Utility of the algal photopigment gyroxanthin-diester in studies pertaining to the red tide dinoflagellate Karenia brevis (Davis) G. Hansen ana Moestrup.

Abstract

Discrimination of the algal photo·pigment gyroxanthin-diester (through High Performance Liquid Chromatography) can be applied to studies of Karenia brevis (Davis) G. Hansen and Moestrup as a biomarker and an indicator of both phytoplankton taxonomy and photophysiology. Four years of HPLC data, collected in nine independent field studies of the ECOHAB Florida project, were used to demonstrate the utility of gyroxanthin-diester in studies involving K. brevis. A weak linear relationship existed between the abundance of K. brevis and the concentration of gyroxanthin-diester; hmvever, the presence and relative abundance of K brevis was still determined using HPLC data. \\t11en gyroxanthin-diester was present, its ratio to chlorophyll {/ was found to be constant. A comparison of the ratios of gyroxanthin-dicster: chlorophyll a and gyroxanthin-diester: diadinoxanthin also provided information concerning photo-physiological state. Taxonomic composition, including the contribution of K brevis to total community composition, was determined using gyroxanthin-diester and the software package ChemTax";.