IN-VIVO FLUORESCENCE CHLOROPHYLL A RATIO AS AN ECOLOGICAL INDICATOR IN OCEANOGRAPHY/

This article reviews the main factors affecting the in vivo fluorescen ce versus chlorophyll relationships of phytoplankton and presents a ca se study based on data from three oceanographic cruises carried out, a t different times of the year, in the Catalan-Balearic Sea. In all thr ee surveys, the in vivo fluorescence/chlorophyll ratio of the upper eu photic layer samples presented a diel variability with a minimum at or before noon time. The relationships between the spatio-temporal distr ibution of this variability and characteristics of photosynthesis vers us irradiance curves obtained during each cruise are discussed.