A point simulation model is considered for the water ecosystem with the following components: aggregated phytoplankton; zooplankton; detritus-associated bacteria; labile or biochemically resistent detritus; dissolved organic carbon, nitrogen, and phosphorus; total dry matter; ammonia-nitrite-nitrate nitrogen; phosphate phosphorus; CO₂-carbon; dissolved oxygen. The nutrition of young fishes and benthic respiration are taken into account. -from English summary