Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Supplemental Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

Hydrographic data was collected during the RVIB Nathaniel B. Palmer cruise (NBP1801) from December 31st, 2017 to March 3rd, 2018. Samples were collected by trace metal rosette (TMR) using the Saito laboratory 8L X-Niskin bottles. Bottles were brought into a clean van, pressurized with high-purity nitrogen gas and filtered through 0.2 micron 142mm Supor membrane filters. Nutrient samples were filled in acid-washed 60mL HDPE bottles and frozen until analysis. 

Nutrient analyses were conducted by Joe Jennings at Oregon State University using a nutrient autoanalyzer following the methods of Noble et al. (2012). Technicon AutoAnalyzer II components were used to measure phosphate and ammonium. Alpkem rapid flow analyzer (RFA) 300 components were used to measure silicic acid, nitrate+nitrite, and nitrite.

For quality control (QC) notes, please see the document "Quality Control notes for NBP1801 nutrients" in the Supplemental Files section. 

NOTE:  The PAR sensor was not present on the first leg of the cruise, so PAR values were not measured until Station 35.  

BCO-DMO processing
- converted Date to YMD format
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions

NSF abstract:
Phytoplankton blooms in the coastal waters of the Ross Sea, Antarctica are typically dominated by either diatoms or Phaeocystis Antarctica (a flagellated algae that often can form large colonies in a gelatinous matrix). The project seeks to determine if an association of bacterial populations with Phaeocystis antarctica colonies can directly supply Phaeocystis with Vitamin B12, which can be an important co-limiting micronutrient in the Ross Sea. The supply of an essential vitamin coupled with the ability to grow at lower iron concentrations may put Phaeocystis at a competitive advantage over diatoms. Because Phaeocystis cells can fix more carbon than diatoms and Phaeocystis are not grazed as efficiently as diatoms, the project will help in refining understanding of carbon dynamics in the region as well as the basis of the food web webs. Such understanding also has the potential to help refine predictive ecological models for the region. The project will conduct public outreach activities and will contribute to undergraduate and graduate research. Engagement of underrepresented students will occur during summer student internships. A collaboration with Italian Antarctic researchers, who have been studying the Terra Nova Bay ecosystem since the 1980s, aims to enhance the project and promote international scientific collaborations.

The study will test whether a mutualistic symbioses between attached bacteria and Phaeocystis provides colonial cells a mechanism for alleviating chronic Vitamin B12 co-limitation effects thereby conferring them with a competitive advantage over diatom communities. The use of drifters in a time series study will provide the opportunity to track in both space and time a developing algal bloom in Terra Nova Bay and to determine community structure and the physiological nutrient status of microbial populations. A combination of flow cytometry, proteomics, metatranscriptomics, radioisotopic and stable isotopic labeling experiments will determine carbon and nutrient uptake rates and the role of bacteria in mitigating potential vitamin B12 and iron limitation. Membrane inlet and proton transfer reaction mass spectrometry will also be used to estimate net community production and release of volatile organic carbon compounds that are climatically active. Understanding how environmental parameters can influence microbial community dynamics in Antarctic coastal waters will advance an understanding of how changes in ocean stratification and chemistry could impact the biogeochemistry and food web dynamics of Southern Ocean ecosystems.