MEPS 266:1-13 (2004)  -  doi:10.3354/meps266001

Wind events and benthic-pelagic coupling in a shallow subtropical bay in Florida

David Lawrence1, Michael J. Dagg1,*, Hongbin Liu1, Shailer R. Cummings2, Peter B. Ortner2, Christopher Kelble3

1Louisiana Universities Marine Consortium, 8124 Highway 56, Chauvin, Louisiana 70344, USA
2Atlantic Oceanographic and Meteorological Laboratory, 4301 Rickenbacker Causeway, Miami, Florida 33149, USA
3Cooperative Institute of Marine and Atmospheric Studies, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA
*Corresponding author. Email:

ABSTRACT: During the winter months (December to April), the SE United States is influenced by continental air masses from the north or northwest which pass at approximately 4 to 7 d intervals. These wind events can cause suspension of bottom sediments in Florida Bay. Over a 9 d period in March 2001, we examined the effects of a wind-mixing event on the pelagic system within the NW part of Florida Bay, where water depth is 2 to 3 m. This event caused significant suspension of bottom materials, large increases in NH4 and PO4, smaller increases in NO3+NO2 and Si(OH)4, a decrease in microzooplankton abundance, and an increase in benthic copepods in the water column. As wind speeds declined, there was a rapid decline in PO4 concentration, gradual declines in suspended sediment, NH4 and Si(OH)4, an increase in chlorophyll a (chl a) stock, an increase in phytoplankton growth and productivity, an increase in microzooplankton grazing rate, and a settling of the benthic harpacticoid community. No grazing response was apparent in the mesozooplankton community. The wind event clearly injected dissolved and particulate benthic materials into the water column, where they directly stimulated the bacterioplankton, phytoplankton and microzooplankton communities within 1 to 2 d after the event. The water column was strongly net heterotrophic at this time, suggesting a large input of dissolved organic matter from the bottom. Stimulation of the pelagic food web continued at least until we completed our study 6 d after the event. By the end of our study, the water column was net autotrophic.


KEY WORDS: Benthic-pelagic coupling · Suspended sediments · Nutrients · Phytoplankon · Microzooplankton grazing · Mesozooplankton grazing · Net heterotrophy · Florida Bay


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