Toxicity may affect predictability of eutrophication models in the coastal sea

Toxic substances in wastewaters that are released into the aquatic environment cause reduction of phytoplankton uptake up to 50 km away from the sources depending on the geometry of the coastal sea and the intensity of existing sources. This conclusion follows from an unusual application of the advection-diffusion-interaction equation to the transport of unknown toxic substances. The consequence is that if existing eutrophication models (without a toxicity submodel) reproduce phytoplankton densities in the coastal sea, then probably they have been miscalibrated. The problem could be solved by coupling transport of toxic substances to an eutrophication model given that results of uptake experiments are available.