Introducing nonlinear, multivariate 'Predictor Surfaces' for quantitative modeling of chemical systems with higher-order, coupled predictor variables

► Novel nonlinear chemometric calibration incorporates higher-order and coupled predictor terms. ► Predictor Surfaces visualize nonlinearities and coupling among chemical parameters. ► Microalgae cells act as in situ bioprobes for quantifying environmental parameters. ► Novel monitoring method for shifts in marine ecosystems and resulting ecological consequences.