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National Science Foundation Award #9018441

Novel Methods to Assess the Effects of Ultraviolet Radiationon Phytoplankton Photosynthesis

 
Investigator(s): John Cullen (PI) ; Michael Lesser (Co-PI) ; Patrick Neale (Co-PI) ; Michael Lesser (Co-PI)
Sponsor: Bigelow Laboratory for Ocean Sciences, ME 04575 2076339600
Start Date/Expiration Date 1991-03-01 to 1993-08-31 (amended 1995-10-27)
Awarded Amount to Date: $224,597
Abstract: One result of the ozone depletion in the Antarctic is an increase in the transmission of ultraviolet radiation to the earth's surface. This project addresses the effect of ultraviolet radiation on phytoplankton physiology. Methods will be developed to generate environmentally-relevant action spectra (wavelength-dependent biological weighing functions) for photoinhibition of photosynthesis in phytoplankton. Action spectra will be measured using an experimental incubator that exposes phytoplankton to combinations of ultraviolet and visible radiation. Photoinhibition will also be examined with new indicator assays. Three types of assay will be tested: 1) fluorescence-based measurements designed to distinguish the primary damage to photosynthesis from ultraviolet vs visible radiation; 2) a spectrophotometric measurement of photosystem II reaction center activity that also might distinguish the effects of ultraviolet radiation from those of excess visible light; 3) a technique to measure repair function that is very sensitive to ultraviolet radiation and to excess visible light. The action spectra will be used to model photoinhibition. The indicator assays will quantify photoinhibition without relying on incubation- based measurements of photosynthesis. Models and methods will be tested by comparison with direct measurements of the harmful effects of ultraviolet and excess visible radiation on photosynthesis by natural phytoplankton in the Antarctic.
NSF Org: OPP - Office of Polar Programs
Award Number: 9018441
Award Instrument: Continuing grant
Program Manager: Polly A. Penhale
OPP Office of Polar Programs
O/D OFFICE OF THE DIRECTOR
NSF Program(s): ANTARCTIC BIOLOGY & MEDICINE, ANTARCTIC BIOLOGY & MEDICINE
Field Application(s): Biological Oceanography, Oceanography, Polar Programs-Related
Program Reference Code(s): GLOBAL CHANGE, 1577
Program Element Code(s): 5111
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