Abstract

Although blooms of cyanobacteria are a nuisance in many freshwater ecosystems for many years now, there is still no standardized method to determine their abundance. In this literature study, wellknown and potentially interesting methods for the determination of cyanobacterial abundance in natural populations are discussed with regard to their applicability in biomonitoring programs. Important criteria are rapidity, practicability, sensitivity, determination level, reproducibility and costs. Remote Sensing, optical partial analysis, and analysis of lipidsoluble pigmints emerge as useful techniques for biomonitoring programs. Each of these methods allows a different determination level. In vivo absorbance, in vivo fluorescence, microscopy, and analysis of water-soluble pigments, lipids, low molecular weight RNA's and specific enzymes are less suitable for biomonitoring programs because they are too time-consuming with reference to the results obtained. Based on this literature survey, RIVM started a study on the applicability of lipid-soluble pigment analysis for the determination of cyanobacterial abundance in freshwater phytoplankton assemblages.