Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures
Microbial oxidation of methane in oxic water bodies is an important control on the amount of dissolved methane which is released from the ocean to the atmosphere. We explored the use of stable isotope methane spikes to quantify methane oxidation rates in Arctic seawater samples. A Picarro G2201-i ca...
Published in: | Limnology and Oceanography: Methods |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2017
|
Subjects: | |
Online Access: | https://epic.awi.de/id/eprint/45456/ https://epic.awi.de/id/eprint/45456/1/Uhlig_et_al-2017-Limnology_and_Oceanography__Methods.pdf https://hdl.handle.net/10013/epic.51638 https://hdl.handle.net/10013/epic.51638.d001 |
id |
ftawi:oai:epic.awi.de:45456 |
---|---|
record_format |
openpolar |
spelling |
ftawi:oai:epic.awi.de:45456 2023-05-15T14:26:41+02:00 Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures Uhlig, Christiane Loose, Brice 2017-07-31 application/pdf https://epic.awi.de/id/eprint/45456/ https://epic.awi.de/id/eprint/45456/1/Uhlig_et_al-2017-Limnology_and_Oceanography__Methods.pdf https://hdl.handle.net/10013/epic.51638 https://hdl.handle.net/10013/epic.51638.d001 unknown https://epic.awi.de/id/eprint/45456/1/Uhlig_et_al-2017-Limnology_and_Oceanography__Methods.pdf https://hdl.handle.net/10013/epic.51638.d001 Uhlig, C. orcid:0000-0001-7278-6522 and Loose, B. (2017) Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures , Limnology & Oceanography: Methods . doi:10.1002/lom3.10199 <https://doi.org/10.1002/lom3.10199> , hdl:10013/epic.51638 EPIC3Limnology & Oceanography: Methods Article isiRev 2017 ftawi 2021-12-24T15:43:17Z Microbial oxidation of methane in oxic water bodies is an important control on the amount of dissolved methane which is released from the ocean to the atmosphere. We explored the use of stable isotope methane spikes to quantify methane oxidation rates in Arctic seawater samples. A Picarro G2201-i cavity ring-down spectrometer was used to determine methane concentration and isotope ratios from headspace samples in foil incubators. The methane mass balance and the change in stable isotope ratios served as independent constraints on methane oxidation. For a fractionation factor of 1.025 oxidation rate constants determined with both methods agreed within 20% for small changes in isotope ratio (e.g., 10‰). For large changes in isotope ratio (e.g., 90‰), which was outside the calibration range, methods diverged. Rate constants down to 0.01 / d could be resolved with high statistical support. Stable isotope infrared spectroscopy to determine methane oxidation in foil incubators (ISMOFI) was successfully tested on under ice seawater from Utqiagvik, Alaska, by repeated sampling from each incubation vessel. Depending on the amount of isotope spike added, we determined oxidation rates of 0.15 ± 0.02 nmol / (L*d) at in situ methane concentration and a maximal oxidation potential of 271 ± 41 nmol / (L*d). The ISMOFI method permits variable incubation durations from days to months in a single incubator. The method is transportable and applicable in a variety of field or seagoing laboratory environments, and it avoids the use of hazardous substances such as radioisotopes and toxic chemicals. Article in Journal/Newspaper Arctic Arctic Arctic Ocean Alaska Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Arctic Arctic Ocean Limnology and Oceanography: Methods 15 8 737 751 |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Microbial oxidation of methane in oxic water bodies is an important control on the amount of dissolved methane which is released from the ocean to the atmosphere. We explored the use of stable isotope methane spikes to quantify methane oxidation rates in Arctic seawater samples. A Picarro G2201-i cavity ring-down spectrometer was used to determine methane concentration and isotope ratios from headspace samples in foil incubators. The methane mass balance and the change in stable isotope ratios served as independent constraints on methane oxidation. For a fractionation factor of 1.025 oxidation rate constants determined with both methods agreed within 20% for small changes in isotope ratio (e.g., 10‰). For large changes in isotope ratio (e.g., 90‰), which was outside the calibration range, methods diverged. Rate constants down to 0.01 / d could be resolved with high statistical support. Stable isotope infrared spectroscopy to determine methane oxidation in foil incubators (ISMOFI) was successfully tested on under ice seawater from Utqiagvik, Alaska, by repeated sampling from each incubation vessel. Depending on the amount of isotope spike added, we determined oxidation rates of 0.15 ± 0.02 nmol / (L*d) at in situ methane concentration and a maximal oxidation potential of 271 ± 41 nmol / (L*d). The ISMOFI method permits variable incubation durations from days to months in a single incubator. The method is transportable and applicable in a variety of field or seagoing laboratory environments, and it avoids the use of hazardous substances such as radioisotopes and toxic chemicals. |
format |
Article in Journal/Newspaper |
author |
Uhlig, Christiane Loose, Brice |
spellingShingle |
Uhlig, Christiane Loose, Brice Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures |
author_facet |
Uhlig, Christiane Loose, Brice |
author_sort |
Uhlig, Christiane |
title |
Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures |
title_short |
Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures |
title_full |
Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures |
title_fullStr |
Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures |
title_full_unstemmed |
Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures |
title_sort |
using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at arctic ocean temperatures |
publishDate |
2017 |
url |
https://epic.awi.de/id/eprint/45456/ https://epic.awi.de/id/eprint/45456/1/Uhlig_et_al-2017-Limnology_and_Oceanography__Methods.pdf https://hdl.handle.net/10013/epic.51638 https://hdl.handle.net/10013/epic.51638.d001 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Arctic Ocean Alaska |
genre_facet |
Arctic Arctic Arctic Ocean Alaska |
op_source |
EPIC3Limnology & Oceanography: Methods |
op_relation |
https://epic.awi.de/id/eprint/45456/1/Uhlig_et_al-2017-Limnology_and_Oceanography__Methods.pdf https://hdl.handle.net/10013/epic.51638.d001 Uhlig, C. orcid:0000-0001-7278-6522 and Loose, B. (2017) Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures , Limnology & Oceanography: Methods . doi:10.1002/lom3.10199 <https://doi.org/10.1002/lom3.10199> , hdl:10013/epic.51638 |
container_title |
Limnology and Oceanography: Methods |
container_volume |
15 |
container_issue |
8 |
container_start_page |
737 |
op_container_end_page |
751 |
_version_ |
1766299969782808576 |