Diel series of pico-cyanobacteria concentration and cell properties from the RV Cape Hatteras cruises CH0409 and CH0510 in the Western Sargasso Sea in 2009 and 2010.

Website: https://www.bco-dmo.org/dataset/716814
Data Type: Cruise Results
Version: 1
Version Date: 2017-10-12

Project
» Top-Down Regulation of Picophytoplankton in the Sargasso Sea: Application of a Reciprocal Transplant / Dilution Approach (Picophytoplankton_Regulation)
ContributorsAffiliationRole
Binder, BrianUniversity of Georgia (UGA)Principal Investigator
Ake, HannahWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Abstract
Diel series of pico-cyanobacteria concentration and cell properties from the RV Cape Hatteras cruises CH0409 and CH0510 in the Western Sargasso Sea in 2009 and 2010.


Coverage

Spatial Extent: N:30.9082 E:-71.8634 S:30.1464 W:-72.8769
Temporal Extent: 2009-05-26 - 2010-05-31

Dataset Description

Diel series of pico-cyanobacteria concentration and cell properties.

These data were published in Hynes et al., 2015 and Rhodes K.L., 2009

Other relevant publication: Binder et al., 1996


Methods & Sampling

Samples were taken using a rosette of Niskin bottles, fixed with freshly titrated paraformaldehyde (pH 7.4–8.1, 0.1% final concentration), held in the dark for 10 min, frozen in liquid nitrogen, and stored in a -80 deg C freezer (CH0409 samples) or in liquid nitrogen (CH0510 samples) until analysis. Preserved samples were analyzed by dual beam flow cytometry on a modified Coulter-EPICS 753 flow cytometer (Binder et al. 1996). Samples were chosen in random order, defrosted in a 30°C water bath (just long enough to melt, ~5 min), and stained with the DNA-specific stain Hoechst 33342 (0.5 ug mL-1 final concentration) (Invitrogen, Carlsbad, California) for a minimum of 20 min in the dark. Prior to analysis, polystyrene fluorescent beads (0.5 um and 1.0 um diameter Flow CheckVR ; Polysciences, Washington, Pennsylvania), were added to each sample, and used to normalize cellular light scatter and red (chlorophyll-derived) fluorescence. Samples were run at an infusion rate of 10 uL min-1 for 10–50 min, depending on cell abundance within the sample.

Mean red fluorescence and forward angle light scatter for each cell type in each sample are linearized and normalized to 1.0 um and 0.5 um diameter beads (see above), respectively. Thus the measurements are relative, and are only meaningful for comparisons of cellular properties within this data set.


Data Processing Description

BCO-DMO Data Processing Notes:

- separated Time.UTC column into two columns - date_UTC and time_UTC
- reformatted date to yyyy/mm/dd and time to 24hr time
- reformatted column names to comply with BCO-DMO standards
- added ISO_DateTime_UTC column


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Data Files

File
picoplankton.csv
(Comma Separated Values (.csv), 25.05 KB)
MD5:6c5920e0b4fd2bc13d945f211fe81b55
Primary data file for dataset ID 716814

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Related Publications

Binder, B.J., Chisholm, S.W., Olson, R.J., Frankel, S.L., Worden, A.Z. (1996). Dynamics of picophytoplankton, ultraphytoplankton, and bacteria in the central equatorial Pacific. Deep-Sea Res. II 43:907-931.
Methods
Hynes, A. M., Rhodes, K. L., & Binder, B. J. (2015). Assessing cell cycle-based methods of measuringProchlorococcusdivision rates using an individual-based model. Limnology and Oceanography: Methods, 13(11), 640–650. doi:10.1002/lom3.10054
General
Rhodes, K.L. (2009). The Role of Physiology in the Formation of Prochlorococcus Sub-Surface Maxima in the Sargasso Sea (Master’s Thesis). University of Georgia, Athens, GA.
General

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Parameters

ParameterDescriptionUnits
Cruise

R/V Cape Hatteras Cruise Designation

unitless
Wx

Experiment Designation

unitless
date_UTC

Sampling date; yyyy/mm/dd

unitless
time_UTC

Sampling time; hh:mm

unitless
Lat

Sampling latitude; E is positive

decimal degrees
Lon

Sampling longitude; N is positive

decimal degrees
Depth

Sample depth

meters
pro

Prochlorococcus cellular concentration

cells per milliliter
syn

Synechococcus cellular concentration

cells per milliliter
pro_red

Mean Prochlorococcus cellular red fluorescence

relative
pro_fals

Mean Prochlorococcus cellular forward angle light scatter

relative
syn_red

Mean Synechococcus cellular red fluorescence

relative
syn_fals

Mean Synechococcus cellular forward angle light scatter

relative
ISO_DateTime_UTC

DateTime UTC; ISO formatted

unitless


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Instruments

Dataset-specific Instrument Name
Coulter-EPICS 753 flow cytometer
Generic Instrument Name
Flow Cytometer
Dataset-specific Description
Used to analyze preserved samples
Generic Instrument Description
Flow cytometers (FC or FCM) are automated instruments that quantitate properties of single cells, one cell at a time. They can measure cell size, cell granularity, the amounts of cell components such as total DNA, newly synthesized DNA, gene expression as the amount messenger RNA for a particular gene, amounts of specific surface receptors, amounts of intracellular proteins, or transient signalling events in living cells. (from: http://www.bio.umass.edu/micro/immunology/facs542/facswhat.htm)

Dataset-specific Instrument Name
Niskin bottle
Generic Instrument Name
Niskin bottle
Dataset-specific Description
Used to take samples in rosette
Generic Instrument Description
A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc.


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Deployments

CH0409

Website
Platform
R/V Cape Hatteras
Report
Start Date
2009-05-20
End Date
2009-06-02
Description
Project: Top-Down Regulation of Picophytoplankton in the Sargasso Sea: Development and Application of a Reciprocal Transplant/Dilution Approach

CH0510

Website
Platform
R/V Cape Hatteras
Report
Start Date
2010-05-20
End Date
2010-06-02
Description
Project: Top-Down Regulation of Picophytoplankton in the Sargasso Sea: Development and Application of a Reciprocal Transplant/Dilution Approach


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Project Information

Top-Down Regulation of Picophytoplankton in the Sargasso Sea: Application of a Reciprocal Transplant / Dilution Approach (Picophytoplankton_Regulation)

Coverage: Western Sargasso Sea (vicinity of 30 N 72 W)


The intellectual merit of the research is to extend our understanding of the biology and ecology of marine picophytoplankton, a group of microbes that are responsible for a large proportion of the total photosynthetic carbon fixation that occurs in the world's oceans. The importance of picophytoplankton as the dominant primary producers in open-ocean ecosystems is well-established. However, the factors that regulate the distribution and abundance of these populations remain poorly understood. The investigators will explore the dynamics of top-down (grazer-mediated) regulation of picophytoplankton populations in a specific context: the maintenance of summertime subsurface maxima in the pico-cyanobacterium Prochlorococcus (but not Synechococcus) in the Sargasso Sea. This phenomenon represents a relatively simple and predictable model system within which to test hypotheses about the regulation of oceanic picophytoplankton in general.
Recent results suggest that despite their abundance, Prochlorococcus in the subsurface maxi-mum are growing (and being grazed) rather slowly, as compared to the smaller population at the surface. In order to understand the factors responsible for this apparent paradox, this project will use a combination of field and laboratory studies to characterize and compare the interactions between Prochorococcus and its protozoan grazers at these two contrasting depths, and in relation to Synechococcus, which forms no such sub-surface maximum.
The broader impacts include training for graduate and undergraduate students. In addition, given the significance of picophytoplankton as primary producers at the base of oceanic microbial food webs, the results of this project should inform efforts to describe and model the broader oceanic ecosystem, and ultimately to understand its role in the global carbon cycle.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)

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