Spectral Fingerprinting of Algal Communities: A Novel Approach to Biofilm Analysis and Biomonitoring¹

A new technique for spectral fingerprinting of major algal groups in the freshwater periphyton (i.e. cyanobacteria, green algae, and diatoms) was developed using confocal laser scanning microscopy. This technique used the differential spectral emission signatures of photosynthetic algae and allowed their spatially explicit quantification and community three‐dimensional reconstruction. Algal biovolume measurements, carried out with this technique, are superior to existing protocols involving chl and ash‐free dry mass assessments because they are nondestructive, localized, and specific at a group level. This technique can be used to generate depth profiles of the periphytic mat with various applications in aquatic ecology and biofilm analysis.