Lake Water Quality Model with Focus on Cyanobacteria

The cause of cyanobacteria's growth and dominance in certain eutrophic lakes is explored via a water quality model application. The one-dimensional lake water quality model includes nitrogen, phosphorus, silica, three phytoplankton groups and zooplankton. Lake Washington was used as the case study due to its unique history of eutrophication during a large wastewater nutrient loading period from in the 1960s and subsequent recovery. Sampling data for a 20-year period surrounding the eutrophication includes speciation of phytoplankton. Results indicate that nutrient loading, specifically phosphorus was the main factor for the persistent dominance of Oscillatoria in Lake Washington. Other key conditions and cyanobacteria traits are analyzed and discussed.