Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment
<p>Methane (<span class="inline-formula">CH<sub>4</sub></span>) production within the oceanic mixed layer is a widespread phenomenon, but the underlying mechanisms are still under debate. Marine algae might contribute to the observed <span class="inlin...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-10-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/16/4129/2019/bg-16-4129-2019.pdf |
| _version_ | 1828835410755715072 |
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| author | T. Klintzsch G. Langer G. Nehrke A. Wieland K. Lenhart K. Lenhart F. Keppler F. Keppler |
| author_facet | T. Klintzsch G. Langer G. Nehrke A. Wieland K. Lenhart K. Lenhart F. Keppler F. Keppler |
| author_sort | T. Klintzsch |
| collection | DOAJ |
| description | <p>Methane (<span class="inline-formula">CH<sub>4</sub></span>) production within the oceanic mixed
layer is a widespread phenomenon, but the underlying mechanisms are still
under debate. Marine algae might contribute to the observed <span class="inline-formula">CH<sub>4</sub></span>
oversaturation in oxic waters, but so far direct evidence for <span class="inline-formula">CH<sub>4</sub></span>
production by marine algae has only been provided for the coccolithophore
<i>Emiliania huxleyi</i>.</p>
<p>In the present study we investigated, next to <i>E. huxleyi</i>, other widespread
haptophytes, i.e., <i>Phaeocystis globosa</i> and <i>Chrysochromulina</i> sp. We performed <span class="inline-formula">CH<sub>4</sub></span> production and stable carbon
isotope measurements and provide unambiguous evidence that all three
investigated marine algae are involved in the production of <span class="inline-formula">CH<sub>4</sub></span> under
oxic conditions. Rates ranged from <span class="inline-formula">1.9±0.6</span> to <span class="inline-formula">3.1±0.4</span> <span class="inline-formula">µ</span>g of <span class="inline-formula">CH<sub>4</sub></span> per gram of POC (particulate organic carbon) per day, with
<i>Chrysochromulina</i> sp. and <i>E. huxleyi</i> showing the lowest and highest rates, respectively. Cellular <span class="inline-formula">CH<sub>4</sub></span>
production rates ranged from <span class="inline-formula">16.8±6.5</span> (<i>P. globosa</i>) to <span class="inline-formula">62.3±6.4</span> ag <span class="inline-formula">CH<sub>4</sub></span> cell<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span> (<i>E. huxleyi</i>; ag <span class="inline-formula">=</span> 10<span class="inline-formula"><sup>−18</sup></span> g). In cultures that
were treated with <span class="inline-formula"><sup>13</sup>C</span>-labeled hydrogen carbonate, <span class="inline-formula"><i>δ</i><sup>13</sup>CH<sub>4</sub></span> values increased with incubation time, resulting from the
conversion of <span class="inline-formula"><sup>13</sup>C</span>–hydrogen carbonate to <span class="inline-formula"><sup>13</sup>CH<sub>4</sub></span>. The addition
of <span class="inline-formula"><sup>13</sup>C</span>-labeled dimethyl sulfide, dimethyl sulfoxide, and methionine
sulfoxide – known algal metabolites that are ubiquitous in marine surface
layers – resulted in the occurrence of <span class="inline-formula"><sup>13</sup>C</span>-enriched <span class="inline-formula">CH<sub>4</sub></span> in
cultures of <i>E. huxleyi</i>, clearly indicating that methylated sulfur compounds are also
precursors of <span class="inline-formula">CH<sub>4</sub></span>. By comparing the algal <span class="inline-formula">CH<sub>4</sub></span> production rates
from our laboratory experiments with results previously reported in two
field studies of the Pacific Ocean and the Baltic Sea, we might conclude that
algae-mediated <span class="inline-formula">CH<sub>4</sub></span> release is contributing to <span class="inline-formula">CH<sub>4</sub></span> oversaturation
in oxic waters. Therefore, we propose that haptophyte mediated <span class="inline-formula">CH<sub>4</sub></span>
production could be a common and important process in marine surface waters.</p> |
| first_indexed | 2024-12-12T18:02:06Z |
| format | Article |
| id | doaj.art-7f9b33a668184690b42b66c541c0cdd3 |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-12T18:02:06Z |
| publishDate | 2019-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-7f9b33a668184690b42b66c541c0cdd32022-12-22T00:16:36ZengCopernicus PublicationsBiogeosciences1726-41701726-41892019-10-01164129414410.5194/bg-16-4129-2019Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environmentT. Klintzsch0G. Langer1G. Nehrke2A. Wieland3K. Lenhart4K. Lenhart5F. Keppler6F. Keppler7Institute of Earth Sciences, University Heidelberg, Im Neuenheimer Feld 234–236, 69120 Heidelberg, GermanyThe Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, Devon, PL1 2PB, UKMarine Biogeosciences, Alfred Wegener Institut – Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyInstitute of Earth Sciences, University Heidelberg, Im Neuenheimer Feld 234–236, 69120 Heidelberg, GermanyInstitute of Earth Sciences, University Heidelberg, Im Neuenheimer Feld 234–236, 69120 Heidelberg, GermanyUniversity of Applied Sciences, Berlinstr. 109, 55411 Bingen, GermanyInstitute of Earth Sciences, University Heidelberg, Im Neuenheimer Feld 234–236, 69120 Heidelberg, GermanyHeidelberg Center for the Environment HCE, Heidelberg University, 69120 Heidelberg, Germany<p>Methane (<span class="inline-formula">CH<sub>4</sub></span>) production within the oceanic mixed layer is a widespread phenomenon, but the underlying mechanisms are still under debate. Marine algae might contribute to the observed <span class="inline-formula">CH<sub>4</sub></span> oversaturation in oxic waters, but so far direct evidence for <span class="inline-formula">CH<sub>4</sub></span> production by marine algae has only been provided for the coccolithophore <i>Emiliania huxleyi</i>.</p> <p>In the present study we investigated, next to <i>E. huxleyi</i>, other widespread haptophytes, i.e., <i>Phaeocystis globosa</i> and <i>Chrysochromulina</i> sp. We performed <span class="inline-formula">CH<sub>4</sub></span> production and stable carbon isotope measurements and provide unambiguous evidence that all three investigated marine algae are involved in the production of <span class="inline-formula">CH<sub>4</sub></span> under oxic conditions. Rates ranged from <span class="inline-formula">1.9±0.6</span> to <span class="inline-formula">3.1±0.4</span> <span class="inline-formula">µ</span>g of <span class="inline-formula">CH<sub>4</sub></span> per gram of POC (particulate organic carbon) per day, with <i>Chrysochromulina</i> sp. and <i>E. huxleyi</i> showing the lowest and highest rates, respectively. Cellular <span class="inline-formula">CH<sub>4</sub></span> production rates ranged from <span class="inline-formula">16.8±6.5</span> (<i>P. globosa</i>) to <span class="inline-formula">62.3±6.4</span> ag <span class="inline-formula">CH<sub>4</sub></span> cell<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span> (<i>E. huxleyi</i>; ag <span class="inline-formula">=</span> 10<span class="inline-formula"><sup>−18</sup></span> g). In cultures that were treated with <span class="inline-formula"><sup>13</sup>C</span>-labeled hydrogen carbonate, <span class="inline-formula"><i>δ</i><sup>13</sup>CH<sub>4</sub></span> values increased with incubation time, resulting from the conversion of <span class="inline-formula"><sup>13</sup>C</span>–hydrogen carbonate to <span class="inline-formula"><sup>13</sup>CH<sub>4</sub></span>. The addition of <span class="inline-formula"><sup>13</sup>C</span>-labeled dimethyl sulfide, dimethyl sulfoxide, and methionine sulfoxide – known algal metabolites that are ubiquitous in marine surface layers – resulted in the occurrence of <span class="inline-formula"><sup>13</sup>C</span>-enriched <span class="inline-formula">CH<sub>4</sub></span> in cultures of <i>E. huxleyi</i>, clearly indicating that methylated sulfur compounds are also precursors of <span class="inline-formula">CH<sub>4</sub></span>. By comparing the algal <span class="inline-formula">CH<sub>4</sub></span> production rates from our laboratory experiments with results previously reported in two field studies of the Pacific Ocean and the Baltic Sea, we might conclude that algae-mediated <span class="inline-formula">CH<sub>4</sub></span> release is contributing to <span class="inline-formula">CH<sub>4</sub></span> oversaturation in oxic waters. Therefore, we propose that haptophyte mediated <span class="inline-formula">CH<sub>4</sub></span> production could be a common and important process in marine surface waters.</p>https://www.biogeosciences.net/16/4129/2019/bg-16-4129-2019.pdf |
| spellingShingle | T. Klintzsch G. Langer G. Nehrke A. Wieland K. Lenhart K. Lenhart F. Keppler F. Keppler Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment Biogeosciences |
| title | Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment |
| title_full | Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment |
| title_fullStr | Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment |
| title_full_unstemmed | Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment |
| title_short | Methane production by three widespread marine phytoplankton species: release rates, precursor compounds, and potential relevance for the environment |
| title_sort | methane production by three widespread marine phytoplankton species release rates precursor compounds and potential relevance for the environment |
| url | https://www.biogeosciences.net/16/4129/2019/bg-16-4129-2019.pdf |
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