Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Cell counts: Ruegeria pomeroyi, Thalassiosira pseudonana, and Alexandrium tamarense cells were measured using a flow cytometer.

DIN: Cadmium reduction method; Nitrate is measured by reducing it to nitrite in an alkaline-buffered solution passing through a column of copper-cadmium metal filings and then measuring nitrite by diazotizing with sulfanilamide and coupling with N-(1-naphthyl)-ethylenediamine dihydrochloride to form a pink colored azo dye which is measured colorimetrically. Instrument: Alpkem and Astoria-Pacific Autoanalyzers

DIP: Orthophosphate method; PO4 is measured colorimetrically as an antimony-phospho-molybdate complex (APHA 4500-P F) that is reduced to an intensely blue-colored complex by ascorbic acid. Instrument: Alpkem and Astoria-Pacific Autoanalyzers

DOC: Combustion method; Total dissolved carbon and dissolved inorganic carbon are determined by combustion of an unacidified and acidified 0.2 micron filtered subsamples. DOC concentration is calculated by subtracting the DIC concentration from the TDC concentration. Instrument: Shimadzu TOC-5000A Total Organic Carbon Analyzer

TOC: Combustion method; Total organic carbon is determined by combustion of an unacidified and unfiltered sample. Instrument: Shimadzu TOC-5000A Total Organic Carbon Analyzer

DMSP: See: Rellinger, A., et al. Occurrence and turnover of DMSP and DMS in deep waters of the Ross Sea, Antarctica. Deep-Sea Research I 56 (2009) 686–702. doi:10.1016/j.dsr.2008.12.010

BCO-DMO Processing notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- replaced commas with underscores

Surface ocean bacterioplankton preside over a divergence point in the marine sulfur cycle where the fate of dimethylsulfoniopropionate (DMSP) is determined. While it is well recognized that this juncture influences the fate of sulfur in the ocean and atmosphere, its regulation by bacterioplankton is not yet understood. Based on recent findings in biogeochemistry, bacterial physiology, bacterial genetics, and ocean instrumentation, the microbial oceanography community is poised to make major advances in knowledge of this control point. This research project is ascertaining how the major taxa of bacterial DMSP degraders in seawater regulate DMSP transformations, and addresses the implications of bacterial functional, genetic, and taxonomic diversity for global sulfur cycling.

The project is founded on the globally important function of bacterial transformation of the ubiquitous organic sulfur compound DMSP in ocean surface waters. Recent genetic discoveries have identified key genes in the two major DMSP degradation pathways, and the stage is now set to identify the factors that regulate gene expression to favor one or the other pathway during DMSP processing. The taxonomy of the bacteria mediating DMSP cycling has been deduced from genomic and metagenomic sequencing surveys to include four major groups of surface ocean bacterioplankton. How regulation of DMSP degradation differs among these groups and maps to phylogeny in co-occurring members is key information for understanding the marine sulfur cycle and predicting its function in a changing ocean. Using model organism studies, microcosm experiments (at Dauphin Island Sea Lab, AL), and time-series field studies with an autonomous sample collection instrument (at Monterey Bay, CA), this project is taking a taxon-specific approach to decipher the regulation of bacterial DMSP degradation.

This research addresses fundamental questions of how the diversity of microbial life influences the geochemical environment of the oceans and atmosphere, linking the genetic basis of metabolic potential to taxonomic diversity. The project is training graduate students and post-doctoral scholars in microbial biodiversity and providing research opportunities and mentoring for undergraduate students. An outreach program is enhance understanding of the role and diversity of marine microorganisms in global elemental cycles among high school students. Advanced Placement Biology students are participating in marine microbial research that covers key learning goals in the AP Biology curriculum. Two high school students are selected each year for summer research internships in PI laboratories.

(adapted from the NSF Synopsis of Program)
Dimensions of Biodiversity is a program solicitation from the NSF Directorate for Biological Sciences. FY 2010 was year one of the program.  [MORE from NSF]

The NSF Dimensions of Biodiversity program seeks to characterize biodiversity on Earth by using integrative, innovative approaches to fill rapidly the most substantial gaps in our understanding. The program will take a broad view of biodiversity, and in its initial phase will focus on the integration of genetic, taxonomic, and functional dimensions of biodiversity. Project investigators are encouraged to integrate these three dimensions to understand the interactions and feedbacks among them. While this focus complements several core NSF programs, it differs by requiring that multiple dimensions of biodiversity be addressed simultaneously, to understand the roles of biodiversity in critical ecological and evolutionary processes.