Monitoring cyanobacteria in inland waters by remote sensing

The absorption of the cyanobacterial pigment phycocyanin (PC) can be detected in the reflectance spectra of inland waters as a trough in the 620-630 nm region. Several algorithms have been proposed for retrieving PC concentrations from reflectance, based on semiempirical band ratios (DEKKER 1993), baseline (SCHALLES & YACOBY 2000), or semiempirical nested band ratios (SIMIS et al. 2005). These algorithms can be applied to the spaceborne sensors EnvisatMERIS and Chris/Proba (CHRIS), thus allowing PC mapping on a continuous spatial and temporal basis. We validated these algorithms with field data obtained in 2001-2007 in 65 lakes and reservoirs in Spain, and obtained thematic maps for Cyanobacteria from MERIS and CHRIS imagery.