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Author Stukel, M.R. ; Decima, M. ; Kelly, T.B.
Title A new approach for incorporating 15N isotopic data into linear inverse ecosystem models with Markov Chain Monte Carlo sampling Type $loc['typeJournal Article']
Year 2018 Publication PloS one Abbreviated Journal PLoS One
Volume 13
Issue 6
Pages e0199123
Keywords Isotopic data ; Nitrogen-based ecosystem models ; Phytoplankton ; Defecation by grazers ; Mortality by phytoplankton
Abstract Oceanographic field programs often use delta15N biogeochemical measurements and in situ rate measurements to investigate nitrogen cycling and planktonic ecosystem structure. However, integrative modeling approaches capable of synthesizing these distinct measurement types are lacking. We develop a novel approach for incorporating delta15N isotopic data into existing Markov Chain Monte Carlo (MCMC) random walk methods for solving linear inverse ecosystem models. We test the ability of this approach to recover food web indices (nitrate uptake, nitrogen fixation, zooplankton trophic level, and secondary production) derived from forward models simulating the planktonic ecosystems of the California Current and Amazon River Plume. We show that the MCMC with delta15N approach typically does a better job of recovering ecosystem structure than the standard MCMC or L2 minimum norm (L2MN) approaches, and also outperforms an L2MN with delta15N approach. Furthermore, we find that the MCMC with delta15N approach is robust to the removal of input equations and hence is well suited to typical pelagic ecosystem studies for which the system is usually vastly under-constrained. Our approach is easily extendable for use with delta13C isotopic measurements or variable carbon:nitrogen stoichiometry.
Address Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, United States of America
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203
ISBN Medium
Area Expedition Conference
Funding strtoupper('2').strtolower('9912928'); strtoupper('P').strtolower('MC6005467')
Approved $loc['no']
Call Number COAPS @ user @
Serial 975
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Author Coles, V.J. ; Stukel, M.R. ; Brooks, M.T. ; Burd, A. ; Crump, B.C. ; Moran, M.A. ; Paul, J.H. ; Satinsky, B.M. ; Yager, P.L. ; Zielinski, B.L. ; Hood, R.R.
Title Ocean biogeochemistry modeled with emergent trait-based genomics Type $loc['typeJournal Article']
Year 2017 Publication Science (New York, N.Y.) Abbreviated Journal Science
Volume 358
Issue 6367
Pages 1149-1154
Keywords Atlantic Ocean ; Biochemical Phenomena/genetics ; Metabolic Networks and Pathways/*genetics ; Metagenome ; *Metagenomics ; Microbial Consortia/*genetics ; Models, Biological ; Seawater/*microbiology ; Transcriptome
Abstract Marine ecosystem models have advanced to incorporate metabolic pathways discovered with genomic sequencing, but direct comparisons between models and “omics” data are lacking. We developed a model that directly simulates metagenomes and metatranscriptomes for comparison with observations. Model microbes were randomly assigned genes for specialized functions, and communities of 68 species were simulated in the Atlantic Ocean. Unfit organisms were replaced, and the model self-organized to develop community genomes and transcriptomes. Emergent communities from simulations that were initialized with different cohorts of randomly generated microbes all produced realistic vertical and horizontal ocean nutrient, genome, and transcriptome gradients. Thus, the library of gene functions available to the community, rather than the distribution of functions among specific organisms, drove community assembly and biogeochemical gradients in the model ocean.
Address Horn Point Laboratory, University of Maryland Center for Environmental Science (UMCES), Post Office Box 775, Cambridge, MD 21613, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0036-8075
ISBN Medium
Area Expedition Conference
Funding strtoupper('2').strtolower('9191900')
Approved $loc['no']
Call Number COAPS @ rl18 @
Serial 989
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Author Brzezinski, M.A. ; Krause, J.W. ; Bundy, R.M. ; Barbeau, K.A. ; Franks, P. ; Goericke, R. ; Landry, M.R. ; Stukel, M.R.
Title Enhanced silica ballasting from iron stress sustains carbon export in a frontal zone within the California Current Type $loc['typeJournal Article']
Year 2015 Publication Journal of Geophysical Research: Oceans Abbreviated Journal J. Geophys. Res. Oceans
Volume 120
Issue 7
Pages 4654-4669
Keywords phytoplankton ; diatoms ; iron limitation ; nutrient ratios ; nutrient stoichiometry ; carbon export
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-9275
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @
Serial 97
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Author Stukel, M.R. ; Kahru, M. ; Benitez-Nelson, C.R. ; Décima, M. ; Goericke, R. ; Landry, M.R. ; Ohman, M.D.
Title Using Lagrangian-based process studies to test satellite algorithms of vertical carbon flux in the eastern North Pacific Ocean Type $loc['typeJournal Article']
Year 2015 Publication Journal of Geophysical Research: Oceans Abbreviated Journal J. Geophys. Res. Oceans
Volume 120
Issue 11
Pages 7208-7222
Keywords satellite-derived export ; carbon export ; model algorithms ; mesozooplankton grazing ; sinking particles ; gravitational flux
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-9275
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @
Serial 113
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Author Stukel, M.R. ; Ducklow, H.W.
Title Stirring Up the Biological Pump: Vertical Mixing and Carbon Export in the Southern Ocean Type $loc['typeJournal Article']
Year 2017 Publication Global Biogeochemical Cycles Abbreviated Journal Global Biogeochem. Cycles
Volume 31
Issue 9
Pages 1420-1434
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Abstract
Address
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0886-6236
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @
Serial 361
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Author Conroy, B.J. ; Steinberg, D.K. ; Stukel, M.R. ; Goes, J.I. ; Coles, V.J.
Title Meso- and microzooplankton grazing in the Amazon River plume and western tropical North Atlantic Type $loc['typeJournal Article']
Year 2016 Publication Limnology and Oceanography Abbreviated Journal Limnol. Oceanogr.
Volume 61
Issue 3
Pages 825-840
Keywords
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0024-3590
ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @
Serial 74
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Author Selph, K.E. ; Landry, M.R. ; Taylor, A.G. ; Gutierrez-Rodriguez, A. ; Stukel, M.R. ; Wokuluk, J. ; Pasulka, A.
Title Phytoplankton production and taxon-specific growth rates in the Costa Rica Dome Type $loc['typeJournal Article']
Year 2016 Publication Journal of Plankton Research Abbreviated Journal J Plankton Res
Volume 38
Issue 2
Pages 199-215
Keywords Costa Rica Dome ; growth ; microzooplankton ; mortality ; phytoplankton
Abstract During summer 2010, we investigated phytoplankton production and growth rates at 19 stations in the eastern tropical Pacific, where winds and strong opposing currents generate the Costa Rica Dome (CRD), an open-ocean upwelling feature. Primary production (14C-incorporation) and group-specific growth and net growth rates (two-treatment seawater dilution method) were estimated from samples incubated in situ at eight depths. Our cruise coincided with a mild El Nino event, and only weak upwelling was observed in the CRD. Nevertheless, the highest phytoplankton abundances were found near the dome center. However, mixed-layer growth rates were lowest in the dome center ( approximately 0.5-0.9 day-1), but higher on the edge of the dome ( approximately 0.9-1.0 day-1) and in adjacent coastal waters (0.9-1.3 day-1). We found good agreement between independent methods to estimate growth rates. Mixed-layer growth rates of Prochlorococcus and Synechococcus were largely balanced by mortality, whereas eukaryotic phytoplankton showed positive net growth ( approximately 0.5-0.6 day-1), that is, growth available to support larger (mesozooplankton) consumer biomass. These are the first group-specific phytoplankton rate estimates in this region, and they demonstrate that integrated primary production is high, exceeding 1 g C m-2 day-1 on average, even during a period of reduced upwelling.
Address Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA; Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0142-7873
ISBN Medium
Area Expedition Conference
Funding PMID:27275025; PMCID:PMC4889980
Approved $loc['no']
Call Number COAPS @ mfield @
Serial 112
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Author Krause, J.W. ; Stukel, M.R. ; Taylor, A.G. ; Taniguchi, D.A.A. ; De Verneil, A. ; Landry, M.R.
Title Net biogenic silica production and the contribution of diatoms to new production and organic matter export in the Costa Rica Dome ecosystem Type $loc['typeJournal Article']
Year 2016 Publication Journal of Plankton Research Abbreviated Journal J Plankton Res
Volume 38
Issue 2
Pages 216-229
Keywords biogenic silica production ; diatom ; new production ; vertical flux
Abstract We determined the net rate of biogenic silica (bSiO2) production and estimated the diatom contribution to new production and organic matter export in the Costa Rica Dome during summer 2010. The shallow thermocline significantly reduces bSiO2 dissolution rates below the mixed layer, leading to significant enhancement of bSiO2 relative to organic matter (silicate-pump condition). This may explain why deep export of bSiO2 in this region is elevated by an order of magnitude relative to comparable systems. Diatom carbon, relative to autotrophic carbon, was low (<3%); however, the contribution of diatoms to new production averaged 3 and 13% using independent approaches. The 4-old discrepancy between methods may be explained by a low average C:Si ratio ( approximately 1.4) for the net produced diatom C relative to the net produced bSiO2. We speculate that this low production ratio is not the result of reduced C, but may arise from a significant contribution of non-diatom silicifying organisms to bSiO2 production. The contribution of diatoms to organic matter export was minor (5.7%). These results, and those of the broader project, suggest substantial food-web transformation of diatom organic matter in the euphotic zone, which creates enriched bSiO2 relative to organic matter within the exported material.
Address Scripps Institution of Oceanography , 9500 Gilman Dr., La Jolla, CA 92093-0227 , USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0142-7873
ISBN Medium
Area Expedition Conference
Funding PMID:27275026; PMCID:PMC4889982
Approved $loc['no']
Call Number COAPS @ mfield @
Serial 105
Permanent link to this record
Author Decima, M. ; Landry, M.R. ; Stukel, M.R. ; Lopez-Lopez, L. ; Krause, J.W.
Title Mesozooplankton biomass and grazing in the Costa Rica Dome: amplifying variability through the plankton food web Type $loc['typeJournal Article']
Year 2016 Publication Journal of Plankton Research Abbreviated Journal J Plankton Res
Volume 38
Issue 2
Pages 317-330
Keywords Omz ; efficiency ; food chain ; secondary production ; trophic transfer
Abstract We investigated standing stocks and grazing rates of mesozooplankton assemblages in the Costa Rica Dome (CRD), an open-ocean upwelling ecosystem in the eastern tropical Pacific. While phytoplankton biomass in the CRD is dominated by picophytoplankton (<2-microm cells) with especially high concentrations of Synechococcus spp., we found high mesozooplankton biomass ( approximately 5 g dry weight m-2) and grazing impact (12-50% integrated water column chlorophyll a), indicative of efficient food web transfer from primary producers to higher levels. In contrast to the relative uniformity in water-column chlorophyll a and mesozooplankton biomass, variability in herbivory was substantial, with lower rates in the central dome region and higher rates in areas offset from the dome center. While grazing rates were unrelated to total phytoplankton, correlations with cyanobacteria (negative) and biogenic SiO2 production (positive) suggest that partitioning of primary production among phytoplankton sizes contributes to the variability observed in mesozooplankton metrics. We propose that advection of upwelled waters away from the dome center is accompanied by changes in mesozooplankton composition and grazing rates, reflecting small changes within the primary producers. Small changes within the phytoplankton community resulting in large changes in the mesozooplankton suggest that the variability in lower trophic level dynamics was effectively amplified through the food web.
Address Dauphin Island Sea Lab , 101 Bienville Blvd, Dauphin Island, AL 36528 , USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0142-7873
ISBN Medium
Area Expedition Conference
Funding PMID:27275033; PMCID:PMC4889985
Approved $loc['no']
Call Number COAPS @ mfield @
Serial 75
Permanent link to this record
Author Stukel, M.R. ; Benitez-Nelson, C.R. ; Decima, M. ; Taylor, A.G. ; Buchwald, C. ; Landry, M.R.
Title The biological pump in the Costa Rica Dome: an open-ocean upwelling system with high new production and low export Type $loc['typeJournal Article']
Year 2016 Publication Journal of Plankton Research Abbreviated Journal J Plankton Res
Volume 38
Issue 2
Pages 348-365
Keywords Eastern Tropical Pacific ; biogeochemistry ; carbon flux ; nutrients ; plankton
Abstract The Costa Rica Dome is a picophytoplankton-dominated, open-ocean upwelling system in the Eastern Tropical Pacific that overlies the ocean's largest oxygen minimum zone. To investigate the efficiency of the biological pump in this unique area, we used shallow (90-150 m) drifting sediment traps and 234Th:238U deficiency measurements to determine export fluxes of carbon, nitrogen and phosphorus in sinking particles. Simultaneous measurements of nitrate uptake and shallow water nitrification allowed us to assess the equilibrium balance of new and export production over a monthly timescale. While f-ratios (new:total production) were reasonably high (0.36 +/- 0.12, mean +/- standard deviation), export efficiencies were considerably lower. Sediment traps suggested e-ratios (export/14C-primary production) at 90-100 m ranging from 0.053 to 0.067. ThE-ratios (234Th disequilibrium-derived export) ranged from 0.038 to 0.088. C:N and N:P stoichiometries of sinking material were both greater than canonical (Redfield) ratios or measured C:N of suspended particulates, and they increased with depth, suggesting that both nitrogen and phosphorus were preferentially remineralized from sinking particles. Our results are consistent with an ecosystem in which mesozooplankton play a major role in energy transfer to higher trophic levels but are relatively inefficient in mediating vertical carbon flux to depth, leading to an imbalance between new production and sinking flux.
Address Scripps Institution of Oceanography , University of California at San Diego , La Jolla, CA 92037 , USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English
Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0142-7873
ISBN Medium
Area Expedition Conference
Funding PMID:27275035; PMCID:PMC4889986
Approved $loc['no']
Call Number COAPS @ mfield @
Serial 90
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