1
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Huang P, Cai M, Chen F, Liu Z, Ke H, Wang W, Zheng X, Wang C. Roles of temperature and ventilation in oxygen consumption: A chemical kinetics view from the van't Hoff-based formulation. MARINE ENVIRONMENTAL RESEARCH 2024; 193:106278. [PMID: 38008015 DOI: 10.1016/j.marenvres.2023.106278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/13/2023] [Accepted: 11/17/2023] [Indexed: 11/28/2023]
Abstract
In this study, we successfully estimated the apparent activation energy of a microbially driven oxygen-consuming reaction (microbial-driven) based on tracer data. The concept of the apparent chemical reaction rate constant was employed to estimate various thermodynamic parameters associated with the oxygen consumption rate in conjunction with Arrhenius/Eyring equations. Normal Ea values of 80-90 kJ mol-1 were found in the upper layers of the South China Sea and Sulu Sea, while higher Ea values (300-1000 kJ mol-1) were observed in the rapidly ventilated Mediterranean Sea, the Sea of Japan, and the Bering Sea with lower temperatures. We classified the characteristics of typical sea basins into four categories. The temperature-dependent oxygen consumption rate relationship in each marine region was systematically calculated to derive the respective thermodynamic characteristic values. This allowed us to parameterize the rate-temperature relationship into thermodynamic quantities, enabling more effective integration of distinct basin characteristics within different sea areas into the marine biochemical model. Parameterization facilitates relatively accurate prediction of changes such as temperature, oxygen consumption rate.
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Affiliation(s)
- Peng Huang
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Mingang Cai
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China; Xiamen Ocean Vocational College, Xiamen, 361100, China.
| | - Fajin Chen
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China; Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Zhiqing Liu
- College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Hongwei Ke
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Weimin Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China; Zhejiang Institute of Tianjin University, Ningbo, 315000, China
| | - Xuehong Zheng
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
| | - Chunhui Wang
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361102, China
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2
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Nguyen PQ, Huang X, Collins DS, Collins JJ, Lu T. Harnessing synthetic biology to enhance ocean health. Trends Biotechnol 2023; 41:860-874. [PMID: 36669947 DOI: 10.1016/j.tibtech.2022.12.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 12/16/2022] [Accepted: 12/22/2022] [Indexed: 01/19/2023]
Abstract
Ocean health is faltering, its capability for regeneration and renewal being eroded by a steady pulse of anthropomorphic impacts. Plastic waste has infiltrated all ocean biomes, climate change threatens coral reefs with extinction, and eutrophication has unleashed vast algal blooms. In the face of these challenges, synthetic biology approaches may hold untapped solutions to mitigate adverse effects, repair ecosystems, and put us on a path towards sustainable stewardship of our planet. Leveraging synthetic biology tools would enable innovative engineering approaches to augment the natural adaptive capacity of ocean biological systems to cope with the swiftness of human-induced change. Here, we present a framework for developing synthetic biology solutions for the challenges of plastic pollution, coral bleaching, and harmful algal blooms.
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Affiliation(s)
- Peter Q Nguyen
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Xiaoning Huang
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Daniel S Collins
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA; Department of Biology and Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - James J Collins
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA; Institute for Medical Engineering & Science, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA.
| | - Ting Lu
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL, USA; Department of Physics, University of Illinois Urbana-Champaign, Urbana, IL, USA; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, IL, USA; National Center for Supercomputing Applications, University of Illinois Urbana-Champaign, Urbana, IL, USA.
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3
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Mandal A, Dutta A, Das R, Mukherjee J. Role of intertidal microbial communities in carbon dioxide sequestration and pollutant removal: A review. MARINE POLLUTION BULLETIN 2021; 170:112626. [PMID: 34153859 DOI: 10.1016/j.marpolbul.2021.112626] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 06/06/2021] [Accepted: 06/08/2021] [Indexed: 05/16/2023]
Abstract
Intertidal microbial communities occur as biofilms or microphytobenthos (MPB) which are sediment-attached assemblages of bacteria, protozoa, fungi, algae, diatoms embedded in extracellular polymeric substances. Despite their global occurrence, they have not been reviewed in light of their structural and functional characteristics. This paper reviews the importance of such microbial communities and their importance in carbon dioxide sequestration as well as pollutant bioremediation. Global annual benthic microalgal productivity was 500 million tons of carbon, 50% of which contributed towards the autochthonous carbon fixation in the estuaries. Primary production by MPB was 27-234 gCm-2y-1 in the estuaries of Asia, Europe and the United States. Mechanisms of heavy metal removal remain to be tested in intertidal communities. Cyanobacteria facilitate hydrocarbon degradation in intertidal biofilms and microbial mats by supporting the associated sulfate-reducing bacteria and aerobic heterotrophs. Physiological cooperation between the microorganisms in intertidal communities imparts enhanced ability to utilize polycyclic aromatic hydrocarbon pollutants by these microorganisms than mono-species communities. Future research may be focused on biochemical characteristics of intertidal mats and biofilms, pollutant-microbial interactions and ecosystem influences.
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Affiliation(s)
- Abhishek Mandal
- School of Environmental Studies, Jadavpur University, 700032, India
| | - Ahana Dutta
- School of Environmental Studies, Jadavpur University, 700032, India
| | - Reshmi Das
- School of Environmental Studies, Jadavpur University, 700032, India.
| | - Joydeep Mukherjee
- School of Environmental Studies, Jadavpur University, 700032, India.
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4
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Li SW, Lin PH, Ho TY, Hsieh CH, Sun CL. Change in rheotactic behavior patterns of dinoflagellates in response to different microfluidic environments. Sci Rep 2021; 11:11105. [PMID: 34045568 PMCID: PMC8160355 DOI: 10.1038/s41598-021-90622-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 05/12/2021] [Indexed: 11/15/2022] Open
Abstract
Plankton live in dynamic fluid environments. Their ability to change in response to different hydrodynamic cues is critical to their energy allocation and resource uptake. This study used a microfluidic device to evaluate the rheotactic behaviors of a model dinoflagellate species, Karlodinium veneficum, in different flow conditions. Although dinoflagellates experienced forced alignment in strong shear (i.e. “trapping”), fluid straining did not play a decisive role in their rheotactic movements. Moderate hydrodynamic magnitude (20 < |uf| < 40 µm s−1) was found to induce an orientation heading towards an oncoming current (positive rheotaxis), as dinoflagellates switched to cross-flow swimming when flow speed exceeded 50 µm s−1. Near the sidewalls of the main channel, the steric mechanism enabled dinoflagellates to adapt upstream orientation through vertical migration. Under oscillatory flow, however, positive rheotaxis dominated with occasional diversion. The varying flow facilitated upstream exploration with directional controlling, through which dinoflagellates exhibited avoidance of both large-amplitude perturbance and very stagnant zones. In the mixed layer where water is not steady, these rheotactic responses could lead to spatial heterogeneity of dinoflagellates. The outcome of this study helps clarify the interaction between swimming behaviors of dinoflagellates and the hydrodynamic environment they reside in.
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Affiliation(s)
- Si-Wei Li
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Po-Hsu Lin
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Tung-Yuan Ho
- Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan
| | - Chih-Hao Hsieh
- Institute of Oceanography, National Taiwan University, Taipei, 10617, Taiwan.,Research Center for Environmental Changes, Academia Sinica, Taipei, 11529, Taiwan.,Institute of Ecology and Evolutionary Biology and Department of Life Science, National Taiwan University, Taipei, 10617, Taiwan.,Mathematics Division, National Center for Theoretical Sciences, Taipei, 10617, Taiwan
| | - Chen-Li Sun
- Department of Mechanical Engineering, National Taiwan University, Taipei, 10617, Taiwan.
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5
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Spietz RL, Lundeen RA, Zhao X, Nicastro D, Ingalls AE, Morris RM. Heterotrophic carbon metabolism and energy acquisition in Candidatus Thioglobus singularis strain PS1, a member of the SUP05 clade of marine Gammaproteobacteria. Environ Microbiol 2019; 21:2391-2401. [PMID: 30951247 DOI: 10.1111/1462-2920.14623] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 11/30/2022]
Abstract
A hallmark of the SUP05 clade of marine Gammaproteobacteria is the ability to use energy obtained from reduced inorganic sulfur to fuel autotrophic fixation of carbon using RuBisCo. However, some SUP05 also have the genetic potential for heterotrophic growth, raising questions about the roles of SUP05 in the marine carbon cycle. We used genomic reconstructions, physiological growth experiments and proteomics to characterize central carbon and energy metabolism in Candidatus Thioglobus singularis strain PS1, a representative from the SUP05 clade that has the genetic potential for autotrophy and heterotrophy. Here, we show that the addition of individual organic compounds and 0.2 μm filtered diatom lysate significantly enhanced the growth of this bacterium. This positive growth response to organic substrates, combined with expression of a complete TCA cycle, heterotrophic pathways for carbon assimilation, and methylotrophic pathways for energy conversion demonstrate strain PS1's capacity for heterotrophic growth. Further, our inability to verify the expression of RuBisCO suggests that carbon fixation was not critical for growth. These results highlight the metabolic diversity of the SUP05 clade that harbours both primary producers and consumers of organic carbon in the oceans and expand our understanding of specific pathways of organic matter oxidation by the heterotrophic SUP05.
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Affiliation(s)
- Rachel L Spietz
- School of Oceanography, University of Washington, Seattle, WA, 98195, USA
| | - Rachel A Lundeen
- School of Oceanography, University of Washington, Seattle, WA, 98195, USA
| | - Xiaowei Zhao
- Department of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Daniela Nicastro
- Department of Cell Biology and Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Anitra E Ingalls
- School of Oceanography, University of Washington, Seattle, WA, 98195, USA
| | - Robert M Morris
- School of Oceanography, University of Washington, Seattle, WA, 98195, USA
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6
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Brewer PG, Peltzer ET. Depth perception: the need to report ocean biogeochemical rates as functions of temperature, not depth. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2016.0319. [PMID: 28784710 PMCID: PMC5559415 DOI: 10.1098/rsta.2016.0319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/21/2017] [Indexed: 05/13/2023]
Abstract
For over 50 years, ocean scientists have oddly represented ocean oxygen consumption rates as a function of depth but not temperature in most biogeochemical models. This unique tradition or tactic inhibits useful discussion of climate change impacts, where specific and fundamental temperature-dependent terms are required. Tracer-based determinations of oxygen consumption rates in the deep sea are nearly universally reported as a function of depth in spite of their well-known microbial basis. In recent work, we have shown that a carefully determined profile of oxygen consumption rates in the Sargasso Sea can be well represented by a classical Arrhenius function with an activation energy of 86.5 kJ mol-1, leading to a Q10 of 3.63. This indicates that for 2°C warming, we will have a 29% increase in ocean oxygen consumption rates, and for 3°C warming, a 47% increase, potentially leading to large-scale ocean hypoxia should a sufficient amount of organic matter be available to microbes. Here, we show that the same principles apply to a worldwide collation of tracer-based oxygen consumption rate data and that some 95% of ocean oxygen consumption is driven by temperature, not depth, and thus will have a strong climate dependence. The Arrhenius/Eyring equations are no simple panacea and they require a non-equilibrium steady state to exist. Where transient events are in progress, this stricture is not obeyed and we show one such possible example.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.
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Affiliation(s)
- Peter G Brewer
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Edward T Peltzer
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
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7
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Brewer PG, Peltzer ET. Depth perception: the need to report ocean biogeochemical rates as functions of temperature, not depth. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017. [PMID: 28784710 DOI: 10.1098/rsta.2017.0319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
For over 50 years, ocean scientists have oddly represented ocean oxygen consumption rates as a function of depth but not temperature in most biogeochemical models. This unique tradition or tactic inhibits useful discussion of climate change impacts, where specific and fundamental temperature-dependent terms are required. Tracer-based determinations of oxygen consumption rates in the deep sea are nearly universally reported as a function of depth in spite of their well-known microbial basis. In recent work, we have shown that a carefully determined profile of oxygen consumption rates in the Sargasso Sea can be well represented by a classical Arrhenius function with an activation energy of 86.5 kJ mol-1, leading to a Q10 of 3.63. This indicates that for 2°C warming, we will have a 29% increase in ocean oxygen consumption rates, and for 3°C warming, a 47% increase, potentially leading to large-scale ocean hypoxia should a sufficient amount of organic matter be available to microbes. Here, we show that the same principles apply to a worldwide collation of tracer-based oxygen consumption rate data and that some 95% of ocean oxygen consumption is driven by temperature, not depth, and thus will have a strong climate dependence. The Arrhenius/Eyring equations are no simple panacea and they require a non-equilibrium steady state to exist. Where transient events are in progress, this stricture is not obeyed and we show one such possible example.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.
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Affiliation(s)
- Peter G Brewer
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Edward T Peltzer
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
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8
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Caruso G, La Ferla R, Azzaro M, Zoppini A, Marino G, Petochi T, Corinaldesi C, Leonardi M, Zaccone R, Fonda Umani S, Caroppo C, Monticelli L, Azzaro F, Decembrini F, Maimone G, Cavallo RA, Stabili L, Hristova Todorova N, K. Karamfilov V, Rastelli E, Cappello S, Acquaviva MI, Narracci M, De Angelis R, Del Negro P, Latini M, Danovaro R. Microbial assemblages for environmental quality assessment: Knowledge, gaps and usefulness in the European Marine Strategy Framework Directive. Crit Rev Microbiol 2015; 42:883-904. [DOI: 10.3109/1040841x.2015.1087380] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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9
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Functional group-specific traits drive phytoplankton dynamics in the oligotrophic ocean. Proc Natl Acad Sci U S A 2015; 112:E5972-9. [PMID: 26460011 DOI: 10.1073/pnas.1518165112] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A diverse microbial assemblage in the ocean is responsible for nearly half of global primary production. It has been hypothesized and experimentally demonstrated that nutrient loading can stimulate blooms of large eukaryotic phytoplankton in oligotrophic systems. Although central to balancing biogeochemical models, knowledge of the metabolic traits that govern the dynamics of these bloom-forming phytoplankton is limited. We used eukaryotic metatranscriptomic techniques to identify the metabolic basis of functional group-specific traits that may drive the shift between net heterotrophy and autotrophy in the oligotrophic ocean. Replicated blooms were simulated by deep seawater (DSW) addition to mimic nutrient loading in the North Pacific Subtropical Gyre, and the transcriptional responses of phytoplankton functional groups were assayed. Responses of the diatom, haptophyte, and dinoflagellate functional groups in simulated blooms were unique, with diatoms and haptophytes significantly (95% confidence) shifting their quantitative metabolic fingerprint from the in situ condition, whereas dinoflagellates showed little response. Significantly differentially abundant genes identified the importance of colimitation by nutrients, metals, and vitamins in eukaryotic phytoplankton metabolism and bloom formation in this system. The variable transcript allocation ratio, used to quantify transcript reallocation following DSW amendment, differed for diatoms and haptophytes, reflecting the long-standing paradigm of phytoplankton r- and K-type growth strategies. Although the underlying metabolic potential of the large eukaryotic phytoplankton was consistently present, the lack of a bloom during the study period suggests a crucial dependence on physical and biogeochemical forcing, which are susceptible to alteration with changing climate.
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10
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Serret P, Robinson C, Aranguren-Gassis M, García-Martín EE, Gist N, Kitidis V, Lozano J, Stephens J, Harris C, Thomas R. Both respiration and photosynthesis determine the scaling of plankton metabolism in the oligotrophic ocean. Nat Commun 2015; 6:6961. [PMID: 25908109 PMCID: PMC4462842 DOI: 10.1038/ncomms7961] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 03/19/2015] [Indexed: 11/09/2022] Open
Abstract
Despite its importance to ocean-climate interactions, the metabolic state of the oligotrophic ocean has remained controversial for >15 years. Positions in the debate are that it is either hetero- or autotrophic, which suggests either substantial unaccounted for organic matter inputs, or that all available photosynthesis (P) estimations (including (14)C) are biased. Here we show the existence of systematic differences in the metabolic state of the North (heterotrophic) and South (autotrophic) Atlantic oligotrophic gyres, resulting from differences in both P and respiration (R). The oligotrophic ocean is neither auto- nor heterotrophic, but functionally diverse. Our results show that the scaling of plankton metabolism by generalized P:R relationships that has sustained the debate is biased, and indicate that the variability of R, and not only of P, needs to be considered in regional estimations of the ocean's metabolic state.
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Affiliation(s)
- Pablo Serret
- Departamento de Ecología y Biología animal, Universidad de Vigo, E36310 Vigo, Spain.,Estación de Ciencias Marinas de Toralla, Universidad de Vigo, Toralla island, E-36331 Vigo, Spain
| | - Carol Robinson
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | | | | | - Niki Gist
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - Vassilis Kitidis
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - José Lozano
- Departamento de Ecología y Biología animal, Universidad de Vigo, E36310 Vigo, Spain.,Estación de Ciencias Marinas de Toralla, Universidad de Vigo, Toralla island, E-36331 Vigo, Spain
| | - John Stephens
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - Carolyn Harris
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK
| | - Rob Thomas
- British Oceanographic Data Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool L3 5DA, UK
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11
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Fassbender AJ, Sabine CL, Lawrence-Slavas N, De Carlo EH, Meinig C, Maenner Jones S. Robust sensor for extended autonomous measurements of surface ocean dissolved inorganic carbon. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:3628-3635. [PMID: 25692825 DOI: 10.1021/es5047183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ocean carbon monitoring efforts have increased dramatically in the past few decades in response to the need for better marine carbon cycle characterization. Autonomous pH and carbon dioxide (CO2) sensors capable of yearlong deployments are now commercially available; however, due to their strong covariance, this is the least desirable pair of carbonate system parameters to measure for high-quality, in situ, carbon-cycle studies. To expand the number of tools available for autonomous carbonate system observations, we have developed a robust surface ocean dissolved inorganic carbon (DIC) sensor capable of extended (>year) field deployments with a laboratory determined uncertainty of ±5 μmol kg(-1). Results from the first two field tests of this prototype sensor indicate that measurements of DIC are ∼90% more accurate than estimates of DIC calculated from contemporaneous and collocated measurements of pH and CO2. The improved accuracy from directly measuring DIC gives rise to new opportunities for quantitative, autonomous carbon-cycle studies.
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Affiliation(s)
- Andrea J Fassbender
- †University of Washington, School of Oceanography, Box 357940, Seattle, Washington 98105, United States
| | - Christopher L Sabine
- ‡National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory, Seattle, Washington 98115, United States
| | - Noah Lawrence-Slavas
- ‡National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory, Seattle, Washington 98115, United States
| | - Eric H De Carlo
- §University of Hawai'i at Ma̅noa, School of Ocean and Earth Science and Technology, Honolulu, Hawaii 96822, United States
| | - Christian Meinig
- ‡National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory, Seattle, Washington 98115, United States
| | - Stacy Maenner Jones
- ‡National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory, Seattle, Washington 98115, United States
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12
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Weinke AD, Kendall ST, Kroll DJ, Strickler EA, Weinert ME, Holcomb TM, Defore AA, Dila DK, Snider MJ, Gereaux LC, Biddanda BA. Systematically variable planktonic carbon metabolism along a land-to-lake gradient in a Great Lakes coastal zone. JOURNAL OF PLANKTON RESEARCH 2014; 36:1528-1542. [PMID: 25954055 PMCID: PMC4226232 DOI: 10.1093/plankt/fbu066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 06/30/2014] [Indexed: 06/04/2023]
Abstract
During the summers of 2002-2013, we measured rates of carbon metabolism in surface waters of six sites across a land-to-lake gradient from the upstream end of drowned river-mouth Muskegon Lake (ML) (freshwater estuary) to 19 km offshore in Lake Michigan (LM) (a Great Lake). Despite considerable inter-year variability, the average rates of gross production (GP), respiration (R) and net production (NP) across ML (604 ± 58, 222 ± 22 and 381 ± 52 µg C L-1 day-1, respectively) decreased steeply in the furthest offshore LM site (22 ± 3, 55 ± 17 and -33 ± 15 µg C L-1day-1, respectively). Along this land-to-lake gradient, GP decreased by 96 ± 1%, whereas R only decreased by 75 ± 9%, variably influencing the carbon balance along this coastal zone. All ML sites were consistently net autotrophic (mean GP:R = 2.7), while the furthest offshore LM site was net heterotrophic (mean GP:R = 0.4). Our study suggests that pelagic waters of this Great Lakes coastal estuary are net carbon sinks that transition into net carbon sources offshore. Reactive and dynamic estuarine coastal zones everywhere may contribute similarly to regional and global carbon cycles.
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Affiliation(s)
- Anthony D. Weinke
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
| | - Scott T. Kendall
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
| | - Daniel J. Kroll
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
- Munson Medical Center, 1105 6th Street, Traverse City, MI 49684, USA
| | - Eric A. Strickler
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
- Salish Sea Expeditions, 647 Horizon View Pl Nw, Bainbridge Isle, WA 98110, USA
| | - Maggie E. Weinert
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
| | - Thomas M. Holcomb
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
- Herman Miller, 855 East Main Street, Mail Stop 0156, Zeeland, MI 49464, USA
| | - Angela A. Defore
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
- USC Baruch Marine Field Lab, U. South Carolina, Po Box 1630, Georgetown, SC 29442, USA
| | - Deborah K. Dila
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
- School of Freshwater Sciences, U. Wisconsin-Milwaukee, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA
| | - Michael J. Snider
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
| | - Leon C. Gereaux
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
| | - Bopaiah A. Biddanda
- Annis Water Resources Institute, Grand Valley State University, 740 West Shoreline Drive, Muskegon, MI 49441, USA
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13
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Wilson JM, Severson R, Beman JM. Ocean-scale patterns in community respiration rates along continuous transects across the Pacific Ocean. PLoS One 2014; 9:e99821. [PMID: 25048960 PMCID: PMC4105538 DOI: 10.1371/journal.pone.0099821] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 05/19/2014] [Indexed: 11/21/2022] Open
Abstract
Community respiration (CR) of organic material to carbon dioxide plays a fundamental role in ecosystems and ocean biogeochemical cycles, as it dictates the amount of production available to higher trophic levels and for export to the deep ocean. Yet how CR varies across large oceanographic gradients is not well-known: CR is measured infrequently and cannot be easily sensed from space. We used continuous oxygen measurements collected by autonomous gliders to quantify surface CR rates across the Pacific Ocean. CR rates were calculated from changes in apparent oxygen utilization and six different estimates of oxygen flux based on wind speed. CR showed substantial spatial variation: rates were lowest in ocean gyres (mean of 6.93 mmol m−3 d−1±8.0 mmol m−3 d−1 standard deviation in the North Pacific Subtropical Gyre) and were more rapid and more variable near the equator (8.69 mmol m−3 d−1±7.32 mmol m−3 d−1 between 10°N and 10°S) and near shore (e.g., 5.62 mmol m−3 d−1±45.6 mmol m−3 d−1 between the coast of California and 124°W, and 17.0 mmol m−3 d−1±13.9 mmol m−3 d−1 between 156°E and the Australian coast). We examined how CR varied with coincident measurements of temperature, turbidity, and chlorophyll concentrations (a proxy for phytoplankton biomass), and found that CR was weakly related to different explanatory variables across the Pacific, but more strongly related to particular variables in different biogeographical areas. Our results indicate that CR is not a simple linear function of chlorophyll or temperature, and that at the scale of the Pacific, the coupling between primary production, ocean warming, and CR is complex and variable. We suggest that this stems from substantial spatial variation in CR captured by high-resolution autonomous measurements.
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Affiliation(s)
- Jesse M. Wilson
- Life and Environmental Sciences, Environmental Systems, and Sierra Nevada Research Institute, University of California Merced, Merced, California, United States of America
- * E-mail:
| | - Rodney Severson
- Life and Environmental Sciences, Environmental Systems, and Sierra Nevada Research Institute, University of California Merced, Merced, California, United States of America
| | - J. Michael Beman
- Life and Environmental Sciences, Environmental Systems, and Sierra Nevada Research Institute, University of California Merced, Merced, California, United States of America
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Siu N, Apple JK, Moyer CL. The Effects of Ocean Acidity and Elevated Temperature on Bacterioplankton Community Structure and Metabolism. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/oje.2014.48038] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Wang P, Li Q, Tian J, Jian Z, Liu C, Li L, Ma W. Long-term cycles in the carbon reservoir of the Quaternary ocean: a perspective from the South China Sea. Natl Sci Rev 2013. [DOI: 10.1093/nsr/nwt028] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
In recent years, long-term, high-resolution records from the deep sea and ice-cores have offered new research opportunities for Quaternary science. Paleoclimate studies are no longer restricted to individual glacial cycles, but extend to long-term (≥105 yr) processes across those cycles. Ocean Drilling Program Leg 184 of the South China Sea in 1999 uncovered well-preserved sediment sections, in which three long-term cycles in Pleistocene carbon isotope (δ13C) sequence have been found and demonstrated to be common in the global ocean. Subsequent discoveries confirm the existence of long-term processes of 105 yr in both the hydrologic (ice-sheet changes) and carbon (biogeochemical changes) cycles, posing the question whether the two processes are related. The present review shows that the long-eccentricity cycles prevail throughout the δ13C and other biogeochemical records in geologic history, and 400-kyr cycles in the oceanic δ13C sequence before the Quaternary can be hypothetically explained by changes in ratio between particulate and dissolved organic carbon (POC/DOC) in the ocean, depending on the monsoon-controlled nutrient supply. This is a ‘DOC hypothesis’. However, ocean restructuring at 1.6 Ma marked by the isolation of a sluggish abyss under the Southern Ocean has obscured the long-eccentricity 400-kyr signal in oceanic δ13C. The last million-year period has experienced two major changes in the climate regime, namely the mid-Pleistocene transition (MPT) centered at 0.9 Ma and the mid-Brunhes event (MBE) around 0.4 Ma. The MPT and MBE were preluded by δ13C maxima-III (δ13Cmax-III) ∼ 1.0 Ma and δ13Cmax-II ∼ 0.5 Ma, respectively. Together with similar hydroclimatic phenomena over corresponding glacial cycles, the two groups of hydrologic and biogeochemical events appear to have been driven largely by oceanographic changes in the Southern Ocean. Therefore, we interpret that the long-term biogeochemical processes originating from the Southern Ocean must have played a crucial role in Quaternary ice-sheet waxing and waning.
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Affiliation(s)
- PinXian Wang
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
| | - QianYu Li
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
| | - Jun Tian
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
| | - ZhiMin Jian
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
| | - ChuanLian Liu
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
| | - Li Li
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
| | - WenTao Ma
- State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
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Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic. PLoS One 2013; 8:e69159. [PMID: 23935946 PMCID: PMC3720584 DOI: 10.1371/journal.pone.0069159] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 06/11/2013] [Indexed: 11/19/2022] Open
Abstract
Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.
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Duarte CM, Regaudie-de-Gioux A, Arrieta JM, Delgado-Huertas A, Agustí S. The oligotrophic ocean is heterotrophic. ANNUAL REVIEW OF MARINE SCIENCE 2012; 5:551-569. [PMID: 22809189 DOI: 10.1146/annurev-marine-121211-172337] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Incubation (in vitro) and incubation-free (in situ) methods, each with their own advantages and limitations, have been used to derive estimates of net community metabolism in the oligotrophic subtropical gyres of the open ocean. The hypothesis that heterotrophic communities are prevalent in most oligotrophic regions is consistent with the available evidence and supported by scaling relationships showing that heterotrophic communities prevail in areas of low gross primary production, low chlorophyll a, and warm water, conditions found in the oligotrophic ocean. Heterotrophic metabolism can prevail where heterotrophic activity is subsidized by organic carbon inputs from the continental shelf or the atmosphere and from nonphotosynthetic autotrophic and mixotrophic metabolic pathways. The growth of the oligotrophic regions is likely to be tilting the metabolic balance of the ocean toward a greater prevalence of heterotrophic communities.
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Affiliation(s)
- Carlos M Duarte
- Department of Global Change Research, Mediterranean Institute of Advanced Studies, Esporles, Spain.
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Juranek LW, Quay PD. Using triple isotopes of dissolved oxygen to evaluate global marine productivity. ANNUAL REVIEW OF MARINE SCIENCE 2012; 5:503-524. [PMID: 22809194 DOI: 10.1146/annurev-marine-121211-172430] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Since the triple isotopic composition of dissolved O(2) ((17)Δ) was introduced as a natural tracer of photosynthetic gross O(2) production (GOP) over 10 years ago, observations of (17)Δ have been used to constrain marine productivity throughout the global ocean. This incubation-independent approach has several advantages: It allows the determination of production free from containment artifacts and reduces logistical hurdles that can make obtaining productivity with traditional incubation-dependent methods difficult. As such, GOP estimates derived from (17)Δ have been used to give insight into potential biases in incubation-based approaches and to evaluate satellite-based estimates of production at the regional scale. With increased use, we have also learned more about the potential biases and uncertainties of this approach, some of which have been addressed by recent method improvements. We recap the major advances the (17)Δ method has brought to improved understanding of biological carbon cycling, from incubation bottles to ocean basins.
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Affiliation(s)
- L W Juranek
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA.
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Nguyen D, Maranger R, Tremblay JÉ, Gosselin M. Respiration and bacterial carbon dynamics in the Amundsen Gulf, western Canadian Arctic. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jc007343] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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20
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Abstract
Oligotrophic subtropical gyres are the largest oceanic ecosystems, covering >40% of the Earth's surface. Unicellular cyanobacteria and the smallest algae (plastidic protists) dominate CO(2) fixation in these ecosystems, competing for dissolved inorganic nutrients. Here we present direct evidence from the surface mixed layer of the subtropical gyres and adjacent equatorial and temperate regions of the Atlantic Ocean, collected on three Atlantic Meridional Transect cruises on consecutive years, that bacterioplankton are fed on by plastidic and aplastidic protists at comparable rates. Rates of bacterivory were similar in the light and dark. Furthermore, because of their higher abundance, it is the plastidic protists, rather than the aplastidic forms, that control bacterivory in these waters. These findings change our basic understanding of food web function in the open ocean, because plastidic protists should now be considered as the main bacterivores as well as the main CO(2) fixers in the oligotrophic gyres.
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Needoba JA, Peterson TD, Johnson KS. Method for the Quantification of Aquatic Primary Production and Net Ecosystem Metabolism Using In Situ Dissolved Oxygen Sensors. SPRINGER PROTOCOLS HANDBOOKS 2012. [DOI: 10.1007/978-1-61779-915-0_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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22
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Abstract
Cells maintain an osmotic pressure essential for growth and division, using organic compatible solutes and inorganic ions. Mg(2+), which is the most abundant divalent cation in living cells, has not been considered an osmotically important solute. Here we show that under carbon limitation or dormancy native marine bacterial communities have a high cellular concentration of Mg(2+) (370-940 mM) and a low cellular concentration of Na(+) (50-170 mM). With input of organic carbon, the average cellular concentration of Mg(2+) decreased 6-12-fold, whereas that of Na(+) increased ca 3-4-fold. The concentration of chlorine, which was in the range of 330-1200 mM, and was the only inorganic counterion of quantitative significance, balanced and followed changes in the concentration of Mg(2+)+Na(+). In an osmotically stable environment, like seawater, any major shift in bacterial osmolyte composition should be related to shifts in growth conditions, and replacing organic compatible solutes with inorganic solutes is presumably a favorable strategy when growing in carbon-limited condition. A high concentration of Mg(2+) in cells may also serve to protect and stabilize macromolecules during periods of non-growth and dormancy. Our results suggest that Mg(2+) has a major role as osmolyte in marine bacteria, and that the [Mg(2+)]/[Na(+)] ratio is related to its physiological condition and nutritional status. Bacterial degradation is a main sink for dissolved organic carbon in the ocean, and understanding the mechanisms limiting bacterial activity is therefore essential for understanding the oceanic C-cycle. The [Mg(2+)]/[Na(+)]-ratio in cells may provide a physiological proxy for the transitions between C-limited and mineral nutrient-limited bacterial growth in the ocean's surface layer.
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Morán XAG, Alonso-Sáez L. Independence of bacteria on phytoplankton? Insufficient support for Fouilland & Mostajir's (2010) suggested new concept. FEMS Microbiol Ecol 2011; 78:203-5; author reply 206-9. [PMID: 21732956 DOI: 10.1111/j.1574-6941.2011.01167.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Decrease in the autotrophic-to-heterotrophic biomass ratio of picoplankton in oligotrophic marine waters due to bottle enclosure. Appl Environ Microbiol 2011; 77:5739-46. [PMID: 21742930 DOI: 10.1128/aem.00066-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the effects of bottle enclosure on autotrophic and heterotrophic picoplankton in North and South subtropical Atlantic oligotrophic waters, where the biomass and metabolism of the microbial community are dominated by the picoplankton size class. We measured changes in both autotrophic (Prochlorococcus, Synechococcus, and picoeukaryotes) and heterotrophic picoplankton biomass during three time series experiments and in 16 endpoint experiments over 24 h in light and dark treatments. Our results showed a divergent effect of bottle incubation on the autotrophic and heterotrophic components of the picoplankton community. The biomass of picophytoplankton showed, on average, a >50% decrease, mostly affecting the picoeukaryotes and, to a lesser extent, Prochlorococcus. In contrast, the biomass of heterotrophic bacteria remained constant or increased during the incubations. We also sampled 10 stations during a Lagrangian study in the North Atlantic subtropical gyre, which enabled us to compare the observed changes in the auto- to heterotrophic picoplankton biomass ratio (AB:HB ratio) inside the incubation bottles with those taking place in situ. While the AB:HB ratio in situ remained fairly constant during the Lagrangian study, it decreased significantly during the 24 h of incubation experiments. Thus, the rapid biomass changes observed in the incubations are artifacts resulting from bottle confinement and do not take place in natural conditions. Our results suggest that short (<1 day) bottle incubations in oligotrophic waters may lead to biased estimates of the microbial metabolic balance by underestimating primary production and/or overestimating bacterial respiration.
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25
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Dave AC, Lozier MS. Local stratification control of marine productivity in the subtropical North Pacific. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jc006507] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Sarmento H, Montoya JM, Vázquez-Domínguez E, Vaqué D, Gasol JM. Warming effects on marine microbial food web processes: how far can we go when it comes to predictions? Philos Trans R Soc Lond B Biol Sci 2010; 365:2137-49. [PMID: 20513721 DOI: 10.1098/rstb.2010.0045] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Previsions of a warmer ocean as a consequence of climatic change point to a 2-6 degrees C temperature rise during this century in surface oceanic waters. Heterotrophic bacteria occupy the central position of the marine microbial food web, and their metabolic activity and interactions with other compartments within the web are regulated by temperature. In particular, key ecosystem processes like bacterial production (BP), respiration (BR), growth efficiency and bacterial-grazer trophic interactions are likely to change in a warmer ocean. Different approaches can be used to predict these changes. Here we combine evidence of the effects of temperature on these processes and interactions coming from laboratory experiments, space-for-time substitutions, long-term data from microbial observatories and theoretical predictions. Some of the evidence we gathered shows opposite trends to warming depending on the spatio-temporal scale of observation, and the complexity of the system under study. In particular, we show that warming (i) increases BR, (ii) increases bacterial losses to their grazers, and thus bacterial-grazer biomass flux within the microbial food web, (iii) increases BP if enough resources are available (as labile organic matter derived from phytoplankton excretion or lysis), and (iv) increases bacterial losses to grazing at lower rates than BP, and hence decreasing the proportion of production removed by grazers. As a consequence, bacterial abundance would also increase and reinforce the already dominant role of microbes in the carbon cycle of a warmer ocean.
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Affiliation(s)
- Hugo Sarmento
- Institut de Ciències del Mar-CSIC, Pg. Marítim de la Barceloneta 37-49, 08003 Barcelona, Catalunya, Spain.
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Cassar N, Barnett BA, Bender ML, Kaiser J, Hamme RC, Tilbrook B. Continuous high-frequency dissolved O2/Ar measurements by equilibrator inlet mass spectrometry. Anal Chem 2010; 81:1855-64. [PMID: 19193192 DOI: 10.1021/ac802300u] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The oxygen (O(2)) concentration in the surface ocean is influenced by biological and physical processes. With concurrent measurements of argon (Ar), which has similar solubility properties as oxygen, we can remove the physical contribution to O(2) supersaturation and determine the biological oxygen supersaturation. Biological O(2) supersaturation in the surface ocean reflects the net metabolic balance between photosynthesis and respiration, i.e., the net community productivity (NCP). We present a new method for continuous shipboard measurements of O(2)/Ar by equilibrator inlet mass spectrometry (EIMS). From these measurements and an appropriate gas exchange parametrization, NCP can be estimated at high spatial and temporal resolution. In the EIMS configuration, seawater from the ship's continuous intake flows through a cartridge enclosing a gas-permeable microporous membrane contactor. Gases in the headspace of the cartridge equilibrate with dissolved gases in the flowing seawater. A fused-silica capillary continuously samples headspace gases, and the O(2)/Ar ratio is measured by mass spectrometry. The ion current measurements on the mass spectrometer reflect the partial pressures of dissolved gases in the water flowing through the equilibrator. Calibration of the O(2)/Ar ion current ratio (32/40) is performed automatically every 2 h by sampling ambient air through a second capillary. A conceptual model demonstrates that the ratio of gases reaching the mass spectrometer is dependent on several parameters, such as the differences in molecular diffusivities and solubilities of the gases. Laboratory experiments and field observations performed by EIMS are discussed. We also present preliminary evidence that other gas measurements, such as N(2)/Ar and pCO(2) measurements, may potentially be performed with EIMS. Finally, we compare the characteristics of the EIMS with the previously described membrane inlet mass spectrometry (MIMS) approach.
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Affiliation(s)
- Nicolas Cassar
- Department of Geosciences, Princeton University, Princeton, New Jersey 08544, USA.
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Torréton JP, Rochelle-Newall E, Pringault O, Jacquet S, Faure V, Briand E. Variability of primary and bacterial production in a coral reef lagoon (New Caledonia). MARINE POLLUTION BULLETIN 2010; 61:335-348. [PMID: 20619862 DOI: 10.1016/j.marpolbul.2010.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We assessed the temporal variability of nutrients, phytoplankton and bacterioplankton at two sites of different trophic status in New Caledonia's South-West lagoon, a tropical coastal ecosystem. During stable meteorological conditions, Chl.a, bacterial production and nutrient concentrations experience weak but consistent daily variation. Short-term (1-2 week interval) fluctuations of planktonic variables are in the same range as annual variations at both sites. A part of these short term variations is linked to local meteorological events (wind in the main channel, precipitation at the coastal station). Although annual variations are weak compared to short term variations, phytoplankton and bacterioplankton production show consistent temporal patterns, with maxima in December-January and April-May and minima in August. Annual bacterial production represents 21% and 34% of particulate primary production at the oligotrophic and mesotrophic sites, respectively. Mineral nutrient availability indicates that nitrogen is probably the primary limiting factor of phytoplankton throughout the year.
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Affiliation(s)
- Jean-Pascal Torréton
- UR 103, CAMELIA, UMR 5119 ECOLAG, Université Montpellier II, Case 093, 34095 Montpellier, France.
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Seasonal dynamics of SAR11 populations in the euphotic and mesopelagic zones of the northwestern Sargasso Sea. ISME JOURNAL 2008; 3:283-95. [PMID: 19052630 DOI: 10.1038/ismej.2008.117] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Bacterioplankton belonging to the SAR11 clade of a-proteobacteria were counted by fluorescence in situ hybridization (FISH) over eight depths in the surface 300 m at the Bermuda Atlantic Time-series Study (BATS) site from 2003 to 2005. SAR11 are dominant heterotrophs in oligotrophic systems; thus, resolving their temporal dynamics can provide important insights to the cycling of organic and inorganic nutrients. This quantitative time-series data revealed distinct annual distribution patterns of SAR11 abundance in the euphotic (0-120) and upper mesopelagic (160-300 m) zones that were reproducibly correlated with seasonal mixing and stratification of the water column. Terminal restriction fragment length polymorphism (T-RFLP) data generated from a decade of samples collected at BATS were combined with the FISH data to model the annual dynamics of SAR11 subclade populations. 16S rRNA gene clone libraries were constructed to verify the correlation of the T-RFLP data with SAR11 clade structure. Clear vertical and temporal transitions were observed in the dominance of three SAR11 ecotypes. The mechanisms that lead to shifts between the different SAR11 populations are not well understood, but are probably a consequence of finely tuned physiological adaptations that partition the populations along physical and chemical gradients in the ecosystem. The correlation between evolutionary descent and temporal/spatial patterns we describe, confirmed that a minimum of three SAR11 ecotypes occupy the Sargasso Sea surface layer, and revealed new details of their population dynamics.
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Borges AV, Ruddick K, Schiettecatte LS, Delille B. Net ecosystem production and carbon dioxide fluxes in the Scheldt estuarine plume. BMC Ecol 2008; 8:15. [PMID: 18778481 PMCID: PMC2556646 DOI: 10.1186/1472-6785-8-15] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2007] [Accepted: 09/08/2008] [Indexed: 11/22/2022] Open
Abstract
Background A time series of 4 consecutive years of measurements of the partial pressure of CO2 (pCO2) in the Scheldt estuarine plume is used here to estimate net ecosystem production (NEP). Results NEP in the Scheldt estuarine plume is estimated from the temporal changes of dissolved inorganic carbon (DIC). The strong seasonal variations of NEP are consistent with previous reports on organic carbon dynamics in the area. These variations are related to successive phytoplankton blooms that partly feed seasonally variable heterotrophy the rest of the year. On an annual time scale the Scheldt estuarine plume behaves as a net heterotrophic system sustained with organic carbon input from the Scheldt inner estuary and the Belgian coast. During one of the years of the time-series the estuarine plume behaved annually as a net autotrophic system. This anomalous ecosystem metabolic behaviour seemed to result from a combination of bottom-up factors affecting the spring phytoplankton bloom (increased nutrient delivery and more favourable incoming light conditions). This net autotrophy seemed to lead to a transient aa accumulation of organic carbon, most probably in the sediments, that fed a stronger heterotrophy the following year. Conclusion The present work highlights the potential of using pCO2 data to derive detailed seasonal estimates of NEP in highly dynamic coastal environments. These can be used to determine potential inter-annual variability of NEP due to natural climatic oscillations or due to changes in anthropogenic impacts.
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Affiliation(s)
- Alberto V Borges
- University of Liège, Chemical Oceanography Unit, Institut de Physique (B5), B-4000, Liège, Belgium.
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31
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Riser SC, Johnson KS. Net production of oxygen in the subtropical ocean. Nature 2008; 451:323-5. [PMID: 18202655 DOI: 10.1038/nature06441] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Accepted: 11/05/2007] [Indexed: 11/09/2022]
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Abstract
Despite the impressive advances that have been made in assessing the diversity of marine microorganisms, the mechanisms that underlie the participation of microorganisms in marine food webs and biogeochemical cycles are poorly understood. Here, we stress the need to examine the biochemical interactions of microorganisms with ocean systems at the nanometre to millimetre scale--a scale that is relevant to microbial activities. The local impact of microorganisms on biogeochemical cycles must then be scaled up to make useful predictions of how marine ecosystems in the whole ocean might respond to global change. This approach to microbial oceanography is not only helpful, but is in fact indispensable.
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Affiliation(s)
- Farooq Azam
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA.
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Abstract
Life on Earth most likely originated as microorganisms in the sea. Over the past approximately 3.5 billion years, microorganisms have shaped and defined Earth's biosphere and have created conditions that have allowed the evolution of macroorganisms and complex biological communities, including human societies. Recent advances in technology have highlighted the vast and previously unknown genetic information that is contained in extant marine microorganisms, from new protein families to novel metabolic processes. Now there is a unique opportunity, using recent advances in molecular ecology, metagenomics, remote sensing of microorganisms and ecological modelling, to achieve a comprehensive understanding of marine microorganisms and their susceptibility to environmental variability and climate change. Contemporary microbial oceanography is truly a sea of opportunity and excitement.
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Affiliation(s)
- David M Karl
- University of Hawaii, Honolulu, Hawaii 96822, USA.
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McGillicuddy DJ, Anderson LA, Bates NR, Bibby T, Buesseler KO, Carlson CA, Davis CS, Ewart C, Falkowski PG, Goldthwait SA, Hansell DA, Jenkins WJ, Johnson R, Kosnyrev VK, Ledwell JR, Li QP, Siegel DA, Steinberg DK. Eddy/wind interactions stimulate extraordinary mid-ocean plankton blooms. Science 2007; 316:1021-6. [PMID: 17510363 DOI: 10.1126/science.1136256] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Episodic eddy-driven upwelling may supply a significant fraction of the nutrients required to sustain primary productivity of the subtropical ocean. New observations in the northwest Atlantic reveal that, although plankton blooms occur in both cyclones and mode-water eddies, the biological responses differ. Mode-water eddies can generate extraordinary diatom biomass and primary production at depth, relative to the time series near Bermuda. These blooms are sustained by eddy/wind interactions, which amplify the eddy-induced upwelling. In contrast, eddy/wind interactions dampen eddy-induced upwelling in cyclones. Carbon export inferred from oxygen anomalies in eddy cores is one to three times as much as annual new production for the region.
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Bloom dynamics in a seasonally forced phytoplankton–zooplankton model: Trigger mechanisms and timing effects. ECOLOGICAL COMPLEXITY 2006. [DOI: 10.1016/j.ecocom.2005.11.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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López-Urrutia A, San Martin E, Harris RP, Irigoien X. Scaling the metabolic balance of the oceans. Proc Natl Acad Sci U S A 2006; 103:8739-44. [PMID: 16731624 PMCID: PMC1482648 DOI: 10.1073/pnas.0601137103] [Citation(s) in RCA: 170] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Oceanic communities are sources or sinks of CO2, depending on the balance between primary production and community respiration. The prediction of how global climate change will modify this metabolic balance of the oceans is limited by the lack of a comprehensive underlying theory. Here, we show that the balance between production and respiration is profoundly affected by environmental temperature. We extend the general metabolic theory of ecology to the production and respiration of oceanic communities and show that ecosystem rates can be reliably scaled from theoretical knowledge of organism physiology and measurement of population abundance. Our theory predicts that the differential temperature-dependence of respiration and photosynthesis at the organism level determines the response of the metabolic balance of the epipelagic ocean to changes in ambient temperature, a prediction that we support with empirical data over the global ocean. Furthermore, our model predicts that there will be a negative feedback of ocean communities to climate warming because they will capture less CO2 with a future increase in ocean temperature. This feedback of marine biota will further aggravate the anthropogenic effects on global warming.
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Affiliation(s)
- Angel López-Urrutia
- Centro Oceanográfico de Gijón, Instituto Español de Oceanografía, Avenida Príncipe de Asturias, 70 bis, E-33212 Gijón, Spain.
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Ferreyra GA, Mostajir B, Schloss IR, Chatila K, Ferrario ME, Sargian P, Roy S, Prod'homme J, Demers S. Ultraviolet-B Radiation Effects on the Structure and Function of Lower Trophic Levels of the Marine Planktonic Food Web. Photochem Photobiol 2006; 82:887-97. [PMID: 17205621 DOI: 10.1562/2006-02-23-ra-810] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The impact of UV-B radiation (UVBR; 280-320 nm) on lower levels of a natural plankton assemblage (bacteria, phytoplankton and microzooplankton) from the St. Lawrence Estuary was studied during 9 days using several immersed outdoor mesocosms. Two exposure treatments were used in triplicate mesocosms: natural UVBR (N treatment, considered as the control treatment) and lamp-enhanced UVBR (H treatment, simulating 60% depletion of the ozone layer). A phytoplankton bloom developed after day 3, but no significant differences were found between treatments during the entire experiment for phytoplankton biomass (chlorophyll a and cell carbon) nor for phytoplankton cell abundances from flow cytometry and optical microscopy of three phytoplankton size classes (picoplankton, nanoplankton and microplankton). In contrast, bacterial abundances showed significantly higher values in the H treatment, attributed to a decrease in predation pressure due to a dramatic reduction in ciliate biomass (approximately 70-80%) in the H treatment relative to the N treatment. The most abundant ciliate species were Strombidinium sp., Prorodon ovum and Tintinnopsis sp.; all showed significantly lower abundances under the H treatment. P. ovum was the less-affected species (50% reduction in the H treatment compared with that of the N control), contrasting with approximately 90% for the other ones. Total specific phytoplanktonic and bacterial production were not affected by enhanced UVBR. However, both the ratio of primary to bacterial biomass and production decreased markedly under the H treatment. In contrast, the ratio of phytoplankton to bacterial plus ciliate carbon biomass showed an opposite trend than the previous results, with higher values in the H treatment at the end of the experiment. These results are explained by the changes in the ciliate biomass and suggest that UVBR can alter the structure of the lower levels of the planktonic community by selectively affecting key species. On the other hand, linearity between particulate organic carbon (POC) and estimated planktonic carbon was lost during the postbloom period in both treatments. On the basis of previous studies, our results can be attributed to the aggregation of carbon released by cells to the water column in the form of transparent exopolymer particles (TEPs) under nutrient limiting conditions. Unexpectedly, POC during such a period was higher in the H treatment than in controls. We hypothesize a decrease in the ingestion of TEPs by ciliates, in coincidence with increased DOC release by phytoplankton cells under enhanced UVBR. The consequences of such results for the carbon cycle in the ocean are discussed.
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Affiliation(s)
- Gustavo A Ferreyra
- Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, 310 Allée des Ursulines, Canada G5L 3A1.
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Duarte CM, Prairie YT. Prevalence of Heterotrophy and Atmospheric CO2 Emissions from Aquatic Ecosystems. Ecosystems 2005. [DOI: 10.1007/s10021-005-0177-4] [Citation(s) in RCA: 251] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Sakamoto CM. Influence of Rossby waves on nutrient dynamics and the plankton community structure in the North Pacific subtropical gyre. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jc001976] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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