HR: 14:45h
AN: OS52H-04    [PDF]
TI: NESPEX: Fast Repetition Rate Fluorometry Across a Shelf Break Front During Summer
AU: * Vaillancourt, R D
EM: vaillanc@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10970 United States
AU: Marra, J
EM: marra@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10970 United States
AU: Prieto, L
EM: pgalvez@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10970 United States
AU: Hales, B
EM: bhales@coas.oregonstate.edu
AF: Oregon State University, College of Oceanic and Atmospheric Sciences, Corvalllis, OR 97331 United States
AB: The shelf break front south of New England is a region of intense horizontal gradients in temperature, salinity, light intensity and nutrient concentrations. Here, we demonstrate that these horizontal environmental gradients profoundly influence the cross-shelf distributions of phytoplankton optical and physiological characteristics. We observed striking differences in the fluorescence kinetics of phytoplankton situated on either side of the front. While Fv/Fm values were fairly constant across the front, the functional absorption cross-section (sigma PSII) was ca. 2-fold higher on the seaward side of the front and co-varied with changes in phytoplankton spectral absorption properties. Discrete and continuous flow data demonstrate the role of light intensity and the production of photoprotective carotenoids in regulating sigma PSII.
DE: 4815 Ecosystems, structure and dynamics
DE: 4847 Optics
DE: 4852 Photochemistry
DE: 4853 Photosynthesis
DE: 4855 Plankton
SC: Ocean Sciences [OS]
MN: 2004 Ocean Sciences Meeting