Award: OCE-1430048

This project explored the use of long range, long endurance unmanned vehicles to explore the biology of the N. Pacific Ocean. The great size of this ocean and remoteness from ports has made documenting and exploring short lived or unpredictable aspects of its biology very difficult. In this project, we were examining the composition and characteristics of a specific type of diatom bloom. These diatoms host a nitrogen fixing symbiont that converts nitrogen gas into biological useable forms. Diatoms are unicellular algae with a glass cell wall whereas the symbiont is a filamentous cyanobacteria (blue-green algae). Together, they are termed a diatom-diazotroph association (DDA). By providing a source of biologically available nitrogen, they eliminate one of the primary limitations on growth and biomass accumulation. However, these blooms are episodic, unpredictable and fall well outside the timeline used to fund research vessels. Our approach was to test the suitability of cheaper, more nimble systems to explore these blooms. Using seed money from the Liquid Robotics PacX award prize to Dr. Tracy Villareal (Univ. of Texas at Austin) and Cara Wilson (NOAA), this NSF award allowed acquisition of holographic imaging equipment and personnel support on a Liquid Robotics SV2 Wave Glider (the Honey Badger). Glider piloting time and technical support in Hawaii was provided by Liquid Robotics, Inc. In May, 2015, we launched the Honey Badger from Hawaii for testing and then initiated the mission on 1 June 2015. Over the next 159 days, the glider successfully navigated over 8,000 km of ocean, acquired over 9,000 images of phytoplankton, and returned a high resolution dataset of temperature, salinity, biomass, variable fluorescence (a measure of phytoplankton health) along with a variety of meteorology and wave data. It was recovered in Nov. 2015. A website (http://oceanview.pfeg.noaa.gov/MAGI/#) was created to allow users and the public to examine the data in near-real time and well as download and manipulate it from a NOAA ERDDAP server. The imagery confirmed that these diatom symbioses are dominant components of these episodic blooms at levels thousands of time the background abundance, that multiple species bloom independently of each other, and that they assembly into aggregates that are a likely source of rapidly sinking material. All indications are that these blooms are physiologically vigorous. We were able to confirm that these vehicles are capable of such extended missions in the open sea, can carry sophisticated equipment specific to the mission, and could be navigated to targets of interest in near real time. The broader impacts of this project were two-fold: developing and illustrating a new integration of technologies for oceanographic work and developing human resources. The total mission costs were less than just the transit costs for a research vessel to and from the study site and illustrated the cost savings possible. The project interfaced several instruments in novel combination for remote sensing and tested specific hypothesis in an active, user-directed mode. One female graduate student was supported and developed skills in large data set manipulation as well as in the use of R and Matlab, advanced analysis and presentation software. Three presentations at national meetings have distributed the results to the scientific community. The data has been uploaded to the NSF data archive BCO-DMO (http://www.bco-dmo.org/project/505589). Last Modified: 06/23/2017 Submitted by: Tracy A Villareal