The effect of light stress on the release of volatile iodocarbons by three species of marine microalgae

We investigated the influence of high light stress on iodocarbon release by three species of marine phytoplankton from different algal classes: the prymnesiophyte Emiliania huxleyi, the prasinophyte Tetraselmis sp., and the diatom Thalassiosira pseudonana. Despite a pronounced decrease in the fluorescence-based maximum quantum yield for photosystem II (F v /F m ), increased iodocarbon release relative to lower light controls was not observed in any of the experiments performed. These findings do not support the hypothesis that upper-ocean iodocarbon concentrations are influenced by light-induced algal stress.