http://lod.bco-dmo.org/id/dataset/854297
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
2021-06-23
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Benthic flux data from sediment cores collected in the York River Estuary, VA in 2020
2021-06-23
publication
2021-06-23
revision
Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)
2021-08-30
publication
https://doi.org/10.26008/1912/bco-dmo.854297.1
Iris C. Anderson
Virginia Institute of Marine Science
principalInvestigator
Mark J. Brush
Virginia Institute of Marine Science
principalInvestigator
Kimberly S. Reece
Virginia Institute of Marine Science
principalInvestigator
Bongkeun Song
Virginia Institute of Marine Science
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: Anderson, I. C., Brush, M. J., Reece, K., Song, B. (2021) Benthic flux data from sediment cores collected in the York River Estuary, VA in 2020. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2021-06-23 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.854297.1 [access date]
Benthic flux Dataset Description: Methods and Sampling: <p><strong>Benthic Fluxes:</strong><br />
In January, June, August, and October of 2020, triplicate sediment cores (5.7 cm diameter, 10 cm height) were collected from three shoal stations and three channel stations during bimonthly cruises of the York River Estuary (YRE) on 24ft Carolina skiffs. In July and September 2020, triplicate sediment cores of the same parameters were collected from three shoal and three channel stations in the lower YRE before and after the occurrence of intense phytoplankton blooms. Depths at which the sediment cores were sampled were about 1m at the shoal stations and 10m at the channel stations. After collection, the sediment cores were stored in coolers on ice. As sampling at all of the stations took six hours, the cores were stored in coolers for one to five hours depending on when a particular station was sampled. After transport, the sediment cores were placed in an environmental chamber under <em>in situ</em> conditions of temperature in buckets filled with ambient YRE water with constant stirring. The cores were left in the dark overnight to equilibrate. The following day, the overlying water in the cores was replaced with filter-sterilized (0.2 μm) site water and capped. The cores were then incubated for seven hours (three hours in the dark, followed by 1 hour for equilibration with light, followed by three hours in the light). Ambient light conditions were simulated by high-intensity UV/ VIS lamps. Dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), dissolved inorganic nitrogen and phosphorus (DIN), and dissolved organic nitrogen (DON) samples were collected every hour throughout the six-hour incubation. DOC, DIN, and DON samples were filtered through 0.45 μm polysulfone filters. For DIC, 12 mL of water were collected and preserved with 0.1 μL of mercuric chloride. Dissolved oxygen (DO) concentrations were monitored every hour using a PreSens OXY-4 SMA (G2) oxygen sensor. Water was simultaneously replaced during sampling with filter sterilized (0.2 μm) site water.</p>
<p>One additional sediment core (5 cm diameter) was taken at each shoal and channel station for sediment characterization (Anderson et al. 2003) and benthic chlorophyll-a analysis. After collection, one of the cores from each site was sectioned at 0-2cm and 2-5 cm. Half of each section was collected in whirlpak bags filled with a volume of KCl equal to 2x the volume of the sediment (35mL for 0-2cm section, 50mL for 2-5cm section), shaken for one hour, centrifuged, filtered (0.45 μm polysulfone), and analyzed for ammonium (NH₄⁺), nitrate (NO₃⁻), and nitrite (NO₂⁻) on a QuikChem FIA+ 8000 Series Latchet autoanalyzer. The other half of each section (0-2cm and 2-5cm) was used to calculate bulk density, water content, and organic content via measurement of wet weights, dry weights, and combusted weights of the sediment sample. To determine benthic chlorophyll-a concentrations, sediment from each site was sampled <em>in situ</em> at 0-3mm and 3-10mm and frozen until analysis. For analysis, acetone extractant (10 mL) was added to the samples, each sample was sonicated for 30 seconds, and the sonicated samples were placed in a freezer for 24 hours before analysis on a spectrophotometer (Lorenzen 1967, Pinckney et al. 1995; Jeffrey and Welchmeyer 1997).</p>
<p><strong>Benthic N Cycling Rates:</strong><br />
Actual rates of denitrification and DNRA were determined via the isotope pairing technique (IPT) (Murphy et al. 2016). IPT relies on using added ¹⁵NO₃⁻ to water overlying sediments to distinguish between direct, coupled, and actual vs. potential rates of denitrification and DNRA. At the time of core collection, an additional set of two cores (5.7 cm diameter, 10 cm height) were collected from each station and kept in the same conditions as the flux cores to serve as T0 cores for IPT. After the flux experiment described above, the cores were uncapped and left in the dark overnight in buckets filled with ambient YRE water with constant stirring. The following morning, each core was spiked with 5.37 mL of 10 mM 98 atom% ¹⁵NO₃⁻ to bring the concentration of nitrate within the cores to 100 μM. A water sample was collected from each core and analyzed for total NO₃⁻ (¹⁴NO₃⁻ + ¹⁵NO₃⁻). The DO concentrations were measured in each core using a PreSens OXY-4 SMA (G2) oxygen sensor. The T0 cores were left uncapped in the environmental chamber and the remaining cores (TF) were capped and placed in buckets of ambient YRE water for one hour to allow the ¹⁵NO₃⁻ to diffuse to the active zone of denitrification and DNRA. The overlying water in the T0 cores was then be sampled for total NO₃ - and the cores were slurried and sampled for ²⁹N₂ and ³⁰N₂ (12 mL of slurry preserved with 0.1 mL of saturated zinc chloride) and KCl-extractable NH₄⁺ (60 mL of slurry placed in whirlpak bags filled with 17.7 g of powdered KCl). The NH₄⁺ was reduced by the OX/MIMS method (Yin et al. 2014) and ²⁹N₂ and ³⁰N₂ measured by the MIMS. The DO concentrations in the TF cores were monitored using the PreSens OXY – 4 SMA (G2) oxygen sensor) every 30 to 60 minutes until DO concentrations reached no less than 70% of initial concentrations (or a 30% drop). Each core was then uncapped and the overlying water sampled and analyzed for total NO₃⁻. The cores were slurried sampled and analyzed for ²⁹N₂, ³⁰N₂, and ¹⁵NH₄⁺ concentrations as described above.</p>
<p><strong>Instruments:</strong><br />
Nutrient analyses (NO₃, NO₂, NH₄) were performed with a Lachat QuikChem 8000 automated ion analyzer (Lachat Instruments, Milwaukee, WI, USA); detection limits for NO₃, and NH₄, are 0.20 and 0.36 μM, respectively). DIC was analyzed on an Apollo, model AS-C3 (Apollo SciTech, Newark DE); DOC on a Shimadzu TOC-VCSN combustion analyzer, and extracted chlorophyll-a on a Beckman Coulter DU800 Spectrophotometer. ²⁹N₂ and ³⁰N₂ measured by the membrane inlet mass spectrometer (MIMS, Balzers Prisma).</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-1737258 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1737258
completed
Iris C. Anderson
Virginia Institute of Marine Science
757-876-9436
P.O Box 1346
Gloucester Point
VA
23062
USA
iris@vims.edu
pointOfContact
Mark J. Brush
Virginia Institute of Marine Science
804-684-7402
P.O Box 1346
Gloucester Point
VA
23062
USA
brush@vims.edu
pointOfContact
Kimberly S. Reece
Virginia Institute of Marine Science
804-684-7407
P.O Box 1346
Gloucester Point
VA
23062
USA
kreece@vims.edu
pointOfContact
Bongkeun Song
Virginia Institute of Marine Science
804-684-7411
P.O Box 1346
Gloucester Point
VA
23692
USA
songb@vims.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Survey_Type
Date
Station
Station_Type
Depth
Lat
Long
Salinity
Temp
NOx_1
NO3_1
NH4_1
Chl_a
Bulk_Denisty
Percent_OM
NH3_1
NO3_2
DIC_1
DO_1
DOC_1
TDN_1
NH3_2
NO3_3
DIC_2
DO_2
DOC_2
TDN_2
DNRA
DNF
NEM
Apollo model AS-C3
Lachat QuikChem 8000
membrane inlet mass spectrometer (MIMS, Balzers Prisma)
Shimadzu TOC-VCSN
Beckman Coulter DU800 Spectrophotometer
theme
None, User defined
cruise type
date
station
depth
latitude
longitude
salinity
water temperature at measurement depth
nitrate plus nitrite
Nitrate
Ammonium
chlorophyll a
density
No BCO-DMO term
Ammonia
dissolved inorganic Carbon
dissolved Oxygen
dissolved organic Carbon
Total Dissolved Nitrogen
featureType
BCO-DMO Standard Parameters
Apollo SciTech AS-C3 Dissolved Inorganic Carbon (DIC) analyzer
Flow Injection Analyzer
Membrane Inlet Mass Spectrometer
Shimadzu TOC-V Analyzer
Spectrophotometer
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.
Alteration of carbon fluxes by intense phytoplankton blooms in a microtidal estuary
https://osprey.bco-dmo.org/project/747588
Alteration of carbon fluxes by intense phytoplankton blooms in a microtidal estuary
<p><em>NSF Award Abstract:</em><br />
Estuaries, coastal water bodies where rivers mix with ocean water, are hotspots for the processing of carbon and nutrients moving from land to the coastal ocean. Within estuaries land-based nutrient inputs can cause intense blooms of single-celled algae called phytoplankton, which can have significant impacts on the ecosystem. As blooms move down-estuary some of the phytoplankton material is buried on the bottom, and some is decomposed, resulting in low oxygen conditions (hypoxia), harmful to marine life, and production of carbon dioxide (CO2), the major greenhouse gas, which can exchange with the atmosphere. The remaining phytoplankton material can be exported to the ocean. The type and amount of carbon exported from the estuary depend both on its biological activity and physical factors such as fresh water discharge, temperature, and light availability. If phytoplankton production is greater than decomposition, the estuary will take up atmospheric CO2 and export phytoplankton carbon to the coastal ocean. On the other hand, if decomposition is greater than production the estuary will be a source of CO2 to the atmosphere and dissolved CO2 to the coastal ocean. The investigators expect that intense phytoplankton blooms will greatly amplify carbon exchanges with the atmosphere, coastal ocean, and bottom sediments. As intense phytoplankton blooms increase in the future due to increased nutrient inputs and temperature, low oxygen events may become more frequent with potential negative impacts on fisheries and increased export of carbon to the coastal ocean and atmosphere. This study will fill critical gaps identified by the Coastal Carbon Synthesis Program in knowledge of how microtidal estuaries transform and export C to the atmosphere, benthos, and coastal ocean. In addition, there will be a strong teaching and training component to this project, with support for graduate and undergraduate students. The graduate student will be partnered with secondary teachers to gain teaching experience and enrich the middle school educational programs. Summer undergraduate interns will be recruited for a summer program from Hampton University, a historically Black college. There will be public outreach through participation in existing programs at VIMS.</p>
<p>Estuaries serve as critical hotspots for the processing of carbon (C) as it transits from land to the coastal ocean. Recent attempts to synthesize what is known about sources and fates of C in estuaries have noted large data gaps; thus, the role of estuaries, especially those that are microtidal, as important sources of carbon dioxide (CO2) to the atmosphere and total organic carbon (TOC) and dissolved inorganic carbon (DIC) to the coastal ocean, or as a C sink in bottom sediments, remains uncertain. Intensive phytoplankton blooms are becoming increasingly frequent in many estuaries and are likely to have important and yet unknown impacts on the C cycle. The trophic status of an estuary will determine in large part the species of C exported to the atmosphere, bottom sediments, and coastal ocean. The overarching objective of this project is to identify the impacts of intense phytoplankton blooms on C speciation, net C fluxes and exchanges in the Lower York River Estuary (LYRE), a representative mesotrophic, microtidal mid-Atlantic estuary. Metabolic processes are hypothesized to be spatially and temporally dynamic, driving the speciation, abundance, and fates of C in the LYRE. High spatiotemporal resolution sampling in the LYRE will capture rates of C cycling under both baseline conditions throughout most of the year, and during periods when the estuary is perturbed by widespread and intense, but patchy, late summer phytoplankton blooms. The short-term effects of physical drivers (wind, temperature, salinity, fresh water discharge, nutrient and organic carbon loads) and biological drivers (metabolic rates, bacterial and phytoplankton abundances and composition) on C transformations, speciation, and exchanges will be assessed. Expected longer term variations in the C cycle due to anthropogenic and natural disturbances will be predicted through use of modeling. In addition, laboratory manipulations will examine the impacts of specific organisms dominating intensive phytoplankton blooms on benthic metabolism, processing of organic C by the microbial community, and C fluxes to the water column.</p>
LYRE
largerWorkCitation
project
eng; USA
oceans
-76.762
-76.3975
37.2217
37.4847
2020-01-29
2020-10-28
York River Estuary, Virginia
0
BCO-DMO catalogue of parameters from Benthic flux data from sediment cores collected in the York River Estuary, VA in 2020
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/854382.rdf
Name: Survey_Type
Units: unitless
Description: <p>bimonthly or intensive cruise</p>
http://lod.bco-dmo.org/id/dataset-parameter/854383.rdf
Name: Date
Units: unitless
Description: <p>date when the survey took place; format: YYYY-MM-DD</p>
http://lod.bco-dmo.org/id/dataset-parameter/854384.rdf
Name: Station
Units: unitless
Description: <p>numerical station number to differentiate sample locations</p>
http://lod.bco-dmo.org/id/dataset-parameter/854385.rdf
Name: Station_Type
Units: unitless
Description: <p>station type to differentiate between channel and shoal stations</p>
http://lod.bco-dmo.org/id/dataset-parameter/854386.rdf
Name: Depth
Units: meters
Description: <p>depth at which cores were collected</p>
http://lod.bco-dmo.org/id/dataset-parameter/854387.rdf
Name: Lat
Units: decimal degrees North
Description: <p>latitude of sample location</p>
http://lod.bco-dmo.org/id/dataset-parameter/854388.rdf
Name: Long
Units: decimal degrees East
Description: <p>longitude of sample location</p>
http://lod.bco-dmo.org/id/dataset-parameter/854389.rdf
Name: Salinity
Units: unitless
Description: <p>Salinity measured in situ</p>
http://lod.bco-dmo.org/id/dataset-parameter/854390.rdf
Name: Temp
Units: degrees Celsius
Description: <p>Temp measured in situ</p>
http://lod.bco-dmo.org/id/dataset-parameter/854391.rdf
Name: NOx_1
Units: micromolar
Description: <p>sediment nitrate/nitrate concentrations</p>
http://lod.bco-dmo.org/id/dataset-parameter/854392.rdf
Name: NO3_1
Units: micromolar
Description: <p>sediment nitrate concentrations</p>
http://lod.bco-dmo.org/id/dataset-parameter/854393.rdf
Name: NH4_1
Units: micromolar
Description: <p>sediment ammonium concentrations</p>
http://lod.bco-dmo.org/id/dataset-parameter/854394.rdf
Name: Chl_a
Units: milligrams per square meter (mg/m2)
Description: <p>sediment chlorphyll-a concentrations</p>
http://lod.bco-dmo.org/id/dataset-parameter/854395.rdf
Name: Bulk_Denisty
Units: grams dry weight per milliliter (g/mL)
Description: <p>bulk density of sediment</p>
http://lod.bco-dmo.org/id/dataset-parameter/854396.rdf
Name: Percent_OM
Units: unitless (percent)
Description: <p>sediment percent organic matter</p>
http://lod.bco-dmo.org/id/dataset-parameter/854397.rdf
Name: NH3_1
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of ammonium in dark</p>
http://lod.bco-dmo.org/id/dataset-parameter/854398.rdf
Name: NO3_2
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of nitrate in dark</p>
http://lod.bco-dmo.org/id/dataset-parameter/854399.rdf
Name: DIC_1
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of dissolved inorganic carbon in dark</p>
http://lod.bco-dmo.org/id/dataset-parameter/854400.rdf
Name: DO_1
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of dissolved oxygen in dark</p>
http://lod.bco-dmo.org/id/dataset-parameter/854401.rdf
Name: DOC_1
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of dissolved inorganic carbon in dark</p>
http://lod.bco-dmo.org/id/dataset-parameter/854402.rdf
Name: TDN_1
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of total dissolved nitrogen in dark</p>
http://lod.bco-dmo.org/id/dataset-parameter/854403.rdf
Name: NH3_2
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of ammonium in light</p>
http://lod.bco-dmo.org/id/dataset-parameter/854404.rdf
Name: NO3_3
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of nitrate in light</p>
http://lod.bco-dmo.org/id/dataset-parameter/854405.rdf
Name: DIC_2
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of dissolved inorganic carbon in light</p>
http://lod.bco-dmo.org/id/dataset-parameter/854406.rdf
Name: DO_2
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of dissolved oxygen in light</p>
http://lod.bco-dmo.org/id/dataset-parameter/854407.rdf
Name: DOC_2
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of dissolved organic carbon in light</p>
http://lod.bco-dmo.org/id/dataset-parameter/854408.rdf
Name: TDN_2
Units: millimoles per square meter per hour (mmol/m2/hour)
Description: <p>flux of total dissolved nitrogen in light</p>
http://lod.bco-dmo.org/id/dataset-parameter/854409.rdf
Name: DNRA
Units: micromoles per square meter per hour (micromole/m2/hour)
Description: <p>actual rate of dissimilatory nitrate reduction to ammonium</p>
http://lod.bco-dmo.org/id/dataset-parameter/854410.rdf
Name: DNF
Units: micromoles per square meter per hour (micromole/m2/hour)
Description: <p>actual rate of denitrification</p>
http://lod.bco-dmo.org/id/dataset-parameter/854411.rdf
Name: NEM
Units: millimoles oxygen per square meter per day (mmol/m2/day)
Description: <p>calculated rate of benthic net ecosystem metabolism</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
11376
https://darchive.mblwhoilibrary.org/server/api/core/bitstreams/fd9df440-6a39-5706-81e1-d8cf62825889/content
download
https://doi.org/10.26008/1912/bco-dmo.854297.1
download
onLine
dataset
<p><strong>Benthic Fluxes:</strong><br />
In January, June, August, and October of 2020, triplicate sediment cores (5.7 cm diameter, 10 cm height) were collected from three shoal stations and three channel stations during bimonthly cruises of the York River Estuary (YRE) on 24ft Carolina skiffs. In July and September 2020, triplicate sediment cores of the same parameters were collected from three shoal and three channel stations in the lower YRE before and after the occurrence of intense phytoplankton blooms. Depths at which the sediment cores were sampled were about 1m at the shoal stations and 10m at the channel stations. After collection, the sediment cores were stored in coolers on ice. As sampling at all of the stations took six hours, the cores were stored in coolers for one to five hours depending on when a particular station was sampled. After transport, the sediment cores were placed in an environmental chamber under <em>in situ</em> conditions of temperature in buckets filled with ambient YRE water with constant stirring. The cores were left in the dark overnight to equilibrate. The following day, the overlying water in the cores was replaced with filter-sterilized (0.2 μm) site water and capped. The cores were then incubated for seven hours (three hours in the dark, followed by 1 hour for equilibration with light, followed by three hours in the light). Ambient light conditions were simulated by high-intensity UV/ VIS lamps. Dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), dissolved inorganic nitrogen and phosphorus (DIN), and dissolved organic nitrogen (DON) samples were collected every hour throughout the six-hour incubation. DOC, DIN, and DON samples were filtered through 0.45 μm polysulfone filters. For DIC, 12 mL of water were collected and preserved with 0.1 μL of mercuric chloride. Dissolved oxygen (DO) concentrations were monitored every hour using a PreSens OXY-4 SMA (G2) oxygen sensor. Water was simultaneously replaced during sampling with filter sterilized (0.2 μm) site water.</p>
<p>One additional sediment core (5 cm diameter) was taken at each shoal and channel station for sediment characterization (Anderson et al. 2003) and benthic chlorophyll-a analysis. After collection, one of the cores from each site was sectioned at 0-2cm and 2-5 cm. Half of each section was collected in whirlpak bags filled with a volume of KCl equal to 2x the volume of the sediment (35mL for 0-2cm section, 50mL for 2-5cm section), shaken for one hour, centrifuged, filtered (0.45 μm polysulfone), and analyzed for ammonium (NH₄⁺), nitrate (NO₃⁻), and nitrite (NO₂⁻) on a QuikChem FIA+ 8000 Series Latchet autoanalyzer. The other half of each section (0-2cm and 2-5cm) was used to calculate bulk density, water content, and organic content via measurement of wet weights, dry weights, and combusted weights of the sediment sample. To determine benthic chlorophyll-a concentrations, sediment from each site was sampled <em>in situ</em> at 0-3mm and 3-10mm and frozen until analysis. For analysis, acetone extractant (10 mL) was added to the samples, each sample was sonicated for 30 seconds, and the sonicated samples were placed in a freezer for 24 hours before analysis on a spectrophotometer (Lorenzen 1967, Pinckney et al. 1995; Jeffrey and Welchmeyer 1997).</p>
<p><strong>Benthic N Cycling Rates:</strong><br />
Actual rates of denitrification and DNRA were determined via the isotope pairing technique (IPT) (Murphy et al. 2016). IPT relies on using added ¹⁵NO₃⁻ to water overlying sediments to distinguish between direct, coupled, and actual vs. potential rates of denitrification and DNRA. At the time of core collection, an additional set of two cores (5.7 cm diameter, 10 cm height) were collected from each station and kept in the same conditions as the flux cores to serve as T0 cores for IPT. After the flux experiment described above, the cores were uncapped and left in the dark overnight in buckets filled with ambient YRE water with constant stirring. The following morning, each core was spiked with 5.37 mL of 10 mM 98 atom% ¹⁵NO₃⁻ to bring the concentration of nitrate within the cores to 100 μM. A water sample was collected from each core and analyzed for total NO₃⁻ (¹⁴NO₃⁻ + ¹⁵NO₃⁻). The DO concentrations were measured in each core using a PreSens OXY-4 SMA (G2) oxygen sensor. The T0 cores were left uncapped in the environmental chamber and the remaining cores (TF) were capped and placed in buckets of ambient YRE water for one hour to allow the ¹⁵NO₃⁻ to diffuse to the active zone of denitrification and DNRA. The overlying water in the T0 cores was then be sampled for total NO₃ - and the cores were slurried and sampled for ²⁹N₂ and ³⁰N₂ (12 mL of slurry preserved with 0.1 mL of saturated zinc chloride) and KCl-extractable NH₄⁺ (60 mL of slurry placed in whirlpak bags filled with 17.7 g of powdered KCl). The NH₄⁺ was reduced by the OX/MIMS method (Yin et al. 2014) and ²⁹N₂ and ³⁰N₂ measured by the MIMS. The DO concentrations in the TF cores were monitored using the PreSens OXY – 4 SMA (G2) oxygen sensor) every 30 to 60 minutes until DO concentrations reached no less than 70% of initial concentrations (or a 30% drop). Each core was then uncapped and the overlying water sampled and analyzed for total NO₃⁻. The cores were slurried sampled and analyzed for ²⁹N₂, ³⁰N₂, and ¹⁵NH₄⁺ concentrations as described above.</p>
<p><strong>Instruments:</strong><br />
Nutrient analyses (NO₃, NO₂, NH₄) were performed with a Lachat QuikChem 8000 automated ion analyzer (Lachat Instruments, Milwaukee, WI, USA); detection limits for NO₃, and NH₄, are 0.20 and 0.36 μM, respectively). DIC was analyzed on an Apollo, model AS-C3 (Apollo SciTech, Newark DE); DOC on a Shimadzu TOC-VCSN combustion analyzer, and extracted chlorophyll-a on a Beckman Coulter DU800 Spectrophotometer. ²⁹N₂ and ³⁰N₂ measured by the membrane inlet mass spectrometer (MIMS, Balzers Prisma).</p>
Specified by the Principal Investigator(s)
<p><strong>BCO-DMO Processing:</strong><br />
- changed date format to YYYY-MM-DD;<br />
- corrected single longitude value that was positive;<br />
- renamed fields.</p>
Specified by the Principal Investigator(s)
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
Apollo model AS-C3
Apollo model AS-C3
PI Supplied Instrument Name: Apollo model AS-C3 PI Supplied Instrument Description:DIC was analyzed on an Apollo, model AS-C3 (Apollo SciTech, Newark DE). Instrument Name: Apollo SciTech AS-C3 Dissolved Inorganic Carbon (DIC) analyzer Instrument Short Name:Apollo SciTech AS-C3 Instrument Description: A Dissolved Inorganic Carbon (DIC) analyzer, for use in aquatic carbon dioxide parameter analysis of coastal waters, sediment pore-waters, and time-series incubation samples. The analyzer consists of a solid state infrared CO2 detector, a mass-flow controller, and a digital pump for transferring accurate amounts of reagent and sample. The analyzer uses an electronic cooling system to keep the reactor temperature below 3 degrees Celsius, and a Nafion dry tube to reduce the water vapour and keep the analyzer drift-free and maintenance-free for longer. The analyzer can handle sample volumes from 0.1 - 1.5 milliliters, however the best results are obtained from sample volumes between 0.5 - 1 milliliters. It takes approximately 3 minutes per analysis, and measurement precision is plus or minus 2 micromoles per kilogram or higher for surface seawater. It is designed for both land based and shipboard laboratory use.
Lachat QuikChem 8000
Lachat QuikChem 8000
PI Supplied Instrument Name: Lachat QuikChem 8000 PI Supplied Instrument Description:Nutrient analyses (NO₃, NO₂, NH₄) were performed with a Lachat QuikChem 8000 automated ion analyzer (Lachat Instruments, Milwaukee, WI, USA). Instrument Name: Flow Injection Analyzer Instrument Short Name:FIA Instrument Description: An instrument that performs flow injection analysis. Flow injection analysis (FIA) is an approach to chemical analysis that is accomplished by injecting a plug of sample into a flowing carrier stream. FIA is an automated method in which a sample is injected into a continuous flow of a carrier solution that mixes with other continuously flowing solutions before reaching a detector. Precision is dramatically increased when FIA is used instead of manual injections and as a result very specific FIA systems have been developed for a wide array of analytical techniques. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB36/
membrane inlet mass spectrometer (MIMS, Balzers Prisma)
membrane inlet mass spectrometer (MIMS, Balzers Prisma)
PI Supplied Instrument Name: membrane inlet mass spectrometer (MIMS, Balzers Prisma) PI Supplied Instrument Description:²⁹N₂ and ³⁰N₂ were measured by the membrane inlet mass spectrometer (MIMS, Balzers Prisma). Instrument Name: Membrane Inlet Mass Spectrometer Instrument Short Name:MIMS Instrument Description: Membrane-introduction mass spectrometry (MIMS) is a method of introducing analytes into the mass spectrometer's vacuum chamber via a semipermeable membrane.
Shimadzu TOC-VCSN
Shimadzu TOC-VCSN
PI Supplied Instrument Name: Shimadzu TOC-VCSN PI Supplied Instrument Description:DOC was analyzed on a Shimadzu TOC-VCSN combustion analyzer. Instrument Name: Shimadzu TOC-V Analyzer Instrument Short Name:Shimadzu TOC-V Instrument Description: A Shimadzu TOC-V Analyzer measures DOC by high temperature combustion method. Community Standard Description: http://onto.nerc.ac.uk/CAST/124
Beckman Coulter DU800 Spectrophotometer
Beckman Coulter DU800 Spectrophotometer
PI Supplied Instrument Name: Beckman Coulter DU800 Spectrophotometer PI Supplied Instrument Description:Extracted chlorophyll-a was analyzed on a Beckman Coulter DU800 Spectrophotometer. Instrument Name: Spectrophotometer Instrument Short Name:Spectrophotometer Instrument Description: An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB20/