DNA Analysis of Surfactant-Associated Bacteria in a Natural Sea Slick in the Gulf of Mexico Observed by TerraSAR-X

  • Kathryn Howe

    Student thesis: Master's ThesisMaster of Science

    Abstract

    Under low wind speed conditions, surfactants accumulate at the air-sea interface, dampen short-gravity capillary (Bragg) waves, and form natural sea slicks that are detectable visually and in synthetic aperture radar (SAR) imagery. Marine organisms, such as phytoplankton, zooplankton, seaweed, and bacteria, produce and degrade surfactants during various life processes. This study coordinates in situ sampling with TerraSAR-X satellite overpasses in order to help guide microbiological analysis of the sea surface microlayer (SML) and associated subsurface water (SSW). Samples were collected in the Gulf of Mexico during a research cruise (LASER) in February 2016 to determine abundance of surfactant associated bacteria in the sea surface microlayer and subsurface water column. By using real time polymerase chain reaction (quantitative PCR, or qPCR) to target Bacillus spp. associated with surfactant production, results indicate that more surfactant-associated bacteria reside in the subsurface water in low wind speed conditions. Sequencing results suggest that Bacillus and Pseudomonas are more abundant in the SSW in low wind speed conditions. These results indicate that these bacteria reside in the SSW, presumably producing surfactants that move to the surface via physical processes, accumulate on and enrich the sea surface microlayer.
    Date of AwardJul 31 2017
    Original languageEnglish
    SupervisorAlexander Soloviev (Supervisor), Brian Haus (Advisor), Mahmood S. Shivji (Advisor) & Aurelien Tartar (Advisor)

    Cite this

    '