Herren, C. M. UCSB, herren@lifesci.ucsb.edu
Alldredge, A. M. UCSB, alldrege@lifesci.ucsb.edu
Case, J. F.. UCSB, case@lifesci.ucsb.edu
Holliday, D. V.. TRACOR Aerospace, Inc., holliday@galileo.tracor.com

 
BIOLUMINESCENCE AND ZOOPLANKTON DISTRIBUTIONS IN EAST SOUND, WA, A THIN LAYERS STUDY SITE
 
It has been suggested that the bioluminescence of microplankton both deters small planktonic grazers, and attracts predators to those grazers. To investigate the co-occurrence of bioluminescence and zooplankton distributions, and to conduct the first field test of a newly developed small bioluminescence bathyphotometer, we simultaneously determined the distributions of zooplankton size classes and stimulated bioluminescence. Hourly vertical profiles of total stimulable bioluminescence from a bathyphotometer, and zooplankton densities from an 8-frequency Tracor acoustic profiling system (TAPS) were collected during a 24-hour study in June 1998. Stimulated luminescence profiles were videotaped with a new vertical profiling bioluminescence camera to compare to the hourly profiles and discrete water samples. Daytime profiles revealed a persistent bioluminescent and fluorescent signal (perhaps due to abundant Noctiluca. sp.)) that coincided with the base of the thermocline. With the onset of darkness the overall intensity of the daytime bioluminescence peak increased. Other distinct bioluminescent peaks appeared at dusk at greater depths, and persisted until dawn. However, these peaks were not linked to fluorescence maxima or to areas where marine snow concentrations were high. The relationship of these nighttime bioluminescent peaks to zooplankton distributions will be discussed.
 
Day: Tuesday, Feb. 2
Time: 10:45 - 11:00am
Location: Hilton of Santa Fe
 
Code: SS05TU1045H