Evaluating the applicability of remote sensing techniques in quantifying microphytobenthic biomass in estuarine ecosystems

The relative contribution of microphytobenthic (MPB) Primary Productivity (PP) to the total primary productivity of intertidal ecosystems is largely unknown. The possibility to estimate MPB PP is a significant contribution to a better understanding of the role of intertidal mudflats for ecosystem functioning. Estimation of MPB PP from the exposed intertidal mudflats in the Dutch Waddenzee, Netherlands was done following a two-step procedure. Firstly, supervised and image based classification method were used to map classes of sediment types since sediment properties are important for MPB PP. Secondly, MPB PP in the Dutch Waddenzee was estimated following the model by Platt and Jassby (1976) for the top sediment layer (2 mm depth) using NDVI as a proxy for MPB biomass. Estimated MPB PP varied spatially and the distribution is similarly comparable to that of derived clay and sand sediment classes, with high MPB PP found in clay sediments and limited amounts on sand. Sensitivity analysis results have shown that MPB PP in mudflats is largely controlled by αB, euphotic depth and Kd.