1. The study investigates bio-optical modeling of phytoplankton functional types (PFTs) in Mantua Lakes, Italy using their pigment composition and absorption coefficients. 2. A sensitivity analysis was performed on a bio-optical model simulating water reflectance as observed by sensors like PRISMA, EnMAP, APEX, and Sentinel-3 based on PFTs, inherent optical properties, and water quality parameters. 3. The results found that different sensors showed varying levels of sensitivity to different phytoplankton pigments like phycoerythrin and phycocyanin depending on wavelength, with APEX performing best due to higher spectral resolution.