Changes in the Humber Bay benthic macroinvertebrate community structure: 1990 to 2012

Session: 55. - Solutions for Lake Ontario: Addressing the Human Footprint on Regional Water Quality

Trudy Watson-Leung, Ontario Ministry of the Environment and Climate Change, [email protected]
Todd Howell, Ontario Ministry of the Environment, Env. Monitoring & Reporting Br, [email protected]

Abstract

The Great Lakes nearshore zone is a highly productive zone that provides disproportionately important habitat for fish and other benthic and pelagic organisms and plants relative to the whole lake.  Since 1994 the Ontario Ministry of the Environment and Climate Change (MOECC) Great Lakes Nearshore Index Monitoring program has been consistently monitoring select stations within the Canadian Great Lakes nearshore. In this presentation the authors focus on the assessment of the benthic macroinvertebrate community in Humber Bay, a Lake Ontario embayment which receives input from the largest watershed in the Toronto Area of Concern (AOC). The authors will discuss the complex interactions of internal (the arrival of the invasive dreissenid mussel and round goby, and subsequent changes in euphotic zone) and external pressures (increasing watershed population and urban density, regulatory changes leading to changes in water and sediment chemistry) driving the pattern of change in the Humber Bay nearshore benthic community from 1990 to 2012, a period of intense change in Lake Ontario and in the Humber River watershed.  Humber Bay serves as an example of what has been happening more broadly in the nearshore of urbanized and urbanizing sites in Lake Ontario over the same period.

1. Keyword
benthos

2. Keyword
Lake Ontario

3. Keyword
invasive species

4. Additional Keyword
Humber Bay