Grazing experiment 5: Carbon and Nitrogen data for low-high pCO2 acclimated Rhodomonas sp. cultures (E Hux Response to pCO2 project)

Website: https://www.bco-dmo.org/dataset/669403
Data Type: experimental
Version:
Version Date: 2016-12-09

Project
» Planktonic interactions in a changing ocean: Biological responses of Emiliania huxleyi to elevated pCO2 and their effects on microzooplankton (E Hux Response to pCO2)
ContributorsAffiliationRole
Olson, Brady M.Western Washington University (WWU)Principal Investigator
Love, BrookeWestern Washington University (WWU)Co-Principal Investigator
Strom, SuzanneWestern Washington University (WWU)Co-Principal Investigator
Still, Kelly AnnWestern Washington University (WWU)Student
Copley, NancyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Dataset Description

Related Reference: 
Still, Kelly Ann, Microzooplankton grazing, growth and gross growth efficiency are affected by pCO2 induced changes in phytoplankton biology. (Masters Thesis) Western Washington University. http://cedar.wwu.edu/cgi/viewcontent.cgi?article=1490&context=wwuet


Methods & Sampling

The phytoplankton Rhodomonas sp. CCMP 755 was grown semi-continuously in atmosphere controlled chambers at three different CO2 treatment concentrations; Ambient (400ppmv), Moderate (750ppmv), and High (1000ppmv).  Cultures were diluted daily starting day 4 with pre-equilibrated media containing f/50 nutrients.  Some of the culture removed was used to evaluate chemical parameters.  Samples for particulate cellular carbon and nitrogen were taken by gently vacuum filtering 100 ml from each pCO2 treatment replicate onto 21 mm muffled glass fiber (GF/F) filters.  After filtration, filters were removed and placed in tin boats.  Samples and controls (media blanks, filter blanks and capsule blanks) were placed in a drying oven for 24 hours at 60 °C, after which time they were removed and placed in a desiccator until analysis. Tin boats containing the filters and controls were folded into pellets, and then combusted using a Micro Cube elemental analyzer interfaced to a PDZ Europa 20-20 isotope ratio mass spectrometer at the UC Davis Stable Isotope Facility.


Data Processing Description

Picograms per cell for carbon and nitrogen were calculated based on standard curves and were then normalized to per cell based on cell counts for the sample day. 

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- nd (no data) was entered into all blank cells
- replaced spaces with underscores


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Data Files

File
expt5_CN.csv
(Comma Separated Values (.csv), 1.64 KB)
MD5:5a17637bbc2b93db3eed92ee5bea6433
Primary data file for dataset ID 669403

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Parameters

ParameterDescriptionUnits
day_treatment_replicateTreatment replicate that names the sample and the day of semi-continuous culture unitless
C_ugparticulate carbon in sample micrograms (ug)
C_pgparticulate carbon in sample picograms (ug)
N_ugparticulate nitrogen in sample micrograms (ug)
N_pgparticulate nitrogen in sample picograms (ug)
total_cellstotal number of cell on the filter cells
C_pg_cellcarbon per cell picograms/cell (pg/cell)
N_pg_cellnitrogen per cell picograms/cell (pg/cell)
C_to_Nratio of carbon to nitrogen dimensionless


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Instruments

Dataset-specific Instrument Name
PDZ Europa 20-20 isotope ratio mass spectrometer
Generic Instrument Name
Isotope-ratio Mass Spectrometer
Generic Instrument Description
The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).

Dataset-specific Instrument Name
Micro Cube elemental analyzer
Generic Instrument Name
Elemental Analyzer
Dataset-specific Description
Used to measure carbon and nitrogen concentrations
Generic Instrument Description
Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material.


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Deployments

Lab_Olson_B

Website
Platform
WWU
Start Date
2011-03-31
End Date
2016-09-15
Description
laboratory experiments


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Project Information

Planktonic interactions in a changing ocean: Biological responses of Emiliania huxleyi to elevated pCO2 and their effects on microzooplankton (E Hux Response to pCO2)


Description from NSF award abstract:
The calcifying Haptophyte Emiliania huxleyi appears to be acutely sensitive to the rising concentration of ocean pCO2. Documented responses by E. huxleyi to elevated pCO2 include modifications to their calcification rate and cell size, malformation of coccoliths, elevated growth rates, increased organic carbon production, lowering of PIC:POC ratios, and elevated production of the active climate gas DMS. Changes in these parameters are mechanisms known to elicit alterations in grazing behavior by microzooplankton, the oceans dominant grazer functional group. The investigators hypothesize that modifications to the physiology and biochemistry of calcifying and non-calcifying Haptophyte Emiliania huxleyi in response to elevated pCO2 will precipitate alterations in microzooplankton grazing dynamics. To test this hypothesis, they will conduct controlled laboratory experiments where several strains of E. huxleyi are grown at several CO2 concentrations. After careful characterization of the biochemical and physiological responses of the E. huxleyi strains to elevated pCO2, they will provide these strains as food to several ecologically-important microzooplankton and document grazing dynamics. E. huxleyi is an ideal organism for the study of phytoplankton and microzooplankton responses to rising anthropogenic CO2, the effects of which in the marine environment are called ocean acidification; E. huxleyi is biogeochemically important, is well studied, numerous strains are in culture that exhibit variation in the parameters described above, and they are readily fed upon by ecologically important microzooplankton.

The implications of changes in microzooplankton grazing for carbon cycling, specifically CaCO3 export, DMS production, nutrient regeneration in surface waters, and carbon transfer between trophic levels are profound, as this grazing, to a large degree, regulates all these processes. E. huxleyi is a model prey organism because it is one of the most biogeochemically influential global phytoplankton. It forms massive seasonal blooms, contributes significantly to marine inorganic and organic carbon cycles, is a large producer of the climatically active gas DMS, and is a source of organic matter for trophic levels both above and below itself. The planned controlled study will increase our knowledge of the mechanisms that drive patterns of change between trophic levels, thus providing a wider array of tools necessary to understand the complex nature of ocean acidification field studies, where competing variables can confound precise interpretation.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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