Kerfoot, J. University of Californiat at Santa Barbara, kerfoot@lifesci.lscf.ucsb.edu
Gorga, J. University of California at Santa Barbara, gorga@lifesci.lscf.ucsb.edu
Prezelin, B. B.. University of California at Santa Barbara, barbara@icess.ucsb.edu

 
DINOFLAGELLATE GROWTH RESPONSES TO OUTDOOR CULTURING IN THE PRESENCE AND ABSENCE OF SOLAR UV RADIATION
 
An outdoor growth facility was developed which allows for simulated in situ growth of unialgal cultures of the red tide dinoflagellate Heterocapsa pygmaea. High light adapted cultures were transferred from indoors to 3 outdoor, spectrally distinct, culturing chambers i. e. PAR only, PAR+UVA radiation and PAR+ UVA+UVB radiation. Solar radiation illuminated outdoor cultures during growth and spectral irradiances were simultaneously monitored. To determine the responses to seasonal variations in solar radiation, studies were carried out in September, December 1997, and January, May, August 1998. Initial exposure to UV radiation sometimes induced settling of a fraction of the suspended population to the transparent bottom of the chamber. In PAR+UVA treatments, populations tended to resuspend themselves within the next few days. By the end of each experiment it appeared that cell densities were best maintained in PAR+UVA treatments for the length of monitoring (6-14 days) in studies to date. However, kinetics varied between experiments. Cell densities decreased in response to exposure to PAR + UVA + UVB radiation at a rate that matched or exceeded that of PAR+UVA cells. Discussion of results and their implications for dinoflagellate growth and photosynthesis will be discussed here and in the poster by Gorga et al.
 
Day: Wednesday, Feb. 3
Time: Poster
Location: Sweeney Center
 
Code: CS65WE1567S