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Hawaii Ocean Experiment - Dynamics of Light and Nutrients (HOE-DYLAN)

Discrete cruise measurements/experiments

1. Sampling during selected HOE-DYLAN cruises

  • Picoeukaryote population dyamics measured via CTD profiles and deckboard incubation experiments (Shimi Rii; KM1215)
  • Measuring the abundance, diversity, distribution, and gene expression of UCYN-A and its associate at Station ALOHA (Anne Thompson; KM1219)
  • Metabolic patterns of eukaryotic phytoplankton and Trichodesmium using metatranscriptome profiling (Sonya Dyhrman, Monica Rouco Molina, Harriet Alexander; KM1217, KM1219)
  • Study of the abundance and distribution of clades I and II of the nitrogen-fixing cyanobacterium Trichodesmium sp. with depth and time (Monica Rouco Molina; KM1217)
  • Hydrogen cycling associated with nitrogen fixation (Sam Wilson; KM1215, KM1219)
  • Metabolism of DMSP, specifically the effect of availability of substrate and C1-compounds. I am also interested in looking at the potential competition between Prochlorococcus and heterotrophic bacteria (especially SAR11) for DMSP and methionine. I will also be conducting experiments related to methane production from methylphosphonic acid (Daniela del Valle; KM1219)
  • Nutrient addition experiments to investigate factors regulating the utilization of DOM by heterotrophic bacteria (Sandra Martinez-Garcia; KM1219)
  • Completing an intercalibration of sample collection methods for colloidal Fe using microfiltration and cross-flow filtration techniques (Jess Fitzsimmons; KM1215)
  • Analysis of low molecular weight acids and photorespiration during incubation experiments and daily profiles (John Casey; KM1219)
  • Analysis of soluble and colloidal Fe-binding ligands by cross flow filtration. The samples will be analyzed by HPLC-ICPMS in order to separate and identify Fe-binding ligands across Fe size fractions (Rene Boiteau; KM1219)
  • Thorium isotopes depth profile for quantification of metal scavenging (Jess Fitzsimmons, Katharina Pahnke; KM1215)
  • Fe isotope profile (Jess Fitzsimmons; KM1215)
  • Screening isolated microbes for reactive oxygen species (ROS) production (Emily Estes; KM1215)
  • Role of ROS, particularly superoxide in the water column. Measuring concentration, decay rates, and production (photochemical and biological) of superoxide (Kelly Roe; KM1215)
  • Characterize biological production and decay rates of hydrogen peroxide under both light and dark conditions (Robin Schneider; KM1215)
  • Measuring the gene expression of size-fractionated microbial communities at 25 m, DCM and 250 m (Kristina Fontanez; KM1219)
  • Response of Prochlorococcus populations to intermittent nitrate upwelling (Paul Berube; KM1215, KM1217, and KM1219)

2. Deckboard incubation experiments

  • Remineralization capabilities of heterotrophic communities at different depths by deckboard incubation studies (Brian Burkhardt; KM1215)
  • Comparison of carbon and nitrogen fixation rates by Trichodesmium colonies under various carbon dioxide, light and nutrient conditions (Rosie Gradoville; KM1217)
  • Characterization of the Trichodesmium phylotypes in colonies collected by net tows (Rosie Gradoville; KM1217)
  • Nitrogen addition experiment to determine the response of photosynthetic picoeukaryote assemblage structure and physiology to variations in nitrogen concentrations and sources (Shimi Rii; KM1215)
  • Ocean acidification experiments (Daniela Böttjer/Donn Viviani; KM1219)
  • Nutrient-pertubation experiments to examine the response of the phytoplankton assemblages in near-surface waters to different N species (Kendra Turk-Kubo; KM1219)
  • Photosynthesis-Irradiance Curves, Day length manipulation experiments, FCM determination of fluorescence to scattering ratios as a function of growth irradiance (Angelique White/Katie Watkins-Brandt/Morgaine McKibben; KM1217 & KM1219)
  • POM-enrichment experiment to examine gene expression of particle-associated surface communities (Kristina Fontanez; KM1219)
  • Nitrification rate measurements associated with the NO2 maximum and using inhibitors for bacteria and archaea (Alex Galan; KM1219)

3. Miscellaneous

  • ALOHA profiler Communicate with the ALOHA profiling mooring
  • Satellite calibration Matching VIIRS data (Curtiss Davis, Ricardo Letelier), with HPLC data (Bob Bidigare), HyperPRO (Benedetto/Angel)