In situ measured seasonal variations in F v/F m of two common Red Sea corals

摘要: Pulse amplitude modulated (PAM) fluorometry has been suggested as a tool for estimating environmental stresses on corals. However, information regarding natural changes in maximal quantum yields (F v/F m) of corals during “normal” (i.e. non-bleaching) years limited. In this study, seasonal variations F m Stylophora pistillata and Favia favus, measured situ, correlated with solar irradiance but not sea temperature. Interactions between temperature were further studied by growing these Pocillopora damicornis under controlled conditions. Exposure to high light normal or temperatures resulted lower values than exposure low at both temperatures. Thus, irradiances may cause decreased least much as, if more than, Such should be taken into account when using PAM diagnostic predicting coral bleaching.