http://lod.bco-dmo.org/id/dataset/965250
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
2025-06-16
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Sediment geochemistry and microbial metabolic activity data on cryptic methane cycling in the Carpinteria Salt Marsh Reserve, California from sampling in July of 2019
2025-06-16
publication
2025-06-16
revision
Marine Biological Laboratory/Woods Hole Oceanographic Institution Library (MBLWHOI DLA)
2025-06-18
publication
https://doi.org/10.26008/1912/bco-dmo.965250.1
Tina Treude
University of California-Los Angeles
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: Treude, T., Krause, S. (2025) Sediment geochemistry and microbial metabolic activity data on cryptic methane cycling in the Carpinteria Salt Marsh Reserve, California from sampling in July of 2019. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2025-06-16 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.965250.1 [access date]
Methods and Sampling: <p>The top 15 to 20 cm of sediment at each station was collected in large (10 cm i.d.) and small (2.6 cm i.d.) polycarbonate push cores. Push cores were carefully inserted into sediment by hand including approximately 5 cm overlying water. Large push cores were inserted approximately 20 cm from each other, while small push cores were inserted approximately 15 cm from each other to provide sufficient space for push core extraction. Sediment surrounding the push cores was carefully removed to place a metal plate under the bottom to safely extract the push cores. Any air headspace within the push cores were filled bubble-free with overlying-water from the station location along the creek or hypersaline pool and sealed with rubber stoppers and electrical tape. Sediment push cores were transported to the home laboratory on the same day, stored in the dark at room temperature and processed within 1 d to 1 week of collection, depending on the analysis type.</p>
<p>One day after collection, one large push core from each station was selected for porewater geochemistry analysis. At all stations the top layer of the sediment was sliced at 1.5 cm followed by 1 cm increments due to natural slopes found at the sediment surfaces during the time of sampling. All sediment was sliced under a constant flow of argon gas to minimize oxidation of oxygen-sensitive substrates. The sediment sections were transferred to pre-argon flushed 50 mL centrifuge vials and centrifuged at 4300 <em>g</em> for 20 mins. Immediately after centrifugation, the separated porewater was analyzed spectrographically for dissolved sulfide according to (Cline, 1969) and iron (II) according to (Grasshoff et al., 1999) using a Shimadzu UV-Spectrophotometer (UV-1800) equipped with a sipper unit. The remaining porewater was frozen (-30 °C) and later measured for dissolved porewater sulfate and chloride concentrations.&nbsp;</p>
<p>Porewater sulfate and chloride was determined using an ion chromatograph (Metrohm 761) (Dale et al., 2015). Analytical precision of these measurements was &lt;1% based on repeated analysis of IAPSO seawater standards. Absolute detection limit of sulfate was 1 mM, which corresponds to 30 mM in the undiluted sample. Porewater salinity at each station was calculated from chlorinity using Knudson’s equation (Salinity = 1.805 * Chlorinity) assuming that the major ionic ratios in the porewater and in seawater are similar (Knudsen, 1901).&nbsp;</p>
<p>For methane concentrations, porosity/density, solid-phase carbon/nitrogen, and molecular analysis, a separate large push core from each station, the top 1.5 cm was sliced followed by 1 cm increments because of natural slopes at the sediment surface found at the time of sampling. For methane concentrations, 2 mL of sediment at each interval was subsampled using a 3 mL cut-off plastic syringe and transferred to a 12 mL glass serum vial filled with 5 mL of 5% NaOH and sealed with grey butyl rubber stoppers. Headspace methane concentrations were later determined using a Shimadzu gas chromatograph (GC-2014) equipped with a packed Haysep D and flame ionizer detector. The column was heated to 80 °C and ultra-high pure helium was used as the carrier gas, set to 12 mL per minute. A methane standard (Scotty Analyzed Gases) was used to calibrate for methane concentrations with a ± 5% precision.</p>
<p>For porosity and density, 8 mL of sediment was collected from each 1 cm layer using a 10 mL plastic cut-off syringe, transferred to pre-weighed plastic 10 mL vials (Wheaton). The wet samples were then weighed and then stored at 4 °C. The samples were later dried at 75 °C for 72 hrs and then reweighed. Sediment porosity was determined by subtracting the dry sediment weight from the wet sediment weight and dividing by the total volume. Sediment density was determined by dividing the wet weight by the total volume of the sample.<br />
<br />
Within the one day of collection, one small sediment whole round push core from each station was used to determine sulfate-reduction rates (SRR) &nbsp;at the home laboratory. Radioactive, carrier-free 35S- SO42- sulfate (35S-SO42-; dissolved in MilliQ water, injection volume 10 µL, activity 260 KBq, specific activity 1.59 TBq mg-1 ) was injected into the whole-round cores at 1 cm intervals and incubated at room temperature and in the dark following (Jørgensen, 1978) . The incubation was stopped after ~24 hours. Sediment samples (including controls) were transferred, preserved, and stored according to Krause and Treude (2021). &nbsp;Samples were analyzed using the cold-chromium distillation method and the results from the analysis were used to calculate the sulfate reduction rates according to (Kallmeyer et al., 2004).<br />
<br />
The present study aimed to follow the methane production by methanogenesis from mono-methylamine (hereafter abbreviated MG-MMA) and the subsequent oxidation of the methane to dissolved inorganic carbon (DIC) by anaerobic oxidation of methane (hereafter abbreviated AOM-MMA) (i.e., cryptic methane cycling) in salt marsh sediments across a salinity gradient. To find evidence of concurrent MG-MMA and AOM-MMA, one small whole round core from each station was injected with radiolabeled 14C-mono-methylamine (14C-MMA) (14C-mono-methylamine dissolved in 1 mL water, injection volume 10 µL, activity 220 KBq, specific activity 1.85-2.22 GBq mmol-1) at 1-cm intervals according to (Krause and Treude, 2021) &nbsp;and stored at room temperature and in the dark for 24 hrs. Incubations were terminated by slicing the sediment at 1-cm intervals into 50 mL wide-mouth glass crimp vials filled with 20 mL of 5% NaOH. After transfer of the sample, vials were immediately sealed with a red butyl stopper and crimped with an aluminum crimp. Control samples were prepared by sectioning the top 5 cm of a separate whole round core from each station in 1-cm intervals into 50 mL wide mouth vials filled with 20 mL of 5% NaOH prior to radiotracer addition. Vials were shaken thoroughly for 1 min to ensure complete biological inactivity and stored upside down at room temperature till further processing. The residual 14C-MMA in the liquid, the 14C-CH4 in the headspace of the sample vials produced by MG-MMA, and the 14C-TIC in the sediments as a result of AOM-MMA samples were determined by the analysis according to (Krause and Treude, 2021).&nbsp;<br />
<br />
To account for the 14C-MMA binding to mineral surfaces (Wang and Lee, 1993, 1994; Xiao et al., 2022), we determined the recovery factor (RF) for the sediment from stations BL, BH and M following the procedure of Krause and Treude (2021). For the HP station, the RF factor previously determined by Krause and Treude (2021) was applied.&nbsp;<br />
<br />
Estimates of metabolic rates of MG-MMA and AOM-MMA were calculated from the results of the 14C-MMA incubations. Natural concentrations of mono-methylamine in the sediment porewater were detectable (&gt; 3 µM) but were below the quantification limit (10 µM). To enable rate calculations for MG-MMA (Eq. 1), we assumed an MMA concentration of 3 µM for all samples, i.e., the detection limits of the NMR analysis. For calculation, please see Krause and Treude (2021). Results from the 14C-MMA incubations were also used to estimate the AOM-MMA rates according to Krause and Treude (2021).<br />
<br />
AOM rates from 14C-CH4 (AOM-CH4) were determined by injecting radiolabeled 14C-CH4 (14C-CH4 dissolved in anoxic MilliQ, injection volume 10 µL, activity 5 KBq, Specific activity 1.852.22 GBq mmol-1) directly into a separate small whole round core from each station at 1-cm intervals. Incubations were stopped after ~24 hours and stored at room temperature until further processing, similar to section 2.6. Sediments were then analyzed in the laboratory using oven combustion (Treude et al., 2005) and acidification/shaking (Joye et al., 2004). The radioactivity captured after the headspace combustion and acidification and shaking analysis were determined by liquid scintillation counting.&nbsp;</p>
<p>Metabolic data from radiotracer incubations were used to calculate metabolic rate constants (k) to compare relative turnover of MMA and CH4. We define the rate constants as the metabolic products divided by the sum of the metabolic reactants and products, divided by the incubation time (Krause et al., 2023).</p>
Funding provided by NSF Division of Earth Sciences (NSF EAR) Award Number: EAR-1852912 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=1852912
completed
Tina Treude
University of California-Los Angeles
310-267-5213
Department of Earth, Planetary, and Space Sciences 595 Charles E. Young Drive, East
Los Angeles
CA
90095-1567
USA
ttreude@g.ucla.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Date
Time_Local_PST
Time_UTC
ISO_DateTime_UTC
Site_Name
Latitude
Longitude
Pushcore_Inner_Diameter
Sediment_Depth
Porewater_Sulfate
Salinity
Porewater_Iron_II
Porewater_Sulfide
Porosity
Methane
Sulfate_Reduction
AOM_CH4
AOM_MMA
MG_MMA
AOM_CH4_k
AOM_MMA_k
MG_MMA_k
Shimadzu gas chromatograph (GC-2014)
Metrohm 761
Shimadzu UV-Spectrophotometer (UV-1800) equipped with a sipper unit
theme
None, User defined
date
time_local
time of day
ISO_DateTime_UTC
site
latitude
longitude
diameter
depth core
sulfate
salinity
Iron
sulfide
sediment porosity
methane
No BCO-DMO term
oxidation
featureType
BCO-DMO Standard Parameters
Gas Chromatograph
Ion Chromatograph
Push Corer
UV Spectrophotometer-Shimadzu
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.
Deciphering the Cryptic Cycling of Methane in Sediments of a Coastal Wetland
https://osprey.bco-dmo.org/project/810674
Deciphering the Cryptic Cycling of Methane in Sediments of a Coastal Wetland
<p><em>NSF Award Abstract:</em><br />
This research project investigates the close relationship between methane production and consumption in sediments by microbes in the oxygen-free zone of a coastal wetland in Southern California. The direct exchange of methane between those two closely related microbial groups, which has been named "cryptic methane cycling", has only recently been identified and little is known about its importance in reducing methane emissions from coastal wetlands. This research will reveal how carbon moves between the two types of microbes, and will identify the microbes involved. It will also reveal the important metabolic reactions responsible and the balance between methane production and consumption under different environmental conditions. Towards broader impacts, this project will provide training for two undergraduate and one graduate student in interdisciplinary wetland science and state of the art laboratory methods. A new freshmen course on global methane emissions will bring undergraduate students into the field to provide education on local coastal wetland environments. Results of the project will be disseminated to public and academic groups and will provide a better understanding of methane production and consumption in coastal wetlands.</p>
<p>Concentrations of atmospheric methane have more than doubled since the pre-industrial era, hence we urgently need to understand the mechanisms that control the emission of this potent greenhouse gas. Recent studies have provided the first evidence for the simultaneous microbial production and consumption of methane in the sulfate reduction zone of organic-rich sediments, a process named the "cryptic methane cycle." In this process, methane is proposed to be passed directly from methylotrophic methanogenesis to anaerobic oxidation of methane (AOM). However, little is known about the identity of the organisms involved, the trail of carbon from one metabolism to the other, or the environmental net result of the two processes. Without the details of this metabolic relationship, methane budgets of sediments remain incomplete. Coastal wetlands are of particular interest for the study of cryptic methane cycling, because their organic and sulfate rich sediments promote the production of methylated substrates for methylotrophic methanogenesis and provide electron acceptors for AOM. Yet, anaerobic microbial removal of methane from this ecosystem, particularly along the sulfate gradient between ocean and land, is still not well understood. Towards intellectual merit, this study elucidates the identity of methanogenic and methanotrophic archaea involved in cryptic methane cycling in a coastal wetland as well as the selection of electron acceptors that fuel methane removal in this metabolic relationship. The research provides new metabolic clues to unravel the versatility of the enzymatic machinery that drives methanogenesis and AOM. By capturing environmental factors that control the balance between the two processes working in close proximity, the results of this work further provide an enhanced understanding of methane dynamics in coastal wetland sediments. This information can be applied to biogeochemical models to improve the prediction of methane emissions from this ecosystem, which is found throughout the global coastal zone. Towards broader impacts, the research provides training in innovative analytical and experimental techniques to two undergraduate and one graduate student. The project further engages 20 undergraduates per year in a newly developed freshman seminar, "Methane - the Other Greenhouse Problem" including a field trip to the local wetland. The goal of the seminar will be to educate students, including those not entering STEM fields, about global sources and sinks of methane and its involvement in global warming now and in the future. Results of this study will be broadly disseminated to educational and public outreach platforms, such as high schools, community colleges, and environmental non-profits to teach scientific methodologies, concepts of biogeochemical cycling, and enhance the appreciation of this vital coastal environment.</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>
Cryptic CH4 Cycling
largerWorkCitation
project
eng; USA
oceans
-119.53665
-119.53366
34.39873
34.40351
2019-07-09
2019-07-09
Carpinteria Salt Marsh Reserve, California, USA
0
BCO-DMO catalogue of parameters from Sediment geochemistry and microbial metabolic activity data on cryptic methane cycling in the Carpinteria Salt Marsh Reserve, California from sampling in July of 2019
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/965274.rdf
Name: Date
Units: unitless
Description: <p>Date of sampling</p>
http://lod.bco-dmo.org/id/dataset-parameter/965275.rdf
Name: Time_Local_PST
Units: unitless
Description: <p>Time of sampling. local time zone, Pacific Standard Time (PST)</p>
http://lod.bco-dmo.org/id/dataset-parameter/965276.rdf
Name: Time_UTC
Units: unitless
Description: <p>Time of sampling (UTC time zone)</p>
http://lod.bco-dmo.org/id/dataset-parameter/965277.rdf
Name: ISO_DateTime_UTC
Units: unitless
Description: <p>Datetime with timezone of sampling (ISO format, UTC time zone)</p>
http://lod.bco-dmo.org/id/dataset-parameter/965278.rdf
Name: Site_Name
Units: unitless
Description: <p>Name given to the sampling site in the Carpinteria Salt Marsh Reserve</p>
http://lod.bco-dmo.org/id/dataset-parameter/965279.rdf
Name: Latitude
Units: decimal degrees
Description: <p>Latitude</p>
http://lod.bco-dmo.org/id/dataset-parameter/965280.rdf
Name: Longitude
Units: decimal degrees
Description: <p>Longitude</p>
http://lod.bco-dmo.org/id/dataset-parameter/965281.rdf
Name: Pushcore_Inner_Diameter
Units: centimeters (cm)
Description: <p>Inner diameter of the sampling coreliner</p>
http://lod.bco-dmo.org/id/dataset-parameter/965282.rdf
Name: Sediment_Depth
Units: centimeters (cm)
Description: <p>Depth section in the sediment</p>
http://lod.bco-dmo.org/id/dataset-parameter/965283.rdf
Name: Porewater_Sulfate
Units: millimolar (mM, mmol L-1)
Description: <p>Sulfate dissolved in sediment porewater</p>
http://lod.bco-dmo.org/id/dataset-parameter/965284.rdf
Name: Salinity
Units: Practical Salinity Units (PSU)
Description: <p>Salinity of the porewater</p>
http://lod.bco-dmo.org/id/dataset-parameter/965285.rdf
Name: Porewater_Iron_II
Units: micromoles per liter (umol L-1)
Description: <p>Iron (Fe2+) dissolved in the sediment porewater</p>
http://lod.bco-dmo.org/id/dataset-parameter/965286.rdf
Name: Porewater_Sulfide
Units: micromoles per liter (umol L-1)
Description: <p>Total Sulfide (H2S, HS-, S2-) dissolved in sediment porewater</p>
http://lod.bco-dmo.org/id/dataset-parameter/965287.rdf
Name: Porosity
Units: volume of void-space over total volume (v/v)
Description: <p>Water content of the sediment (expressed as void volume fraction)</p>
http://lod.bco-dmo.org/id/dataset-parameter/965288.rdf
Name: Methane
Units: micromoles per liter (umol L-1)
Description: <p>Methane per volume wet sediment</p>
http://lod.bco-dmo.org/id/dataset-parameter/965289.rdf
Name: Sulfate_Reduction
Units: nanomoles per cubic centimeter per day (nmol cm-3 d-1)
Description: <p>Microbial sulfate reduction per volume wet sediment determined by 35S-sulfate incubations</p>
http://lod.bco-dmo.org/id/dataset-parameter/965290.rdf
Name: AOM_CH4
Units: nanomoles per cubic centimeter per day (nmol cm-3 d-1)
Description: <p>Microbial anaerobic oxidation of methane (AOM) per volume wet sediment determined by 14C-methane incubations</p>
http://lod.bco-dmo.org/id/dataset-parameter/965291.rdf
Name: AOM_MMA
Units: nanomoles per cubic centimeter per day (nmol cm-3 d-1)
Description: <p>Microbial anaerobic oxidation of methane (AOM) per volume wet sediment determined via 14C-monomethylamine</p>
http://lod.bco-dmo.org/id/dataset-parameter/965292.rdf
Name: MG_MMA
Units: nanomoles per cubic centimeter per day (nmol cm-3 d-1)
Description: <p>Microbial methanogenesis per volume wet sediment determined via 14C-mono-methylamine</p>
http://lod.bco-dmo.org/id/dataset-parameter/965293.rdf
Name: AOM_CH4_k
Units: per day (d-1)
Description: <p>Rate constant of anaerobic oxidation of methane (AOM) from 14C-methane turnover</p>
http://lod.bco-dmo.org/id/dataset-parameter/965294.rdf
Name: AOM_MMA_k
Units: per day (d-1)
Description: <p>Rate constant of anaerobic oxidation of methane (AOM) from 14C-methane turnover of methane produced from 14C-monomethylamine</p>
http://lod.bco-dmo.org/id/dataset-parameter/965295.rdf
Name: MG_MMA_k
Units: per day (d-1)
Description: <p>Rate constant of methanogenesis from 14C-monomethylamine turnover</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
30939
https://darchive.mblwhoilibrary.org/server/api/core/bitstreams/a836ad70-703a-4818-a541-b8ad069ee0ff/content
download
https://doi.org/10.26008/1912/bco-dmo.965250.1
download
onLine
dataset
<p>The top 15 to 20 cm of sediment at each station was collected in large (10 cm i.d.) and small (2.6 cm i.d.) polycarbonate push cores. Push cores were carefully inserted into sediment by hand including approximately 5 cm overlying water. Large push cores were inserted approximately 20 cm from each other, while small push cores were inserted approximately 15 cm from each other to provide sufficient space for push core extraction. Sediment surrounding the push cores was carefully removed to place a metal plate under the bottom to safely extract the push cores. Any air headspace within the push cores were filled bubble-free with overlying-water from the station location along the creek or hypersaline pool and sealed with rubber stoppers and electrical tape. Sediment push cores were transported to the home laboratory on the same day, stored in the dark at room temperature and processed within 1 d to 1 week of collection, depending on the analysis type.</p>
<p>One day after collection, one large push core from each station was selected for porewater geochemistry analysis. At all stations the top layer of the sediment was sliced at 1.5 cm followed by 1 cm increments due to natural slopes found at the sediment surfaces during the time of sampling. All sediment was sliced under a constant flow of argon gas to minimize oxidation of oxygen-sensitive substrates. The sediment sections were transferred to pre-argon flushed 50 mL centrifuge vials and centrifuged at 4300 <em>g</em> for 20 mins. Immediately after centrifugation, the separated porewater was analyzed spectrographically for dissolved sulfide according to (Cline, 1969) and iron (II) according to (Grasshoff et al., 1999) using a Shimadzu UV-Spectrophotometer (UV-1800) equipped with a sipper unit. The remaining porewater was frozen (-30 °C) and later measured for dissolved porewater sulfate and chloride concentrations.&nbsp;</p>
<p>Porewater sulfate and chloride was determined using an ion chromatograph (Metrohm 761) (Dale et al., 2015). Analytical precision of these measurements was &lt;1% based on repeated analysis of IAPSO seawater standards. Absolute detection limit of sulfate was 1 mM, which corresponds to 30 mM in the undiluted sample. Porewater salinity at each station was calculated from chlorinity using Knudson’s equation (Salinity = 1.805 * Chlorinity) assuming that the major ionic ratios in the porewater and in seawater are similar (Knudsen, 1901).&nbsp;</p>
<p>For methane concentrations, porosity/density, solid-phase carbon/nitrogen, and molecular analysis, a separate large push core from each station, the top 1.5 cm was sliced followed by 1 cm increments because of natural slopes at the sediment surface found at the time of sampling. For methane concentrations, 2 mL of sediment at each interval was subsampled using a 3 mL cut-off plastic syringe and transferred to a 12 mL glass serum vial filled with 5 mL of 5% NaOH and sealed with grey butyl rubber stoppers. Headspace methane concentrations were later determined using a Shimadzu gas chromatograph (GC-2014) equipped with a packed Haysep D and flame ionizer detector. The column was heated to 80 °C and ultra-high pure helium was used as the carrier gas, set to 12 mL per minute. A methane standard (Scotty Analyzed Gases) was used to calibrate for methane concentrations with a ± 5% precision.</p>
<p>For porosity and density, 8 mL of sediment was collected from each 1 cm layer using a 10 mL plastic cut-off syringe, transferred to pre-weighed plastic 10 mL vials (Wheaton). The wet samples were then weighed and then stored at 4 °C. The samples were later dried at 75 °C for 72 hrs and then reweighed. Sediment porosity was determined by subtracting the dry sediment weight from the wet sediment weight and dividing by the total volume. Sediment density was determined by dividing the wet weight by the total volume of the sample.<br />
<br />
Within the one day of collection, one small sediment whole round push core from each station was used to determine sulfate-reduction rates (SRR) &nbsp;at the home laboratory. Radioactive, carrier-free 35S- SO42- sulfate (35S-SO42-; dissolved in MilliQ water, injection volume 10 µL, activity 260 KBq, specific activity 1.59 TBq mg-1 ) was injected into the whole-round cores at 1 cm intervals and incubated at room temperature and in the dark following (Jørgensen, 1978) . The incubation was stopped after ~24 hours. Sediment samples (including controls) were transferred, preserved, and stored according to Krause and Treude (2021). &nbsp;Samples were analyzed using the cold-chromium distillation method and the results from the analysis were used to calculate the sulfate reduction rates according to (Kallmeyer et al., 2004).<br />
<br />
The present study aimed to follow the methane production by methanogenesis from mono-methylamine (hereafter abbreviated MG-MMA) and the subsequent oxidation of the methane to dissolved inorganic carbon (DIC) by anaerobic oxidation of methane (hereafter abbreviated AOM-MMA) (i.e., cryptic methane cycling) in salt marsh sediments across a salinity gradient. To find evidence of concurrent MG-MMA and AOM-MMA, one small whole round core from each station was injected with radiolabeled 14C-mono-methylamine (14C-MMA) (14C-mono-methylamine dissolved in 1 mL water, injection volume 10 µL, activity 220 KBq, specific activity 1.85-2.22 GBq mmol-1) at 1-cm intervals according to (Krause and Treude, 2021) &nbsp;and stored at room temperature and in the dark for 24 hrs. Incubations were terminated by slicing the sediment at 1-cm intervals into 50 mL wide-mouth glass crimp vials filled with 20 mL of 5% NaOH. After transfer of the sample, vials were immediately sealed with a red butyl stopper and crimped with an aluminum crimp. Control samples were prepared by sectioning the top 5 cm of a separate whole round core from each station in 1-cm intervals into 50 mL wide mouth vials filled with 20 mL of 5% NaOH prior to radiotracer addition. Vials were shaken thoroughly for 1 min to ensure complete biological inactivity and stored upside down at room temperature till further processing. The residual 14C-MMA in the liquid, the 14C-CH4 in the headspace of the sample vials produced by MG-MMA, and the 14C-TIC in the sediments as a result of AOM-MMA samples were determined by the analysis according to (Krause and Treude, 2021).&nbsp;<br />
<br />
To account for the 14C-MMA binding to mineral surfaces (Wang and Lee, 1993, 1994; Xiao et al., 2022), we determined the recovery factor (RF) for the sediment from stations BL, BH and M following the procedure of Krause and Treude (2021). For the HP station, the RF factor previously determined by Krause and Treude (2021) was applied.&nbsp;<br />
<br />
Estimates of metabolic rates of MG-MMA and AOM-MMA were calculated from the results of the 14C-MMA incubations. Natural concentrations of mono-methylamine in the sediment porewater were detectable (&gt; 3 µM) but were below the quantification limit (10 µM). To enable rate calculations for MG-MMA (Eq. 1), we assumed an MMA concentration of 3 µM for all samples, i.e., the detection limits of the NMR analysis. For calculation, please see Krause and Treude (2021). Results from the 14C-MMA incubations were also used to estimate the AOM-MMA rates according to Krause and Treude (2021).<br />
<br />
AOM rates from 14C-CH4 (AOM-CH4) were determined by injecting radiolabeled 14C-CH4 (14C-CH4 dissolved in anoxic MilliQ, injection volume 10 µL, activity 5 KBq, Specific activity 1.852.22 GBq mmol-1) directly into a separate small whole round core from each station at 1-cm intervals. Incubations were stopped after ~24 hours and stored at room temperature until further processing, similar to section 2.6. Sediments were then analyzed in the laboratory using oven combustion (Treude et al., 2005) and acidification/shaking (Joye et al., 2004). The radioactivity captured after the headspace combustion and acidification and shaking analysis were determined by liquid scintillation counting.&nbsp;</p>
<p>Metabolic data from radiotracer incubations were used to calculate metabolic rate constants (k) to compare relative turnover of MMA and CH4. We define the rate constants as the metabolic products divided by the sum of the metabolic reactants and products, divided by the incubation time (Krause et al., 2023).</p>
Specified by the Principal Investigator(s)
* Sheet 1 of submitted file "Krause et al., CSMR2019_datasets_BCO-DMO_Revised.xlsx" was imported into the BCO-DMO data system for this dataset. Values "NA" imported as missing data values. Table will appear as Data File: 965250_v1_cryptic-ch4-cycling.csv (along with other download format options).
Missing Data Identifiers:
* In the BCO-DMO data system missing data identifiers are displayed according to the format of data you access. For example, in csv files it will be blank (null) values. In Matlab .mat files it will be NaN values. When viewing data online at BCO-DMO, the missing value will be shown as blank (null) values.
* Column names adjusted to conform to BCO-DMO naming conventions designed to support broad re-use by a variety of research tools and scripting languages. [Only numbers, letters, and underscores. Can not start with a number]
* ISO DateTime with timezone (UTC) column added
* latitude and longitude rounded to 5 decimal places
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
Shimadzu gas chromatograph (GC-2014)
Shimadzu gas chromatograph (GC-2014)
PI Supplied Instrument Name: Shimadzu gas chromatograph (GC-2014) PI Supplied Instrument Description:Headspace methane concentrations were later determined using a Shimadzu gas chromatograph (GC-2014) equipped with a packed Haysep D and flame ionizer detector Instrument Name: Gas Chromatograph Instrument Short Name:Gas Chromatograph Instrument Description: Instrument separating gases, volatile substances, or substances dissolved in a volatile solvent by transporting an inert gas through a column packed with a sorbent to a detector for assay. (from SeaDataNet, BODC) Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB02/
Metrohm 761
Metrohm 761
PI Supplied Instrument Name: Metrohm 761 PI Supplied Instrument Description:ion chromatograph (Metrohm 761) (Dale et al., 2015) Instrument Name: Ion Chromatograph Instrument Short Name:Ion Chromatograph Instrument Description: Ion chromatography is a form of liquid chromatography that measures concentrations of ionic species by separating them based on their interaction with a resin. Ionic species separate differently depending on species type and size. Ion chromatographs are able to measure concentrations of major anions, such as fluoride, chloride, nitrate, nitrite, and sulfate, as well as major cations such as lithium, sodium, ammonium, potassium, calcium, and magnesium in the parts-per-billion (ppb) range. (from http://serc.carleton.edu/microbelife/research_methods/biogeochemical/ic.html)
PI Supplied Instrument Name: Instrument Name: Push Corer Instrument Short Name: Instrument Description: Capable of being performed in numerous environments, push coring is just as it sounds. Push coring is simply pushing the core barrel (often an aluminum or polycarbonate tube) into the sediment by hand. A push core is useful in that it causes very little disturbance to the more delicate upper layers of a sub-aqueous sediment.
Description obtained from: http://web.whoi.edu/coastal-group/about/how-we-work/field-methods/coring/
Shimadzu UV-Spectrophotometer (UV-1800) equipped with a sipper unit
Shimadzu UV-Spectrophotometer (UV-1800) equipped with a sipper unit
PI Supplied Instrument Name: Shimadzu UV-Spectrophotometer (UV-1800) equipped with a sipper unit Instrument Name: UV Spectrophotometer-Shimadzu Instrument Short Name:UV Spectrophotometer-Shimadzu Instrument Description: The Shimadzu UV Spectrophotometer is manufactured by Shimadzu Scientific Instruments (ssi.shimadzu.com). Shimadzu manufacturers several models of spectrophotometer; refer to dataset for make/model information. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB20/