Deciphering water quality drivers on the urban shores of Lake Ontario

Session: Poster session

Todd Howell, Ontario Ministry of the Environment, Env. Monitoring & Reporting Br, [email protected]
Bogdan Hlevca, Ministry of Environment and Climate Change, [email protected]

Abstract

The Greater Toronto Area is a growing urban landscape on the shores of Lake Ontario. Urban rivers, waste water treatment plants and storm sewers load poor quality water to the coastline.  The land-effects footprint is diluted by onshore circulation of oligotrophic water from the offshore.  Dreissenid mussels, seemingly re-calibrating the lake ecosystem, enhance proliferation of benthic algae through effects on water transparency and possibly nutrient cycling.   Monitoring of water quality at the land-lake margin has become increasingly multifaceted. Knowledge of land-based inputs loaded to the lake, key to inferring threats to water resources, is obtained through sensor-based mapping of water quality over the coastline which depicts geographic pattern used to infer extent of impacts. Tracking onshore circulation as a dilutant of the nearshore is accomplished using moored sensors, lake surveys and modelling.  Detecting interaction of ecosystem change with water resource concerns has become an element of monitoring necessitating inclusion of biological surveys in water quality studies. This presentation examines the approach used by the Ontario Ministry of Environment and Climate Change to monitor nearshore Lake Ontario and decipher the drivers of water quality at a time of continued urban growth and a changing lake ecosystem

1. Keyword
coastal ecosystems

2. Keyword
nutrients

3. Keyword
urban areas