HR: 08:55h
AN: OS41E-04 INVITED     [Abstracts]
TI: Phytoplankton Dynamics on the New England Inner Shelf: Time Series Observations at the Martha's Vineyard Coastal Observatory
AU: * Sosik, H M
EM: hsosik@whoi.edu
AF: Woods Hole Oceanographic Institution, Biology Department, MS 32, Woods Hols, MA 02543-1049 United States
AU: Olson, R J
EM: rolson@whoi.edu
AF: Woods Hole Oceanographic Institution, Biology Department, MS 32, Woods Hols, MA 02543-1049 United States
AU: Shalapyonok, A
EM: ashalapyonok@whoi.edu
AF: Woods Hole Oceanographic Institution, Biology Department, MS 32, Woods Hols, MA 02543-1049 United States
AB: Cabled coastal ocean observatories combined with new sensor developments are permitting studies of plankton community structure and rate processes with unprecedented detail. To better understand what regulates phytoplankton dynamics on the inner continental shelf of the northeastern US, we have begun time series observations at the Martha's Vineyard Coastal Observatory (MVCO), a nearshore cabled research facility. We deployed a custom-built submersible automated flow cytometer (FlowCytobot) during spring to autumn of 2003 and 2004. FlowCytobot makes near continuous measurements of pico/nanophytoplankton abundance, cell size, and cell fluorescence characteristics. Our observations show a classic late spring bloom of \it{Synechococcus}\rm, which was also accompanied by an increase in abundance of picoeukaryotic phytoplankton. Subsequently, there were changes in cell abundance and in size structure of the community over a range of time scales throughout the summer and autumn. In addition to cell abundance, FlowCytobot observations also allow us to monitor changes in daily growth rate of specific populations of cells. Application of a matrix population model that represents diel changes in size distribution of \it{Synechococcus} \rm suggests that there are substantial variations in cell specific growth rate at MVCO, presumably in response to changing growth conditions in the region. Longer times series of phytoplankton abundance and growth rate at this site are likely to provide important insights into seasonal and interannual regulation of the nearshore ecosystem.
DE: 4815 Ecosystems, structure and dynamics
DE: 4842 Modeling
DE: 4847 Optics
DE: 4855 Plankton
DE: 4894 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting