Effect of pigment composition on absorption properties of phytoplankton

Absorption spectra of several phytoplankton species were decomposed, after correction for the particle effect, to estimate in vivo absorption properties of the major light-harvesting pigments in algae. A Gaussian shape is suitable, theoretically and empirically, to represent the absorption spectra of individual photosynthetic components. The Gaussian parameters agreed well with the expected pigment compositions of 3 groups of algae, and the peak heights were linearly correlated with the concentrations of any one of the 4 major pigments measured in the samples. The linear relationship did not vary with phytoplankton species. We present here the first estimates of the 'true' in vivo specific absorption coefficients of 4 major pigments, after correction for particle effect. The results are used to reconstruct the in vivo absorption spectrum of a multi-species sample.