Contributors | Affiliation | Role |
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Thamatrakoln, Kimberlee | Rutgers University (Rutgers IMCS) | Principal Investigator, Contact |
Brzezinski, Mark A. | University of California-Santa Barbara (UCSB-LifeSci) | Co-Principal Investigator |
Ake, Hannah | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
Photosynthetic data on water collected by CTD and measured using fast repetition rate fluorometry.
Photosynthetic parameters were measured using fast repetition rate fluorometry on whole seawater collected by CTD. See reference below for details on data analysis.
Photosynthetic parameters were corrected for background fluorescence by measuring 0.2 µm filtered seawater from 1-2 depths. Fo and Fm of background samples were subtracted from sample Fo and Fm and corrected values were used to calculate Fv/Fm, where Fv=Fm-Fo (Kolber et al. 1998)
DMO Notes:
-File was resubmitted by PI after some consultation with several columns and rows removed
-Column names were changed to meet BCO-DMO standards
- Some spaces were removed from cell contents
- cruise_id and ISO_DateTime_UTC column were added
File |
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photosynthetic_data.csv (Comma Separated Values (.csv), 4.45 KB) MD5:3a1d21a92492aafc6354c6ec2dcc10c8 Primary data file for dataset ID 652739 |
Parameter | Description | Units |
cruise_id | cruise identification where samples where collected | unitless |
CTD | CTD cast | unitless |
depth | depth at which samples were collected | meters |
date_local | local date of sample collection; mm/dd/yy | unitless |
time_local | local time of sample collection; HH:MM:SSpp | unitless |
Fluor_min | minimal fluorescence yield corrected for background fluorescence. Fo | relative units |
Fluor_max | maximal fluorescence yield corrected for background fluorescence. Fm | relative units |
FvFm | maximum quantum yield corrected for background fluorescence; Fv divided by Fm | dimensionless |
functional_absorption | Functional absorption cross-section of photosystem II (measured using 450 nm excitation; units A2); sigma | unitless |
connectivity_p | connectivity factor defines the efficiency of exciton energy transfer between individual photosynthetic units; originally p | unitless |
ISO_DateTime_UTC | DateTime (UTC) ISO formatted | unitless |
Dataset-specific Instrument Name | Fast Repetition Rate Fluorometer |
Generic Instrument Name | Fast Repetition Rate Fluorometer |
Dataset-specific Description | Photosynthetic parameters were measured. |
Generic Instrument Description | An FRRf is used for measuring the fluorescence of a sample of phytoplankton photosynthetic competency (Fv/Fm). |
Website | |
Platform | R/V Oceanus |
Report | |
Start Date | 2015-04-19 |
End Date | 2015-05-02 |
Description | Data for the project "Linking physiological and molecular aspects of diatom silicification in field populations" (PIs Kimberlee Thamatrakoln and Mark Brzezinski) were collected on this cruise. |
Description from NSF award abstract:
Diatoms, unicellular, eukaryotic photoautotrophs, are among the most ecologically successful and functionally diverse organisms in the ocean. In addition to contributing one-fifth of total global primary productivity, diatoms are also the largest group of silicifying organisms in the ocean. Thus, diatoms form a critical link between the carbon and silicon (Si) cycles. The goal of this project is to understand the molecular regulation of silicification processes in natural diatom populations to better understand the processes controlling diatom productivity in the sea. Through culture studies and two research cruises, this research will couple classical measurements of silicon uptake and silica production with molecular and biochemical analyses of Silicification-Related Gene (SiRG) and protein expression. The proposed cruise track off the West Coast of the US will target gradients in Si and iron (Fe) concentrations with the following goals: 1) Characterize the expression pattern of SiRGs, 2) Correlate SiRG expression patterns to Si concentrations, silicon uptake kinetics, and silica production rates, 3) Develop a method to normalize uptake kinetics and silica production to SiRG expression levels as a more accurate measure of diatom activity and growth, 4) Characterize the diel periodicity of silica production and SiRG expression.
It is estimated that diatoms process 240 Teramoles of biogenic silica each year and that each molecule of silicon is cycled through a diatom 39 times before being exported to the deep ocean. Decades of oceanographic and field research have provided detailed insight into the dynamics of silicon uptake and silica production in natural populations, but a molecular understanding of the factors that influence silicification processes is required for further understanding the regulation of silicon and carbon fluxes in the ocean. Characterizing the genetic potential for silicification will provide new information on the factors that regulate the distribution of diatoms and influence in situ rates of silicon uptake and silica production. This research is expected to provide significant information about the molecular regulation of silicification in natural populations and the physiological basis of Si limitation in the sea.
Funding Source | Award |
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NSF Division of Ocean Sciences (NSF OCE) | |
NSF Division of Ocean Sciences (NSF OCE) |