Methane production by three widespread marine phytoplankton species

• Verfasst von: Klintzsch, Thomas [VerfasserIn]
• Verfasst von: Langer, Gerald [VerfasserIn]
• Verfasst von: Nehrke, Gernot [VerfasserIn]
• Verfasst von: Wieland, Anna [VerfasserIn]
• Verfasst von: Lenhart, Katharina [VerfasserIn]
• Verfasst von: Keppler, Frank [VerfasserIn]
• Titel: Methane production by three widespread marine phytoplankton species
• Titelzusatz: release rates, precursor compounds, and potential relevance for the environment
• Verf.angabe: Thomas Klintzsch, Gerald Langer, Gernot Nehrke, Anna Wieland, Katharina Lenhart, and Frank Keppler
• E-Jahr: 2019
• Jahr: 28 Oct 2019
• Umfang: 16 S.
• Fussnoten: Gesehen am 31.10.2019
• Titel Quelle: Enthalten in: Biogeosciences
• Ort Quelle: Katlenburg-Lindau [u.a.] : Copernicus, 2004
• Jahr Quelle: 2019
• Band/Heft Quelle: 16(2019), 20, Seite 4129-4144
• ISSN Quelle: 1726-4189
• DOI: doi:10.5194/bg-16-4129-2019
• Datenträger: Online-Ressource
• Sprache: eng
• Bibliogr. Hinweis: Forschungsdaten: Klintzsch, Thomas, 1986 - : Methane production by three widespread marine phytoplankton species
• K10plus-PPN: 1680798073
• K10plus-PPN:
  Universitätsbibliothek
• Lokale URL UB: Zum Volltext

Abstract

<p><strong>Abstract.</strong> Methane (<span class="inline-formula">CH₄</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">CH₄</span> oversaturation in oxic waters, but so far direct evidence for <span class="inline-formula">CH₄</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">CH₄</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">CH₄</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>&thinsp;<span class="inline-formula">µ</span>g of <span class="inline-formula">CH₄</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">CH₄</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>&thinsp;ag&thinsp;<span class="inline-formula">CH₄</span>&thinsp;cell<span class="inline-formula">⁻¹</span>&thinsp;d<span class="inline-formula">⁻¹</span> (<i>E. huxleyi</i>; ag&thinsp;<span class="inline-formula">=</span>&thinsp;10<span class="inline-formula">⁻¹⁸</span>&thinsp;g). In cultures that were treated with <span class="inline-formula">¹³C</span>-labeled hydrogen carbonate, <span class="inline-formula"><i>δ</i>¹³CH₄</span> values increased with incubation time, resulting from the conversion of <span class="inline-formula">¹³C</span>-hydrogen carbonate to <span class="inline-formula">¹³CH₄</span>. The addition of <span class="inline-formula">¹³C</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">¹³C</span>-enriched <span class="inline-formula">CH₄</span> in cultures of <i>E. huxleyi</i>, clearly indicating that methylated sulfur compounds are also precursors of <span class="inline-formula">CH₄</span>. By comparing the algal <span class="inline-formula">CH₄</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">CH₄</span> release is contributing to <span class="inline-formula">CH₄</span> oversaturation in oxic waters. Therefore, we propose that haptophyte mediated <span class="inline-formula">CH₄</span> production could be a common and important process in marine surface waters.</p>