Management of the Phosphorus–Cladophora Dynamic at a Site on Lake Ontario Using a Multi-Module Bioavailable P Model

The filamentous green alga Cladophora grows to nuisance proportions in Lake Ontario. Stimulated by high phosphorus concentrations, growth results the degradation of beaches and clogging industrial water intakes with attendant loss beneficial uses. We develop a multi-module bioavailable model examine efficacy management strategies mitigating algal growth. platform includes modules simulating hydrodynamics (FVCOM), phosphorus-phytoplankton dynamics (GEM) (GLCMv3). is applied along 25 km stretch Ontario nearshore, extending east from Toronto, ON receiving effluent three wastewater treatment plants. Simulation identify Duffin Creek plant as driving force for conditions growth, reflected concentrations dimensions plant’s footprint. demonstrate that removal chemically enhanced secondary insufficient provide relief conditions. Tertiary (chemically ballasted flocculation) shown eliminate phosphorus-saturated associated effluent, providing local Management guidance presented here has wider application at sites highly urbanized Canadian nearshore