Colleges and Schools

Permanent URI for this community

http://hdl.handle.net/1969.1/2815

Browse

Browsing Colleges and Schools by Author "2008 Ocean Sciences Meeting: From the Watershed to the Global Ocean, Orlando, FL (USA), 2-7 Mar 2008"

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    Development and evolution of operational forecast systems for the coastal and estuarine environment in NOAA's National Ocean Service
    (American Geophysical Union, 2008) Aikman, F; Vincent, M; Patchen, R; 2008 Ocean Sciences Meeting: From the Watershed to the Global Ocean, Orlando, FL (USA), 2-7 Mar 2008
    NOAA's National Ocean Service (NOS) applies hydrodynamic models for the development, transition and implementation of operational forecast systems (OFS) in U.S. estuaries, ports, lakes and the coastal ocean. These systems have applications in the support of marine navigation, emergency response, as well as marine ecological applications. There are currently nine water bodies in which OFS's are functioning (the Chesapeake Bay, the Port of NY/NJ, Galveston Bay, the St Johns River, and the five Great Lakes). OFS's are under development for the Columbia River, Delaware and Tampa Bays, as well as for Cook Inlet, AK and elsewhere. Once evaluated and deemed accurate by NOS standards, the OFS's are transitioned into the operational environment.
  • No Thumbnail Available
    Item
    How Will Changes in Freshwater Inflow (Frequency versus Magnitude) Impact the Ecosystem Health of Galveston Bay?
    (American Geophysical Union, 2008) Thronson, AM; Hsiu-Ping, L; Davis, SE; Roelke, DL; Quigg, AS; 2008 Ocean Sciences Meeting: From the Watershed to the Global Ocean, Orlando, FL (USA), 2-7 Mar 2008
    With a rapidly expanding urban population in Texas coastal municipalities, water regulators and managers are faced with the challenge of meeting human needs, potentially by freshwater diversions, while maintaining critical freshwater inflows to estuaries to preserve their overall health. We used a flow-through boat-mounted Dataflow unit and a PHYTO-PAM (Phytoplankton Pulse Amplitude Modulated fluorometer) to map various water quality parameters and primary productivity respectively across Galveston Bay throughout 2006. Tightly gridded transects took two days to complete. An integrated GPS allowed us to reference all measurements for each variable. Discrete water samples were collected for nutrient analysis and light/dark bottle primary productivity measurements. We found complex relationships between the freshwater inflow (frequency, magnitude), water quality (temperature, salinity, dissolved organic matter, chlorophyll, nutrients) and phytoplankton responses (productivity, community structure). Spatial and temporal patterns were deconvoluted with seasonality and the magnitude of a freshwater inflow event being the two principal driving factors regulating primary productivity. Understanding these relationships will provide scientists and regulators with information to assess estuary health in Galveston Bay as well as other estuaries along the Texas coast.
  • No Thumbnail Available
    Item
    Hypoxia Formation Along Coastal Texas Due to Brazos River Flooding: Summer 2007
    (American Geophysical Union, 2008) DiMarco, SF; Dellapenna, T; Shormann, D; Denton, W; Howard, MK; May,; 2008 Ocean Sciences Meeting: From the Watershed to the Global Ocean, Orlando, FL (USA), 2-7 Mar 2008
    Record setting rainfall over Texas during MayaAugust 2007 led to unseasonably large summer freshwater discharge of the Brazos River into the Gulf of Mexico. A National Marine Fisheries Service cruise in late June 2007 showed a plume of hypoxic near-bottom oxygen concentrations (less than 2.0 mg/l) extending from the Brazos River mouth southwestward along the Texas coast to Matagorda Bay. Subsequent nearshore observations along the Texas coast in July showed persistently low dissolved oxygen and highly stratified conditions. In August, a four-vessel survey was conducted to provide estimates of the spatial distribution of water column stability, dissolved oxygen, organic material, particulate, chlorophyll, and nutrient concentrations between Galveston and Matagorda Bay, Texas. Low dissolved oxygen concentrations were correlated with freshwater capping. High surface silicate was coincident with large diatom numbers. Bottom nutrient concentrations were consistent with remineralization processes. Coastal observations on 18 September show the Texas hypoxic region was dissipated by mixing resulting from winds associated with Hurricane Humberto. Analysis of recent water quality data indicates that Texas coastal hypoxia may be more frequent than previously thought.
  • No Thumbnail Available
    Item
    River Inflow Effects on Structure and Function of Two Texas Estuaries
    (American Geophysical Union, 2008) Davis, SE; Roelke, DL; Li, HP; Liu, KJ; Pinckney, J; Quigg, A; 2008 Ocean Sciences Meeting: From the Watershed to the Global Ocean, Orlando, FL (USA), 2-7 Mar 2008
    River inflow and nutrient loading to an estuary contribute greatly to estuarine water quality and ecosystem health, and in some estuaries, poor health, reduced productivity, and even losses of coastal wetlands have been linked to modifications in freshwater input. Given the rapid development in Texas and the stateas plans for water diversion along the coast, an understanding of the importance of natural variation in freshwater inflow events to estuaries is needed. From 2005-2006 we conducted monthly samplings in the Guadalupe (i.e. San Antonio Bay) and Trinity-San Jacinto (i.e. Galveston Bay) estuaries to map water quality at a high spatial resolution and sample fixed stations along the estuarine gradient for nutrient content and water column productivity. Variations in river inflow conditions during this period yielded a range of spatial patterns in surface water quality with consistently strong negative correlation between CDOM and salinity and positive correlation between chlorophyll a and CDOM. We also observed strong river source signals of nitrogen and phosphorus from these different watersheds and consistent, net autotrophic conditions in the water column of both estuaries.