Table of Contents

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

Samples for quantification of B-vitamins B1, B7, CB12 and Methionine were collected at a six of depths within the euphotic zone (5-250m). Seawater was collected from each CTD depth using Niskin bottles and immediately filtered. Particulate samples for chlorophyll quantifications were collected using in-line 0.2um, 3µm and 10um pore-size filters and a peristaltic pump (flow rate < 50 ml per minute), transferred into sterile cryovials and were immediately stored at -80 degrees C until analysis. Pigments were extracted from the filters in 3 mL of methanol, BHT(butylated hydroxytoluene) was added and placed in a -20 degrees C freezer overnight. For chlorophyll-a measurements, 100 microliters of the pigment extraction were diluted in acetone (50x dilution) and analyzed using a Turner 10AU fluorometer.

B-vitamins and Methionine samples were analyzed as in Suffridge et al. 2017. Two liters of seawater were filtered through um pore-size filters and then preconcentrated using a C18 resin (HF Bondesil (Agilent Technologies) and analyzed by liquid chromatography/triple mass spectrometry (LC/MS/MS/MS). The LCMS system consists of a ThermoTSQ Quantum Access electro-spray ionization triple quadrupole mass spectrometer, coupled to a Thermo Accela High Speed Liquid Chromatography system. The LC system used a stable- bond C18 reversed-phase column (DiscoveryHSC18 10cm × 2.1mm,5 μm column, Supelco Analytical) with a100 uL sample loop. In order to increase the sensitivity and precision, theLC/MS was run in full-loop mode (100 ul/injection).

Bacterial cell counts were heterotrophic prokaryotes were enumerated by flow-cytometry (Becton–Dickinson FACScalibur) (Gasol & del Giorgio, 2000).

Data Processing: The LC-MS data was processed using Xcalibur and LCQUAN quantitative softwares from Thermo Scientific.

Problem report: The SPOT sampling for the months of May and July were carried out on the research vessel  Nerissa of the Orange County Sanitation District. This was because the RV Yellowfin was in the dry dock for maintenance and repairs. Unfortunately, the light intensity for those two months is missing due to problems with the sensor. 

BCO-DMO Processing:
- replaced spaces with underscores in cruise names;
- changed date format from m/d/yyyy to yyyy-mm-dd;
- separated time column into Time_start and Time_end
- converted Latitude and Longitude from degrees and minutes to decimal degrees, added new columns and removed original;
- modified parameter names (replaced spaces and decimals with underscores, removed units)
- filled in empty cells with "nd"; replaced NaN with "nd" ("no data").

Description from NSF award abstract:
B-vitamins (thiamin (B1), biotin (B7), and cobalamin (B12)) are organic molecules used by all organisms for many biochemical reactions ranging from DNA and amino acid synthesis to carbon dioxide assimilation. Despite their metabolic importance, many marine organisms cannot make them and need to obtain them from the environment. Because the requirement for a specific vitamin is different for different organisms, changes in the species composition of algae could be explained by their different B-vitamin requirements. For example, changes in the biological properties of waters during an algal bloom (removal of needed vitamins and release of other vitamins) may favor algae that require the vitamin released by the previous bloom (setting up a floral succession). This selective preconditioning of the waters may be one factor in the seasonal succession of algal species. However, evaluating the role of vitamins in marine ecology has been difficult. No study to date has been comprehensive enough to estimate the importance of vitamins in primary productivity and species succession. This is especially true in coastal upwelling regions that although relatively small in area, are orders of magnitude more productive than their open-ocean counterparts. In fact, those regions contribute a significant portion of the world fisheries. Therefore, in order to try to predict future changes in the world ocean due to human activity, the variables that influence or control the algal communities that dominate the very productive food chains of upwelling regions need to be identified.

This study will investigate how the availability of B-vitamins affects the dynamics of algal- and bacterioplankton population growth in coastal waters of an upwelling region off Southern California. This comprehensive field investigation will determine in situ temporal concentrations of several dissolved and particulate B-vitamins, inorganic micro- and macronutrients, concurrently with seasonal changes in phytoplankton and bacterial abundances and species composition at a long-term time series station within the San Pedro Basin near Los Angeles. Those measurements will be complemented with field incubation experiments with natural plankton assemblages to study the effect of organic and inorganic nutrient amendments on phytoplankton and bacterial community structure. This study will establish for the first time that the availability of ambient B-vitamins influence algal and bacterial species succession in a highly productive coastal upwelling region and that multiple and differing B-vitamin requirements limit growth of some phytoplankton species in those areas. Furthermore, this study will try to show that coastal upwelling transports some B-vitamins to the phytoplankton community in the photic zone from bacterially-influenced source waters within the upper mesopelagic zone.