Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures
Abstract 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 G...
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crwiley:10.1002/lom3.10199 2024-06-02T08:01:54+00:00 Using stable isotopes and gas concentrations for independent constraints on microbial methane oxidation at Arctic Ocean temperatures Uhlig, Christiane Loose, Brice American Chemical Society Petroleum Research Fund 2017 http://dx.doi.org/10.1002/lom3.10199 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Flom3.10199 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lom3.10199 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Limnology and Oceanography: Methods volume 15, issue 8, page 737-751 ISSN 1541-5856 1541-5856 journal-article 2017 crwiley https://doi.org/10.1002/lom3.10199 2024-05-03T10:43:19Z Abstract 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 −1 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 −1 d −1 at in situ methane concentration and a maximal oxidation potential of 271 ± 41 nmol L −1 d −1 . 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 Ocean Alaska Wiley Online Library Arctic Arctic Ocean Limnology and Oceanography: Methods 15 8 737 751 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract 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 −1 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 −1 d −1 at in situ methane concentration and a maximal oxidation potential of 271 ± 41 nmol L −1 d −1 . 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. |
author2 |
American Chemical Society Petroleum Research Fund |
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 |
publisher |
Wiley |
publishDate |
2017 |
url |
http://dx.doi.org/10.1002/lom3.10199 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Flom3.10199 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lom3.10199 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Alaska |
genre_facet |
Arctic Arctic Ocean Alaska |
op_source |
Limnology and Oceanography: Methods volume 15, issue 8, page 737-751 ISSN 1541-5856 1541-5856 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/lom3.10199 |
container_title |
Limnology and Oceanography: Methods |
container_volume |
15 |
container_issue |
8 |
container_start_page |
737 |
op_container_end_page |
751 |
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1800746399416975360 |