Measurement of vertical distribution of isoprene in surface seawater, its chemical fate, and its emission from several phytoplankton monocultures

Milne, Peter J.; Riemer, D. D.; Zika, Rod G.; Brand, Larry E.

doi:10.1016/0304-4203(94)00059-m

Cited by 124 publications

(135 citation statements)

References 21 publications

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“…Marine isoprene production appears to be closely related to phytoplankton (19,20) with supersaturated levels observed in surface seawater (21). Isoprene levels increased by a factor of four in the patch and were strongly correlated with productivity (CO 2 uptake, O 2 , and fluorescence) (Fig.…”

Section: Resultsmentioning

confidence: 85%

Changing concentrations of CO, CH ₄ , C ₅ H ₈ , CH ₃ Br, CH ₃ I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

Wingenter

Haase

Strutton

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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Oceanic iron (Fe) fertilization experiments have advanced the understanding of how Fe regulates biological productivity and air-sea carbon dioxide (CO2) exchange. However, little is known about the production and consumption of halocarbons and other gases as a result of Fe addition. Besides metabolizing inorganic carbon, marine microorganisms produce and consume many other trace gases. Several of these gases, which individually impact global climate, stratospheric ozone concentration, or local photochemistry, have not been previously quantified during an Feenrichment experiment. We describe results for selected dissolved trace gases including methane (CH4), isoprene (C5H8), methyl bromide (CH 3Br), dimethyl sulfide, and oxygen (O2), which increased subsequent to Fe fertilization, and the associated decreases in concentrations of carbon monoxide (CO), methyl iodide (CH 3I), and CO 2 observed during the Southern Ocean Iron Enrichment Experiments. P revious iron (Fe) fertilization experiments have been conducted in the North (1) and equatorial Pacific (2, 3) and in the Southern Ocean (4, 5). The Southern Ocean, the largest of the high-nutrient low-chlorophyll regions, represents 6% of the global ocean and has the potential to enhance carbon sequestration by Fe fertilization (6-9), which could slow carbon dioxide (CO 2 ) accumulation in the atmosphere and potentially help alleviate global warming. Experimental MethodsThe experimental design and other results of the Southern Ocean Iron Enrichment Experiment (SOFeX) are presented in an overview paper (8). Of the two regions fertilized with Fe during SOFeX, we focus here on the region north of the Antarctic Polar Front. An area Ϸ15 ϫ 15 km at 56.2°S, 172.0°W (southeast of New Zealand in the southwest Pacific sector of the Southern Ocean) was fertilized with a solution of acidified iron sulfate (FeSO 4 ) over 48 h to a concentration of Ϸ1.2 ϫ 10 Ϫ9 mol⅐liter Ϫ1 (1.2 nM) beginning on January 12, 2002. The background Fe concentration ([Fe]) was Ϸ0.1 nM. A second (36 h) application of FeSO 4 (Ϸ1.2 nM) ended on January 17. These Fe additions were intended to simulate glacial era concentrations of iron in the Southern Ocean (8, 10). The region, or patch, was allowed time to bloom and then was surveyed over a 50-h period, between February 8 and 10, 4 weeks after the first Fe application. By this time the patch had reached a surface area that was a factor of 10 larger than during the initial Fe addition with iron concentrations in the patch of Ϸ0.3 nM (8). During this survey we approached the patch from the South working our way northeast, while crisscrossing the patch. After the shape and orientation of the patch became apparent [elongated and stretching from the southwest to the northeast (11)], more intensive sampling began along the patch. Observations of fluorescence, the partial pressure of CO 2 in seawater (pCO 2 ) (Fig. 1A), dissolved O 2 (Fig. 1B), chlorophyll, and primary productivity indicated a pronounced change in biological activity in the mixed layer (upper 40-5...

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Section: Resultsmentioning

confidence: 85%

Changing concentrations of CO, CH ₄ , C ₅ H ₈ , CH ₃ Br, CH ₃ I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

Wingenter

Haase

Strutton

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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“…Little is known about the sources of methanol in the water column. Methanol may be deposited from the atmosphere and produced by phytoplankton (Milne et al, 1995;Heikes et al, 2002) and bacterial transformation of algal carbohydrates (Sieburth and Keller, 1988). OM43 have been associated with phytoplankton blooms (Morris et al, 2006), however, our identification of OM43 methanol dehydrogenase and hexulose-6-phosphate synthase proteins in all samples suggest methylotrophic populations are sustained in the Northwest Atlantic even at times of low phytoplankton abundance.…”

Section: One Carbon Metabolismmentioning

confidence: 99%

Metaproteomic analysis of a winter to spring succession in coastal northwest Atlantic Ocean microbial plankton

et al. 2014

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In this study, we used comparative metaproteomics to investigate the metabolic activity of microbial plankton inhabiting a seasonally hypoxic basin in the Northwest Atlantic Ocean (Bedford Basin). From winter to spring, we observed a seasonal increase in high-affinity membrane transport proteins involved in scavenging of organic substrates; Rhodobacterales transporters were strongly associated with the spring phytoplankton bloom, whereas SAR11 transporters were abundant in the underlying waters. A diverse array of transporters for organic compounds were similar to the SAR324 clade, revealing an active heterotrophic lifestyle in coastal waters. Proteins involved in methanol oxidation (from the OM43 clade) and carbon monoxide (from a wide variety of bacteria) were identified throughout Bedford Basin. Metabolic niche partitioning between the SUP05 and ARCTIC96BD-19 clades, which together comprise the Gamma-proteobacterial sulfur oxidizers group was apparent. ARCTIC96BD-19 proteins involved in the transport of organic compounds indicated that in productive coastal waters this lineage tends toward a heterotrophic metabolism. In contrast, the identification of sulfur oxidation proteins from SUP05 indicated the use of reduced sulfur as an energy source in hypoxic bottom water. We identified an abundance of Marine Group I Thaumarchaeota proteins in the hypoxic deep layer, including proteins for nitrification and carbon fixation. No transporters for organic compounds were detected among the thaumarchaeal proteins, suggesting a reliance on autotrophic carbon assimilation. In summary, our analyses revealed the spatiotemporal structure of numerous metabolic activities in the coastal ocean that are central to carbon, nitrogen and sulfur cycling in the sea.

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“…A total global oceanic emission of 0.1-1.2 Tg C/yr has been estimated from in-situ observations (Bonsang et al, 1992;Milne et al, 1995;Broadgate et al, 1997) and satellite observations of ocean biological productivity (Palmer and Shaw, 2005), which is small compared with an estimated global terrestrial isoprene source of ∼400-750 Tg C/yr (Müller et al, 2008;Guenther et al, 2006). Nevertheless, the high reactivity of isoprene means that an ocean source has the potential to perturb photochemistry in the remote marine atmosphere where reactive VOC loadings are small due to the distance from continental sources (e.g.…”

Section: Emission Of Isoprene From the Oceansmentioning

confidence: 99%

Evaluation of the global oceanic isoprene source and its impacts on marine organic carbon aerosol

et al. 2009

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Abstract. We have combined the first satellite maps of the global distribution of phytoplankton functional type and new measurements of phytoplankton-specific isoprene productivities, with available remote marine isoprene observations and a global model, to evaluate our understanding of the marine isoprene source and its impacts on organic aerosol abundances. Using satellite products to scale up data on phytoplankton-specific isoprene productivity to the global oceans, we infer a mean "bottom-up" oceanic isoprene emission of 0.31±0.08 (1σ )Tg/yr. By minimising the mean bias between the model and isoprene observations in the marine atmosphere remote from the continents, we produce a "topdown" oceanic isoprene source estimate of 1.9 Tg/yr. We suggest our reliance on limited atmospheric isoprene data, difficulties in simulating in-situ isoprene production rates in laboratory phytoplankton cultures, and limited knowledge of isoprene production mechanisms across the broad range of phytoplankton communities in the oceans under different environmental conditions as contributors to this difference between the two estimates. Inclusion of secondary organic aerosol (SOA) production from oceanic isoprene in the model with a 2% yield produces small contributions (0.01-1.4%) to observed organic carbon (OC) aerosol mass at three remote marine sites in the Northern and Southern Hemispheres. Based on these findings we suggest an insignificant role for isoprene in modulating remote marine aerosol abundances, giving further support to a recently postulated primary OC source in the remote marine atmosphere.

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Measurement of vertical distribution of isoprene in surface seawater, its chemical fate, and its emission from several phytoplankton monocultures

Cited by 124 publications

References 21 publications

Changing concentrations of CO, CH ₄ , C ₅ H ₈ , CH ₃ Br, CH ₃ I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

Changing concentrations of CO, CH ₄ , C ₅ H ₈ , CH ₃ Br, CH ₃ I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

Metaproteomic analysis of a winter to spring succession in coastal northwest Atlantic Ocean microbial plankton

Evaluation of the global oceanic isoprene source and its impacts on marine organic carbon aerosol

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Measurement of vertical distribution of isoprene in surface seawater, its chemical fate, and its emission from several phytoplankton monocultures

Cited by 124 publications

References 21 publications

Changing concentrations of CO, CH 4 , C 5 H 8 , CH 3 Br, CH 3 I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

Changing concentrations of CO, CH 4 , C 5 H 8 , CH 3 Br, CH 3 I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

Metaproteomic analysis of a winter to spring succession in coastal northwest Atlantic Ocean microbial plankton

Evaluation of the global oceanic isoprene source and its impacts on marine organic carbon aerosol

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Changing concentrations of CO, CH ₄ , C ₅ H ₈ , CH ₃ Br, CH ₃ I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments

Changing concentrations of CO, CH ₄ , C ₅ H ₈ , CH ₃ Br, CH ₃ I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments