Fluorescence Induction of Chlorophyll-A for Monitoring the Physiological Condition of Phytoplankton And Macroalgae

The fluorescence yield of in vivo chlorophyll a is an intrinsic probe of photosynthesis and offers the possibility of rapidly determining the photosynthetic capacity and hence the physiological condition of algae. Progress in the interpretation of fluorescence signals, coupled with the availability and improvements in electro-optic components, has resulted in advances in the application of the technique to oceanography and mariculture. Induction fluorescence may be excited by constant, modulated or pulsed illumination techniques. The advantages and specific instrumentation requirements of these techniques are reviewed. The growth rate of Chondrus crispus, an economically important macroalga, is negatively correlated with variable fluorescence when grown under natural or fluorescent illumination and under nutrient sufficient conditions.