Understanding the drivers of Lake Ontario nearshore nuisance algae blooms: Can models get us any closer?
Citation:
Pauer, J., W. Melendez, M. Moffett, T. Hollenhorst, T. Brown, AND D. Woodruff. Understanding the drivers of Lake Ontario nearshore nuisance algae blooms: Can models get us any closer? International Association for Great Lakes Research, Brockport, NY, June 10 - 14, 2019.
Impact/Purpose:
Elevated phosphorus concentrations and nuisance algae are ongoing concerns in the nearshore of Lake Ontario. It is unclear whether the source of phosphorus is mainly from the lake tributaries (intra-basin loads) or from Lake Erie via the Niagara River (inter-basin loads). The link between phosphorus and algae growth and standing crop, especially Cladophora, is also not fully understood. Here we developed a simple mathematical model to quantify the intra-basin and inter-basin phosphorus loads and their impact to the nearshore of Lake Ontario, and to provide insight and further our understanding of phosphorus and other drivers of the nuisance algae. The model development and calibration will be supported by results from the 2013 and 2008 Lake Ontario Cooperative Science and Monitoring Initiatives (CSMI), and the 2018 CSMI results when available.
Description:
As part of the 2018 CSMI, several sampling and research studies were undertaken to address ecological concerns in Lake Ontario. One such concern is persistent nuisance algae in the nearshore. Phosphorus is an important driver of algae growth such as for Cladophora, although the mechanism is not fully understood. It is also unclear what the major sources of phosphorus are. Is it inter-basin loads (Lake Erie via the Niagara River) or intra-basin loads (Lake Ontario tributaries)? Mathematical models can be useful to address these issues in large complex systems such as the Great lakes where several drivers are responsible for excessive algal growth. We developed a simple biogeochemical model to describe and predict phosphorus and resulting algal concentration at several locations in the southern shore of Lake Ontario. The goal is to combine observations with model results to determine the fate and transport of nutrients and algae in the lake. Here we show initial results and discuss challenges and next steps.