Nutrient loading estimates during extreme rain events in the Bay of Quinte

Session: 06. - Ecosystem Health and Recovery of the Bay of Quinte, Lake Ontario

Felix Ouellet, ECCC-ECCC Environment and Climate Change Canada, [email protected]
Agnes Richards, Environment Canada, [email protected]
Alex Neumann, University of Toronto Scarborough, [email protected]
Dong-Kyun Kim, University of Toronto Scarborough, [email protected]
Stefan Markovic, University of Toronto Scarborough, [email protected]
Shan Mugalingam, Lower Trent Conservation, [email protected]
Jay Guo, ECCC-ECCC Environment and Climate Change Canada, [email protected]
Jorge Hurtado, ECCC-ECCC Environment and Climate Change Canada, [email protected]
Maria Dittrich, University of Toronto Scarborough, [email protected]
George Arhonditsis, University of Toronto Scarborough, [email protected]

Abstract

The Bay of Quinte Remedial Action Plan (RAP) team, has set restoration targets corresponding to the beneficial use impairments, as identified in the Great Lakes Water Quality Agreement (GLWQA). A Bayesian application of Spatially -Referenced Regressions on Watershed attributes (SPARROW) model estimated loadings into the bay at about 45 tonnes/year. Estimates of nutrient loads derived from monitoring information (e.g., provincial water quality network) often miss rain events which can result in elevated levels of nutrients in the tributaries. Field studies focusing on nutrient hot-spots (e.g., Napanee River) were performed in the Bay of Quinte to capture rain events using automated samplers that were remotely controlled to sample during high flow events. River samples were taken every at the start of rain events for 24 hours. During rain events, TP increased with flow by about 3-4 times above baseline. Bioavailable phosphorous, associated with algal blooms, ranged between 50 – 80% of TP. A stochastic approach will be used to account for different sources of variation such as measurement error associated with field calculations of loads, seasonal variability (based on field work), and prediction errors.

1. Keyword
Bay of Quinte

2. Keyword
nutrients

3. Keyword
Lake Ontario

4. Additional Keyword
loadings

5. Additional Keyword
extreme events