High resolution 3D-ecosystem model for the Neva Bay and estuary - model validation and future scenarios

We have used a simple 3D-ecosystem model to describe nutrient dynamics and biomass production in the Neva Bay off St. Petersburg. The River Neva is responsible for carrying the waste waters of St. Petersburg to the Gulf of Finland. Literature values of chlorophyll-a concentrations and satellite images have been used for model validation. The results indicate that our model can reproduce both the temporal and spatial variation in the phytoplankton biomass with reasonable accuracy. The model was used to analyse scenarios describing the ecological effects of planned water protection measures.. More efficient phosphorus purification was found to be the most effective measure for improving the water quality off St. Petersburg.