Contributors | Affiliation | Role |
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Binder, Brian | University of Georgia (UGA) | Principal Investigator |
Ake, Hannah | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
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
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.
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
File |
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picoplankton.csv (Comma Separated Values (.csv), 25.05 KB) MD5:6c5920e0b4fd2bc13d945f211fe81b55 Primary data file for dataset ID 716814 |
Parameter | Description | Units |
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 |
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. |
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 |
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 |
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.
Funding Source | Award |
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NSF Division of Ocean Sciences (NSF OCE) |