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    Grazing experiment 4: Carbonate chemistry data for low-high pCO2 acclimated Rhodomonas sp. cultures, 2011-2016 (E Hux Response to pCO2 project)

Grazing experiment 4: Carbonate chemistry data for low-high pCO2 acclimated Rhodomonas sp. cultures, 2011-2016 (E Hux Response to pCO2 project)

Website: https://www.bco-dmo.org/dataset/668621
Data Type: experimental
Version Date: 2016-12-06

» Planktonic interactions in a changing ocean: Biological responses of Emiliania huxleyi to elevated pCO2 and their effects on microzooplankton (E Hux Response to pCO2)
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
Kendall, KaseyWestern Washington University (WWU)Student
Copley, NancyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Dataset Description

Related Reference: 

Kendall, K., Marine Microzooplankton are Indirectly Affected by Ocean Acidification Through Direct Effects on Their Phytoplankton Prey. (Masters Thesis) Western Washington University. ​http://cedar.wwu.edu/wwuet/448/

Acquisition Description

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 pH were filtered through a GFF to remove cells and loose coccoliths both of which increase optical scatter.  Samples were warmed to 25°C in a water bath and run within three hours of sampling.  pH was analyzed spectrophotometrically with m-cresol dye on an Agilent 8453A UV-VIS Diode Array Spectrophotometer.  Samples for total alkalinity were taken on growth days 5, 7 and 10.  Alkalinity was measured by gran titration using a Titrando 888, and 0.1 N HCl titrant, in a temperature controlled titration vessel (+/1 5 ueq/kg).  Other parameters were calculated with CO2sys.

Processing Description

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

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treatment_repsample identifier: treatment replicate that names the sample and the day of semi-continuous culture unitless
pHpH: The measure of the acidity or basicity of an aqueous solution unitless; pH scale
pCO2Partial pressure of carbon dioxide in the water body by computation from pH and alkalinity parts per million by volume (ppmv)
DICdissolved inorganic carbon micromoles/kilogram (umol/kg)
total_alkalinitytotal alkalinity of the culture material removed micromoles/kilogram (umol/kg)

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Dataset-specific Instrument Name
Generic Instrument Name
Automatic titrator
Dataset-specific Description
Titrando 888
Generic Instrument Description
Instruments that incrementally add quantified aliquots of a reagent to a sample until the end-point of a chemical reaction is reached.

Dataset-specific Instrument Name
Agilent 8453A UV-VIS Diode Array Spectrophotometer
Generic Instrument Name
Generic Instrument Description
An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples.

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Start Date
End Date
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 SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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This document is created by info v 4.1f 5 Oct 2018 from the content of the BCO-DMO metadata database.    2022-05-18  16:38:48