Quantifying cyanobacterial phycocyanin concentration in turbid productive waters: A quasi-analytical approach

Abstract In this research, we present a novel technique to monitor cyanobacterial bloom using remote sensing measurements. We have used a multi-band quasi analytical algorithm that determines phytoplankton absorption coefficients, a ϕ ( λ ), from above surface remote sensing reflectance, R rs ( λ ). In situ data including remote sensing reflectance, phytoplankton pigment concentration, and absorption coefficients of optically active constituents in the water were collected from highly turbid and productive aquaculture ponds. These shallow ( Ictalurus punctatus aquaculture and had high nitrogen and phosphorus loading rates from manufactured feeds added to ponds to promote rapid fish growth. These practices resulted in high phytoplankton biomass (chlorophyll- a concentrations = 59.4–1376.6 mg m − 3 ) with communities dominated by filamentous, gas-vacuolate cyanobacteria. A novel technique was developed to further decompose the a ϕ to obtain phycocyanin absorption coefficient, a PC , at 620 nm, a primary peak of phycocyanin absorption spectrum. Validation of the model produced mean and median absolute relative errors of 36.2% and 22.0%. Overall, the model performance was higher in the higher range of PC concentration (> 150 μg l − 1 ). Results demonstrate that the new approach will be suitable for quantifying phycocyanin concentration in cyanobacteria dominated turbid productive waters.