Contributors | Affiliation | Role |
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Brzezinski, Mark A. | University of California-Santa Barbara (UCSB-MSI) | Principal Investigator |
Rauch, Shannon | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
See the following protocol documents:
32Si Sample Processing (.doc)
Biogenic Si Analysis (.doc)
Dissolved Si Analysis (.doc)
BCO-DMO Processing Notes:
- replaced spaces with underscores;
- added column for lon (in negative degrees east rather than positive degrees west);
- modified parameter names to conform with BCO-DMO naming conventions;
- removed "ms" (meters) from sample depth column and bottom depth column;
- replaced ~ with 'nd' to indicate 'no data';
- replaced 'sfc' with '1' in depth_sample column (per email from Janice Jones on 21 Aug 2015).
File |
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IrnBru.csv (Comma Separated Values (.csv), 39.65 KB) MD5:ec4cbd2c91515dab0e5433bfe1ce99cc Primary data file for dataset ID 564697 |
Parameter | Description | Units |
cruise_id | Cruise during which sample was collected. | dimensionless |
event | Event number from Bruland event log. | dimensionless |
station | Sampling station number or location. | dimensionless |
date_utc | UTC date (day-month-year). | dd-mon-YYYY |
julian_day_utc | UTC julian day of year. | dimensionless |
time_utc | UTC time (hours:minutes). | HH:MM |
lat | Latitude in decimal degrees. Positive values = North. | decimal degrees |
lon | Longitude in decimal degrees. Positive values = East. | decimal degrees |
depth_sample | Samplling depth in meters. | meters (m) |
depth_bottom | Bottom depth in meters. | meters (m) |
cast_type | Cast type (CTD or experiment). | dimensionless |
bottle_rosette | Rosette bottle number. | dimensionless |
pcnt_lo | Percent light level (PAR sensor) | percent (%) |
bottle_carboy | Sample identifier. | dimensionless |
depth_target | Target depth for sample collection. | meters (m) |
BRZ_dSi | Silicic acid concentration (also known as dissolved silicon concentration or dSi). | micromoles Si per Liter (umol/L) |
bSi | Particulate biogenic silica in micromoles Si per liter. | micromoles Si per Liter (umol/L) |
Si32_rho | Silica production rate. | micromoles Si per Liter per day (umol Si/L/d) |
Si32_Vb | Biomass normalized silica production rate. | per day (d-1) |
Si32_E_rho | Silica production rate after the addition of 20 mM sodium silicate. | micromoles Si per Liter per day (umol Si/L/d) |
Si32_E_Vb | Biomass normalized silica production rate after the addition of 20 mM sodium silicate. | per day (d-1) |
ISO_DateTime_UTC | Date and time formatted to ISO 8601 standard. | YYYY-mm-ddTHH:MM:SS.xx |
Website | |
Platform | R/V Melville |
Start Date | 2014-07-03 |
End Date | 2014-07-26 |
Description | Deployment MV1405 on R/V Melville. Cruise took place during July 2014. |
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) |