Miller, Carrie J. (2007-05). Factors influencing algal biomass in hydrologically dynamic salt ponds in a subtropical salt marsh. Master's Thesis. Thesis uri icon

abstract

  • The interface between land and water is often a dynamic zone that responds to
    relatively short-term climatic and hydrologic forces. Coastal salt marshes occupy this
    zone between land and sea and typically are comprised of vegetated marsh intersected by
    channels and shallow ponds that are subject to flooding by winds, tides, and storm
    surges. Coastal salt marshes are widely regarded as zones of high macrophyte
    productivity. However, microalgae may contribute more to salt marsh productivity than
    previously realized, underscoring the importance of understanding algal dynamics in
    such systems. Benthic and planktonic chlorophyll-a (surrogate for total algal biomass),
    sediment AFDW, total suspended solids, salinity, and nutrients were examined in marsh
    ponds in the subtropical Guadalupe Estuary, TX, USA to determine the effects of
    hydrologic connections on algal biomass in this system. From May 2005 - May 2006
    there were several pond connection, disconnection, and desiccation events. During
    periods of disconnection, algal biomass was higher in both the benthos and the water
    column than during connection events when supposed flushing occurred. Connection
    events also flushed out high NH4 accumulating in pond surface waters, but did not increase NOx. Therefore, the primary source of DIN seemed to be nutrient cycling
    within the ponds. There was a temporal effect on surface water salinity, which increased
    throughout the sampling period as bay water levels and subsequent pond connections
    decreased, demonstrating interannual variability and the link between seasons (wet vs.
    dry) and marsh inundation patterns (high water periods vs. low water periods) in this
    estuary.

publication date

  • May 2007