Lesser, M. P.. University of New Hampshire, mpl@christa.unh.edu
Gorbunov, M. P.. Rutgers University,
Zbigniew, K. Rutgers University,
Falkowski, P. Rutgers University,

 
ACTIVE CHLOROPHYLL FLUORESCENCE AND CORALS: A NON-DESTRUCTIVE MEASUREMENT OF ENVIRONMENTAL STRESS IN SITU
 
Active chlorophyll a fluorescence (685 nm) can be used to ascertain the relative amounts of photodamage and photoprotection contributing to changes in photosynthetic efficiency. Recent studies have demonstrated a significant effect of elevated temperatures on variable fluorescence, and therefore PSII function, in the zooxanthellae of several coral hosts. Active fluorescence measurements using fast repetition rate fluorometer (FRRF) technology should be very useful for studies on the photosynthetic physiology of zooxanthellae within the coral host in a non-destructive manner. A hand-held, diver operated, in situ FRRF was used on corals from shallow waters in the Bahamas. These corals exhibit a repeatable diurnal pattern for the quantum yield of fluorescence of PSII. Mid-day depressions, representing non-photochemical quenching were evident in Montastraea faveolata, and other species of coral. FRRF can also be used to predict bleaching in corals. Bleaching experiments showed significant depressions in active fluorescence 3-5 days before visible signs (e.g. colony paling) were observed. Additionally, during a natural bleaching event significant differences were observed between colonies of the same species that were not bleached and those that were visibly paler and bleaching. Bleached colonies always had significantly lower variable fluorescent values indicating damage or stress on PSII within the zooxanthellae.
 
Day: Tuesday, Feb. 2
Time: Poster
Location: Sweeney Center
 
Code: SS41TU1581S