St. Petersburg
FL
33701
USA
tmconway@usf.edu
pointOfContact
Hannah Hunt
University of South Florida
hannahhunt@usf.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Sample_ID
Station_ID
STING_ID
DateTime_UTC
DateTime_Local
Latitude
Longitude
dFe
SD
n_dFe
dFe_FLAG
d56Fe
SD_2
n_d56Fe
d56Fe_FLAG
Diver
Thermo Neptune Multicollecter Inductively Coupled Plasma Mass Spectrometer
Trace metal clean diaphragm pump
theme
None, User defined
sample identification
station
ISO_DateTime_UTC
ISO_DateTime_Local
latitude
longitude
Iron
standard deviation
count
quality flag
Fe 54 to Fe 56 ratio
featureType
BCO-DMO Standard Parameters
Diving Mask and Snorkel
Inductively Coupled Plasma Mass Spectrometer
Pump
instrument
BCO-DMO Standard Instruments
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: Linking iron and nitrogen sources in an oligotrophic coastal margin: Nitrogen fixation and the role of boundary fluxes
https://osprey.bco-dmo.org/project/880516
Collaborative Research: Linking iron and nitrogen sources in an oligotrophic coastal margin: Nitrogen fixation and the role of boundary fluxes
<p><strong>NSF Award Abstract:</strong><br />
This project will investigate how groundwater discharge delivers important nutrients to the coastal ecosystems of the West Florida Shelf. Preliminary studies indicate that groundwater may supply both dissolved organic nitrogen (DON) and iron in this region. In coastal ecosystems like the West Florida Shelf that have very low nitrate and ammonium concentrations, DON is the main form of nitrogen available to organisms. Nitrogen cycling is strongly affected by iron availability because iron is essential for both photosynthesis and for nitrogen fixation. This study will investigate the sources and composition of DON and iron, and their influence on the coastal ecosystem. The team will sample offshore groundwater wells, river and estuarine waters, and conduct two expeditions across the West Florida Shelf in winter and summer. Investigators will participate in K-12 and outreach activities to increase awareness of the project and related science. The project will fund the work of six graduate and eight undergraduate students across five institutions, furthering NSF’s goals of education and training.</p>
<p>Motivated by preliminary observations of unexplained, tightly-correlated DON and dissolved iron concentrations across the West Florida Shelf (WFS), the proposed work will quantify the flux and isotopic signatures of submarine groundwater discharge (SGD)-derived DON and iron to the WFS, and evaluate the bioavailability of this temporally-variable source using four seasonal near-shore campaigns sampling offshore groundwater wells, estuarine, and riverine endmembers and two cross-shelf cruises. The work will evaluate whether SGD stimulates nitrogen fixation on the WFS, and the potential for the stimulated nitrogen fixation to further modify the chemistry of DON and dissolved iron in the region. The cross-shelf cruises will investigate hypothesized periods of maximum SGD and Trichodesmium abundance (June), and reduced river discharge and SGD (February), thus comparing two distinct biogeochemical regimes. The concentrations and isotopic compositions of DON and dissolved iron, molecular composition of DON, and the concentration and composition of iron-binding ligands will be characterized. Nitrogen fixation rates and Trichodesmium spp. abundance and expression of iron stress genes will be measured. Fluxes of DON and iron from SGD and rivers will be quantified with radium isotope mass balances. The impacts of SGD on nitrogen fixation and DON/ligand production will be constrained with incubations of natural phytoplankton communities with submarine groundwater amendments. Two hypotheses will be tested: 1) SGD is the dominant source of bioavailable DON and dissolved iron on the WFS, and 2) SGD-alleviation of iron stress changes the dominant Trichodesmium species on the WFS, increases nitrogen fixation rates and modifies DON and iron composition. Overall, the work will establish connections between marine nitrogen and iron cycling and evaluate the potential for coastal inputs to modify water along the WFS before export to the Atlantic Ocean. This study will thus provide a framework to consider these boundary fluxes in oligotrophic coastal systems and the relative importance of rivers and SGD as sources of nitrogen and iron in other analogous locations, such as coastal systems in Australia, India, and Africa, where nitrogen fixation and SGD have also been documented.</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>
West Florida Shelf DON and Fe
largerWorkCitation
project
eng; USA
oceans
-81.847330594924
-81.847330594924
26.38724
29.09216
2022-11-14
2024-03-08
Gulf of Mexico/America, West Florida Shelf
0
BCO-DMO catalogue of parameters from Dissolved iron and iron isotopes for SGD well, river, and estuary samples collected between November 2022 and March 2024 along the West Florida Shelf
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/996007.rdf
Name: Sample_ID
Units: unitless
Description: <p>Sample identification</p>
http://lod.bco-dmo.org/id/dataset-parameter/996008.rdf
Name: Station_ID
Units: unitless
Description: <p>Station identification for submarine groundwater discharge wells, rivers, and estuaries; see Methods section for description of station codes and corresponding locations</p>
http://lod.bco-dmo.org/id/dataset-parameter/996009.rdf
Name: STING_ID
Units: unitless
Description: <p>STING project identification (Submarine Groundwater Discharge, Trichodesmium, Iron & Nitrogen in the Gulf of Mexico)</p>
http://lod.bco-dmo.org/id/dataset-parameter/996010.rdf
Name: DateTime_UTC
Units: unitless
Description: <p>Date and time of sample collection (UTC)</p>
http://lod.bco-dmo.org/id/dataset-parameter/996012.rdf
Name: DateTime_Local
Units: unitless
Description: <p>Date and time of sample collection (US Eastern Time)</p>
http://lod.bco-dmo.org/id/dataset-parameter/996013.rdf
Name: Latitude
Units: decimal degrees
Description: <p>Latitude of sample collection; a positive value indicates a Northern coordinate</p>
http://lod.bco-dmo.org/id/dataset-parameter/996015.rdf
Name: Longitude
Units: decimal degrees
Description: <p>Longitude of sample collection; a negative value indicates an Western coordinate</p>
http://lod.bco-dmo.org/id/dataset-parameter/996017.rdf
Name: dFe
Units: nanomoles per kilogram (nmol kg-1)
Description: <p>Dissolved iron (Fe) concentration</p>
http://lod.bco-dmo.org/id/dataset-parameter/996018.rdf
Name: SD
Units: nanomoles per kilogram (nmol kg-1)
Description: <p>1 standard deviation of Dissolved (Fe) concentration</p>
http://lod.bco-dmo.org/id/dataset-parameter/996019.rdf
Name: n_dFe
Units: unitless
Description: <p>Number of analyses used in calculating dFe</p>
http://lod.bco-dmo.org/id/dataset-parameter/996020.rdf
Name: dFe_FLAG
Units: unitless
Description: <p>Quality flag for Dissolved iron (Fe) concentration where 1= 'good value' And 2='probably good value'</p>
http://lod.bco-dmo.org/id/dataset-parameter/996021.rdf
Name: d56Fe
Units: per mil
Description: <p>Dissolved δ56Fe relative to the IRMM-014 Standard, which = (((56Fe/54Fe)(sample))/((56Fe/54Fe)(IRMM-014)) - 1)x1000</p>
http://lod.bco-dmo.org/id/dataset-parameter/996022.rdf
Name: SD_2
Units: per mil
Description: <p>2 standard deviations of dissolved δ56Fe analysis</p>
http://lod.bco-dmo.org/id/dataset-parameter/996023.rdf
Name: n_d56Fe
Units: unitless
Description: <p>Number of analyses used in calculating δ56Fe</p>
http://lod.bco-dmo.org/id/dataset-parameter/996024.rdf
Name: d56Fe_FLAG
Units: unitless
Description: <p>Quality flag for dissolved δ56Fe values where 1= 'good value' And 2='probably good value'</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
https://doi.org/10.26008/1912/bco-dmo.995970.1
download
onLine
dataset
<p><strong>Sample Collection</strong></p>
<p><em>SGD Wells</em></p>
<p>Submarine groundwater samples were collected by U.S. Geological survey (USGS) small boat from three offshore well transects, each with three well location. Samples were taken from well head (GWd) and from surface (SB) and bottom waters (BW). Divers, using acid-cleaned Teflon tubing attached to a trace metal clean diaphragm pump. First, bottom waters were collected, then the well uncapped, adequately purged, and sampled. All samples were filtered through 0.2 um Acropak Supor Cartridges (Pall, USA) into acid-cleaned LDPE bottles. NC5, NC10, NC15 = Nature Coast Transect, IRB25, IRB30, IRB35 = Indian Rocks Transect, VH45, VH50, VH55 = Venice Headlands Transect. More details are provided in Hunt (2025).</p>
<p><em>Rivers and Estuaries</em></p>
<p>River Sample sites were located on land and samples were collected from five rivers (Hillsborough, Alafia, Manatee, Peace, and Caloosahatchee), using trace metal clean protocols. Estuary samples were collected in collaboration with Mote Marine Laboratory via small boat (RV Eugenie Clark), also using trace metal clean protocols. All water samples for dissolved Fe and d56Fe were syringe filtered using acid-cleaned 50 mL Henke Jet HDPE syringes and 0.2 um PVDF membrane Titan3 syringe filters into acid-cleaned LDPE bottles. AR1-2 = Alafia River, HB1-2 = Hillsborough, MR1-2 = Manatee, PR1 = Peace River, CR1 = Caloosahatchee, CS and E= Estuary sample locations. More details are provided in Hunt (2025).</p>
<p><strong>Sample Processing</strong></p>
<p>Samples were acidified back on shore at the University of South Florida (USF) using 2.4 mL 10 M Teflon-distilled HCl per liter of sample and stored for at least 6 months before processing.&nbsp;Samples were then processed for dissolved Fe isotope and concentration analysis at the University of South Florida following Sieber et al. (2019), modified from Conway et al (2013). Briefly, an Fe double-spike was added prior to batch extraction using Nobias PA-1 chelating resin, followed by purification by anion-exchange chromatography using AG-MP1 resin. Concentration and isotope analyses were performed on a Thermo Neptune Plus MC-ICPMS (Multicollecter Inductively Coupled Plasma Mass Spectrometer)&nbsp;in the Tampa Bay Plasma Facility at the University of South Florida using the double spike technique via a ~100 uL min<sup>-1</sup>&nbsp;PFA nebulizer and Apex Ω introduction system, Pt Jet Sampler cone and an Al X skimmer cone.</p>
<p><strong>Sample Analysis</strong></p>
<p>Dissolved Fe stable isotope ratios are expressed in delta notation (δ<sup>56</sup>Fe) relative to the IRMM-014 standard. A secondary Fe standard, NIST-3126, was analyzed over 56 sessions to provide an estimate of long-term instrumental precision. We obtain a value of +0.36 ± 0.06‰ (2SD, n = 772; runs = 56), in agreement with consensus values (Hunt 2025; Conway et al., 2013). Therefore, we consider a 2SD uncertainty of 0.06‰ as an estimate of analytical precision, and have applied it to all samples, except for low concentration samples where the larger internal error is considered a more conservative estimate of uncertainty. Dissolved Fe concentrations were calculated using the isotope dilution technique based on on-peak blank, interference and mass-bias corrected&nbsp;<sup>57</sup>Fe/<sup>56</sup>Fe ratios measured simultaneously with isotope analysis. We express uncertainty (1SD) on Fe concentrations as 2%, based on Conway et al. (2013).</p>
Specified by the Principal Investigator(s)
<p>Data was processed in Microsoft Excel using an in-house double spike reduction scheme from Sieber et al (2021), based on Siebert et al (2001).</p>
Specified by the Principal Investigator(s)
- Loaded sheet 1 from "BCO-DMO_STING_Rivers_Estuaries_Wells_Conway V1.0.xlsx" (xlsx format) using filename as resource name; missing values treated as empty string, "nd", and "NaN"; duplicate headers deduplicated
- Converted DateTime field from "%m/%d/%y %H:%M" to "%Y-%m-%dT%H:%M" datetime format, stored back to DateTime field
- Edited row 57: set Longitude to "-81.97959" from "81.97959"
- Renamed deduplicated fields: "n (1)" to "n_dFe", "n (2)" to "n_d56Fe", "DateTime" to "DateTime_Local", "2SD" to "SD_2", to comply with BCO-DMO naming conventions (parameter should not start with number)
- Converted DateTime_Local from "%Y-%m-%dT%H:%M" (America/New_York) to "%Y-%m-%dT%H:%MZ" (UTC), stored in new field DateTime_UTC
- Exported file to "995970_v1_sting_fe_and_fe_isotopes.csv"
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
Diver
Diver
PI Supplied Instrument Name: Diver PI Supplied Instrument Description:Divers, using acid-cleaned teflon tubing attached to a trace metal clean diaphragm pump. Instrument Name: Diving Mask and Snorkel Instrument Short Name: Instrument Description: A diving mask (also half mask, dive mask or scuba mask) is an item of diving equipment that allows underwater divers, including, scuba divers, free-divers, and snorkelers to see clearly underwater.
Snorkel: A breathing apparatus for swimmers and surface divers that allows swimming or continuous use of a face mask without lifting the head to breathe, consisting of a tube that curves out of the mouth and extends above the surface of the water.
Thermo Neptune Multicollecter Inductively Coupled Plasma Mass Spectrometer
Thermo Neptune Multicollecter Inductively Coupled Plasma Mass Spectrometer
PI Supplied Instrument Name: Thermo Neptune Multicollecter Inductively Coupled Plasma Mass Spectrometer PI Supplied Instrument Description:Concentration and isotope analyses were performed on a Thermo Neptune Plus MC-ICPMS (Multicollecter Inductively Coupled Plasma Mass Spectrometer) in the Tampa Bay Plasma Facility at the University of South Florida using the double spike technique via a ~100 uL min-1 PFA nebulizer and Apex Ω introduction introduction system, Pt Jet Sampler cone and an Al X skimmer cone. Instrument Name: Inductively Coupled Plasma Mass Spectrometer Instrument Short Name:ICP Mass Spec Instrument Description: An ICP Mass Spec is an instrument that passes nebulized samples into an inductively-coupled gas plasma (8-10000 K) where they are atomized and ionized. Ions of specific mass-to-charge ratios are quantified in a quadrupole mass spectrometer. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB15/
Trace metal clean diaphragm pump
Trace metal clean diaphragm pump
PI Supplied Instrument Name: Trace metal clean diaphragm pump PI Supplied Instrument Description:Divers, using acid-cleaned teflon tubing attached to a trace metal clean diaphragm pump. Instrument Name: Pump Instrument Short Name: Instrument Description: A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps