Aquatic Sciences Meeting, Albuquerque 2001
| PC19 Benthic Processes and Ecology |
| Date: Thursday, February 15, 2001 |
| Location: Southwest Hall |
| Jurado, J, L, University of Miami/RSMAS, Miami, USA, jjurado@rsmas.miami.edu |
| Hitchcock, G, L, University of Miami/RSMAS, Miami, USA, ghitchcock@rsmas.miami.edu |
| THE INFLUENCE OF EXOGENOUS SILICATE, SILICATE REGENERATION AND BENTHIC-PELAGIC COUPLING ON DIATOM BLOOM DYNAMICS IN NORTHWESTERN BASINS OF FLORIDA BAY |
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| Exogenous silicate input and silicate regeneration are hypothesized as important factors that contribute to the annual development, maintenance and termination of diatom blooms in northwestern basins of Florida Bay. Annual diatom bloom development begins in June with the onset of the wet season and increased freshwater input to coastal waters. Diatom abundance is inversely related to silicate concentration during bloom periods with maximum abundance occurring in near-shore waters off Cape Sable, Florida. However, diatom growth is often nitrogen-limited during bloom periods. Silicate regeneration in the water column and benthos are important mechanisms by which the diatom blooms are sustained. Water column silica dissolution satisfied up to 100% of the daily diatom silicate demand in summer and ca. 40% in winter. Benthic chambers indicate rates of silicate regeneration with maximum rates of 24.53 to 71.60 umoles/m2/hr in early summer. Comparison of light and dark chambers showed benthic microalgae influenced the benthic silicate flux with reductions of 62 and 52%, respectively. Termination of the bloom occurs in early winter as reduced rates of freshwater flow and silicate dissolution contribute to silicate-limiting growth conditions by early spring. |
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