Skip to content
University of Maryland LibrariesDigital Repository at the University of Maryland
    • Login
    View Item 
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Nitrogen Uptake and Physiology of Dinoflagellate Blooms in the East China Sea

    Thumbnail
    View/Open
    umi-umd-5460.pdf (1.716Mb)
    No. of downloads: 962

    Date
    2008-05-06
    Author
    Li, Ji
    Advisor
    Glibert, Patricia
    Metadata
    Show full item record
    Abstract
    Frequent and large scale harmful algal blooms have developed in the highly eutrophic water in the Changjiang River estuary and East China Sea coast in the past decade. Sampling and experiments were conducted during late spring and early summer of 2005 to study the dinoflagellate blooms in this region when large scale (> 15,000 km2) mixed dinoflagellate blooms developed. Karenia mikimotoi was the dominant harmful algal bloom (HAB) species in the first stage of the bloom and was succeeded by Prorocentrum donghaiense approximately 2 weeks later. Samples were collected from different stations along both north-south and west-east transects during 3 cruises. Nitrogen (N) uptake experiments were conducted during the time period that covered pre-bloom, bloom development and bloom decline. Kinetics of N uptake by phytoplankton assemblages were measured as a function of substrate concentration (4 N sources, NO3−, NH4+, urea, glycine) with 15N isotope techniques. The bloom progression was related to the change in available N and phosphorus (P) composition. Reduced N, especially NH4+ and urea, were preferentially taken up during the blooms. Both the biological availability of reduced N and the N:P ratio were suggested to be important factors for the bloom development. High inorganic nitrogen loading from the river and phosphorus from coastal water supported the bloom development. Relatively high organic nitrogen levels, and low DIN:DIP led to a succession of dinoflagellates. The temporal and spatial variability in kinetics parameters were reported as N-specific maximum uptake rates (Vmax, h-1), absolute maximum N uptake rates (ρmax, µM h-1) and half-saturation constant (Ks, µmol L-1) during the bloom progression. The results of comparison these indices with ambient nutrients and bloom progression confirmed the preferentially taken up of N by different species during the blooms. Remarkable correspondence was found about the nutrient ratios and specific uptake rates of urea between blooms in the East China Sea and in analogous blooms on the West Florida Shelf. Similar N uptake rates were also shown between the East China Sea and the Chesapeake Bay. These findings suggest that there may be general relationships between these blooms species and the availability of different nutrients and the N:P ratio. To more firmly estimate these relationships, additional laboratory experiments and more comparison among different ecosystem will be required. Such relationships will contribute to our understanding of, and ability to model, these bloom dynamics.
    URI
    http://hdl.handle.net/1903/8245
    Collections
    • Biology Theses and Dissertations
    • MEES Theses and Dissertations
    • UMD Theses and Dissertations

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility
     

     

    Browse

    All of DRUMCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister
    Pages
    About DRUMAbout Download Statistics

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility