HPLC analysis of phytoplankton pigments from Lake Kinneret with special reference to the bloom-forming dinoflagellate Peridinium gatunense (Dinophyceae) and chlorophyll degradatio products

Abstract

Photosynthetic pigments extracted from the paniculate material of the water column of Lake Kinneret were studied throughout the periods of May 1988-June 1989, and November 1993-November 1994, by means of HPLC. The temporal and vertical variation of the pigment suite found agreed with the microscopically determined phytoplankton record. The regression calculations of taxon-specific biomass with the corresponding signature pigments suggest that pigment analysis may be a useful tool for the monitoring of bloom-forming species, e.g. the dinoflagellate Peridinium gatunense Nygaard. The HPLC pigment analysis permitted the identification and quantification of chlorophyll degradation products, providing for the first time information about their composition in Lake Kinneret. Chlorophyllide a was the major detectable degradation product of chlorophyll a, varying between 1 and 9% of the chlorophyll a concentration. Other chlorophyll a derivatives appeared mostly in minor quantities. Pheophytin a was virtually lacking in all the samples. Removal rates of pigments, measured by sedimentation traps, indicated that the degradation of chlorophyll a via chlorophyllide a is a dynamic process that continues during the sedimentation of the phytoplankton particles.