Theses and Dissertations from UMD

Permanent URI for this communityhttp://hdl.handle.net/1903/2

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM

More information is available at Theses and Dissertations at University of Maryland Libraries.

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    Nutrient effects on phytoplankton community composition in the eutrophic Anacostia River and a focus on diatom physiology
    (2019) Gleich, Samantha Julia; Glibert, Patricia M; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The Anacostia River, Washington D.C., is a freshwater ecosystem that historically received high concentrations of nutrients from sewage and stormwater outfalls. Restoration efforts have been implemented recently that may improve water quality and alter the relative abundance of different phytoplankton taxa in the river. To determine the effects that environmental shifts may have on diatom abundance and phytoplankton community composition in the Anacostia River, a mesocosm experiment and laboratory studies were conducted. The results of the mesocosm study revealed that diatoms were consistently outcompeted by cyanobacteria. Additionally, phosphorus enrichment led to a 50% increase in cyanobacterial abundance and decreased the abundance of diatoms. In the culture study, shifts in water temperature and nutrient availability altered diatom growth rates, photosynthesis, silica deposition, and NO3- reduction. Together, these studies highlight the interactive effects that nutrient availability and temperature may have on the physiology and subsequent growth of diatoms in the Anacostia River.